# SPDX-FileCopyrightText: 2025 Dennis Fink <me+coding@dennisfink.me>
#
# SPDX-License-Identifier: BSD-3-Clause

# bash completion for transcode.sh
# Install to:
#   /etc/bash_completion.d/transcode.sh
# or source manually:
#   source transcode.sh.bash-completion.sh
#
# Each option that takes an argument is supported in all three forms:
#   short          -f list.txt
#   long space     --encode-file list.txt
#   long equals    --encode-file=list.txt

function _transcode_sh() {
  local cur prev
  _init_completion -n = || return

  local -r preset_dir="${XDG_CONFIG_HOME:-$HOME/.config}/transcode.sh/presets"

  # ---------------------------------------------------------------------------
  # Helper: collect preset names from the preset directory
  # ---------------------------------------------------------------------------
  function _transcode_presets() {
    local presets=()
    if [[ -d "$preset_dir" ]]; then
      local f
      while IFS= read -r f; do
        f="${f##*/}" # basename
        f="${f%.sh}" # strip .sh extension
        presets+=("$f")
      done < <(find "$preset_dir" -maxdepth 1 -name '*.sh' -type f 2>/dev/null)
    fi
    printf '%s\n' "${presets[@]}"
  }

  local codecs='h264 hevc av1 vp8 vp9 mpeg2video mpeg4 mjpeg theora'
  local nice_vals='0 5 10 15 19'
  local hwaccel_methods='auto cuda vaapi dxva2 d3d11va videotoolbox qsv'
  local ffmpeg_loglevels='quiet panic fatal error warning info verbose debug trace'
  local video_streams='v:0 v:1 v:2 v:3'

  # ---------------------------------------------------------------------------
  # Handle --option=VALUE: cur contains the entire "--opt=val" token.
  # Strip the "opt=" prefix and delegate to the appropriate completer.
  # This must be checked before the $prev dispatch below.
  # ---------------------------------------------------------------------------
  case "$cur" in
  --config-file=*)
    cur="${cur#*=}"
    _filedir
    return
    ;;
  --encode-file=*)
    cur="${cur#*=}"
    _filedir
    return
    ;;
  --preset=*)
    cur="${cur#*=}"
    COMPREPLY=($(compgen -W "$(_transcode_presets)" -- "$cur"))
    return
    ;;
  --nice=*)
    cur="${cur#*=}"
    COMPREPLY=($(compgen -W "$nice_vals" -- "$cur"))
    return
    ;;
  --hwaccel=*)
    cur="${cur#*=}"
    COMPREPLY=($(compgen -W "$hwaccel_methods" -- "$cur"))
    return
    ;;
  --video-stream=*)
    cur="${cur#*=}"
    COMPREPLY=($(compgen -W "$video_streams" -- "$cur"))
    return
    ;;
  --skip-codec=*)
    cur="${cur#*=}"
    COMPREPLY=($(compgen -W "$codecs" -- "$cur"))
    return
    ;;
  --backup-dir=*)
    cur="${cur#*=}"
    _filedir -d
    return
    ;;
  --output-dir=*)
    cur="${cur#*=}"
    _filedir -d
    return
    ;;
  --size-report-file=*)
    cur="${cur#*=}"
    _filedir
    return
    ;;
  --ffmpeg-loglevel=*)
    cur="${cur#*=}"
    COMPREPLY=($(compgen -W "$ffmpeg_loglevels" -- "$cur"))
    return
    ;;
  esac

  # ---------------------------------------------------------------------------
  # Handle VALUE after short and long space forms.
  # The dispatch order mirrors the help output where practical.
  # $prev is the option word, $cur is the value being typed.
  # ---------------------------------------------------------------------------
  case "$prev" in
  --config-file)
    _filedir
    return
    ;;
  -f | --encode-file)
    _filedir
    return
    ;;
  -p | --preset)
    COMPREPLY=($(compgen -W "$(_transcode_presets)" -- "$cur"))
    return
    ;;
  -N | --nice)
    COMPREPLY=($(compgen -W "$nice_vals" -- "$cur"))
    return
    ;;
  --hwaccel)
    COMPREPLY=($(compgen -W "$hwaccel_methods" -- "$cur"))
    return
    ;;
  --video-stream)
    COMPREPLY=($(compgen -W "$video_streams" -- "$cur"))
    return
    ;;
  --ffmpeg-loglevel)
    COMPREPLY=($(compgen -W "$ffmpeg_loglevels" -- "$cur"))
    return
    ;;
  -S | --skip-codec)
    COMPREPLY=($(compgen -W "$codecs" -- "$cur"))
    return
    ;;
  --backup-dir)
    _filedir -d
    return
    ;;
  --output-dir)
    _filedir -d
    return
    ;;
  --size-report-file)
    _filedir
    return
    ;;
  esac

  # ---------------------------------------------------------------------------
  # Complete option names themselves.
  # For options that accept an argument we list both the bare long form
  # (--nice) and the equals form (--nice=) so the user can choose their
  # preferred style.  compopt -o nospace is applied when the sole match
  # ends with '=' to avoid an unwanted trailing space in that case.
  # ---------------------------------------------------------------------------
  case "$cur" in
  --*)
    local longopts='
      --config-file
      --config-file=
      --no-config
      --encode-file
      --encode-file=
      --preset
      --preset=
      --nice
      --nice=
      --hwaccel
      --hwaccel=
      --no-hwaccel
      --video-stream
      --video-stream=
      --skip-codec
      --skip-codec=
      --skip-codec-override
      --dry-run
      --backup-dir
      --backup-dir=
      --output-dir
      --output-dir=
      --only-if-smaller
      --no-only-if-smaller
      --verify-output
      --no-verify-output
      --continue
      --no-continue
      --size-report
      --no-size-report
      --size-report-file
      --size-report-file=
      --ffmpeg-loglevel
      --ffmpeg-loglevel=
      --quiet
      --verbose
      --color
      --no-color
      --help
      --version
      --list-presets
    '
    COMPREPLY=($(compgen -W "$longopts" -- "$cur"))
    # Suppress the trailing space when the only completion ends with '='
    [[ ${#COMPREPLY[@]} -eq 1 && "${COMPREPLY[0]}" == *= ]] &&
      compopt -o nospace
    return
    ;;
  -*)
    local shortopts='-f -p -N -S -n -l -c -s -q -v -h -? --'
    COMPREPLY=($(compgen -W "$shortopts" -- "$cur"))
    return
    ;;
  esac

  # ---------------------------------------------------------------------------
  # Default: complete positional FILE arguments with common media extensions
  # ---------------------------------------------------------------------------
  _filedir '@(mkv|mp4|mov|avi|webm|flv|wmv|m4v|ts|mts|m2ts|mpg|mpeg|ogv|3gp|rm|rmvb)'
}

complete -F _transcode_sh transcode.sh
complete -F _transcode_sh transcode