# Inventory Barcode System Deployment Script (PowerShell)
# This script handles production deployment with Docker on Windows

param(
    [Parameter(Position=0)]
    [ValidateSet("deploy", "rollback", "status", "logs", "stop", "restart")]
    [string]$Action = "deploy"
)

# Configuration
$APP_NAME = "inventory-barcode-system"
$DOCKER_IMAGE = "$APP_NAME:latest"
$CONTAINER_NAME = "$APP_NAME-container"
$BACKUP_DIR = "./data/backups"
$LOG_FILE = "./logs/deployment.log"

# Ensure log directory exists
if (!(Test-Path -Path "./logs")) {
    New-Item -ItemType Directory -Path "./logs" -Force | Out-Null
}

# Logging functions
function Write-Log {
    param([string]$Message)
    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    Write-Host "[$timestamp] $Message" -ForegroundColor Green
    "[$timestamp] $Message" | Out-File -FilePath $LOG_FILE -Append
}

function Write-Error-Log {
    param([string]$Message)
    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    Write-Host "[ERROR] $Message" -ForegroundColor Red
    "[ERROR] $Message" | Out-File -FilePath $LOG_FILE -Append
    exit 1
}

function Write-Warning-Log {
    param([string]$Message)
    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    Write-Host "[WARNING] $Message" -ForegroundColor Yellow
    "[WARNING] $Message" | Out-File -FilePath $LOG_FILE -Append
}

# Check prerequisites
function Test-Prerequisites {
    Write-Log "Checking prerequisites..."
    
    # Check if Docker is installed
    try {
        docker --version | Out-Null
    }
    catch {
        Write-Error-Log "Docker is not installed. Please install Docker Desktop first."
    }
    
    # Check if Docker Compose is available
    try {
        docker-compose --version | Out-Null
    }
    catch {
        Write-Error-Log "Docker Compose is not available. Please ensure Docker Desktop is properly installed."
    }
    
    # Check if .env file exists
    if (!(Test-Path -Path ".env")) {
        Write-Warning-Log ".env file not found. Creating from .env.example..."
        if (Test-Path -Path ".env.example") {
            Copy-Item ".env.example" ".env"
            Write-Log "Please edit .env file with your configuration before continuing."
            exit 0
        }
        else {
            Write-Error-Log ".env.example file not found. Cannot create .env file."
        }
    }
    
    Write-Log "Prerequisites check completed successfully."
}

# Create necessary directories
function New-Directories {
    Write-Log "Creating necessary directories..."
    
    $directories = @("data/exports", "data/backups", "data/temp", "logs")
    
    foreach ($dir in $directories) {
        if (!(Test-Path -Path $dir)) {
            New-Item -ItemType Directory -Path $dir -Force | Out-Null
        }
    }
    
    Write-Log "Directories created successfully."
}

# Backup existing database
function Backup-Database {
    if (Test-Path -Path "./inventory.db") {
        Write-Log "Backing up existing database..."
        
        $timestamp = Get-Date -Format "yyyyMMdd-HHmmss"
        $backupFile = "$BACKUP_DIR/pre-deployment-backup-$timestamp.db"
        
        if (!(Test-Path -Path $BACKUP_DIR)) {
            New-Item -ItemType Directory -Path $BACKUP_DIR -Force | Out-Null
        }
        
        Copy-Item "./inventory.db" $backupFile
        Write-Log "Database backed up to: $backupFile"
    }
    else {
        Write-Log "No existing database found. Skipping backup."
    }
}

# Build Docker image
function Build-Image {
    Write-Log "Building Docker image..."
    
    $result = docker build -t $DOCKER_IMAGE .
    
    if ($LASTEXITCODE -eq 0) {
        Write-Log "Docker image built successfully."
    }
    else {
        Write-Error-Log "Failed to build Docker image."
    }
}

# Stop existing container
function Stop-Existing {
    Write-Log "Stopping existing container..."
    
    $existingContainer = docker ps -q -f name=$CONTAINER_NAME
    
    if ($existingContainer) {
        docker stop $CONTAINER_NAME | Out-Null
        docker rm $CONTAINER_NAME | Out-Null
        Write-Log "Existing container stopped and removed."
    }
    else {
        Write-Log "No existing container found."
    }
}

