#!/bin/sh

set -eu

VIEW_ARTIST="artist"
VIEW_RELEASEGROUP="rg"
VIEW_RELEASE="release"
VIEW_SEARCH_ARTIST="search-artist"
VIEW_SEARCH_ALBUM="search-album"
VIEW_LIST_ARTISTS="list-artists"
VIEW_LIST_ALBUMS="list-albums"
VIEW_SELECT_ARTIST="select-artist"
VIEW_PLAYLIST="playlist"
VIEW_QUIT="quit"
MODE_NORMAL="hidden"
MODE_INSERT="show"

# Load helper methods
. "sh/info.sh"

# Load helper methods
. "sh/helper.sh"

# Load configuration
. "sh/config.sh"

# Load theme
. "sh/theme.sh"

# Load keys
. "sh/keys.sh"

# Load filters
. "sh/filter.sh"

# Load AWK scripts
. "sh/awk.sh"

# Load tools
. "sh/tools.sh"

# Load MusicBrainz and Discogs methods
. "sh/api.sh"

# Load mpv methods
. "sh/mpv.sh"

# Load preview methods
. "sh/preview.sh"

# Load cache functionality
. "sh/cache.sh"

# Load MusicBrainz wrappers
. "sh/mb.sh"

# Load local file handling
. "sh/local.sh"

# Load list-generating methods
. "sh/lists.sh"

# State management
. "sh/state.sh"

# FZF handlers
. "sh/fzf.sh"

case "${1:-}" in
"--lines")
  view=${2:-}
  mbid=${3:-}
  case "$view" in
  "$VIEW_ARTIST")
    list_releasegroups "$mbid"
    ;;
  "$VIEW_RELEASEGROUP")
    list_releases "$mbid"
    ;;
  "$VIEW_RELEASE")
    list_recordings "$mbid"
    ;;
  "$VIEW_LIST_ARTISTS")
    list_local_artists
    ;;
  "$VIEW_LIST_ALBUMS")
    list_local_releasegroups
    ;;
  esac
  exit 0
  ;;
"--filter")
  mode=$2
  view=$3
  q="$(default_query "$view" "$FZF_KEY")"
  printf "show-input+change-query(%s )" "$q"
  [ "$mode" = "$MODE_NORMAL" ] && printf "+hide-input"
  exit 0
  ;;
"--jumpto-artist")
  mode=$2
  view=$3
  mbid_cur="${4:-}"
  mbid="${5:-}"
  case "$view" in
  "$VIEW_ARTIST" | "$VIEW_SEARCH_ALBUM" | "$VIEW_LIST_ALBUMS") j="$(mb_releasegroup "$mbid" | $JQ -r --compact-output '."artist-credit"')" ;;
  "$VIEW_RELEASEGROUP") j="$(mb_release "$mbid" | $JQ -r --compact-output '."artist-credit"')" ;;
  "$VIEW_RELEASE") j="$(mb_release "$mbid_cur" | $JQ -r --compact-output ".media | map(.tracks) | flatten[] | select(.id == \"$mbid\") | .\"artist-credit\"")" ;;
  "$VIEW_SEARCH_ARTIST" | "$VIEW_LIST_ARTISTS") aid="$mbid" ;;
  esac
  if [ "${j:-}" ]; then
    cnt=$(echo "$j" | $JQ 'length')
    [ "$cnt" -eq 1 ] && aid="$(echo "$j" | $JQ -r '.[0].artist.id')"
  fi
  [ "${aid:-}" ] && $0 --draw "$mode" "$VIEW_ARTIST" "$aid" || printf "print(%s)+print(%s)+accept" "$VIEW_SELECT_ARTIST" "$j"
  exit 0
  ;;
"--draw")
  debug "call to $*"
  # Generate fzf command to draw screen.
  #
  # @argument $2: mode (default `normal`)
  # @argument $3: view (default list artists)
  # @argument $4: MusicBrainz ID (optional)
  # @argument $5: level (optional)
  #
  # The argument `level` specifies the view relative to `view`: If `level` is
  # set to +1, then the specified MusicBrainz ID is an ID of an object one level
  # deeper than `view`. Alternatively, the argument `level` may be set to `-1`.
  # Anything else is interpreted as "on the level of `view`".
  #
  # The choice of possible arguments ($5) depends on the view.
  # These views are independent of the MusicBrainz ID ($4) and of the argument
  # ($5):
  # - VIEW_SEARCH_ARTIST: Get ready to query MusicBrainz for artists
  # - VIEW_SEARCH_ALBUM: Get ready to query MusicBrainz for albums
  # - VIEW_LIST_ARTISTS: List all locally available artists
  # - VIEW_LIST_ALBUMS: List al locally available albums
  #
  # If no argument ($5) is specified, then the remaining views act as follows:
  # - VIEW_ARTIST: Display all release groups of that artist
  # - VIEW_RELEASEGROUP: Display all releases within that release group
  # - VIEW_RELEASE: Display track list of specified release
  #
  # Here, if the argument is set to `-1`, then the parent entry is displayed:
  # - VIEW_ARTIST: Divert view to VIEW_LIST_ARTISTS
  # - VIEW_RELEASEGROUP: For single-artist release groups, divert to
  #   VIEW_ARTIST of that artist, else display the artist selection.
  # - VIEW_RELEASE: Divert view to VIEW_LIST_RELEASEGROUP.
  #
  # Alternatively, if the argument is set to `+1`, then the child entry is
  # displayed:
  # - VIEW_ARTIST: Divert view to VIEW_LIST_ARTISTS
  # - VIEW_RELEASEGROUP: For single-artist release groups, divert to
  #   VIEW_ARTIST of that artist, else display the artist selection.
  # - VIEW_RELEASE: Divert view to VIEW_LIST_RELEASEGROUP.
  #
  # Hence, the view is only diverted in this last case.
  mode="${2:-"$MODE_NORMAL"}"
  view="${3:-"$VIEW_LIST_ARTISTS"}"
  mbid="${4:-}"
  level="${5:-}"
  # Change state, if we are being diverted.
  case "$level" in
  "-1")
    case "$view" in
    "$VIEW_ARTIST")
      view="$VIEW_LIST_ARTISTS"
      mbid=""
      ;;
    "$VIEW_RELEASEGROUP")
      view="$VIEW_ARTIST"
      mbid="$(mb_releasegroup "$mbid" | $JQ -r --compact-output '."artist-credit"[0].artist.id')"
      ;;
    "$VIEW_RELEASE")
      view="$VIEW_RELEASEGROUP"
      mbid="$(mb_release "$mbid" | $JQ -r --compact-output '."release-group".id')"
      ;;
    esac
    ;;
  "+1")
    case "$view" in
    "$VIEW_SEARCH_ARTIST" | "$VIEW_LIST_ARTISTS") view="$VIEW_ARTIST" ;;
    "$VIEW_ARTIST" | "$VIEW_SEARCH_ALBUM" | "$VIEW_LIST_ALBUMS") view="$VIEW_RELEASEGROUP" ;;
    "$VIEW_RELEASEGROUP") view="$VIEW_RELEASE" ;;
    esac
    ;;
  *) ;;
  esac
  # Set initial query
  printf "show-input+change-query(%s )" "$(default_query "$view")"
  # Store current state
  printf "+change-border-label(%s)+change-list-label(%s)" "$view" "$mbid"
  # Set header
  fzf_command_set_header "$view" "$mbid"
  # Load lines
  printf "+reload($0 --lines %s %s)" "$view" "$mbid"
  [ "$mode" = "$MODE_NORMAL" ] && printf "+hide-input"
  exit 0
  ;;
"--fzf-reload")
  fzf_handle_reload
  exit 0
  ;;
"--fzf-load")
  fzf_handle_load
  exit 0
  ;;
"--fzf-info")
  fzf_info
  exit 0
  ;;
"--fzf-change-reload")
  fzf_reload_after_change
  exit 0
  ;;
"--fzf-change")
  fzf_handle_change
  exit 0
  ;;
"--fzf-key")
  fzf_handle_key "${2:-}" "${3:-}" "${4:-}"
  exit 0
  ;;
"--decorate")
  [ ! "${2:-}" ] && err "You did not specify a directory." && exit 1
  [ ! -d "$2" ] && err "Path $2 does not point to a directory." && exit 1
  if ! decorate "$2"; then
    err "Something went wrong. Are you're files tagged correctly?"
    exit 1
  fi
  exit 0
  ;;
"--reload")
  [ ! "${2:-}" ] && err "Path to decorated music is missing." && exit 1
  [ ! -d "$2" ] && err "Path does not point to a directory." && exit 1
  info "Reloading information of local music directory $2"
  load_local "$2" || err "Failed to load local data"
  info "Done"
  exit 0
  ;;
"--internal-preview-artist")
  __preview_artist "$2"
  exit 0
  ;;
"--playlist")
  list_playlist
  exit 0
  ;;
"--help")
  cat <<EOF
Usage: $0 [OPTION]

