package docker

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
)

type Manager struct {
	ClientDir string
}

func NewManager(clientDir string) *Manager {
	return &Manager{
		ClientDir: clientDir,
	}
}

func getComposeCommand() ([]string, error) {
	// Try docker compose (v2) first
	cmd := exec.Command("docker", "compose", "version")
	if err := cmd.Run(); err == nil {
		return []string{"docker", "compose"}, nil
	}

	// Fall back to docker-compose (v1)
	cmd = exec.Command("docker-compose", "--version")
	if err := cmd.Run(); err == nil {
		return []string{"docker-compose"}, nil
	}

	return nil, fmt.Errorf("neither 'docker compose' nor 'docker-compose' is available. Please install Docker Compose")
}

func (m *Manager) Build() error {
	dockerfilePath := filepath.Join(m.ClientDir, "Dockerfile")
	if _, err := os.Stat(dockerfilePath); os.IsNotExist(err) {
		return fmt.Errorf("Dockerfile not found at %s", dockerfilePath)
	}

	// Use docker-compose build to ensure it respects docker-compose.yml configuration
	// and rebuilds when Dockerfile changes
	composeCmd, err := getComposeCommand()
	if err != nil {
		// Fallback to docker build if compose is not available
		cmd := exec.Command("docker", "build", "--no-cache", "-t", "sslh-lab-client", m.ClientDir)
		cmd.Stdout = os.Stdout
		cmd.Stderr = os.Stderr
		if err := cmd.Run(); err != nil {
			return fmt.Errorf("failed to build Docker image: %w", err)
		}
		return nil
	}

	// Use docker-compose build which will rebuild if Dockerfile changed
	args := append(composeCmd, "-f", filepath.Join(m.ClientDir, "docker-compose.yml"), "build", "--no-cache")
	cmd := exec.Command(args[0], args[1:]...)
	cmd.Dir = m.ClientDir
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	if err := cmd.Run(); err != nil {
		return fmt.Errorf("failed to build Docker image: %w", err)
	}

	return nil
}

func (m *Manager) Run() error {
	composeFile := filepath.Join(m.ClientDir, "docker-compose.yml")
	if _, err := os.Stat(composeFile); os.IsNotExist(err) {
		return fmt.Errorf("docker-compose.yml not found at %s", composeFile)
	}

	composeCmd, err := getComposeCommand()
	if err != nil {
		return err
	}

	args := append(composeCmd, "-f", composeFile, "up", "-d")
	cmd := exec.Command(args[0], args[1:]...)
	cmd.Dir = m.ClientDir
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	if err := cmd.Run(); err != nil {
		return fmt.Errorf("failed to run Docker container: %w", err)
	}

	return nil
}

func (m *Manager) Stop() error {
	composeFile := filepath.Join(m.ClientDir, "docker-compose.yml")
	if _, err := os.Stat(composeFile); os.IsNotExist(err) {
		return fmt.Errorf("docker-compose.yml not found at %s", composeFile)
	}

	composeCmd, err := getComposeCommand()
	if err != nil {
		return err
	}

	args := append(composeCmd, "-f", composeFile, "down")
	cmd := exec.Command(args[0], args[1:]...)
	cmd.Dir = m.ClientDir
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	if err := cmd.Run(); err != nil {
		return fmt.Errorf("failed to stop Docker container: %w", err)
	}

	return nil
}

func (m *Manager) Status() (string, error) {
	cmd := exec.Command("docker", "ps", "--filter", "name=sslh-lab-client", "--format", "{{.Status}}")
	output, err := cmd.Output()
	if err != nil {
		return "", fmt.Errorf("failed to check container status: %w", err)
	}

	return string(output), nil
}

func (m *Manager) IsRunning() bool {
	cmd := exec.Command("docker", "ps", "--filter", "name=sslh-lab-client", "--format", "{{.Names}}")
	output, err := cmd.Output()
	if err != nil {
		return false
	}
	return len(output) > 0 && string(output) == "sslh-lab-client\n"
}

func (m *Manager) Connect(shell string) error {
	if !m.IsRunning() {
		return fmt.Errorf("container is not running. Start it first with 'sslh-lab client'")
	}

	cmd := exec.Command("docker", "exec", "-it", "sslh-lab-client", shell)
	cmd.Stdin = os.Stdin
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr

	err := cmd.Run()
	
	// Exit code 255 is common when user exits normally (Ctrl+D or 'exit' command)
	// Exit code 130 is common when user presses Ctrl+C
	// These are not errors, just normal ways to disconnect
	if exitError, ok := err.(*exec.ExitError); ok {
		exitCode := exitError.ExitCode()
		if exitCode == 255 || exitCode == 130 || exitCode == 0 {
			return nil
		}
	}
	
	// If err is nil (exit code 0), return nil
	if err == nil {
		return nil
	}
	
	// For other errors, return them
	return err
}