#compdef lttng
#
# Copyright (c) 2015-2023 Philippe Proulx <eeppeliteloop@gmail.com>
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
#
# This is a Zsh completion function for the lttng(1) command (see
# <https://lttng.org/>), for versions 2.5 to 2.14.
#
# If you want, at your own risk, the function to work with versions
# above 2.14, set `LTTNG_ZSH_COMP_IGNORE_VERSION_LIMIT=1`.
#
# Each subcommand changes the command part of the current context so
# that you can target a specific subcommand with `zstyle`, for
# example:
#
#     $ zstyle ':completion:*:*:lttng-start:*:sessions' verbose yes
#     $ zstyle ':completion:*:*:lttng-add-context:type-option:*' \
#              group-order perf-context-types static-context-types
#
# The relevant style arguments and tags are:
#
# `actions` tag (with the `lttng-snapshot` command):
#     Snapshot action names.
#
# `channel` argument and `channels` tag:
#     Channel names.
#
#     The `verbose` style controls whether or not this function adds
#     completions as a list (with channel information for each item) or
#     simple channel names.
#
#     If the verbose style is enabled, then the information part of each
#     item starts with either `  [enabled` or `  [disabled` (note the
#     two leading spaces), depending on the status of the channel.
#
# `commands` tag:
#     lttng(1) subcommand names.
#
# `log-levels` tag:
#     Log level names.
#
# `session` argument and `sessions` tag:
#     Recording session names.
#
#     The `verbose` style controls whether or not this function adds
#     completions as a list (with recording session information for each
#     item) or simple recording session names.
#
#     If the verbose style is enabled, then the information part of each
#     item starts with either `  [active` or `  [inactive` (note the two
#     leading spaces), depending on the status of the recording session.
#
# `type-option` argument:
#     `static-context-types` tag:
#         Statically-known context field types.
#
#     `perf-context-types` tag:
#         perf counter context field types.
#
# `triggers` tag:
#     Trigger names.

# Sets the `minor_version` variable to the minor version of LTTng-tools,
# or to `0` if not found.
__lttng_set_minor_version() {
  minor_version=0

  local -a match

  if [[ $($prog_name --version) =~ '[[:blank:]]+2\.([[:digit:]]+)' ]]; then
    minor_version=$match[1]
  fi
}

# Runs the `lttng` command with `"$@"` using `$tracing_group`.
__lttng_run() {
  $prog_name --no-sessiond --group=$tracing_group "$@" 2>/dev/null
}

# Runs the `lttng --mi=xml` command using the selected tracing group
# (`$tracing_group`) with:
#
# `$1`:
#     A message of what's expected to show on error.
#
# Other arguments:
#     Passed to the command as is.
#
# This function returns 1 with LTTng-tools < 2.6 and if `xmllint` isn't
# available.
__lttng_mi_run() {
  local -r msg=$1

  shift

  if ((minor_version < 6)); then
    # MI output requires LTTng-tools ≥ 2.6
    _message -e descriptions $msg
    return 1
  fi

  if ((! $+commands[xmllint])); then
    # XML output parsing requires xmllint
    _message -e descriptions $msg
    return 1
  fi

  __lttng_run --mi=xml "$@"

  if (($? != 0)); then
    # Command failed
    _message -e descriptions $msg
    return 1
  fi
}

# Call this instead of _arguments() within this function when you don't
# need the `-C` option.
__lttng_arguments() {
  _arguments -s -W : "$@"
}

# Returns whether or not the verbose style is enabled for the given
# argument (`$1`) and tag (`$2`), using `$curcontext` for the other
# parts of the full completion context.
__lttng_style_is_verbose() {
  local -r arg=$1 tag=$2
  local -r ccparts=("${(@s.:.)curcontext}")

  zstyle -t :completion:${ccparts[1]}:${ccparts[2]}:${ccparts[3]}:$arg:$tag verbose
}

# Returns 0 if a Linux kernel tracing domain option is set in
# `$opt_args`, or `1` otherwise.
__lttng_kernel_domain_opt_is_set() {
  (($+opt_args[-k] || $+opt_args[--kernel] ||
    $+opt_args[domain--k] || $+opt_args[domain---kernel]))
}

# Returns 0 if a user space tracing domain option is set in
# `$opt_args`, or `1` otherwise.
__lttng_user_domain_opt_is_set() {
  (($+opt_args[-u] || $+opt_args[--userspace] ||
    $+opt_args[domain--u] || $+opt_args[domain---userspace]))
}

# Returns 0 if a `java.util.logging` tracing domain option is set in
# `$opt_args`, or `1` otherwise.
__lttng_jul_domain_opt_is_set() {
  (($+opt_args[-j] || $+opt_args[--jul] ||
    $+opt_args[domain--j] || $+opt_args[domain---jul]))
}

# Returns 0 if an Apache log4j tracing domain option is set in
# `$opt_args`, or `1` otherwise.
__lttng_log4j_domain_opt_is_set() {
  (($+opt_args[-l] || $+opt_args[--log4j] ||
    $+opt_args[domain--l] || $+opt_args[domain---log4j]))
}

# Returns 0 if a Python tracing domain option is set in `$opt_args`,
# or `1` otherwise.
__lttng_python_domain_opt_is_set() {
  (($+opt_args[-p] || $+opt_args[--python] ||
    $+opt_args[domain--p] || $+opt_args[domain---python]))
}

# Adds completions for the name of an `lttng` command.
__lttng_complete_cmd_name() {
  # LTTng-tools 2.5+
  local cmd_names=(
    'add-context:add context fields to be recorded'
    'create:create a recording session'
    'destroy:destroy a recording session'
    'disable-channel:disable channels'
    'disable-event:disable recording event rules'
    'enable-channel:create or enable a channel'
    'enable-event:create or enable recording event rules'
    'help:show the help of a command'
    'list:list recording sessions and instrumentation points'
    'set-session:set the current recording session'
    'snapshot:take a recording session snapshot'
    'start:start a recording session'
    'stop:stop a recording session'
    'version:show LTTng-tools version information'
    'view:launch a trace reader'
  )

  # LTTng-tools 2.6+
  if ((minor_version >= 6)); then
    cmd_names+=(
      'load:load recording session configurations'
      'save:save recording session configurations'
    )
  fi

  # LTTng-tools 2.7+
  if ((minor_version >= 7)); then
    cmd_names+=(
      'track:allow specific processes to record events'
      'untrack:disallow specific processes to record events'
    )
  fi

  # LTTng-tools 2.8+
  if ((minor_version >= 8)); then
    cmd_names+=(
      'status:show the status of the current recording session'
    )
  fi

  # LTTng-tools 2.9+
  if ((minor_version >= 9)); then
    cmd_names+=(
      'regenerate:regenerate specific recording session data'
    )
  fi

  # LTTng-tools 2.11+
  if ((minor_version >= 11)); then
    cmd_names+=(
      'rotate:archive the current trace chunk of a recording session'
      'enable-rotation:set a recording session rotation schedule'
      'disable-rotation:unset a recording session rotation schedule'
    )
  fi

  # LTTng-tools 2.12+
  if ((minor_version >= 12)); then
    cmd_names+=(
      'clear:clear a recording session'
    )
  fi

  # LTTng-tools 2.13+
  if ((minor_version >= 13)); then
    cmd_names+=(
      'add-trigger:add a trigger'
      'list-triggers:list triggers'
      'remove-trigger:remove a trigger'
    )
  fi

