#!/usr/bin/env bash
#
# Mully's Bar karaoke night: one-time setup for a Mac.
#
#   curl -fsSL https://www.adamscampustoolbox.org.uk/guides/mullys-karaoke/setup-mac.sh | bash
#
# Installs Homebrew (if missing), Node.js, yt-dlp, ffmpeg, Karaoke Eternal
# and Open Video Downloader, creates ~/Desktop/KaraokeSongs, and puts three
# apps on the Desktop:
#
#   Mully's Karaoke.app      starts the server, opens the browser
#   Open Video Downloader    (link to the app) paste a YouTube link, download
#   Song Search.app          type a song name, grabs the top YouTube result
#
# Open Video Downloader (github.com/jely2002/youtube-dl-gui) is preset to save
# MP4s into KaraokeSongs. It only takes links, so Song Search covers "I only
# know the song name".
#
# Our two .apps are only wrappers with an icon: each opens Terminal on a
# script kept in ~/Library/Application Support/MullysKaraoke, which is where
# the actual launcher and search downloader live.
#
# Safe to run again: anything already installed is left alone and the
# shortcuts are rewritten (shortcuts from older versions of this script are
# replaced).
#
# Guide: https://www.adamscampustoolbox.org.uk/committee-tips/mullys-karaoke
#
# Everything lives inside main(), called on the last line. When this script is
# piped into bash, bash reads it from stdin as it goes; wrapping it means the
# whole file is read before anything runs, so an installer that reads stdin
# can't swallow the rest of the script.

set -euo pipefail

main() {
  mkdir -p "$HOME/Desktop/KaraokeSongs"

  # ── Homebrew ──────────────────────────────────────────────────────────────
  if ! command -v brew >/dev/null 2>&1 && [ ! -x /opt/homebrew/bin/brew ] && [ ! -x /usr/local/bin/brew ]; then
    echo "==> Installing Homebrew (it will ask for your Mac password)"
    # </dev/tty: the installer needs a real keyboard for the sudo prompt and
    # its "Press RETURN" confirmation, not this piped script.
    /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)" </dev/tty
  fi
  load_brew

  # ── Tools ─────────────────────────────────────────────────────────────────
  local pkg
  for pkg in node yt-dlp ffmpeg; do
    if brew list --formula "$pkg" >/dev/null 2>&1; then
      echo "==> $pkg already installed"
    else
      echo "==> Installing $pkg"
      brew install "$pkg"
    fi
  done

  # Karaoke Eternal 2.x needs Node 24 or newer. An older node earlier on the
  # PATH (nvm, an old installer) would make the npm install fail obscurely.
  local node_major
  node_major="$(node -p 'process.versions.node.split(".")[0]')"
  if [ "$node_major" -lt 24 ]; then
    echo "!! $(command -v node) is Node $node_major; Karaoke Eternal needs Node 24+."
    echo "!! Run 'brew upgrade node' (or switch your nvm version) and run this again."
    exit 1
  fi

  echo "==> Installing Karaoke Eternal"
  npm install -g karaoke-eternal
  set_queue_placeholder

  # ── Open Video Downloader ─────────────────────────────────────────────────
  # Notarised, so Gatekeeper opens it without a prompt. It fetches its own
  # copies of yt-dlp and ffmpeg on first launch and keeps them updated.
  if [ -d "/Applications/$OVD_APP" ] || [ -d "$HOME/Applications/$OVD_APP" ] ||
     brew list --cask open-video-downloader >/dev/null 2>&1; then
    echo "==> Open Video Downloader already installed"
  else
    echo "==> Installing Open Video Downloader"
    if ! brew install --cask open-video-downloader; then
      echo "!! Open Video Downloader did not install; Song Search still works."
      echo "!! Try again later with: brew install --cask open-video-downloader"
    fi
  fi
  configure_ovd

  install_shortcuts

  echo ""
  echo "Setup complete. Your Desktop now has:"
  echo "  Mully's Karaoke"
  echo "  Open Video Downloader"
  echo "  Song Search"
  echo "  KaraokeSongs (folder)"
}