GENERAL OPTIONS:
  --help                        Show this help and exit.
  --artists                     Default options, list artists of local music
  --albums                      List albums of local music
  --search-artist [<query>]     Search artist on MusicBrainz
  --search-album [<query>]      Search album on MusicBrainz
  --artist <mbid>               List release groups of given artist <mbid>
  --releasegroup <mbid>         List releases in given release group <mbid>
  --release <mbid>              Show release given by <mbid>
  --ni-search-artist [<query>]  Non-interactive search on MusicBrainz
  --ni-search-album [<query>]   Non-interactive search on MusicBrainz

MANAGE LOCAL MUSIC:
  --decorate <path>             Decorate directory containing a tagged release
  --reload <path>               Populate database with decorated local music from <path>
EOF
  exit 0
  ;;
"--refresh-view")
  precompute_view
  exit 0
  ;;
esac

# Set window title
printf '\033]0;%s\007' "$WINDOW_TITLE"

# Generate filenames for temporary files
tmpdir=$(mktemp -d)
LOCKFILE="$tmpdir/lock"
RESULTS="$tmpdir/results"
PIDFILE="$tmpdir/pid"
trap 'rm -rf "$tmpdir"' EXIT INT
export LOCKFILE RESULTS PIDFILE

statedir=$(mktemp -d)
STATEFILE="$statedir/state"
ARGSFILE="$statedir/state-args"
STATEFILE_LAST="$statedir/state2"
ARGSFILE_LAST="$statedir/state-args2"
touch "$STATEFILE" "$ARGSFILE" "$STATEFILE_LAST" "$ARGSFILE_LAST"
export STATEFILE ARGSFILE STATEFILE_LAST ARGSFILE_LAST

# Views and modes

case "${1:-}" in
"--artist")
  [ ! "${2:-}" ] && err "MusicBrainz Artist ID not specified (see --help)" && exit 1
  VIEW="$VIEW_ARTIST"
  MODE="$MODE_NORMAL"
  MBID="$2"
  ;;
"--releasegroup")
  [ ! "${2:-}" ] && err "MusicBrainz Release-Group ID not specified (see --help)" && exit 1
  VIEW="$VIEW_RELEASEGROUP"
  MODE="$MODE_NORMAL"
  MBID="$2"
  ;;
"--release")
  [ ! "${2:-}" ] && err "MusicBrainz Release ID not specified (see --help)" && exit 1
  VIEW="$VIEW_RELEASE"
  MODE="$MODE_NORMAL"
  MBID="$2"
  ;;
"--search-artist")
  state_init "$VIEW_SEARCH_ARTIST" "$MODE_INSERT" "${2:-}"
  VIEW="$VIEW_SEARCH_ARTIST"
  MODE="$MODE_INSERT"
  MBID=""
  ;;
"--search-album")
  VIEW="$VIEW_SEARCH_ALBUM"
  MODE="$MODE_INSERT"
  MBID=""
  ;;
"--artists" | "")
  VIEW="$VIEW_LIST_ARTISTS"
  MODE="$MODE_NORMAL"
  MBID=""
  ;;
"--albums")
  VIEW="$VIEW_LIST_ALBUMS"
  MODE="$MODE_NORMAL"
  MBID=""
  ;;
*)
  err "Unknown option $1 (see --help)"
  exit 1
  ;;
esac

