#!/bin/dash

DATA_DIR="$HOME/.cache/youtube_channels"
DOWNLOAD_DIR="$HOME/ytvideos"
CATEGORY_LIST="$HOME/.local/share/categories.txt"
CHANNEL_LIST="$HOME/.local/share/channels.txt"
CUSTOM_LIST_DIR="$DATA_DIR/custom_lists"

mkdir -p "$DATA_DIR" "$DOWNLOAD_DIR" "$CUSTOM_LIST_DIR"

sort_videos() {
  local data_file="$1"
  local sort_option="$2"

  case $sort_option in
    "@@sv") sort -nr -t"	" -k3 "$data_file" ;;
    "@@sd") sort -nr -t"	" -k4 "$data_file" ;;
         *) sort -nr -t"	" -k5 "$data_file" ;;
  esac | cut -f1
}

get_videos() {
  local channel_name="$1"
  local sort_option="$2"
  local data_file="$DATA_DIR/$channel_name.tsv"
  sort_videos "$data_file" "$sort_option"
}

video_url() {
  local channel_name="$1"
  local video_title="$2"
  local data_file="$DATA_DIR/$channel_name.tsv"
  sed -n "s/$video_title\t\([^\t]*\)\t.*$/\1/p" "$data_file"
}

rofi_action() {
  echo "Watch\nDownload\nSend To a List" | dmenu -i -l 3 -p "Choose an action for the video"
}

rofi_custom_list_action() {
  echo "$(ls "$CUSTOM_LIST_DIR")\nCreate a List\nDelete a List" | dmenu -i -l 10 -p "Choose an action or list" 
}

list_video_action() {
  echo "Watch\nDownload\nDelete" | dmenu -i -l 3 -p "Choose an action for the video"
}

add_to_list() {
  local video_title="$1"
  local channel_name="$2"
  local list_name="$3"
  echo "$channel_name: $video_title" >> "$CUSTOM_LIST_DIR/$list_name"
}

custom_list_menu() {
  while true; do
    local list="$(rofi_custom_list_action)"
    [ -z "$list" ] && return
    case "$list" in
      "Create a List")
        local new_list=$(dmenu -i -l 0 -p "Enter the name of the new list")
        [ -n "$new_list" ] && touch "$CUSTOM_LIST_DIR/$new_list"
        ;;
      "Delete a List")
        local delete_list=$(ls "$CUSTOM_LIST_DIR" | dmenu -i -l 10 -p "Choose a list to delete")
        [ -n "$delete_list" ] && rm "$CUSTOM_LIST_DIR/$delete_list"
        ;;
      *)
        custom_list_video_menu "$list"
        ;;
    esac
  done
}

custom_list_video_menu() {
  local list_name="$1"
  local video_info
  local video_title
  local channel_name
  while true; do
    video_info=$(cat "$CUSTOM_LIST_DIR/$list_name" | dmenu -i -l 20 -p "Choose a video")
    [ -z "$video_info" ] && return
    channel_name="${video_info%%: *}"
    video_title="${video_info##*: }"
    custom_list_video_action_menu "$video_title" "$channel_name" "$list_name"
  done
}

custom_list_video_action_menu() {
  local video_title="$1"
  local channel_name="$2"
  local list_name="$3"

  local action
  action=$(list_video_action)

  case $action in
    Watch)
      play_video "$video_title" "$channel_name"
      ;;
    Download)
      download_video "$video_title" "$channel_name" && notify-send "Downloading has finished."
      ;;
    Delete)
      escaped_video_title="$(echo "$video_title" | tr -d '|')"
      sed -i "/$escaped_video_title/d" "$CUSTOM_LIST_DIR/$list_name"
      ;;
    *)
      return
      ;;
  esac
}

play_video() {
  local video_title="$1"
  local channel_name="$2"
  local video_url="$(video_url "$channel_name" "$video_title")"
  mpv "$video_url"
}

