#Requires -RunAsAdministrator
#Requires -Version 5.1
<#
.SYNOPSIS
    Downloads, registers, and installs act_runner as a Windows service.

.DESCRIPTION
    1. Downloads the act_runner binary from the specified URL (or Gitea releases).
    2. Registers the runner with the Gitea instance using a registration token.
    3. Installs it as a Windows service that auto-starts with the system.

    Prerequisites:
      - Run as Administrator
      - NSSM (Non-Sucking Service Manager) must be installed and in PATH,
        OR use the built-in sc.exe method (creates a wrapper via PowerShell).
      - The Gitea instance must be reachable from this host.

.PARAMETER GiteaURL
    Base URL of your Gitea instance. Example: http://192.168.1.50:3000

.PARAMETER RegistrationToken
    Runner registration token from Gitea:
    Admin Panel → Settings → Actions → Runners → "Create Runner Token"

.PARAMETER InstallDir
    Directory where act_runner will be installed.
    Default: F:\CI\act_runner

.PARAMETER RunnerName
    Display name for this runner in the Gitea UI.
    Default: local-windows-runner

.PARAMETER ActRunnerVersion
    Version tag to download. Default: latest (resolves via GitHub API).
    Example: v0.2.11

.PARAMETER ServiceName
    Windows service name. Default: act_runner

.EXAMPLE
    .\Install-Runner.ps1 `
        -GiteaURL          "http://192.168.1.50:3000" `
        -RegistrationToken "abc123xyz"
#>
[CmdletBinding()]
param(
    [Parameter(Mandatory)]
    [string] $GiteaURL,

    [Parameter(Mandatory)]
    [string] $RegistrationToken,

    [string] $InstallDir = 'F:\CI\act_runner',

    [string] $RunnerName = 'local-windows-runner',

    [string] $ActRunnerVersion = 'latest',

    [string] $ServiceName = 'act_runner'
)

Set-StrictMode -Version Latest
$ErrorActionPreference = 'Stop'

# ── Resolve download URL ──────────────────────────────────────────────────────
if ($ActRunnerVersion -eq 'latest') {
    Write-Host "[Install-Runner] Resolving latest act_runner version from Gitea releases..."
    try {
        $releaseInfo = Invoke-RestMethod -Uri 'https://dl.gitea.com/act_runner/version.json' -UseBasicParsing
        $ActRunnerVersion = $releaseInfo.latest
    }
    catch {
        Write-Warning "Could not resolve latest version automatically. Set -ActRunnerVersion explicitly."
        Write-Warning "Find releases at: https://gitea.com/gitea/act_runner/releases"
        throw
    }
}

$downloadUrl = "https://dl.gitea.com/act_runner/${ActRunnerVersion}/act_runner-${ActRunnerVersion}-windows-amd64.exe"
$binaryPath  = Join-Path $InstallDir 'act_runner.exe'
$configPath  = Join-Path $InstallDir 'config.yaml'

Write-Host "[Install-Runner] Version    : $ActRunnerVersion"
Write-Host "[Install-Runner] Install dir: $InstallDir"
Write-Host "[Install-Runner] Service    : $ServiceName"

# ── Create install directory ──────────────────────────────────────────────────
if (-not (Test-Path $InstallDir)) {
    New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null
    Write-Host "[Install-Runner] Created directory: $InstallDir"
}

# ── Download act_runner binary ────────────────────────────────────────────────
if (Test-Path $binaryPath) {
    Write-Host "[Install-Runner] act_runner.exe already exists — skipping download."
    Write-Host "             Delete $binaryPath to force re-download."
}
else {
    Write-Host "[Install-Runner] Downloading from: $downloadUrl"
    Invoke-WebRequest -Uri $downloadUrl -OutFile $binaryPath -UseBasicParsing
    Write-Host "[Install-Runner] Downloaded: $binaryPath"
}

# ── Copy config.yaml if not already present ───────────────────────────────────
$repoConfigPath = Join-Path $PSScriptRoot 'config.yaml'
if (-not (Test-Path $configPath)) {
    if (Test-Path $repoConfigPath) {
        Copy-Item $repoConfigPath $configPath
        Write-Host "[Install-Runner] Copied config.yaml from repo to $configPath"
        Write-Host "             Review and update paths in $configPath before proceeding."
    }
    else {
        Write-Warning "[Install-Runner] config.yaml not found at $repoConfigPath"
        Write-Warning "             Generating default config and registering without custom config."
        # Generate default config
        Push-Location $InstallDir
        & $binaryPath generate-config | Out-File $configPath -Encoding UTF8
        Pop-Location
    }
}
else {
    Write-Host "[Install-Runner] Using existing config.yaml: $configPath"
}

# ── Register runner with Gitea ────────────────────────────────────────────────
$stateFile = Join-Path $InstallDir '.runner'
if (Test-Path $stateFile) {
    Write-Host "[Install-Runner] Runner already registered (.runner state file exists)."
    Write-Host "             Delete $stateFile to re-register."
}
else {
    Write-Host "[Install-Runner] Registering runner with Gitea at $GiteaURL..."
    Push-Location $InstallDir
    try {
        & $binaryPath register `
            --no-interactive `
            --instance  $GiteaURL `
            --token     $RegistrationToken `
            --name      $RunnerName `
            --labels    'windows-build:host,dotnet:host,msbuild:host' `
            --config    $configPath
        if ($LASTEXITCODE -ne 0) {
            throw "act_runner register exited with code $LASTEXITCODE"
        }
    }
    finally {
        Pop-Location
    }
    Write-Host "[Install-Runner] Runner registered successfully."
}

# ── Install as Windows service ────────────────────────────────────────────────
$existingService = Get-Service -Name $ServiceName -ErrorAction SilentlyContinue

if ($existingService) {
    Write-Host "[Install-Runner] Service '$ServiceName' already exists."
    Write-Host "             Stopping and updating..."
    Stop-Service -Name $ServiceName -Force -ErrorAction SilentlyContinue
}

# Build service command (act_runner daemon with explicit config)
$serviceCmd = "`"$binaryPath`" daemon --config `"$configPath`""

if ($existingService) {
    # Update existing service binary path
    sc.exe config $ServiceName binpath= $serviceCmd | Out-Null
}
else {
    # Create new service
    New-Service `
        -Name        $ServiceName `
        -BinaryPathName $serviceCmd `
        -DisplayName 'Gitea act_runner (CI/CD)' `
        -Description 'Gitea Actions runner for ephemeral VMware build VMs' `
        -StartupType Automatic | Out-Null
    Write-Host "[Install-Runner] Service created: $ServiceName"
}

# Configure service recovery: restart on failure
sc.exe failure $ServiceName reset= 86400 actions= restart/5000/restart/10000/restart/30000 | Out-Null

# Start the service
Start-Service -Name $ServiceName
Write-Host "[Install-Runner] Service '$ServiceName' started."

# ── Verify ────────────────────────────────────────────────────────────────────
Start-Sleep -Seconds 3
$svc = Get-Service -Name $ServiceName
if ($svc.Status -eq 'Running') {
    Write-Host "[Install-Runner] act_runner is running as a Windows service."
    Write-Host "[Install-Runner] Check Gitea Admin → Settings → Actions → Runners to confirm it appears Online."
}
else {
    Write-Warning "[Install-Runner] Service status: $($svc.Status). Check Windows Event Log for errors."
}

Write-Host ""
Write-Host "Installation complete."
Write-Host "  Binary  : $binaryPath"
Write-Host "  Config  : $configPath"
Write-Host "  Service : $ServiceName (startup: Automatic)"