# Karaoke Eternal shows "CAN HAZ MOAR SONGZ?" on the projector when the queue
# is empty. Swap it for our own line in the installed client bundle (a
# minified build/client/958.<hash>.js, where the text is a double-quoted JS
# string). The apostrophe is the typographic one, written into the bundle as
# the JS escape \u2019 (doubled below for node -e), so the string's double
# quotes are untouched and file encoding never comes into it. Re-running npm install restores the original, which
# is why this runs straight after it every time. A future version that moved
# or reworded the text only gets a warning.
set_queue_placeholder() {
  local client
  client="$(npm root -g)/karaoke-eternal/build/client"
  if ! CLIENT_DIR="$client" node -e '
    const fs = require("fs");
    const path = require("path");
    const dir = process.env.CLIENT_DIR;
    const from = "CAN HAZ MOAR SONGZ?";
    const to = "Mully\\u2019s Karaoke Night";
    let patched = 0, done = 0;
    for (const f of fs.readdirSync(dir)) {
      if (!/\.js$/.test(f)) continue;
      const file = path.join(dir, f);
      const src = fs.readFileSync(file, "utf8");
      if (src.includes(from)) {
        fs.writeFileSync(file, src.split(from).join(to));
        // A precompressed copy would be served instead of the patched file.
        for (const ext of [".gz", ".br"]) fs.rmSync(file + ext, { force: true });
        patched++;
      } else if (src.includes(to)) {
        done++;
      }
    }
    if (!patched && !done) process.exit(2);
  '; then
    echo "!! Could not set the empty-queue text; Karaoke Eternal will show its own."
  else
    echo "==> Empty-queue text set to: Mully's Karaoke Night"
  fi
}

OVD_APP="Open Video Downloader.app"

# Presets Open Video Downloader: MP4s into ~/Desktop/KaraokeSongs, named
# "Artist - Title". Its settings are a JSON file (tauri-plugin-store, key
# "config", camelCase fields from src-tauri/src/state/config_models.rs in its
# repo); the app fills in anything missing with its defaults, so only the
# fields we care about are written, merged into whatever is already there.
configure_ovd() {
  local support_dir="$HOME/Library/Application Support/MullysKaraoke"
  mkdir -p "$support_dir"
  write_ovd_preset "$support_dir/ovd-preset.js"
  OVD_CONFIG="$HOME/Library/Application Support/com.jelleglebbeek.youtube-dl-gui/config.store.json" \
    SONGS_DIR="$HOME/Desktop/KaraokeSongs" \
    node "$support_dir/ovd-preset.js" ||
    echo "!! Could not preset Open Video Downloader; set its Locations to KaraokeSongs by hand."
}

write_ovd_preset() {
  cat >"$1" <<'PRESET'
// Presets Open Video Downloader for Mully's karaoke. Run by the setup script
// with OVD_CONFIG (its config.store.json) and SONGS_DIR set.
const fs = require("fs");
const path = require("path");
const file = process.env.OVD_CONFIG;
const obj = (v) => (v && typeof v === "object" && !Array.isArray(v) ? v : {});
let store = {};
try {
  store = obj(JSON.parse(fs.readFileSync(file, "utf8").replace(/^\uFEFF/, "")));
} catch {
  // No settings yet (app never opened): start from nothing.
}
const config = (store.config = obj(store.config));
const output = (config.output = obj(config.output));
output.downloadDir = process.env.SONGS_DIR;
// "Artist - " only when YouTube knows the artist; otherwise the upload title,
// which karaoke channels already write as "Artist - Title (Karaoke Version)".
output.fileNameTemplate = "%(artist&{} - |)s%(title)s.%(ext)s";
output.video = obj(output.video);
output.video.container = "mp4";
// A link from a playlist downloads just that one video.
const input = (config.input = obj(config.input));
input.preferVideoInMixedLinks = true;
fs.mkdirSync(path.dirname(file), { recursive: true });
fs.writeFileSync(file, JSON.stringify(store, null, 2));
PRESET
}

# Put Homebrew on this script's PATH (Apple Silicon or Intel).
load_brew() {
  local b
  for b in /opt/homebrew/bin/brew /usr/local/bin/brew; do
    if [ -x "$b" ]; then
      eval "$("$b" shellenv)"
      return 0
    fi
  done
  command -v brew >/dev/null 2>&1 || {
    echo "!! Homebrew did not install. See https://brew.sh and run this again."
    exit 1
  }
}