  # Add completions
  local expl

  _describe -t commands command cmd_names
}

# Adds completions for the name of an `lttng snapshot` action.
__lttng_complete_snapshot_action_name() {
  local -r action_names=(
    'add-output:add a snapshot output'
    'del-output:remove a snapshot output'
    'list-output:show the snapshot output'
    'record:take a snapshot'
  )

  # Add completions
  local expl

  _describe -t actions 'snapshot action' action_names
}

# Adds user ID completions.
#
# The added completions are displayed as user names, but the actual
# completions are corresponding user IDs.
__lttng_complete_uid() {
  if [[ ! -f /etc/passwd ]]; then
    # Weird flex but ok
    _message -e descriptions 'user ID'
    return
  fi

  # Read user names and IDs from `/etc/passwd`
  local line
  local -a uids names fields

  while read -r line; do
    if [[ -z ${line// } ]]; then
      # Skip empty line
      continue
    fi

    # Extract user ID and name
    fields=("${(@s/:/)line}")
    uids+=($fields[3])
    names+=("$fields[1]")
  done < /etc/passwd

  # Add completions
  local expl

  _wanted users expl 'user ID' compadd -d names -a uids
}

# Adds completions for a context field type (for the `--type` option of
# the `add-context` command).
#
# This function replaces the argument field of the current context with
# `type-option`.
#
# This function relies on the tracing domain options of `$opt_args` to
# restrict the offered completions. Without a tracing domain option,
# this function adds all the possible context field type completions.
#
# This function runs `lttng add-context --list` to get the list of
# available context field types.
#
# This function adds completions with both the `static-context-types`
# and `perf-context-types` tags so that the Zsh user can hide a group or
# select them with the `group-order` and `tag-order` style.
__lttng_complete_context_type() {
  # Statically-known context field types
  local kernel_types=(
    pid procname prio nice vpid tid vtid ppid vppid hostname
    interruptible preemptible need_reschedule migratable
    callstack-kernel callstack-user cgroup_ns ipc_ns mnt_ns net_ns
    pid_ns time_ns user_ns uts_ns uid euid suid gid egid sgid vuid veuid
    vsuid vgid vegid vsgid
  )
  local user_types=(
    vpid pthread_id procname ip cgroup_ns ipc_ns mnt_ns net_ns pid_ns
    time_ns user_ns uts_ns vuid veuid vsuid vgid vegid vsgid
  )

  # Set `types` and `domain` depending on the selected tracing domain
  local -a types
  local domain descr_suffix

  if __lttng_kernel_domain_opt_is_set; then
    # Kernel context field types
    types=($kernel_types)
    domain=k
  elif __lttng_user_domain_opt_is_set; then
    # User space context field types
    types=($user_types)
    domain=u
  else
    # No supported tracing domain: offer all context field types
    types=($user_types $kernel_types)
    descr_suffix=' (all tracing domains)'
  fi

  # Get XML list of available context field types
  local -r msg='context type'
  local list_xml

  list_xml=$(__lttng_mi_run $msg add-context --list)

  if (($? != 0)); then
    return 1
  fi

  # Convert to one context field type per line
  local lines

  lines=$(__lttng_xmllint_xpath $list_xml '//*[local-name()="symbol"]/text()')

  if (($? != 0)); then
    _guard '^-*' $msg
    return
  fi

  # Filter context field types depending on the selected tracing domain
  local -a static_items perf_items
  local line

  while read -r line; do
    if (($types[(Ie)$line])); then
      # Statically-known context field type
      static_items+=$line
    elif [[ $line = perf:cpu:* && $domain != u ]]; then
      # Per-CPU perf counter
      perf_items+=$line
    elif [[ $line = perf:thread:* && $domain != k ]]; then
      # Per-thread perf counter
      perf_items+=$line
    elif [[ $line = perf:* && $domain != u ]]; then
      # Other perf counter (Linux kernel tracing domain or none)
      perf_items+=$line
    fi
  done <<< $lines

  # Add completions
  _alternative -C type-option \
    "static-context-types:statically-known context type${descr_suffix}:compadd -a static_items" \
    "perf-context-types:perf counter context type${descr_suffix}:compadd -a perf_items"
}

# Adds completions for a trigger name.
#
# Relies on `$opt_args[--owner-uid]` to restrict the offered
# completions.
__lttng_complete_trigger_name() {
  # Get XML list of available triggers
  local msg='trigger name'
  local list_xml

  list_xml=$(__lttng_mi_run $msg list-triggers)

  if (($? != 0)); then
    return 1
  fi

  # Create the owner UID predicate XPath part
  local owner_uid_xpath

  if (($+opt_args[--owner-uid])); then
    owner_uid_xpath="[./*[local-name()='owner_uid'] = ${opt_args[--owner-uid]}]"
  fi

  # Convert to one trigger name per line
  local lines

  lines=$(__lttng_xmllint_xpath $list_xml "//*[local-name()='trigger']$owner_uid_xpath/*[local-name()='name']/text()")

  if (($? != 0)); then
    _guard '^-*' $msg
    return
  fi

  local -a trigger_names

  while read -r line; do
    trigger_names+=$line
  done <<< $lines

  # Add completions
  local expl

  _wanted triggers expl $msg compadd -a trigger_names
}

# Runs `xmllint` with:
#
# `$1`:
#     An XML document to parse.
#
# `$2`:
#     An XPath to extract data.
__lttng_xmllint_xpath() {
  local -r xml=$1 xpath=$2

  xmllint --xpath $xpath - <<< $xml 2>/dev/null
}

# Prints the equivalent recording session status adjective (`active` or
# `inactive`) for an `enabled` XML property, or `unknown` on error.
__lttng_session_status_from_enabled_prop() {
  local -r prop=$1

  case $prop in
    true) echo -n active;;
    false) echo -n inactive;;
    *) echo -n unknown;;
  esac
}

# Prints the value of the immediate XML property named `$3` of the child
# node named `$2` within the parent node `$1`.
__lttng_immediate_prop_from_xml() {
  local -r node_xml=$1 node_name=$2 prop_name=$3

  __lttng_xmllint_xpath $node_xml "/*[local-name()='$node_name']/*[local-name()='$prop_name']/text()"
}

# Prints the value of the immediate XML `name` property of the child
# node named `$2` within the parent node `$1`.
__lttng_name_prop_from_xml() {
  local -r node_xml=$1 node_name=$2

  __lttng_immediate_prop_from_xml $node_xml $node_name name
}

# Prints the value of the immediate XML `enabled` property of the child
# node named `$2` within the parent node `$1`.
__lttng_enabled_prop_from_xml() {
  local -r node_xml=$1 node_name=$2

  __lttng_immediate_prop_from_xml $node_xml $node_name enabled
}

# Adds completions for a recording session name.
#
# Arguments:
#
# `$1`:
#     One of:
#
#     `all`:
#         Add completions for active and inactive recording sessions.
#
#     `active`:
#         Only add completions for active recording sessions.
#
#     `inactive`:
#         Only add completions for inactive recording sessions.
#
# `$2`:
#     One of:
#
#     `all`:
#         Add completions for recording sessions regardless of their
#         mode.
#
#     `snapshot`:
#         Only add completions for snapshot recording sessions.
#
#     `live`:
#         Only add completions for LTTng live recording sessions.
__lttng_complete_session_name() {
  local -r req_status=$1 req_mode=$2