# Deploy with Docker Compose
function Start-Deployment {
    Write-Log "Deploying application with Docker Compose..."
    
    # Stop existing services
    docker-compose down | Out-Null
    
    # Start services
    docker-compose up -d
    
    if ($LASTEXITCODE -eq 0) {
        Write-Log "Application deployed successfully."
    }
    else {
        Write-Error-Log "Failed to deploy application."
    }
}

# Health check
function Test-Health {
    Write-Log "Performing health check..."
    
    # Wait for application to start
    Start-Sleep -Seconds 10
    
    # Check if container is running
    $runningContainer = docker ps -q -f name=$APP_NAME
    if (!$runningContainer) {
        Write-Error-Log "Container is not running."
    }
    
    # Check application health endpoint
    $maxAttempts = 30
    $attempt = 1
    
    while ($attempt -le $maxAttempts) {
        try {
            $response = Invoke-WebRequest -Uri "http://localhost:3000/health" -UseBasicParsing -TimeoutSec 5
            if ($response.StatusCode -eq 200) {
                Write-Log "Health check passed. Application is running."
                return
            }
        }
        catch {
            # Continue to retry
        }
        
        Write-Log "Health check attempt $attempt/$maxAttempts failed. Retrying in 5 seconds..."
        Start-Sleep -Seconds 5
        $attempt++
    }
    
    Write-Error-Log "Health check failed after $maxAttempts attempts."
}

# Show deployment status
function Show-Status {
    Write-Log "Deployment Status:"
    Write-Host ""
    Write-Host "Container Status:"
    docker ps -f name=$APP_NAME
    Write-Host ""
    Write-Host "Application Logs (last 20 lines):"
    docker-compose logs --tail=20
    Write-Host ""
    Write-Host "Access the application at: http://localhost:3000"
    Write-Host "Health check endpoint: http://localhost:3000/health"
}

# Rollback function
function Start-Rollback {
    Write-Warning-Log "Rolling back deployment..."
    
    # Stop current deployment
    docker-compose down | Out-Null
    
    # Restore database backup if exists
    $latestBackup = Get-ChildItem -Path "$BACKUP_DIR/pre-deployment-backup-*.db" -ErrorAction SilentlyContinue | 
                   Sort-Object LastWriteTime -Descending | 
                   Select-Object -First 1
    
    if ($latestBackup) {
        Write-Log "Restoring database from: $($latestBackup.FullName)"
        Copy-Item $latestBackup.FullName "./inventory.db"
    }
    
    Write-Warning-Log "Rollback completed. Please check your previous deployment."
}

# Main deployment function
function Start-MainDeployment {
    Write-Log "Starting deployment of $APP_NAME..."
    
    try {
        Test-Prerequisites
        New-Directories
        Backup-Database
        Build-Image
        Stop-Existing
        Start-Deployment
        Test-Health
        Show-Status
        
        Write-Log "Deployment completed successfully!"
    }
    catch {
        Write-Error-Log "Deployment failed: $($_.Exception.Message)"
        Start-Rollback
    }
}

# Handle command line arguments
switch ($Action) {
    "deploy" {
        Start-MainDeployment
    }
    "rollback" {
        Start-Rollback
    }
    "status" {
        Show-Status
    }
    "logs" {
        docker-compose logs -f
    }
    "stop" {
        Write-Log "Stopping application..."
        docker-compose down
        Write-Log "Application stopped."
    }
    "restart" {
        Write-Log "Restarting application..."
        docker-compose restart
        Write-Log "Application restarted."
    }
    default {
        Write-Host "Usage: .\deploy.ps1 {deploy|rollback|status|logs|stop|restart}"
        Write-Host ""
        Write-Host "Commands:"
        Write-Host "  deploy   - Deploy the application (default)"
        Write-Host "  rollback - Rollback to previous version"
        Write-Host "  status   - Show deployment status"
        Write-Host "  logs     - Show application logs"
        Write-Host "  stop     - Stop the application"
        Write-Host "  restart  - Restart the application"
    }
}