package app

import (
	"context"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/spf13/cobra"
	"gopkg.in/yaml.v3"

	"github.com/wild-cloud/wild-cli/internal/config"
	"github.com/wild-cloud/wild-cli/internal/environment"
	"github.com/wild-cloud/wild-cli/internal/external"
	"github.com/wild-cloud/wild-cli/internal/output"
)

var (
	force  bool
	dryRun bool
)

func newDeployCommand() *cobra.Command {
	cmd := &cobra.Command{
		Use:   "deploy <name>",
		Short: "Deploy an application to the cluster",
		Long: `Deploy an application to the Kubernetes cluster.

This processes the app templates with current configuration and
deploys them using kubectl and kustomize.

Examples:
  wild app deploy nextcloud
  wild app deploy postgresql --force
  wild app deploy myapp --dry-run`,
		Args: cobra.ExactArgs(1),
		RunE: runDeploy,
	}

	cmd.Flags().BoolVar(&force, "force", false, "force deployment (replace existing resources)")
	cmd.Flags().BoolVar(&dryRun, "dry-run", false, "show what would be deployed without making changes")

	return cmd
}

func runDeploy(cmd *cobra.Command, args []string) error {
	appName := args[0]

	output.Header("Deploying Application")
	output.Info("App: " + appName)

	// Initialize environment
	env := environment.New()
	if err := env.RequiresProject(); err != nil {
		return err
	}

	// Check if app exists in project
	appDir := filepath.Join(env.AppsDir(), appName)
	if _, err := os.Stat(appDir); os.IsNotExist(err) {
		return fmt.Errorf("app '%s' not found in project. Run 'wild app add %s' first", appName, appName)
	}

	// Check external tools
	toolManager := external.NewManager()
	if err := toolManager.CheckTools(cmd.Context(), []string{"kubectl"}); err != nil {
		return fmt.Errorf("required tools not available: %w", err)
	}

	// Load configuration
	configMgr := config.NewManager(env.ConfigPath(), env.SecretsPath())

	// Check if app is enabled
	enabledValue, err := configMgr.Get("apps." + appName + ".enabled")
	if err != nil || enabledValue == nil {
		output.Warning("App '" + appName + "' is not configured")
		output.Info("Run: wild config set apps." + appName + ".enabled true")
		return nil
	}

	enabled, ok := enabledValue.(bool)
	if !ok || !enabled {
		output.Warning("App '" + appName + "' is disabled")
		output.Info("Run: wild config set apps." + appName + ".enabled true")
		return nil
	}

	// Process templates with configuration
	output.Info("Processing templates...")
	processedDir := filepath.Join(env.WildCloudDir(), "processed", appName)
	if err := os.RemoveAll(processedDir); err != nil {
		return fmt.Errorf("cleaning processed directory: %w", err)
	}

	if err := processAppTemplates(appDir, processedDir, configMgr); err != nil {
		return fmt.Errorf("processing templates: %w", err)
	}

	// Deploy secrets if required
	if err := deployAppSecrets(cmd.Context(), appName, appDir, configMgr, toolManager.Kubectl()); err != nil {
		return fmt.Errorf("deploying secrets: %w", err)
	}

	// Deploy using kubectl + kustomize
	output.Info("Deploying to cluster...")
	kubectl := toolManager.Kubectl()

	if err := kubectl.ApplyKustomize(cmd.Context(), processedDir, "", dryRun); err != nil {
		return fmt.Errorf("deploying with kubectl: %w", err)
	}

	if dryRun {
		output.Success("Dry run completed - no changes made")
	} else {
		output.Success("App '" + appName + "' deployed successfully")
	}

	// Show next steps
	output.Info("")
	output.Info("Monitor deployment:")
	output.Info("  kubectl get pods -n " + appName)
	output.Info("  kubectl logs -f deployment/" + appName + " -n " + appName)

	return nil
}

// processAppTemplates processes app templates with configuration
func processAppTemplates(appDir, processedDir string, configMgr *config.Manager) error {
	// Create template engine
	engine, err := config.NewTemplateEngine(configMgr)
	if err != nil {
		return fmt.Errorf("creating template engine: %w", err)
	}

	// Walk through app directory
	return filepath.Walk(appDir, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		// Calculate relative path
		relPath, err := filepath.Rel(appDir, path)
		if err != nil {
			return err
		}

		destPath := filepath.Join(processedDir, relPath)

		if info.IsDir() {
			return os.MkdirAll(destPath, info.Mode())
		}

		// Read file content
		content, err := os.ReadFile(path)
		if err != nil {
			return err
		}

		// Process as template if it's a YAML file
		if strings.HasSuffix(path, ".yaml") || strings.HasSuffix(path, ".yml") {
			processed, err := engine.Process(string(content))
			if err != nil {
				return fmt.Errorf("processing template %s: %w", relPath, err)
			}
			content = []byte(processed)
		}

		// Write processed content
		if err := os.MkdirAll(filepath.Dir(destPath), 0755); err != nil {
			return err
		}

		return os.WriteFile(destPath, content, info.Mode())
	})
}

// deployAppSecrets deploys application secrets
func deployAppSecrets(ctx context.Context, appName, appDir string, configMgr *config.Manager, kubectl *external.KubectlTool) error {
	// Check for manifest.yaml with required secrets
	manifestPath := filepath.Join(appDir, "manifest.yaml")
	manifestData, err := os.ReadFile(manifestPath)
	if os.IsNotExist(err) {
		return nil // No manifest, no secrets needed
	}
	if err != nil {
		return fmt.Errorf("reading manifest: %w", err)
	}

	var manifest struct {
		RequiredSecrets []string `yaml:"requiredSecrets"`
	}

	if err := yaml.Unmarshal(manifestData, &manifest); err != nil {
		return fmt.Errorf("parsing manifest: %w", err)
	}

	if len(manifest.RequiredSecrets) == 0 {
		return nil // No secrets required
	}

	output.Info("Deploying secrets...")

	// Collect secret data
	secretData := make(map[string]string)
	for _, secretPath := range manifest.RequiredSecrets {
		value, err := configMgr.GetSecret(secretPath)
		if err != nil || value == nil {
			return fmt.Errorf("required secret '%s' not found", secretPath)
		}

		secretData[secretPath] = fmt.Sprintf("%v", value)
	}

	// Create secret in cluster
	secretName := appName + "-secrets"
	if err := kubectl.CreateSecret(ctx, secretName, appName, secretData); err != nil {
		return fmt.Errorf("creating secret: %w", err)
	}

	output.Success("Secrets deployed")
	return nil
}