  # Get XML document (summary of recording sessions)
  local session_summaries_xml

  session_summaries_xml=$(__lttng_mi_run 'recording session name' list)

  if (($? != 0)); then
    return 1
  fi

  # Count recording sessions
  local -i session_count

  session_count=$(__lttng_xmllint_xpath $session_summaries_xml 'count(//*[local-name()="session"])')

  if (($? != 0 || session_count == 0)); then
    _guard '^-*' 'recording session name'
    return
  fi

  # Append the name and info of one recording session at a time
  local -a session_names session_infos
  local -i index iprop
  local session_name session_summary_xml snapshot_mode session_status session_info

  # For each recording session summary
  for index in {1..$session_count}; do
    # Get recording session summary XML node
    session_summary_xml=$(__lttng_xmllint_xpath $session_summaries_xml "//*[local-name()='session'][$index]")

    if (($? != 0)); then
      continue
    fi

    # Get recording session name
    session_name=$(__lttng_name_prop_from_xml $session_summary_xml session)

    if (($? != 0)); then
      continue
    fi

    # Get recording session status
    session_status=$(__lttng_enabled_prop_from_xml $session_summary_xml session)

    if (($? != 0)); then
      continue
    fi

    session_status=$(__lttng_session_status_from_enabled_prop $session_status)

    if [[ $req_status != all && $req_status != $session_status ]]; then
      # Skip recording session with unexpected status
      continue
    fi

    # Get recording session mode
    session_mode=
    iprop=$(__lttng_immediate_prop_from_xml $session_summary_xml session snapshot_mode)

    if (($? == 0 && iprop)); then
      session_mode=snapshot
    else
      iprop=$(__lttng_immediate_prop_from_xml $session_summary_xml session live_timer_interval)

      if (($? == 0 && iprop)); then
        session_mode=live
      fi
    fi

    if [[ $req_mode != all && $req_mode != $session_mode ]]; then
      # Skip recording session with unexpected mode
      continue
    fi

    session_info=$session_status

    if [[ -n $session_mode ]]; then
      session_info+=", $session_mode mode"
    fi

    session_names+=("$session_name")
    session_infos+=($session_info)
  done

  # No recording sessions: show message
  if (($#session_names == 0)); then
    _guard '^-*' 'recording session name'
    return
  fi

  # Compute maximum session info length
  local -i max_info_len=0 len

  for session_info in $session_infos; do
    len=$#session_info

    if ((len > max_info_len)); then
      max_info_len=$len
    fi
  done

  # Compute maximum session name length
  local -i max_name_len=0

  for session_name in $session_names; do
    len=$#session_name

    if ((len > max_name_len)); then
      max_name_len=$len
    fi
  done

  # Some room for the longest info string, two spaces, and two brackets
  local -ir max_possible_name_len=$((COLUMNS - max_info_len - 5))

  if ((max_name_len > max_possible_name_len)); then
    # Clamp
    max_name_len=$max_possible_name_len
  fi

  # Create the dislay strings (name, status, mode)
  local -a disps

  for index in {1..${#session_names}}; do
    disps+=("${(r:$max_name_len:: :)session_names[$index]}  [$session_infos[$index]]")
  done

  # Add completions
  local expl

  if __lttng_style_is_verbose session sessions; then
    # Verbose mode (list with infos)
    _wanted -C session sessions expl 'recording session name' \
      compadd -d disps -l -a session_names
  else
    # Just the recording session names
    _wanted -C session sessions expl 'recording session name' \
      compadd -a session_names
  fi
}

# Prints the name of the Unix user's current recording session, if any.
__lttng_cur_session_name() {
  local -r lttngrc_path=${LTTNG_HOME:-$HOME}/.lttngrc

  if [[ ! -f $lttngrc_path ]]; then
    return 1
  fi

  local cur_session_name
  local -a match

  while read -r line; do
    if [[ $line =~ 'session=([^[:blank:]]+)' ]]; then
      cur_session_name=$match[1]
      break
    fi
  done < $lttngrc_path

  if [[ -z $cur_session_name ]]; then
    return 1
  fi

  echo -n $cur_session_name
}

# Prints the equivalent status adjective (`enabled` or `disabled`) for
# an `enabled` XML property, or `unknown` on error.
__lttng_status_from_enabled_prop() {
  local -r prop=$1

  case $prop in
    true) echo -n enabled;;
    false) echo -n disabled;;
    *) echo -n unknown;;
  esac
}

# Prints the XML document of `lttng list $2` (specifics of a single
# recording session).
#
# `$1` is a message of what's expected to show on error.
__lttng_session_xml() {
  local -r msg=$1 session_name=$2

  __lttng_mi_run $msg list $session_name
}

# Adds completions for a channel name.
#
# This function relies on the tracing domain options of `$opt_args`,
# `$opt_args[-s]`, `$opt_args[--session]`, and the first non-option
# argument to restrict the offered completions.
#
# Arguments:
#
# `$1`:
#     One of:
#
#     `all`:
#         Add completions for enabled and disabled channels.
#
#     `enabled`:
#         Only add completions for enabled channels.
#
#     `disabled`:
#         Only add completions for disabled channels.
#
# `$2`:
#     `opt`:
#         Use `$opt_args[-s]` and `$opt_args[--session]` to find the
#         name of the selected recording session.
#
#     `arg`:
#         Use `$line[1]` to find the name of the selected recording
#         session.
__lttng_complete_channel_name() {
  local -r req_status=$1 session_name_src=$2

  shift 2

  # Find the recording session name to use
  local session_name

  if [[ $session_name_src = opt ]]; then
    if (($+opt_args[-s])); then
      session_name=$opt_args[-s]
    elif (($+opt_args[--session])); then
      session_name=$opt_args[--session]
    fi
  elif [[ $session_name_src = arg ]]; then
    session_name=$line[1]
  fi

  if [[ -z $session_name ]]; then
    # Fall back to current recording session
    session_name=$(__lttng_cur_session_name)

    if (($? != 0)); then
      _guard '^-*' 'channel name'
      return
    fi
  fi

  # Get XML document (detailed recording session)
  local session_xml

  session_xml=$(__lttng_session_xml 'channel name' $session_name)

  if (($? != 0)); then
    return 1
  fi

  # Count tracing domains
  local -i domain_count

  domain_count=$(__lttng_xmllint_xpath $session_xml 'count(//*[local-name()="domain"])')

  if (($? != 0 || domain_count == 0)); then
    _guard '^-*' 'channel name'
    return
  fi

  # Append the name and info of one channel at a time
  local domain_xml domain prop
  local channel_xml channel_name channel_status channel_erl_mode
  local -a channel_names channel_infos
  local -i channel_count domain_index channel_index