# Start mpv
mpv_start

# main loop
# states are stored in (in)visible labels
#
# mode: [$MODE_NORMAL, $MODE_INSERT]
# The mode is reflected on the input visibility. The variable $FZF_INPUT_STATE
# is set to "hidden" if and only if the mode is `normal`. To swtich to `normal`
# mode, we call `hide-input`. To switch to insert mode, we call `show-input`.
#
# view: [$VIEW_*]
# The view is stored in $FZF_BORDER_LABEL. To set the view, call
# `change-border-label($VIEW)`.
#
# argument: string
# The argument is stored in $FZF_LIST_LABEL. To set the argument, call
# `change-list-label($arg)`.
IN_NORMAL_MODE="[ \"\$FZF_INPUT_STATE\" = \"hidden\" ]"
IN_VIEW_PATTERN="[ \"\$FZF_BORDER_LABEL\" = \"%s\" ]"
IN_LIST_ARTISTS_VIEW="$(printf "$IN_VIEW_PATTERN" "$VIEW_LIST_ARTISTS")"
IN_LIST_ALBUMS_VIEW="$(printf "$IN_VIEW_PATTERN" "$VIEW_LIST_ALBUMS")"
IN_SEARCH_ARTIST_VIEW="$(printf "$IN_VIEW_PATTERN" "$VIEW_SEARCH_ARTIST")"
IN_SEARCH_ALBUM_VIEW="$(printf "$IN_VIEW_PATTERN" "$VIEW_SEARCH_ALBUM")"
FZF_CURRENT_MODE="\$FZF_INPUT_STATE"
FZF_CURRENT_VIEW="\$FZF_BORDER_LABEL"
PUT_FZF_KEY_LOGIC="case \"\$FZF_KEY\" in \"space\") echo \"put( )\";; \"backspace\"|\"bspace\"|\"bs\") echo \"backward-delete-char\";; \"delete\"|\"del\") echo \"delete-char\";; *) echo \"put(\$FZF_KEY)\";; esac"
while true; do
  case "$VIEW" in
  "$VIEW_SELECT_ARTIST")
    sel=$(
      echo "$ARGS" |
        list_artists_from_json |
        $FZF \
          --bind="$KEYS_HALFPAGE_DOWN,$KEYS_HALFPAGE_UP,\
$KEYS_BROWSE,\
$KEYS_OPEN,\
$KEYS_FILTER_LOCAL:transform:$0 --fzf-key {2} {3} {4}" \
          -0 -1 \
          --border="bold" \
          --border-label="Select artist" \
          --delimiter="\t" \
          --prompt="$SEARCH_PROMPT" \
          --margin="5%,20%" \
          --bind="$KEYS_FILTER_LOCAL:change-query('$QUERY_LOCAL' )" \
          --accept-nth="{3}" \
          --with-nth="{1}" || true
    )
    [ "$sel" ] || continue
    MODE="$MODE_NORMAL"
    VIEW="$VIEW_ARTIST"
    MBID="$sel"
    ;;
  "$VIEW_PLAYLIST")
    list_playlist |
      $FZF \
        --reverse \
        --no-sort \
        --border=double \
        --border-label="   Playlist   " \
        --no-input \
        --margin="2%,10%" \
        --bind="$KEYS_ALL:transform:$0 --fzf-key {2} {3} {4}" \
        --bind="r,ctrl-r:reload:$0 --playlist" \
        --delimiter="\t" \
        --with-nth="{1}" >/dev/null
    ;;
  "$VIEW_QUIT")
    debug "Quitting..."
    break
    ;;
  *)
    # Main instance
    #
    # KEY-BINDINGS:
    # Key variables contain comma-delimited sequences of keys. Every key
    # variable starts with `KEYS_`. Key variables with the prefix `KEYS_I_` are
    # exclusive to the `insert` mode. Key variables with the prefix `KEYS_N_`
    # are exclusive to the `normal` mode. All other keys are bound to both
    # modes. It is important that the keys used in `KEYS_N_` variables are
    # naturally printable or modifications of the input string. See
    # `$PUT_FZF_KEY_LOGIC` for details.
    #
    # Here is a list of all keys grouped by type (see `src/sh/keys.sh`).
    #--bind="start:change-border-label($VIEW)+change-list-label($MBID)+$MODE-input+transform:$0 --display" \
    sel=$(
      printf "" | $FZF \
        --reverse \
        --info="inline-right" \
        --header-first \
        --header-border="bottom" \
        --bind="start:transform:$0 --draw $MODE $VIEW $MBID" \
        --bind="$KEYS_I_NORMAL:transform:$IN_NORMAL_MODE || echo \"hide-input\"" \
        --bind="$KEYS_N_INSERT:transform:$IN_NORMAL_MODE && echo \"show-input\" || $PUT_FZF_KEY_LOGIC" \
        --bind="$KEYS_DOWN:down" \
        --bind="$KEYS_UP:up" \
        --bind="$KEYS_HALFPAGE_DOWN:half-page-down" \
        --bind="$KEYS_HALFPAGE_UP:half-page-up" \
        --bind="$KEYS_N_DOWN:transform:$IN_NORMAL_MODE && echo \"down\" || $PUT_FZF_KEY_LOGIC" \
        --bind="$KEYS_N_UP:transform:$IN_NORMAL_MODE && echo \"up\" || $PUT_FZF_KEY_LOGIC" \
        --bind="$KEYS_N_BOT:transform:$IN_NORMAL_MODE && echo \"last\" || $PUT_FZF_KEY_LOGIC" \
        --bind="$KEYS_N_TOP:transform:$IN_NORMAL_MODE && echo \"first\" || $PUT_FZF_KEY_LOGIC" \
        --bind="$KEYS_IN:transform:[ {3} ] && $0 --draw $FZF_CURRENT_MODE $FZF_CURRENT_VIEW {3} \"+1\"" \
        --bind="$KEYS_OUT:transform:[ {2} ] && $0 --draw $FZF_CURRENT_MODE $FZF_CURRENT_VIEW {2} \"-1\"" \
        --bind="$KEYS_N_IN:transform:$IN_NORMAL_MODE && ([ {3} ] && $0 --draw $FZF_CURRENT_MODE $FZF_CURRENT_VIEW {3} \"+1\") || $PUT_FZF_KEY_LOGIC" \
        --bind="$KEYS_N_OUT:transform:$IN_NORMAL_MODE && ([ {2} ] && $0 --draw $FZF_CURRENT_MODE $FZF_CURRENT_VIEW {2} \"-1\") || $PUT_FZF_KEY_LOGIC" \
        --bind="$KEYS_SELECT_ARTIST:transform:$0 --jumpto-artist $FZF_CURRENT_MODE $FZF_CURRENT_VIEW {2} {3}" \
        --bind="$KEYS_LIST_ARTISTS:transform:$0 --draw \$FZF_INPUT_STATE $VIEW_LIST_ARTISTS" \
        --bind="$KEYS_LIST_ALBUMS:transform:$0 --draw \$FZF_INPUT_STATE $VIEW_LIST_ALBUMS" \
        --bind="$KEYS_SEARCH_ARTIST:transform:$0 --draw $MODE_INSERT $VIEW_SEARCH_ARTIST" \
