# Mully's Bar karaoke night: one-time setup for Windows 10/11.
#
#   irm https://www.adamscampustoolbox.org.uk/guides/mullys-karaoke/setup-win.ps1 | iex
#
# Installs Node.js LTS, yt-dlp, ffmpeg and Open Video Downloader (via winget)
# and Karaoke Eternal (via npm), creates a KaraokeSongs folder on the Desktop,
# and puts three shortcuts on the Desktop:
#
#   Mully's Karaoke          starts the server, opens the browser
#   Open Video Downloader    paste a YouTube link, download it
#   Song Search              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 shortcuts are .lnk files with their own icons. Everything they run
# is kept in %LOCALAPPDATA%\MullysKaraoke: thin .bat wrappers around
# PowerShell scripts, so double-clicking works (a .ps1 opens in Notepad) and
# no command line has to survive cmd/VBScript quoting.
#
# 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
#
# This file is deliberately plain ASCII: Windows PowerShell 5.1 can mis-decode
# anything else when it arrives through irm.

Write-Host "Setting up Mully's Bar karaoke..." -ForegroundColor Green

$desktop = [Environment]::GetFolderPath('Desktop')   # follows OneDrive Desktop redirection
$songsDir = Join-Path $desktop 'KaraokeSongs'
$supportDir = Join-Path $env:LOCALAPPDATA 'MullysKaraoke'
$iconsUrl = 'https://www.adamscampustoolbox.org.uk/guides/mullys-karaoke/icons'
New-Item -ItemType Directory -Force -Path $songsDir, $supportDir | Out-Null

function Update-SessionPath {
  $env:Path = [Environment]::GetEnvironmentVariable('Path', 'Machine') + ';' +
              [Environment]::GetEnvironmentVariable('Path', 'User')
}

# ---- Tools (winget) ---------------------------------------------------------

if (-not (Get-Command winget -ErrorAction SilentlyContinue)) {
  Write-Host "winget is missing. Install 'App Installer' from the Microsoft Store, then run this again." -ForegroundColor Red
  return
}

function Install-WingetPackage([string]$id) {
  # 'winget list' exits 0 when the package is already installed; 'winget
  # install' on an installed package exits non-zero, so check first.
  $null = winget list --id $id --exact --accept-source-agreements
  if ($LASTEXITCODE -eq 0) {
    Write-Host "==> $id already installed"
    return
  }
  Write-Host "==> Installing $id"
  winget install --id $id --exact --silent --accept-package-agreements --accept-source-agreements
  if ($LASTEXITCODE -ne 0) {
    Write-Host "!! winget could not install $id (exit code $LASTEXITCODE)." -ForegroundColor Yellow
  }
}

Install-WingetPackage 'OpenJS.NodeJS.LTS'
Install-WingetPackage 'yt-dlp.yt-dlp'
Install-WingetPackage 'Gyan.FFmpeg'
# Open Video Downloader: fetches its own yt-dlp and ffmpeg on first launch and
# keeps them updated. Installs per user, no admin prompt.
Install-WingetPackage 'jely2002.youtube-dl-gui'
Update-SessionPath

if (-not (Get-Command node.exe -ErrorAction SilentlyContinue)) {
  Write-Host "!! Node.js is not on the PATH. Close this window, open a new PowerShell and run the command again." -ForegroundColor Red
  return
}

# Karaoke Eternal 2.x needs Node 24 or newer.
$nodeMajor = [int]((node.exe -p "process.versions.node.split('.')[0]") | Select-Object -First 1)
if ($nodeMajor -lt 24) {
  Write-Host "!! Node $nodeMajor is installed; Karaoke Eternal needs Node 24+." -ForegroundColor Red
  Write-Host "!! Run: winget upgrade OpenJS.NodeJS.LTS   then run this setup again." -ForegroundColor Red
  return
}

# ---- Karaoke Eternal (npm) ----------------------------------------------------

# npm.cmd, not npm: plain 'npm' resolves to npm.ps1, which the default
# execution policy refuses to run.
Write-Host '==> Installing Karaoke Eternal'
npm.cmd install -g karaoke-eternal
if ($LASTEXITCODE -ne 0) {
  Write-Host '!! npm install failed; see the messages above.' -ForegroundColor Red
  return
}
Update-SessionPath

# 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, so the quotes are untouched and this file stays ASCII.
# 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.
$placeholderFrom = 'CAN HAZ MOAR SONGZ?'
$placeholderTo = 'Mully\u2019s Karaoke Night'
$placeholderSet = $false
try {
  $npmRoot = (npm.cmd root -g | Select-Object -First 1).Trim()
  $clientDir = Join-Path $npmRoot 'karaoke-eternal\build\client'
  $utf8NoBom = New-Object System.Text.UTF8Encoding($false)
  foreach ($bundle in (Get-ChildItem -LiteralPath $clientDir -Filter '*.js' -File -ErrorAction Stop)) {
    $text = [IO.File]::ReadAllText($bundle.FullName, $utf8NoBom)
    if ($text.Contains($placeholderFrom)) {
      [IO.File]::WriteAllText($bundle.FullName, $text.Replace($placeholderFrom, $placeholderTo), $utf8NoBom)
      # A precompressed copy would be served instead of the patched file.
      foreach ($ext in '.gz', '.br') {
        Remove-Item -LiteralPath ($bundle.FullName + $ext) -Force -ErrorAction SilentlyContinue
      }
      $placeholderSet = $true
    } elseif ($text.Contains($placeholderTo)) {
      $placeholderSet = $true
    }
  }
} catch {
  # No install folder, or a bundle we could not rewrite: warn below.
}
if ($placeholderSet) {
  Write-Host "==> Empty-queue text set to: Mully's Karaoke Night"
} else {
  Write-Host "!! Could not set the empty-queue text; Karaoke Eternal will show its own." -ForegroundColor Yellow
}