  # For each tracing domain
  for domain_index in {1..$domain_count}; do
    # Get tracing domain XML node
    domain_xml=$(__lttng_xmllint_xpath $session_xml "//*[local-name()='domain'][$domain_index]")

    if (($? != 0)); then
      continue
    fi

    # Get tracing domain type
    domain=$(__lttng_xmllint_xpath $domain_xml '/*/*[local-name()="type"]/text()')

    if (($? != 0)); then
      continue
    fi

    # Skip unexpected tracing domains
    if [[ $domain = KERNEL ]]; then
      if __lttng_user_domain_opt_is_set; then
        # Skip unexpected Linux kernel tracing domain
        continue
      fi

      domain='Linux kernel'
    fi

    if [[ $domain = UST ]]; then
      if __lttng_kernel_domain_opt_is_set; then
        # Skip unexpected user space tracing domain
        continue
      fi

      domain='user space'
    fi

    # Count channels within tracing domain
    channel_count=$(__lttng_xmllint_xpath $domain_xml 'count(//*[local-name()="channel"])')

    if (($? != 0 || channel_count == 0)); then
      continue
    fi

    # For each channel
    for channel_index in {1..$channel_count}; do
      # Get channel XML node
      channel_xml=$(__lttng_xmllint_xpath $domain_xml "//*[local-name()='channel'][$channel_index]")

      if (($? != 0)); then
        continue
      fi

      # Get channel name
      channel_name=$(__lttng_name_prop_from_xml $channel_xml channel)

      if (($? != 0)); then
        continue
      fi

      # Get channel status
      channel_status=$(__lttng_enabled_prop_from_xml $channel_xml channel)

      if (($? != 0)); then
        continue
      fi

      channel_status=$(__lttng_status_from_enabled_prop $channel_status)

      if [[ $req_status != all && $req_status != $channel_status ]]; then
        # Skip channel with unexpected status
        continue
      fi

      # Get channel event record loss mode
      channel_erl_mode=$(__lttng_xmllint_xpath $channel_xml '//*[local-name()="attributes"]/*[local-name()="overwrite_mode"]/text()')

      if (($? != 0)); then
        continue
      fi

      if [[ $channel_erl_mode = DISCARD ]]; then
        channel_erl_mode=discard
      elif [[ $channel_erl_mode = OVERWRITE ]]; then
        channel_erl_mode=overwrite
      fi

      channel_names+=("$channel_name")
      channel_infos+=("$channel_status, $domain, $channel_erl_mode mode")
    done
  done

  # No channels: show message
  if (($#channel_names == 0)); then
    _guard '^-*' 'channel name'
    return
  fi

  # Compute maximum channel info length
  local channel_info
  local -i max_info_len=0 len

  for channel_info in $channel_infos; do
    len=$#channel_info

    if ((len > max_info_len)); then
      max_info_len=$len
    fi
  done

  # Compute maximum channel name length
  local -i max_name_len=0

  for channel_name in $channel_names; do
    len=$#channel_name

    if ((len > max_name_len)); then
      max_name_len=$len
    fi
  done

  # Some room for the longest info string, two spaces, and two brackets
  local -ir max_possible_name_len=$((COLUMNS - max_info_len - 5))

  if ((max_name_len > max_possible_name_len)); then
    # Clamp
    max_name_len=$max_possible_name_len
  fi

  # Create the dislay strings (name, status, tracing domain, mode)
  local -a disps

  for channel_index in {1..${#channel_names}}; do
    disps+=("${(r:$max_name_len:: :)channel_names[$channel_index]}  [$channel_infos[$channel_index]]")
  done

  # Add completions
  local expl

  if __lttng_style_is_verbose channel channels; then
    # Verbose mode (list with infos).
    #
    # Using `-2` as Linux kernel and user space channels may have the
    # same name, but we want to show the different infos.
    _wanted -C channel channels expl 'channel name' \
      compadd "$@" -2 -d disps -l -a channel_names
  else
    # Just the channel names, no duplicates
    _wanted -C channel channels expl 'channel name' \
      compadd "$@" -a channel_names
  fi
}

# Add completions for instrumentation point names.
#
# This function relies on the tracing domain options of `$opt_args` and
# `$opt_args[ip---syscall]` to restrict the offered completions.
__lttng_complete_ip_name() {
  local msg
  local -a list_opts

  if __lttng_kernel_domain_opt_is_set; then
    list_opts=(-k)

    if (($+opt_args[ip---syscall])); then
      msg='system call name (no `sys_` prefix)'
      list_opts+=(--syscall)
    else
      msg='Linux kernel tracepoint name'
    fi
  elif __lttng_user_domain_opt_is_set; then
    msg='user space tracepoint name'
    list_opts=(-u)
  elif __lttng_jul_domain_opt_is_set; then
    msg='`java.util.logging` logger name'
    list_opts=(-j)
  elif __lttng_log4j_domain_opt_is_set; then
    msg='Apache log4j logger name'
    list_opts=(-l)
  elif __lttng_python_domain_opt_is_set; then
    msg='Python logger name'
    list_opts=(-p)
  else
    # No tracing domain option
    _guard '^-*' 'instrumentation point or recording event rule name'
    return
  fi

  # Get XML list of available instrumentation point names
  local list_xml

  list_xml=$(__lttng_mi_run $msg list $list_opts)

  if (($? != 0)); then
    return 1
  fi

  # Convert to one instrumentation point name per line
  local ip_names

  ip_names=$(__lttng_xmllint_xpath $list_xml '//*[local-name()="event"]//*[local-name()="name"]/text()')

  if (($? != 0)) || [[ -z $ip_names ]]; then
    # `xmllint` error or no instrumentation points
    _guard '^-*' $msg
    return
  fi

  local ip_name
  local -a items

  while read -r ip_name; do
    if [[ -z $ip_name ]]; then
      continue
    fi

    items+=($ip_name)
  done <<< $ip_names

  # Add completions
  local expl

  _wanted instrumentation-points expl $msg compadd "$@" -a items
}

# Adds completions for the arguments of the `add-context` command.
__lttng_complete_add_context_cmd() {
  local specs=(
    $help_opt_specs
    '(- : *)--list[list the available context field types]'
    '(--list -s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name inactive all'
    '(--list -c --channel)'{-c+,--channel=}'[select a specific channel]: : __lttng_complete_channel_name enabled opt'
    '(--list)*'{-t+,--type=}'[add a context field to be recorded]: : __lttng_complete_context_type'
    + '(domain)'
    '(--list)'{-k,--kernel}'[select the Linux kernel tracing domain]'
    '(--list)'{-u,--userspace}'[select the user space tracing domain]'
  )

  # The Java tracing domain options require LTTng-tools ≥ 2.8 (for
  # application-specific context field types).
  if ((minor_version >= 8)); then
    specs+=(
      '(--list)'{-j,--jul}'[select the `java.util.logging` tracing domain]'
      '(--list)'{-l,--log4j}'[select the Apache log4j tracing domain]'
    )
  fi

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for log level names.
#
# This function relies on the tracing domain options of `$opt_args` to
# restrict the offered completions.
__lttng_complete_log_level() {
  local -a log_levels

  # Fill the `log_levels` array depending on the tracing domain option
  if __lttng_user_domain_opt_is_set; then
    log_levels=(
      EMERG
      ALERT
      CRIT
      ERR
      WARNING
      NOTICE
      INFO
      DEBUG_SYSTEM
      DEBUG_PROGRAM
      DEBUG_PROCESS
      DEBUG_MODULE
      DEBUG_UNIT
      DEBUG_FUNCTION
      DEBUG_LINE
      DEBUG
    )
  elif __lttng_jul_domain_opt_is_set; then
    log_levels=(
      OFF
      SEVERE
      WARNING
      INFO
      CONFIG
      FINE
      FINER
      FINEST
      ALL
    )
  elif __lttng_log4j_domain_opt_is_set; then
    log_levels=(
      OFF
      FATAL
      ERROR
      WARN
      INFO
      DEBUG
      TRACE
      ALL
    )
  elif __lttng_python_domain_opt_is_set; then
    log_levels=(
      CRITICAL
      ERROR
      WARNING
      INFO
      DEBUG
      NOTSET
    )
  else
    # No tracing domain option
    _guard '^-*' 'log level name'
  fi