        --bind="$KEYS_SEARCH_ALBUM:transform:$0 --draw $MODE_INSERT $VIEW_SEARCH_ALBUM" \
        --bind="$KEYS_SWITCH_ARTIST_ALBUM:transform:case \"$FZF_CURRENT_VIEW\" in
\"$VIEW_LIST_ARTISTS\") $0 --draw $FZF_CURRENT_MODE $VIEW_LIST_ALBUMS ;;
\"$VIEW_LIST_ALBUMS\") $0 --draw $FZF_CURRENT_MODE $VIEW_LIST_ARTISTS ;;
\"$VIEW_SEARCH_ARTIST\") $0 --draw $MODE_INSERT $VIEW_SEARCH_ALBUM ;;
\"$VIEW_SEARCH_ALBUM\") $0 --draw $MODE_INSERT $VIEW_SEARCH_ARTIST ;;
esac" \
        --bind="$KEYS_SWITCH_LOCAL_REMOTE:transform:case \"$FZF_CURRENT_VIEW\" in
\"$VIEW_LIST_ARTISTS\") $0 --draw $MODE_INSERT $VIEW_SEARCH_ARTIST ;;
\"$VIEW_LIST_ALBUMS\") $0 --draw $MODE_INSERT $VIEW_SEARCH_ALBUM ;;
\"$VIEW_SEARCH_ARTIST\") $0 --draw $MODE_NORMAL $VIEW_LIST_ARTISTS ;;
\"$VIEW_SEARCH_ALBUM\") $0 --draw $MODE_NORMAL $VIEW_LIST_ALBUMS ;;
esac" \
        --bind="$KEYS_FILTER:transform:$0 --filter $FZF_CURRENT_MODE $FZF_CURRENT_VIEW" \
        --bind="$KEYS_BROWSE:execute-silent:
[ {3} ] || exit 0
case \"\$FZF_BORDER_LABEL\" in
  \"$VIEW_LIST_ARTISTS\" | \"$VIEW_SEARCH_ARTIST\") t=\"artist\" ;;
  \"$VIEW_ARTIST\" | \"$VIEW_SEARCH_ALBUM\" | \"$VIEW_LIST_ALBUMS\") t=\"release-group\" ;;
  \"$VIEW_RELEASEGROUP\") t=\"release\" ;;
  \"$VIEW_RELEASE\") t=\"track\" ;;
esac
open \"https://musicbrainz.org/\$t/{r3}\"" \
        --bind="$KEYS_OPEN:execute-silent:
[ {4} ] || exit 0
open \"\$(dirname {4})\"" \
        --bind="$KEYS_SELECT_ARTIST:" \
        --bind="$KEYS_FILTER_LOCAL:" \
        --bind="$KEYS_FILTER_1:" \
        --bind="$KEYS_FILTER_2:" \
        --bind="$KEYS_FILTER_3:" \
        --bind="$KEYS_FILTER_4:" \
        --bind="$KEYS_SWITCH_ARTIST_ALBUM:" \
        --bind="$KEYS_SWITCH_LOCAL_REMOTE:" \
        --bind="$KEYS_PLAY:" \
        --bind="$KEYS_QUEUE:" \
        --bind="$KEYS_SHOW_PLAYLIST:" \
        --bind="$KEYS_QUIT:print($VIEW_QUIT)+accept" \
        --delimiter="\t" \
        --with-nth="{1}" || true
    )
    VIEW="$(echo "$sel" | head -1)"
    ARGS="$(echo "$sel" | head -2 | tail -1)"
    debug "FZF terminated: view=$VIEW, ARGS=$ARGS"
    ;;
  esac
done
#[ \"$MODE\" = \"$MODE_NORMAL\" ] && echo \"+hide-input\" || echo \"+show-input\"
#        --bind="load:transform:$0 --fzf-load" \
#        --bind="change:execute-silent($0 --fzf-change &)+reload:$0 --fzf-change-reload" \
#        --bind="$KEYS_ALL:transform:$0 --fzf-key {2} {3} {4}" \
#        --preview-window="right,25%,border-left,wrap,<30(hidden)" \
#        --preview="$0 --internal-preview-artist {3}" \