# Writes the launcher and Song Search into Application Support and wraps each
# in a small .app on the Desktop, so Finder shows a proper icon. Links Open
# Video Downloader onto the Desktop too.
install_shortcuts() {
  local support_dir="$HOME/Library/Application Support/MullysKaraoke"
  local icons_url="https://www.adamscampustoolbox.org.uk/guides/mullys-karaoke/icons"
  mkdir -p "$support_dir" "$HOME/Desktop"

  # ── yt-dlp settings (shared by the downloader) ────────────────────────────
  write_ytdlp_config "$support_dir/yt-dlp.conf"

  # ── Launcher ──────────────────────────────────────────────────────────────
  cat >"$support_dir/launch.command" <<'LAUNCHER'
#!/usr/bin/env bash
# Starts Karaoke Eternal on port 8888 and opens it in the browser.
# Close this window (or press Ctrl+C) to stop the karaoke server.

# Finder starts this without Homebrew on the PATH on a fresh Mac.
for b in /opt/homebrew/bin/brew /usr/local/bin/brew; do
  if [ -x "$b" ]; then eval "$("$b" shellenv)"; break; fi
done

PORT=8888

printf '\033]0;%s\007' "Mully's Karaoke"
clear
echo "========================================================"
echo "        MULLY'S BASEMENT KARAOKE IS RUNNING"
echo "========================================================"
echo "  Karaoke opens in your browser at http://localhost:${PORT}"
echo "  Leave this window open. Close it to stop karaoke."
echo "========================================================"
echo ""

# Open the host's browser once the server is actually answering.
(
  for _ in $(seq 1 60); do
    if curl -s -o /dev/null "http://localhost:${PORT}/"; then
      open "http://localhost:${PORT}/"
      exit 0
    fi
    sleep 1
  done
) &

exec karaoke-eternal-server --port "$PORT" --scan all
LAUNCHER

  # ── Song Search ───────────────────────────────────────────────────────────
  cat >"$support_dir/download.command" <<'DOWNLOADER'
#!/usr/bin/env bash
# Asks for search words (or a YouTube link) and downloads the top result into
# ~/Desktop/KaraokeSongs as "Artist - Title.mp4".

for b in /opt/homebrew/bin/brew /usr/local/bin/brew; do
  if [ -x "$b" ]; then eval "$("$b" shellenv)"; break; fi
done

SONGS_DIR="$HOME/Desktop/KaraokeSongs"
CONFIG="$HOME/Library/Application Support/MullysKaraoke/yt-dlp.conf"

printf '\033]0;%s\007' "Song Search"
QUERY="$(osascript \
  -e 'display dialog "Type the song to search YouTube for (e.g. Taylor Swift Cruel Summer karaoke), or paste a link:" default answer "" with title "Song Search"' \
  -e 'text returned of result' 2>/dev/null)"

# Cancel, or OK on an empty box: nothing to do.
[ -n "$QUERY" ] || exit 0

case "$QUERY" in
  http://* | https://*) TARGET="$QUERY" ;;
  *) TARGET="ytsearch1:$QUERY" ;;
esac

echo "Fetching: $QUERY"
mkdir -p "$SONGS_DIR"
if yt-dlp --ignore-config --config-locations "$CONFIG" -P "$SONGS_DIR" "$TARGET"; then
  osascript -e 'display notification "Saved to KaraokeSongs." with title "Song Search"'
  echo ""
  echo "Done. Check the file name above reads Artist - Title; rename it in"
  echo "KaraokeSongs if the two came out the wrong way round."
else
  osascript -e 'display notification "Download failed. See the Terminal window." with title "Song Search"'
  echo ""
  echo "Download failed. If yt-dlp is out of date, run: brew upgrade yt-dlp"
fi
DOWNLOADER
  chmod +x "$support_dir/launch.command" "$support_dir/download.command"

  # ── Desktop apps ──────────────────────────────────────────────────────────
  make_app "Mully's Karaoke" mullys-karaoke launch.command "$support_dir" "$icons_url"
  make_app "Song Search" song-downloader download.command "$support_dir" "$icons_url"