  # Add completions
  local expl

  _wanted log-levels expl 'log level name' compadd -a log_levels
}

# Adds completions for a trigger condition type.
__lttng_complete_trigger_condition_type() {
  local -r types=(
    'event-rule-matches:an event rule matches an event'
  )

  # Add completions
  local expl

  _describe 'trigger condition type' types
}

# Adds completions for a trigger action type.
__lttng_complete_trigger_action_type() {
  local -r types=(
    'notify:send a notification through the notification mechanism'
    'start-session:start a recording session'
    'stop-session:stop a recording session'
    'rotate-session:archive the current trace chunk of a recording session'
    'snapshot-session:take a recording session snapshot'
  )

  # Add completions
  local expl

  _describe 'trigger action type' types
}

# Adds completions for the arguments of the `add-trigger` command.
#
# Note that those completions are incomplete, in that:
#
# • A valid event rule specification, as per lttng-event-rule(7),
#   must follow `--condition=event-rule-matches`.
#
# • `--capture` options are possible within an `event-rule-matches`
#   condition specifier.
#
# • The `--rate-policy` option and other arguments, sometimes mandatory,
#   are possible within an action specifier.
#
# Having full completion for condition and action specifiers require
# more Zsh magic as _arguments(), like most command-line argument
# parsers, doesn't take option positions into account.
__lttng_complete_add_trigger_cmd() {
  local -r specs=(
    $help_opt_specs
    '(-n --name)'{-n+,--name=}'[set the trigger name]:new trigger name:'
    '--owner-uid=[add the trigger as another Unix user]: : __lttng_complete_uid'
    '--condition=[set the condition type and arguments]: : __lttng_complete_trigger_condition_type'
    '*--action=[set the action type and arguments]: : __lttng_complete_trigger_action_type'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `clear` command.
__lttng_complete_clear_cmd() {
  local -r specs=(
    $help_opt_specs
    '(-a --all):: : __lttng_complete_session_name all all'
    '(1 -a --all)'{-a,--all}'[clear all recording sessions]'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `create` command.
__lttng_complete_create_cmd() {
  local specs=(
    $help_opt_specs
    ':: :_guard "^-*" "new recording session name"'
    '(-C --ctrl-url output)'{-C+,--ctrl-url=}'[set the control URL]:control URL:'
    '(-D --data-url output)'{-D+,--data-url=}'[set the trace data output URL]:trace data output URL:'
  )

  # The `--shm-path` option requires LTTng-tools ≥ 2.7
  if ((minor_version >= 7)); then
    specs+=(
      '--shm-path=[write shared memory files to a specific directory]:shared memory file directory:_files -/'
    )
  fi

  # Add the remaining option groups
  specs+=(
    + '(output)'
    '(-D --data-url -C --ctrl-url --live)--no-output[disable trace data output]'
    '(-D --data-url -C --ctrl-url --live)'{-o+,--output=}'[set the local trace data output directory]:trace data output directory:_files -/'
    '(-D --data-url -C --ctrl-url)'{-U+,--set-url=}'[set the trace data output and control URL]:trace data output and control URL:'
    + '(mode)'
    '(-o --output --no-output)--live=[create an LTTng live recording session]:live timer period (µs):'
    '--snapshot[create a snapshot recording session]'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `destroy` command.
__lttng_complete_destroy_cmd() {
  local specs=(
    $help_opt_specs
    '(-a --all):: : __lttng_complete_session_name all all'
    '(1 -a --all)'{-a,--all}'[destroy all recording sessions]'
  )

  # The `--no-wait` option requires LTTng-tools ≥ 2.8
  if ((minor_version >= 8)); then
    specs+=(
      '(-n --no-wait)'{-n,--no-wait}'[exit immediately]'
    )
  fi

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `disable-channel` command.
__lttng_complete_disable_channel_cmd() {
  local -r specs=(
    $help_opt_specs
    '(-s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name all all'
    ': : _sequence __lttng_complete_channel_name enabled opt'
    + '(domain)'
    {-k,--kernel}'[select the Linux kernel tracing domain]'
    {-u,--userspace}'[select the user space tracing domain]'
  )

  # Add completions
  __lttng_arguments $specs
}

# Prints the XML tracing domain name value depending on the tracing
# domain option (in `$opt_args`), or prints nothing and returns 1 when
# not available.
__lttng_xml_domain_name_from_opt() {
  if __lttng_kernel_domain_opt_is_set; then
    echo -n KERNEL
  elif __lttng_user_domain_opt_is_set; then
    echo -n UST
  elif __lttng_jul_domain_opt_is_set; then
    echo -n JUL
  elif __lttng_log4j_domain_opt_is_set; then
    echo -n LOG4J
  elif __lttng_python_domain_opt_is_set; then
    echo -n PYTHON
  else
    return 1
  fi
}

# Prints the XML instrumentation point type value depending on the
# instrumentation point option (in `$opt_args`).
__lttng_xml_ip_type_from_opt() {
  if (($+opt_args[--syscall] || $+opt_args[ip---syscall])); then
    echo -n SYSCALL
  elif (($+opt_args[--probe] || $+opt_args[ip---probe])); then
    echo -n PROBE
  elif (($+opt_args[--function] || $+opt_args[ip---function])); then
    echo -n FUNCTION
  else
    echo -n TRACEPOINT
  fi
}

# Adds completions for an old, enabled recording event rule name
# condition (for the `disable-event` command).
__lttng_complete_old_enabled_er_name_cond() {
  local -r msg='recording event rule name condition'

  # Find the recording session name to use
  local session_name

  if (($+opt_args[-s])); then
    session_name=$opt_args[-s]
  elif (($+opt_args[--session])); then
    session_name=$opt_args[--session]
  else
    # Fall back to current recording session
    session_name=$(__lttng_cur_session_name)

    if (($? != 0)); then
      _guard '^-*' $msg
    fi
  fi

  # Find the channel name to use (`channel0` is the default name)
  local channel_name=channel0

  if (($+opt_args[-c])); then
    channel_name=$opt_args[-c]
  elif (($+opt_args[--channel])); then
    channel_name=$opt_args[--channel]
  fi

  # Create tracing domain XPath part
  local domain_xpath
  local xml_domain_val

  xml_domain_val=$(__lttng_xml_domain_name_from_opt)

  if (($? == 0)); then
    domain_xpath="*[local-name() = 'domain'][*[local-name() = 'type'] = '$xml_domain_val']//"
  fi

  # Create channel XPath part
  local -r channel_xpath="*[local-name() = 'channel'][*[local-name() = 'name'] = '$channel_name']//"

  # Create instrumentation point type XPath part
  local -r xml_ip_type_val=$(__lttng_xml_ip_type_from_opt)
  local -r ip_type_xpath="[*[local-name() = 'type'] = '$xml_ip_type_val']"