download_video() {
  local video_title="$1"
  local channel_name="$2"
  local video_url=$(video_url "$channel_name" "$video_title")
  local channel_download_dir="$DOWNLOAD_DIR/$channel_name"
  mkdir -p "$channel_download_dir"
  yt-dlp -o "$channel_download_dir/%(title)s.%(ext)s" "$video_url"
}

get_all_videos() {
  local sort_option="$1"
  local all_videos_file="$DATA_DIR/all_videos.tsv"

  rm -f "$all_videos_file"
  while IFS= read -r line
  do
    local channel_name="${line%%=*}"
    cat "$DATA_DIR/$channel_name.tsv" >> "$all_videos_file"
  done < "$CHANNEL_LIST"

  sort_videos "$all_videos_file" "$sort_option"
}

browse_all_channels() {
  while true; do
    video_title=$(get_all_videos | dmenu -i -l 20 -p "Choose a video or enter @@sv or @@sd")

    [ -z "$video_title" ] && break || {
      [ "$video_title" = "@@sv" -o "$video_title" = "@@sd" ] && sort_option="$video_title" && video_title=$(get_all_videos "$sort_option" | i -l 20 -dmenu -i -p "Choose a video")
    }

    [ -n "$video_title" -a "$video_title" != "@@sv" -a "$video_title" != "@@sd" ] && {
      while read -r line; do
        channel_name="${line%%=*}"
        grep -qF "$video_title" "${DATA_DIR}/${channel_name}.tsv" && break
      done < "$CHANNEL_LIST"

      video_action_menu "$video_title" "$channel_name"
    }
  done
}

category_menu() {
  while true; do
    local category=$(echo "$(cut -d= -f1 "$CATEGORY_LIST")" | dmenu -i -l 12 -p "Choose a category")
    [ -z "$category" ] && return

    channel_menu "$category"
  done
}

channel_menu() {
  local category="$1"
  local channels
  local channel_name
  local IFS="|"

  channels=$(sed -n "s/^${category}=\(.*\)$/\1/p" "$CATEGORY_LIST")
  set -- $channels

  while true; do
    channel_name=$(printf '%s\n' "$@" | dmenu -i -l 20 -p "Choose a channel")
    [ -z "$channel_name" ] && return

    video_menu "$channel_name"
  done
}

video_menu() {
  local channel_name="$1"
  local video_title
  local sort_option

  while true; do
    video_title=$(get_videos "$channel_name" | dmenu -i -l 20 -p "Choose a video")
    [ -z "$video_title" ] && return
    [ "$video_title" = "@@sv" -o "$video_title" = "@@sd" ] && {
      sort_option="$video_title"
      video_title=$(get_videos "$channel_name" "$sort_option" | dmenu -i -l 20 -p "Choose a video")
    }

    video_action_menu "$video_title" "$channel_name"
  done
}

video_action_menu() {
  local video_title="$1"
  local channel_name="$2"

  while [ -n "$video_title" ] && [ "$video_title" != "@@sv" ] && [ "$video_title" != "@@sd" ]; do
    local action
    action=$(rofi_action)

    case $action in
      Watch)
        play_video "$video_title" "$channel_name"
        ;;
      Download)
        download_video "$video_title" "$channel_name" && notify-send "Downloading has finished."
        ;;
      "Send To a List")
        list_name=$(ls "$CUSTOM_LIST_DIR" | dmenu -i -l 10 -p "Choose a list")
        [ -n "$list_name" ] && add_to_list "$video_title" "$channel_name" "$list_name"
        ;;
      *)
        return
        ;;
    esac
  done
}

while true; do
  main_choice=$(echo "All Channels\nCategories\nCustom Lists\n$(cut -d= -f1 "$CHANNEL_LIST")" | dmenu -i -l 20 -p "Choose an Option or a Category")

  [ -z "$main_choice" ] && exit

  case "$main_choice" in
    "All Channels") browse_all_channels ;;
    "Categories") category_menu ;;
    "Custom Lists") custom_list_menu ;;
              *) video_menu "$main_choice" ;;
  esac
done