  # Open Video Downloader lives in Applications; a link on the Desktop shows
  # its own icon. Never replace a real file or folder of that name.
  local ovd_link="$HOME/Desktop/Open Video Downloader" ovd_dir
  for ovd_dir in /Applications "$HOME/Applications"; do
    if [ -d "$ovd_dir/$OVD_APP" ]; then
      if [ -L "$ovd_link" ] || [ ! -e "$ovd_link" ]; then
        rm -f "$ovd_link"
        ln -s "$ovd_dir/$OVD_APP" "$ovd_link"
      fi
      break
    fi
  done

  # Shortcuts and settings left by earlier versions of this script.
  rm -rf "$HOME/Desktop/Song Downloader.app"
  rm -f "$HOME/Desktop/1. Mully's Karaoke.command" \
        "$HOME/Desktop/2. yt-dlp Song Downloader.command" \
        "$HOME/.mullys-karaoke/yt-dlp.conf"
  rmdir "$HOME/.mullys-karaoke" 2>/dev/null || true
}

# make_app NAME ICON SCRIPT SUPPORT_DIR ICONS_URL
#
# Builds ~/Desktop/NAME.app: an Info.plist naming the icon, and an executable
# that opens SCRIPT (in SUPPORT_DIR) in a Terminal window. Made on this Mac
# rather than downloaded, it carries no quarantine flag, so Gatekeeper lets it
# open without the "unidentified developer" prompt.
make_app() {
  local name="$1" icon="$2" script="$3" support_dir="$4" icons_url="$5"
  local app="$HOME/Desktop/$name.app"

  rm -rf "$app"
  mkdir -p "$app/Contents/MacOS" "$app/Contents/Resources"

  # A missing icon only costs the artwork: the app still works.
  if ! curl -fsSL "$icons_url/$icon.icns" -o "$app/Contents/Resources/$icon.icns"; then
    echo "!! Could not download the $name icon; the shortcut will use a plain one."
    rm -f "$app/Contents/Resources/$icon.icns"
  fi

  cat >"$app/Contents/MacOS/run" <<RUN
#!/bin/bash
exec open -a Terminal "$support_dir/$script"
RUN
  chmod +x "$app/Contents/MacOS/run"

  cat >"$app/Contents/Info.plist" <<PLIST
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>CFBundleName</key><string>$name</string>
  <key>CFBundleDisplayName</key><string>$name</string>
  <key>CFBundleIdentifier</key><string>uk.org.adamscampustoolbox.$icon</string>
  <key>CFBundleExecutable</key><string>run</string>
  <key>CFBundleIconFile</key><string>$icon.icns</string>
  <key>CFBundlePackageType</key><string>APPL</string>
  <key>CFBundleShortVersionString</key><string>1.0</string>
  <key>CFBundleInfoDictionaryVersion</key><string>6.0</string>
  <!-- Only a hop to Terminal: no Dock icon for the wrapper itself. -->
  <key>LSUIElement</key><true/>
</dict>
</plist>
PLIST

  # Finder caches icons; touching the bundle and re-registering it makes the
  # new one show straight away.
  touch "$app"
  local lsregister=/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister
  if [ -x "$lsregister" ]; then "$lsregister" -f "$app" >/dev/null 2>&1 || true; fi
}

write_ytdlp_config() {
  cat >"$1" <<'CONF'
# yt-dlp settings for the Mully's karaoke downloader.
# Karaoke Eternal reads "Artist - Title" from the file name, and plays MP4.

# A link from a playlist downloads just that one video.
--no-playlist
# MP4 (H.264 + AAC where available), merged with ffmpeg.
-t mp4
# YouTube needs a JavaScript runtime; Node is already installed.
--js-runtimes node
# Drop bracketed clutter: (Karaoke Version), [Official Video], (Lyrics), ...
--replace-in-metadata title '(?i)\s*[\(\[][^\)\]]*(karaok|lyric|instrumental|official|video|audio|version|\bhd\b|\b4k\b)[^\)\]]*[\)\]]' ''
# Auto-generated "Artist - Topic" channels: keep just the artist.
--replace-in-metadata uploader ' - Topic$' ''
# Most karaoke uploads are titled "Artist - Title": split that out.
--parse-metadata 'title:(?P<artist>.+?) - (?P<title>.+)'
# Otherwise fall back to the channel name as the artist.
-o '%(artist,creator,uploader)s - %(title)s.%(ext)s'
CONF
}

main "$@"