  # Get XML document (detailed recording session)
  local session_xml

  session_xml=$(__lttng_session_xml $msg $session_name)

  if (($? != 0)); then
    return 1
  fi

  # Convert to one recording event rule name per line
  local lines

  lines=$(__lttng_xmllint_xpath $session_xml "//$domain_xpath${channel_xpath}*[local-name() = 'event']${ip_type_xpath}[*[local-name() = 'enabled'] = 'true']/*[local-name() = 'name']/text()")

  if (($? != 0)); then
    _guard '^-*' $msg
    return
  fi

  local -a er_names

  while read -r line; do
    if [[ -z ${line// } ]]; then
      # Skip empty line
      continue
    fi

    er_names+=$line
  done <<< $lines

  # Add completions
  local expl

  _wanted -C event events expl $msg compadd "$@" -a er_names
}

# Adds completions for the arguments of the `disable-event` command.
__lttng_complete_disable_event_cmd() {
  local -r kernel_ip_opt_excl=(--syscall --probe --function)
  local specs=(
    $help_opt_specs
    '(-s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name all all'
    '(-c --channel)'{-c+,--channel=}'[select a specific channel]: : __lttng_complete_channel_name all opt'
    + '(names)'
    {-a,--all-events}'[disable all recording event rules]'
    ': :_sequence __lttng_complete_old_enabled_er_name_cond'
    + '(domain)'
    {-k,--kernel}'[select the Linux kernel tracing domain]'
    "($kernel_ip_opt_excl)"{-u,--userspace}'[select the user space tracing domain]'
    "($kernel_ip_opt_excl)"{-j,--jul}'[select the `java.util.logging` tracing domain]'
  )

  # Add tracing domain option specifications based on the minor version
  # of LTTng-tools.
  if ((minor_version >= 6)); then
    specs+=(
      "($kernel_ip_opt_excl)"{-l,--log4j}'[select the Apache log4j tracing domain]'
    )
  fi

  if ((minor_version >= 7)); then
    specs+=(
      "($kernel_ip_opt_excl)"{-p,--python}'[select the Python tracing domain]'
    )
  fi

  # Add instrumentation point type option specifications based on the
  # minor version of LTTng-tools.
  if ((minor_version >= 6)); then
    specs+=(
      + '(ip)'
      "($non_kernel_domain_opt_excl)--syscall[disable recording ER matching Linux system call events]"
    )
  fi

  if ((minor_version >= 7)); then
    specs+=(
      '--tracepoint[disable recording ER matching tracepoint events]'
      "($non_kernel_domain_opt_excl)--probe[disable recording ER matching kprobe events]"
      "($non_kernel_domain_opt_excl)--function[disable recording ER matching kretprobe events]"
    )
  fi

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `disable-rotation` command.
__lttng_complete_disable_rotation_cmd() {
  local -r specs=(
    $help_opt_specs
    '(-s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name all all'
    '--timer[disable the periodic rotation schedule]'
    '--size[disable the size-based rotation schedule]'
  )

  __lttng_arguments $specs
}

# Adds completions for a channel output type (`mmap` and, possibly,
# `splice`) (for the `--output` option of the `enable-channel` command).
#
# This function replaces the argument field of the current context with
# `output-opt`.
#
# This function relies on the user space tracing domain options of
# `$opt_args` to restrict the offered completions. Without the user
# space tracing domain option, this function adds the `splice`
# completion too.
__lttng_complete_channel_output_type() {
  local output_types=(mmap)

  if ! __lttng_user_domain_opt_is_set; then
    # Linux kernel tracing domain or none
    output_types+=(splice)
  fi

  local expl

  _wanted -C 'output-opt' values expl 'output type' compadd -a output_types
}

# Adds completions for the non-option argument of the `enable-channel`
# command.
#
# This function either, depending on the keys of `$opt_args`:
#
# At least one creation option:
#     Shows a message to enter the new channel name.
#
# Otherwise:
#     Adds completions for a comma-separated list of known channel names
#     using __lttng_complete_channel_name().
__lttng_complete_enable_channel_cmd_names() {
  local key
  local -r enable_opts=(
    -s --session
    domain---kernel domain--k
    domain---userspace domain--u
  )

  # For each key of `$opt_args`
  for key in "${(@k)opt_args}"; do
    if (($enable_opts[(Ie)$key])); then
      # Enabling option exists: skip
      continue
    fi

    # Creation option exists: single name
    _guard '^-*' 'new channel name'
    return
  done

  # Comma-separated list of existing channel names
  _sequence __lttng_complete_channel_name disabled opt
}

# Adds completions for the arguments of the `enable-channel` command.
__lttng_complete_enable_channel_cmd() {
  local specs=(
    $help_opt_specs
    '--switch-timer=[set the switch timer period]:switch timer period (µs):'
    '--read-timer=[set the read timer period]:read timer period (µs):'
    '--subbuf-size=[set the size of each sub-buffer]:sub-buffer size (bytes; `k`/`M`/`G` suffixes supported):'
    '--num-subbuf=[set the number of sub-buffers per ring buffer]:sub-buffer count:'
    '--tracefile-size=[set the maximum size of each trace file]:trace file size (bytes; `k`/`M`/`G` suffixes supported):'
    '--tracefile-count=[set the maximum number of trace files]:maximum trace file count:'
    '--output=[set the output type]: : __lttng_complete_channel_output_type'
    '(-s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name all all'
    ': : __lttng_complete_enable_channel_cmd_names'
  )

  # The `--blocking-timeout` and `--monitor-timer` options require
  # LTTng-tools ≥ 2.10.
  if ((minor_version >= 10)); then
    specs+=(
      '(--kernel --overwrite --buffers-global)--blocking-timeout=[set the blocking timeout]:blocking timeout (µs):'
      '--monitor-timer=[set the monitor timer period]:monitor timer period (µs):'
    )
  fi

  # Add the remaining option groups
  specs+=(
    + '(domain)'
    '(--blocking-timeout --buffers-uid --buffers-pid)'{-k,--kernel}'[select the Linux kernel tracing domain]'
    '(--buffers-global)'{-u,--userspace}'[select the user space tracing domain]'
    + '(loss-mode)'
    '--discard[discard event records with no available sub-buffer]'
    '(--blocking-timeout)--overwrite[overwrite oldest sub-buffer with no available sub-buffer]'
    + '(buffering)'
    '(-k --kernel)--buffers-uid[use per-user ring buffers]'
    '(-k --kernel)--buffers-pid[use per-process ring buffers]'
    '(-u --userspace --blocking-timeout)--buffers-global[use global ring buffers]'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `enable-event` command.
__lttng_complete_enable_event_cmd() {
  local -r kernel_opts_excl=(
    -k --kernel
    --syscall
    --probe
    --userspace-probe
    --function
  )
  local -r non_kernel_opts_excl=(
    $non_kernel_domain_opt_excl
    -x --exclude
    log-level
  )
  local -r exclude_opt_excl=(
    $kernel_opts_excl
    -j --jul
    -l --log4j
    -p --python
    -x --exclude
  )
  local ip_specs=(
    '--tracepoint[only match LTTng tracepoint events]'
    "($non_kernel_opts_excl)--syscall[only match Linux system call events]"
    "($non_kernel_opts_excl)--probe=[only match kprobe events]:kprobe location:"
    "($non_kernel_opts_excl)--function=[only match kretprobe events]:kretprobe location:"
  )
  local domain_specs=(
    "($non_kernel_opts_excl)"{-k,--kernel}'[select the Linux kernel tracing domain]'
    "($kernel_opts_excl)"{-u,--userspace}'[select the user space tracing domain]'
    "($kernel_opts_excl -x --exclude)"{-j,--jul}'[select the `java.util.logging` tracing domain]'
  )

  # The Apache log4j tracing domain options require LTTng-tools ≥ 2.6
  if ((minor_version >= 6)); then
    domain_specs+=(
      "($kernel_opts_excl -x --exclude)"{-l,--log4j}'[select the Apache log4j tracing domain]'
    )
  fi