# ---- yt-dlp settings ------------------------------------------------------------

# A config file rather than command-line flags: Windows PowerShell 5.1 drops
# empty-string arguments ('') to native programs, which --replace-in-metadata
# needs.
$ytdlpConfig = @'
# 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'
'@
Set-Content -Path (Join-Path $supportDir 'yt-dlp.conf') -Value $ytdlpConfig -Encoding ASCII

# ---- Open Video Downloader settings ------------------------------------------------

# Preset: MP4s into 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 these fields are written, merged into
# whatever is already there. Node does the merge: it writes UTF-8 without a
# BOM, which the app's JSON reader needs.
$ovdPreset = @'
// 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));
'@
$ovdPresetPath = Join-Path $supportDir 'ovd-preset.js'
Set-Content -Path $ovdPresetPath -Value $ovdPreset -Encoding ASCII
$env:OVD_CONFIG = Join-Path $env:APPDATA 'com.jelleglebbeek.youtube-dl-gui\config.store.json'
$env:SONGS_DIR = $songsDir
node.exe $ovdPresetPath
if ($LASTEXITCODE -ne 0) {
  Write-Host '!! Could not preset Open Video Downloader; set its Locations to KaraokeSongs by hand.' -ForegroundColor Yellow
}

# ---- Launcher -------------------------------------------------------------------

$launchScript = @'
# Starts Karaoke Eternal on port 8888 and opens it in the browser.
# Close this window (or press Ctrl+C) to stop the karaoke server.
$Host.UI.RawUI.WindowTitle = "Mully's Karaoke"
$env:Path = [Environment]::GetEnvironmentVariable('Path', 'Machine') + ';' +
            [Environment]::GetEnvironmentVariable('Path', 'User')
$port = 8888

Clear-Host
Write-Host '========================================================'
Write-Host "        MULLY'S BASEMENT KARAOKE IS RUNNING"
Write-Host '========================================================'
Write-Host "  Karaoke opens in your browser at http://localhost:$port"
Write-Host '  Leave this window open. Close it to stop karaoke.'
Write-Host '========================================================'
Write-Host ''

$main = Join-Path (npm.cmd root -g) 'karaoke-eternal\build\server\main.js'
$node = (Get-Command node.exe).Source
$server = Start-Process -FilePath $node -ArgumentList "`"$main`" --port $port --scan all" -NoNewWindow -PassThru

# Open the host's browser once the server is actually answering.
for ($i = 0; $i -lt 60; $i++) {
  try {
    Invoke-WebRequest -Uri "http://localhost:$port/" -UseBasicParsing -TimeoutSec 2 | Out-Null
    Start-Process "http://localhost:$port/"
    break
  } catch {
    Start-Sleep -Seconds 1
  }
}
$server.WaitForExit()
'@
Set-Content -Path (Join-Path $supportDir 'launch.ps1') -Value $launchScript -Encoding ASCII

$launchBat = @'
@echo off
powershell -NoProfile -ExecutionPolicy Bypass -File "%LOCALAPPDATA%\MullysKaraoke\launch.ps1"
pause
'@
Set-Content -Path (Join-Path $supportDir 'launch.bat') -Value $launchBat -Encoding ASCII

# ---- Song Search ----------------------------------------------------------------

$downloadScript = @'
# Asks for search words (or a YouTube link) and downloads the top result into
# the Desktop KaraokeSongs folder as "Artist - Title.mp4".
$Host.UI.RawUI.WindowTitle = 'Song Search'
$env:Path = [Environment]::GetEnvironmentVariable('Path', 'Machine') + ';' +
            [Environment]::GetEnvironmentVariable('Path', 'User')
$songsDir = Join-Path ([Environment]::GetFolderPath('Desktop')) 'KaraokeSongs'
$config = Join-Path $env:LOCALAPPDATA 'MullysKaraoke\yt-dlp.conf'

Add-Type -AssemblyName Microsoft.VisualBasic
$query = [Microsoft.VisualBasic.Interaction]::InputBox(
  "Type the song to search YouTube for, or paste a link.`r`n`r`n(e.g. Taylor Swift Cruel Summer karaoke)",
  'Song Search')

# Cancel, or OK on an empty box: nothing to do. Double quotes are dropped
# because Windows PowerShell 5.1 passes them to programs unescaped.
$query = ($query -replace '"', '').Trim()
if (-not $query) { exit }

if ($query -match '^https?://') { $target = $query } else { $target = "ytsearch1:$query" }

