# Maily installer for Windows (x64), in PowerShell:
#
#   irm https://maily.thanaelfontaine.eu/install.ps1 | iex
#
# Downloads the latest release from GitHub (https://github.com/ThanaelFontaine/Maily/releases),
# checks it against its published SHA-256, installs it in %LOCALAPPDATA%\Programs\Maily and adds
# Maily to the Start menu. Running it again updates Maily. Your accounts and mail live in the data
# folder and are kept. No administrator rights needed.
#
# Options (environment variables): $env:MAILY_VERSION = "0.9.0" installs that version,
# $env:MAILY_INSTALL_DIR = "C:\path" installs somewhere else.

& {
  $ErrorActionPreference = 'Stop'
  $ProgressPreference = 'SilentlyContinue'   # the progress bar slows Invoke-WebRequest down a lot
  [Net.ServicePointManager]::SecurityProtocol = [Net.ServicePointManager]::SecurityProtocol -bor [Net.SecurityProtocolType]::Tls12

  $repo = 'ThanaelFontaine/Maily'
  $site = 'https://maily.thanaelfontaine.eu'

  if (-not [Environment]::Is64BitOperatingSystem) {
    throw "Maily: the ready-made app needs 64-bit Windows. Run Maily from source: https://github.com/$repo#option-b-run-from-source"
  }

  # The version: the one asked for, or the latest release.
  $version = $env:MAILY_VERSION
  if (-not $version) {
    $release = Invoke-RestMethod -UseBasicParsing -Uri "https://api.github.com/repos/$repo/releases/latest" -Headers @{ 'User-Agent' = 'Maily-installer' }
    $version = $release.tag_name
  }
  $version = $version.TrimStart('v')
  if ($version -notmatch '^\d+(\.\d+)*$') { throw "Maily: could not find the latest version (got: $version)." }

  $file = "Maily-$version-windows-x64.zip"
  $url = "https://github.com/$repo/releases/download/v$version/$file"
  $tmp = Join-Path ([IO.Path]::GetTempPath()) ("maily-" + [Guid]::NewGuid().ToString('N'))
  New-Item -ItemType Directory -Path $tmp | Out-Null

  try {
    Write-Host "Downloading Maily $version for Windows..."
    Invoke-WebRequest -UseBasicParsing -Uri $url -OutFile (Join-Path $tmp $file)
    Invoke-WebRequest -UseBasicParsing -Uri "$url.sha256" -OutFile (Join-Path $tmp "$file.sha256")

    # The .sha256 file reads "<hash>  <name>".
    $expected = ((Get-Content -Raw (Join-Path $tmp "$file.sha256")).Trim() -split '\s+')[0]
    $actual = (Get-FileHash -Algorithm SHA256 -Path (Join-Path $tmp $file)).Hash
    if (-not $expected -or $expected -ne $actual) {   # -ne ignores case
      throw "Maily: the download does not match its SHA-256 checksum. Nothing was installed."
    }
    Write-Host "Checksum verified."

    if (Get-Process -Name Maily -ErrorAction SilentlyContinue) {
      throw "Maily: Maily is open. Close it, then run this command again."
    }

    $dest = $env:MAILY_INSTALL_DIR
    if (-not $dest) { $dest = Join-Path $env:LOCALAPPDATA 'Programs\Maily' }
    Expand-Archive -Path (Join-Path $tmp $file) -DestinationPath (Join-Path $tmp 'x') -Force
    $new = Join-Path $tmp 'x\Maily'
    if (-not (Test-Path (Join-Path $new 'Maily.exe'))) { throw "Maily: the archive does not hold Maily\Maily.exe." }
    New-Item -ItemType Directory -Force -Path (Split-Path $dest) | Out-Null
    if (Test-Path $dest) { Remove-Item -Recurse -Force $dest }
    Move-Item -Path $new -Destination $dest
    $exe = Join-Path $dest 'Maily.exe'

    # Start menu shortcut, for the current user.
    $programs = [Environment]::GetFolderPath('Programs')
    $shell = New-Object -ComObject WScript.Shell
    $link = $shell.CreateShortcut((Join-Path $programs 'Maily.lnk'))
    $link.TargetPath = $exe
    $link.WorkingDirectory = $dest
    $link.Description = 'All your mailboxes, every AI, one connection'
    $link.Save()

    Write-Host ""
    Write-Host "Maily $version is installed in $dest."
    Write-Host "Open it from the Start menu (Maily), or run: & '$exe'"
    Write-Host "If the window stays blank, install the Microsoft Edge WebView2 Runtime: https://developer.microsoft.com/microsoft-edge/webview2/consumer/"
    Write-Host ""
    Write-Host "To update Maily later, run the same command again. Maily also tells you when a new version is out."
    Write-Host "Next: connect your mailboxes and your AIs, $site/#start"
  }
  finally {
    Remove-Item -Recurse -Force $tmp -ErrorAction SilentlyContinue
  }
}