  # The Python tracing domain options require LTTng-tools 2.7
  if ((minor_version >= 7)); then
    domain_specs+=(
      "($kernel_opts_excl -x --exclude)"{-p,--python}'[select the Python tracing domain]'
    )
  fi

  # The Linux user space probe instrumentation options require LTTng-tools 2.11
  if ((minor_version >= 11)); then
    ip_specs+=(
      "($non_kernel_opts_excl)--userspace-probe=[only match Linux user space probe events]:user space probe location:"
    )
  fi

  # Add completions.
  #
  # There's no way, based on the command-line arguments, to distinguish
  # between creating a new recording event rule and enabling an
  # existing, disabled recording event rule here.
  #
  # For example, given this:
  #
  #     $ lttng enable-event --kernel --syscall <TAB>
  #
  # At this point, the user might want the list of existing, disabled
  # kernel system call recording event rule names (current recording
  # session, default channel name), or the full list of available system
  # call instrumentation point names.
  #
  # This function makes the arbitrary choice to provide the available
  # instrumentation point names (__lttng_complete_ip_name()) because,
  # interactively, it seems to be more common/useful than disabling
  # existing recording event rules.
  local -r specs=(
    $help_opt_specs
    '(--probe --userspace-probe --function -f --filter)'{-f+,--filter=}'[only match events which satisfy an expression]:filter expression:'
    "($exclude_opt_excl)"{-x+,--exclude=}'[exclude event name patterns]:comma-separated list of patterns:'
    '(-s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name all all'
    '(-c --channel)'{-c+,--channel=}'[select a specific channel]: : __lttng_complete_channel_name all opt'
    + '(log-level)'
    "($kernel_opts_excl)--loglevel=[only match events with specific log levels]: : __lttng_complete_log_level"
    "($kernel_opts_excl)--loglevel-only=[only match events with an exact log level]: : __lttng_complete_log_level"
    + '(names)'
    {-a,--all}'[match events regardless of their name]'
    ': :_sequence __lttng_complete_ip_name'
    + '(ip)' $ip_specs
    + '(domain)' $domain_specs
  )

  __lttng_arguments $specs
}

# Adds completions for the arguments of the `enable-rotation` command.
__lttng_complete_enable_rotation_cmd() {
  local -r specs=(
    $help_opt_specs
    '(-s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name all all'
    '--timer=[rotate periodically]:period (µs; `ms`/`s`/`m`/`h` suffixes supported):'
    '--size=[rotate based on flushed size of current trace chunk]:size (bytes; `k`/`M`/`G` suffixes supported):'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `help` command.
__lttng_complete_help_cmd() {
  local -r specs=(
    $help_opt_specs
    ': : __lttng_complete_cmd_name'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `list` command.
__lttng_complete_list_cmd() {
  local -r domain_opt_excl=(
    -d --domain
    -f --fields
    -c --channel
    -k --kernel
    -u --userspace
    -j --jul
    -l --log4j
    -p --python
    --syscall
  )
  local specs=(
    $help_opt_specs
    '(-d --domain -f --fields --syscall -c --channel 1)'{-f,--fields}'[show instrumentation point fields]'
    "($domain_opt_excl)"{-d,--domain}'[show tracing domains with at least one channel]'
    '(-d --domain -f --fields --syscall -c --channel)'{-c+,--channel=}'[list the objects of a specific channel]: : __lttng_complete_channel_name all arg'
    '(-d --domain -f --fields --syscall):recording session name: __lttng_complete_session_name all all'
    '(-d --domain -k --kernel)'{-k,--kernel}'[list Linux kernel tracing domain objects]'
    '(-d --domain -u --userspace)'{-u,--userspace}'[list user space tracing domain objects]'
    '(-d --domain -j --jul)'{-j,--jul}'[list `java.util.logging` tracing domain objects]'
  )

  # The Apache log4j tracing domain and `--syscall` options require
  # LTTng-tools ≥ 2.6.
  if ((minor_version >= 6)); then
    specs+=(
      '(-d --domain -l --log4j)'{-l,--log4j}'[list Apache log4j tracing domain objects]'
      '(-d --domain)--syscall[list Linux kernel system calls]'
    )
  fi

  # The Python tracing domain options require LTTng-tools 2.7
  if ((minor_version >= 7)); then
    specs+=(
      '(-d --domain -p --python)'{-p,--python}'[list Python tracing domain objects]'
    )
  fi

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `list-triggers` command.
__lttng_complete_list_triggers_cmd() {
  __lttng_arguments $help_opt_specs
}

# Adds completions for the arguments of the `load` command.
__lttng_complete_load_cmd() {
  local specs=(
    $help_opt_specs
    '(-f --force)'{-f,--force}'[overwrite existing recording sessions]'
    '(-i --input-path)'{-i+,--input-path=}'[load recording session configurations from a specific path]:recording session configuration path:_files'
    '(-a --all --override-name 1)'{-a,--all}'[load all recording session configurations]'
    '(-a --all):recording session configuration name:_guard "^-*" "recording session name"'
  )

  if ((minor_version >= 9)); then
    specs+=(
      '--override-url=[override the loaded recording session output URL]:output URL:'
      '(-a --all)--override-name=[override the loaded recording session name]:recording session name:'
    )
  fi

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `metadata` command
# (deprecated).
__lttng_complete_metadata_cmd() {
  local -r specs=(
    $help_opt_specs
    ':action:(regenerate)'
    '(-s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name all all'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `regenerate` command.
__lttng_complete_regenerate_cmd() {
  local -r specs=(
    $help_opt_specs
    ':trace data type:(metadata statedump)'
    '(-s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name all all'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `remove-trigger` command.
__lttng_complete_remove_trigger_cmd() {
  local -r specs=(
    $help_opt_specs
    '--owner-uid=[remove the trigger as another Unix user]: : __lttng_complete_uid'
    ': : __lttng_complete_trigger_name'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `rotate` command.
__lttng_complete_rotate_cmd() {
  local -r specs=(
    $help_opt_specs
    '(-n --no-wait)'{-n,--no-wait}'[exit immediately]'
    ': : __lttng_complete_session_name all all'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `save` command.
__lttng_complete_save_cmd() {
  local -r specs=(
    $help_opt_specs
    '(-f --force)'{-f,--force}'[overwrite existing recording session configuration files]'
    '(-o --output-path)'{-o+,--output-path=}'[save recording session configuration files to a specific directory]:recording session configuration directory:_files -/'
    '(-a --all 1)'{-a,--all}'[save all recording session configurations]'
    '(-a --all): : __lttng_complete_session_name all all'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `set-session` command.
__lttng_complete_set_session_cmd() {
  local -r specs=(
    $help_opt_specs
    ': : __lttng_complete_session_name all all'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `snapshot` command.
__lttng_complete_snapshot_cmd() {
  local specs=(
    $help_opt_specs
    '(-): : __lttng_complete_snapshot_action_name' \
    '(-)*:: :->action-args' \
  )