Write-Host "Fetching: $query"
New-Item -ItemType Directory -Force -Path $songsDir | Out-Null
yt-dlp.exe --ignore-config --config-locations $config -P $songsDir $target
Write-Host ''
if ($LASTEXITCODE -eq 0) {
  Write-Host 'Saved to KaraokeSongs.' -ForegroundColor Green
  Write-Host 'Check the file name above reads Artist - Title; rename it in'
  Write-Host 'KaraokeSongs if the two came out the wrong way round.'
} else {
  Write-Host 'Download failed. If yt-dlp is out of date, run: winget upgrade yt-dlp.yt-dlp' -ForegroundColor Red
}
Read-Host 'Press Enter to close'
'@
Set-Content -Path (Join-Path $supportDir 'download.ps1') -Value $downloadScript -Encoding ASCII

$downloadBat = @'
@echo off
powershell -NoProfile -ExecutionPolicy Bypass -File "%LOCALAPPDATA%\MullysKaraoke\download.ps1"
'@
Set-Content -Path (Join-Path $supportDir 'download.bat') -Value $downloadBat -Encoding ASCII

# ---- Desktop shortcuts ------------------------------------------------------------

# A shortcut whose icon failed to download still works; it just looks plain.
function New-KaraokeShortcut([string]$name, [string]$icon, [string]$target) {
  $iconPath = Join-Path $supportDir "$icon.ico"
  $ProgressPreference = 'SilentlyContinue'   # PS 5.1's progress bar slows downloads to a crawl
  try {
    Invoke-WebRequest -Uri "$iconsUrl/$icon.ico" -OutFile $iconPath -UseBasicParsing
  } catch {
    Write-Host "!! Could not download the $name icon; the shortcut will use a plain one." -ForegroundColor Yellow
  }
  $shell = New-Object -ComObject WScript.Shell
  $link = $shell.CreateShortcut((Join-Path $desktop "$name.lnk"))
  $link.TargetPath = Join-Path $supportDir $target
  $link.WorkingDirectory = $supportDir
  $link.Description = $name
  if (Test-Path $iconPath) { $link.IconLocation = "$iconPath,0" }
  $link.Save()
}

New-KaraokeShortcut "Mully's Karaoke" 'mullys-karaoke' 'launch.bat'
New-KaraokeShortcut 'Song Search' 'song-downloader' 'download.bat'

# Open Video Downloader: a Desktop shortcut to its own .exe (and icon). Its
# silent installer may already have made one of the same name; this replaces
# it. The uninstall entry says where it went; per-user installs default to
# %LOCALAPPDATA%\Open Video Downloader.
function Find-OvdExe {
  $keys = 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*',
          'HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*',
          'HKLM:\Software\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\*'
  $entry = Get-ItemProperty $keys -ErrorAction SilentlyContinue |
    Where-Object { $_.DisplayName -like 'Open Video Downloader*' } | Select-Object -First 1
  $candidates = @()
  if ($entry) {
    if ($entry.DisplayIcon) { $candidates += (($entry.DisplayIcon -split ',')[0]).Trim('"') }
    if ($entry.InstallLocation) { $candidates += Join-Path $entry.InstallLocation.Trim('"') 'open-video-downloader.exe' }
  }
  $candidates += Join-Path $env:LOCALAPPDATA 'Open Video Downloader\open-video-downloader.exe'
  $candidates += Join-Path $env:ProgramFiles 'Open Video Downloader\open-video-downloader.exe'
  foreach ($c in $candidates) {
    if ($c -and $c -like '*.exe' -and (Test-Path -LiteralPath $c)) { return $c }
  }
  return $null
}

$ovdExe = Find-OvdExe
if ($ovdExe) {
  $shell = New-Object -ComObject WScript.Shell
  $link = $shell.CreateShortcut((Join-Path $desktop 'Open Video Downloader.lnk'))
  $link.TargetPath = $ovdExe
  $link.WorkingDirectory = Split-Path $ovdExe
  $link.Description = 'Open Video Downloader'
  $link.IconLocation = "$ovdExe,0"
  $link.Save()
} else {
  Write-Host '!! Open Video Downloader was not found; Song Search still works.' -ForegroundColor Yellow
  Write-Host '!! Try again later with: winget install jely2002.youtube-dl-gui' -ForegroundColor Yellow
}

# Shortcuts left on the Desktop by earlier versions of this script.
foreach ($old in @('Song Downloader.lnk', "1. Mully's Karaoke.bat", '2. yt-dlp Song Downloader.bat', '2. yt-dlp Song Downloader.vbs')) {
  Remove-Item -LiteralPath (Join-Path $desktop $old) -Force -ErrorAction SilentlyContinue
}

Write-Host ''
Write-Host 'Setup complete. Your Desktop now has:' -ForegroundColor Green
Write-Host "  Mully's Karaoke"
Write-Host '  Open Video Downloader'
Write-Host '  Song Search'
Write-Host "  KaraokeSongs folder: $songsDir"