$ErrorActionPreference = 'Stop'

function Write-Step {
    param([string]$Message)
    Write-Host "==> $Message"
}

$BinDir = Join-Path $DeployRoot 'bin'
$StartupScript = Join-Path $BinDir 'startup.bat'
$ReleaseDir = Join-Path $DeployRoot 'releases'
$DeployTmp = Join-Path $DeployRoot 'deploy-tmp'
$ArtifactZip = Join-Path $DeployTmp 'artifact.zip'
$ExtractDir = Join-Path $DeployTmp 'artifact'

if (-not (Test-Path $DeployRoot)) {
    throw "Deploy root not found: $DeployRoot"
}

if (-not (Test-Path $BinDir)) {
    throw "Bin directory not found: $BinDir"
}

if (-not (Test-Path $StartupScript)) {
    throw "Startup script not found: $StartupScript"
}

$CurrentJar = Get-ChildItem $BinDir -Filter 'kkFileView-*.jar' | Sort-Object LastWriteTime -Descending | Select-Object -First 1
if (-not $CurrentJar) {
    throw "No kkFileView jar found in $BinDir"
}

$JarName = $CurrentJar.Name
$JarPath = $CurrentJar.FullName

Write-Step "Deploy root: $DeployRoot"
Write-Step "Current jar: $JarPath"
Write-Step "Startup script: $StartupScript"
Write-Step "Health url: $HealthUrl"

if ($DryRun -eq 'true') {
    Write-Step "Dry run enabled, remote validation finished"
    return
}

New-Item -ItemType Directory -Force -Path $ReleaseDir | Out-Null
New-Item -ItemType Directory -Force -Path $DeployTmp | Out-Null

if (Test-Path $ArtifactZip) {
    Remove-Item $ArtifactZip -Force
}

if (Test-Path $ExtractDir) {
    Remove-Item $ExtractDir -Recurse -Force
}

$Headers = @{
    Authorization = "Bearer $GitHubToken"
    Accept = "application/vnd.github+json"
    "X-GitHub-Api-Version" = "2022-11-28"
    "User-Agent" = "kkFileView-auto-deploy"
}

$ArtifactsApi = "https://api.github.com/repos/$Repository/actions/runs/$RunId/artifacts"
Write-Step "Resolving workflow artifact: $ArtifactName"
$ArtifactsResponse = Invoke-RestMethod -Headers $Headers -Uri $ArtifactsApi -Method Get
$Artifact = $ArtifactsResponse.artifacts | Where-Object { $_.name -eq $ArtifactName } | Select-Object -First 1

if (-not $Artifact) {
    throw "Artifact '$ArtifactName' not found for workflow run $RunId"
}

Write-Step "Downloading artifact from GitHub Actions"
Invoke-WebRequest -Headers $Headers -Uri $Artifact.archive_download_url -OutFile $ArtifactZip
Expand-Archive -LiteralPath $ArtifactZip -DestinationPath $ExtractDir -Force

$DownloadedJar = Get-ChildItem $ExtractDir -Filter 'kkFileView-*.jar' -Recurse | Select-Object -First 1
if (-not $DownloadedJar) {
    throw "No kkFileView jar found inside artifact '$ArtifactName'"
}

$Timestamp = Get-Date -Format 'yyyyMMddHHmmss'
$BackupJar = Join-Path $ReleaseDir ("{0}.{1}.bak" -f $JarName, $Timestamp)

function Stop-KkFileView {
    $Processes = Get-CimInstance Win32_Process | Where-Object {
        $_.Name -match '^java(\.exe)?$' -and $_.CommandLine -like "*-jar $JarName*"
    }

    foreach ($Process in $Processes) {
        Write-Step "Stopping java process $($Process.ProcessId)"
        Stop-Process -Id $Process.ProcessId -Force -ErrorAction SilentlyContinue
    }
}

function Start-KkFileView {
    Write-Step "Starting kkFileView"
    Start-Process -FilePath 'cmd.exe' -ArgumentList '/c', "`"$StartupScript`"" -WorkingDirectory $BinDir -WindowStyle Hidden
}

function Wait-Health {
    param([string]$Url)

    for ($i = 0; $i -lt 24; $i++) {
        Start-Sleep -Seconds 5
        try {
            $Response = Invoke-WebRequest -Uri $Url -UseBasicParsing -TimeoutSec 5
            if ($Response.StatusCode -eq 200) {
                return $true
            }
        } catch {
            Start-Sleep -Milliseconds 200
        }
    }

    return $false
}

Write-Step "Backing up current jar to $BackupJar"
Copy-Item $JarPath $BackupJar -Force

Stop-KkFileView
Start-Sleep -Seconds 3

Write-Step "Replacing jar with artifact output"
Copy-Item $DownloadedJar.FullName $JarPath -Force

Start-KkFileView

if (-not (Wait-Health -Url $HealthUrl)) {
    Write-Step "Health check failed, rolling back"
    Stop-KkFileView
    Start-Sleep -Seconds 2
    Copy-Item $BackupJar $JarPath -Force
    Start-KkFileView

    if (-not (Wait-Health -Url $HealthUrl)) {
        throw "Deployment failed and rollback health check also failed"
    }

    throw "Deployment failed, rollback completed successfully"
}

Write-Step "Deployment completed successfully"