  # Add action name completions
  local curcontext=$curcontext state state_descr line
  local -A opt_args

  _arguments -C -s -W : $specs

  if (($? == 0)); then
    # Completions added: we're done
    return
  fi

  # Add action-specific completions
  local -r common_session_specs=(
    '(-s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name all snapshot'
  )
  local -r common_output_specs=(
    '(-m --max-size)'{-m+,--max-size=}'[set the maximum total size of all snapshot files]:maximum size (bytes; `k`/`M`/`G` suffixes supported):'
    '(-n --name)'{-n+,--name=}'[set the snapshot output name]:snapshot output name:'
    '(1 -C --ctrl-url output)'{-C+,--ctrl-url=}'[set the control URL]:control URL:'
    '(1 -D --data-url output)'{-D+,--data-url=}'[set the trace data output URL]:trace data output URL:'
    '(-C --ctrl-url -D --data-url): :_guard "^-*" "snapshot output URL"'
  )

  if [[ $state[1] = action-args ]]; then
    # Add completions for the arguments of the specific snapshot action
    curcontext=${curcontext%:*:*}:lttng-snapshot-$line[1]:

    case $line[1] in
      add-output | record)
        specs=($common_session_specs $common_output_specs);;
      del-output)
        specs=($common_session_specs ':snapshot output index:(1)');;
      list-output)
        specs=($common_session_specs);;
      *)
        _message "unknown snapshot action \`$line[1]\`"
        return 1
        ;;
    esac

    # Add completions
    __lttng_arguments $specs
    return
  fi

  return 1
}

# Adds completions for the arguments of the `start` command.
__lttng_complete_start_cmd() {
  local -r specs=(
    $help_opt_specs
    ': : __lttng_complete_session_name inactive all'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `stop` command.
__lttng_complete_stop_cmd() {
  local -r specs=(
    $help_opt_specs
    '(-n --no-wait)'{-n,--no-wait}'[exit immediately]'
    ': : __lttng_complete_session_name active all'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `status` command.
__lttng_complete_status_cmd() {
  __lttng_arguments $help_opt_specs
}

# Adds completions for the arguments of the `track` command.
__lttng_complete_track_cmd() {
  local specs=(
    $help_opt_specs
    '(-s --session)'{-s+,--session=}'[select a specific recording session]: : __lttng_complete_session_name all all'
    '(-a --all)'{-a,--all}'[add all possible values to the selected inclusion sets]'
    '(-p --pid)'{-p+,--pid=}'[add values to the process ID inclusion set]:process ID(s):_sequence _pids'
  )

  # Virtual PID and user/group inclusion sets require LTTng-tools ≥ 2.12
  if ((minor_version >= 12)); then
    specs+=(
      '--vpid=[add values to the virtual process ID inclusion set]:virtual process ID(s):_sequence _pids'
      '(-u --userspace)--uid=[add values to the user ID inclusion set]:user(s):_sequence _users'
      '--vuid=[add values to the virtual user ID inclusion set]:virtual user(s):_sequence _users'
      '(-u --userspace)--gid=[add values to the group ID inclusion set]:group(s):_sequence _groups'
      '--vgid=[add values to the virtual group ID inclusion set]:virtual group(s):_sequence _groups'
    )
  fi

  # Append tracing domain specifications
  specs+=(
    + '(domain)'
    {-k,--kernel}'[select the Linux kernel tracing domain]'
    "(--uid --gid)"{-u,--userspace}'[select the user space tracing domain]'
  )

  # Add completions
  __lttng_arguments $specs
}

# Adds completions for the arguments of the `untrack` command.
__lttng_complete_untrack_cmd() {
  # As of LTTng-tools 2.13, the `track` and `untrack` commands expect
  # the same arguments.
  __lttng_complete_track_cmd
}

# Adds completions for the arguments of the `version` command.
__lttng_complete_version_cmd() {
  __lttng_arguments $help_opt_specs
}

# Adds completions for the arguments of the `view` command.
__lttng_complete_view_cmd() {
  local -r specs=(
    $help_opt_specs
    '(-e --viewer)'{-e+,--viewer=}'[set the trace reader path]:trace reader path:_files'
    '(-t --trace-path): : __lttng_complete_session_name all all'
    '(1 -t --trace-path)'{-t+,--trace-path=}'[set the trace directory to pass to the reader]:trace directory:_files -/'
  )

  # Add completions
  __lttng_arguments $specs
}

# Add completions for the specific `lttng` command named `$line[1]`.
__lttng_complete_cmd() {
  # An lttng(1) command: replace `lttng` with `lttng-$line[1]` (for
  # example, `lttng-add-trigger`).
  curcontext=${curcontext%:*:*}:lttng-$line[1]:

  # Keep the tracing group: we need to execute `lttng` for some
  # completions and use the required tracing group to connect to the
  # same session daemon.
  #
  # The default tracing group is `tracing`.
  local tracing_group=tracing

  if (($+opt_args[-g])); then
    tracing_group=$opt_args[-g]
  elif (($+opt_args[--group])); then
    tracing_group=$opt_args[--group]
  fi

  # Add command completions: dispatch to a dedicated function
  local -r func_name=__lttng_complete_${line[1]//-/_}_cmd

  if ! typeset -f $func_name >/dev/null; then
    _message "unknown command \`$line[1]\`"
    return 1
  fi

  local -A opt_args

  $func_name
}

# Save program name
local -r prog_name=$words[1]

# First, set the `minor_version` variable to the minor version of
# LTTng-tools. Some features depend on a specific version and this
# completion function supports many versions from LTTng-tools 2.5.
local -i minor_version

__lttng_set_minor_version

# Exit now with LTTng-tools < 2.5 or LTTng-tools > 2.14
local -r ignore_version_limit=${LTTNG_ZSH_COMP_IGNORE_VERSION_LIMIT:-0}

if ((minor_version < 5 || (minor_version > 14 && !ignore_version_limit))); then
  _message "completion not available for LTTng-tools 2.$minor_version; please update the completion files or set \`LTTNG_ZSH_COMP_IGNORE_VERSION_LIMIT=1\`"
  return 1
fi

# Common help option specifications
local -r help_opt_specs=(
  '(- : *)'{-h,--help}'[show help]'
)

# Common non Linux kernel tracing domain option exclusions
local -r non_kernel_domain_opt_excl=(-u --userspace -j --jul -l --log4j -p --python)

# General option specifications
local gen_opt_specs=(
  $help_opt_specs
  '(- : *)--list-commands[list the available commands and quit]'
  '--relayd-path=[set the relay daemon path]:relay daemon path:_files -g \*lttng-relayd'
  '--group=[set the tracing group]:tracing group:_groups'
  '(-q --quiet)*'{-v,--verbose}'[increase verbosity]'
  '(-q --quiet -v --verbose)'{-q,--quiet}'[suppress all messages, including warnings and errors]'
  '(- : *)'{-V,--version}'[show version and quit]'
)

# MI output requires LTTng-tools ≥ 2.6
if ((minor_version >= 6)); then
  gen_opt_specs+=(
    '(-m --mi)'{-m+,--mi=}'[use the machine interface output]:machine interface type:(xml)'
  )
fi

# Append session daemon option specifications
gen_opt_specs+=(
  + '(sessiond)'
  {-n,--no-sessiond}'[do not spawn a session daemon]'
  '--sessiond-path=[set the session daemon path]:session daemon path:_files -g \*lttng-sessiond'
)

# Add general option and command name completions
local curcontext=$curcontext state state_descr line
local -A opt_args

_arguments -C -s -W : \
  '(-): : __lttng_complete_cmd_name' \
  '(-)*:: :->cmd-args' \
  $gen_opt_specs

local -ir main_ret=$?

if ((main_ret == 0)); then
  # Completions added: we're done
  return
fi

if [[ $state[1] = cmd-args ]]; then
  # Add completions for the arguments of the specific command
  __lttng_complete_cmd
  return
fi

return $main_ret