[CmdletBinding()]
param()

$ErrorActionPreference = "Stop"
$bundleUrl = "https://git.okk.cool/purp1e/zed-sync/raw/branch/master/zed-settings-sync.json"
$utf8 = New-Object System.Text.UTF8Encoding($false)

function Require-Command([string]$Name, [string]$InstallHint) {
  if (-not (Get-Command $Name -ErrorAction SilentlyContinue)) {
    throw "$Name is required. Install it first: $InstallHint"
  }
}

function Test-AllowedPath([string]$Path) {
  $fixed = @(
    "settings.json",
    "keymap.json",
    "tasks.json",
    "debug.json",
    "scripts/toggle-file-scan-exclusions.mjs",
    "scripts/file-exclusions.json",
    "scripts/zed-settings-sync.mjs"
  )
  $segments = $Path.Split("/")
  if (
    $Path.StartsWith("/") -or
    $Path.Contains("\") -or
    $segments -contains "" -or
    $segments -contains "." -or
    $segments -contains ".."
  ) {
    return $false
  }
  return $fixed -contains $Path -or $Path.StartsWith("snippets/") -or $Path.StartsWith("themes/")
}

function Write-Atomic([string]$Path, [string]$Contents) {
  $directory = Split-Path $Path -Parent
  New-Item -ItemType Directory -Force -Path $directory | Out-Null
  $temporary = Join-Path $directory ".$([IO.Path]::GetFileName($Path)).$PID.tmp"
  try {
    [IO.File]::WriteAllText($temporary, $Contents, $utf8)
    Move-Item -LiteralPath $temporary -Destination $Path -Force
  } finally {
    Remove-Item -LiteralPath $temporary -Force -ErrorAction SilentlyContinue
  }
}

Require-Command "node" "winget install OpenJS.NodeJS.LTS"
if ($env:ZED_SETTINGS_BUNDLE_PATH) {
  $bundleSource = [IO.File]::ReadAllText($env:ZED_SETTINGS_BUNDLE_PATH, [Text.Encoding]::UTF8)
} else {
  Write-Host "Downloading the public Zed configuration bundle..."
  $bundleSource = (Invoke-WebRequest -UseBasicParsing -Uri $bundleUrl).Content
}
try {
  $bundle = $bundleSource | ConvertFrom-Json
} catch {
  throw "The downloaded bundle contains invalid JSON: $($_.Exception.Message)"
}

$properties = @($bundle.PSObject.Properties)
foreach ($required in @("settings.json", "keymap.json", "tasks.json")) {
  if (-not ($properties.Name -contains $required)) { throw "The bundle is missing $required." }
}
foreach ($property in $properties) {
  if (-not (Test-AllowedPath $property.Name) -or $property.Value -isnot [string]) {
    throw "Invalid bundle file: $($property.Name)"
  }
}

$target = Join-Path $env:APPDATA "Zed"
$timestamp = Get-Date -Format "yyyyMMdd-HHmmss"
$backup = Join-Path $target "backups\bootstrap-$timestamp"
New-Item -ItemType Directory -Force -Path $target, $backup, (Join-Path $target "scripts") | Out-Null

foreach ($property in $properties) {
  $existing = Join-Path $target ($property.Name.Replace("/", "\"))
  if (Test-Path -LiteralPath $existing) {
    $backupPath = Join-Path $backup ($property.Name.Replace("/", "\"))
    New-Item -ItemType Directory -Force -Path (Split-Path $backupPath -Parent) | Out-Null
    Copy-Item -LiteralPath $existing -Destination $backupPath -Force
  }
}

$toggleScript = (Join-Path $target "scripts\toggle-file-scan-exclusions.mjs").Replace("\", "/")
$syncScript = (Join-Path $target "scripts\zed-settings-sync.mjs").Replace("\", "/")
foreach ($property in $properties) {
  $destination = Join-Path $target ($property.Name.Replace("/", "\"))
  $contents = [string]$property.Value
  if ($property.Name -eq "tasks.json") {
    $contents = $contents.Replace("__TOGGLE_SCRIPT__", $toggleScript).Replace("__SYNC_SCRIPT__", $syncScript)
  }
  Write-Atomic $destination $contents
}

$statePath = Join-Path $target "scripts\settings-sync.json"
if (-not (Test-Path -LiteralPath $statePath)) {
  $state = [ordered]@{
    gist_id = ""
    last_synced_hash = ""
    auto_sync = $false
    interval_minutes = 15
    last_run_at = ""
    last_result = ""
  } | ConvertTo-Json
  Write-Atomic $statePath "$state`n"
} else {
  $existingState = Get-Content -LiteralPath $statePath -Raw | ConvertFrom-Json
  $state = [ordered]@{
    gist_id = if ($existingState.gist_id -is [string]) { $existingState.gist_id } else { "" }
    last_synced_hash = if ($existingState.last_synced_hash -is [string]) { $existingState.last_synced_hash } else { "" }
    auto_sync = $existingState.auto_sync -eq $true
    interval_minutes = if ($existingState.interval_minutes -is [int] -and $existingState.interval_minutes -ge 5) { $existingState.interval_minutes } else { 15 }
    last_run_at = if ($existingState.last_run_at -is [string]) { $existingState.last_run_at } else { "" }
    last_result = if ($existingState.last_result -is [string]) { $existingState.last_result } else { "" }
  } | ConvertTo-Json
  Write-Atomic $statePath "$state`n"
}

Write-Host ""
Write-Host "Installed Zed settings to $target"
Write-Host "Previous settings were backed up to $backup"
Write-Host "GitHub and Gist setup are optional and did not block installation."

if ($env:ZED_SYNC_SKIP_SETUP -ne "1") {
  try {
    $answer = Read-Host "Run the GitHub sync setup now? [Y/n]"
    if ([string]::IsNullOrWhiteSpace($answer) -or $answer -match "^[Yy]") {
      & node $syncScript setup
      if ($LASTEXITCODE -ne 0) {
        Write-Warning "Sync setup did not complete. Local installation is still valid; run the setup Task from Zed later."
      }
    }
  } catch {
    Write-Warning "Could not start interactive sync setup. Run 'Zed Settings: Set Up / Reconfigure Sync...' from Zed later."
  }
}

Write-Host "Restart or reload Zed to use the installed configuration."