package app

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

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

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

// AppManifest represents the structure of manifest.yaml files
type AppManifest struct {
	Name        string `yaml:"name"`
	Version     string `yaml:"version"`
	Description string `yaml:"description"`
	Install     bool   `yaml:"install"`
	Icon        string `yaml:"icon"`
	Requires    []struct {
		Name string `yaml:"name"`
	} `yaml:"requires"`
}

// AppInfo represents an installable app with its status
type AppInfo struct {
	Name             string
	Version          string
	Description      string
	Icon             string
	Requires         []string
	Installed        bool
	InstalledVersion string
}

var (
	searchQuery  string
	verbose      bool
	outputFormat string
)

func newListCommand() *cobra.Command {
	cmd := &cobra.Command{
		Use:   "list",
		Short: "List available applications",
		Long: `List all available Wild Cloud apps with their metadata.

This command shows applications from the Wild Cloud installation directory.
Apps are read from WC_ROOT/apps and filtered to show only installable ones.

Examples:
  wild app list
  wild app list --search database
  wild app list --verbose`,
		RunE: runList,
	}

	cmd.Flags().StringVar(&searchQuery, "search", "", "search applications by name or description")
	cmd.Flags().BoolVarP(&verbose, "verbose", "v", false, "show additional metadata (icon, requires)")
	cmd.Flags().StringVar(&outputFormat, "format", "table", "output format: table, json, yaml")

	return cmd
}

func runList(cmd *cobra.Command, args []string) error {
	// Initialize environment
	env := environment.New()
	if err := env.RequiresInstallation(); err != nil {
		return err
	}

	// Get apps directory from WC_ROOT
	appsDir := filepath.Join(env.WCRoot(), "apps")
	if _, err := os.Stat(appsDir); os.IsNotExist(err) {
		return fmt.Errorf("apps directory not found at %s", appsDir)
	}

	// Get project apps directory if available
	var projectAppsDir string
	if env.WCHome() != "" {
		projectAppsDir = filepath.Join(env.WCHome(), "apps")
	}

	// Read all installable apps
	apps, err := getInstallableApps(appsDir, projectAppsDir)
	if err != nil {
		return fmt.Errorf("failed to read apps: %w", err)
	}

	// Filter by search query
	if searchQuery != "" {
		apps = filterApps(apps, searchQuery)
	}

	if len(apps) == 0 {
		output.Warning("No applications found matching criteria")
		return nil
	}

	// Display results based on format
	switch outputFormat {
	case "json":
		return outputJSON(apps)
	case "yaml":
		return outputYAML(apps)
	default:
		return outputTable(apps, verbose)
	}
}

// getInstallableApps reads apps from WC_ROOT/apps directory and checks installation status
func getInstallableApps(appsDir, projectAppsDir string) ([]AppInfo, error) {
	var apps []AppInfo

	entries, err := os.ReadDir(appsDir)
	if err != nil {
		return nil, fmt.Errorf("reading apps directory: %w", err)
	}

	for _, entry := range entries {
		if !entry.IsDir() {
			continue
		}

		appName := entry.Name()
		appDir := filepath.Join(appsDir, appName)
		manifestPath := filepath.Join(appDir, "manifest.yaml")

		// Skip if no manifest.yaml
		if _, err := os.Stat(manifestPath); os.IsNotExist(err) {
			continue
		}

		// Parse manifest
		manifestData, err := os.ReadFile(manifestPath)
		if err != nil {
			continue
		}

		var manifest AppManifest
		if err := yaml.Unmarshal(manifestData, &manifest); err != nil {
			continue
		}

		// Skip if not installable
		if !manifest.Install {
			continue
		}

		// Extract requires list
		var requires []string
		for _, req := range manifest.Requires {
			requires = append(requires, req.Name)
		}

		// Check installation status
		installed := false
		installedVersion := ""
		if projectAppsDir != "" {
			projectManifestPath := filepath.Join(projectAppsDir, appName, "manifest.yaml")
			if projectManifestData, err := os.ReadFile(projectManifestPath); err == nil {
				var projectManifest AppManifest
				if err := yaml.Unmarshal(projectManifestData, &projectManifest); err == nil {
					installed = true
					installedVersion = projectManifest.Version
				}
			}
		}

		app := AppInfo{
			Name:             manifest.Name,
			Version:          manifest.Version,
			Description:      manifest.Description,
			Icon:             manifest.Icon,
			Requires:         requires,
			Installed:        installed,
			InstalledVersion: installedVersion,
		}

		apps = append(apps, app)
	}

	return apps, nil
}

// filterApps filters apps by search query (name or description)
func filterApps(apps []AppInfo, query string) []AppInfo {
	query = strings.ToLower(query)
	var filtered []AppInfo

	for _, app := range apps {
		if strings.Contains(strings.ToLower(app.Name), query) ||
			strings.Contains(strings.ToLower(app.Description), query) {
			filtered = append(filtered, app)
		}
	}

	return filtered
}

// outputTable displays apps in table format
func outputTable(apps []AppInfo, verbose bool) error {
	if verbose {
		output.Header("Available Wild Cloud Apps (verbose)")
		output.Printf("%-15s %-10s %-12s %-40s %-15s %s\n", "NAME", "VERSION", "INSTALLED", "DESCRIPTION", "REQUIRES", "ICON")
		output.Printf("%-15s %-10s %-12s %-40s %-15s %s\n", "----", "-------", "---------", "-----------", "--------", "----")
	} else {
		output.Header("Available Wild Cloud Apps")
		output.Printf("%-15s %-10s %-12s %s\n", "NAME", "VERSION", "INSTALLED", "DESCRIPTION")
		output.Printf("%-15s %-10s %-12s %s\n", "----", "-------", "---------", "-----------")
	}

	for _, app := range apps {
		installedStatus := "NO"
		if app.Installed {
			installedStatus = app.InstalledVersion
		}

		description := app.Description
		if len(description) > 40 && !verbose {
			description = description[:37] + "..."
		}

		if verbose {
			requiresList := strings.Join(app.Requires, ",")
			if len(requiresList) > 15 {
				requiresList = requiresList[:12] + "..."
			}
			icon := app.Icon
			if len(icon) > 30 {
				icon = icon[:27] + "..."
			}
			output.Printf("%-15s %-10s %-12s %-40s %-15s %s\n", app.Name, app.Version, installedStatus, description, requiresList, icon)
		} else {
			output.Printf("%-15s %-10s %-12s %s\n", app.Name, app.Version, installedStatus, description)
		}
	}

	output.Info("")
	output.Info(fmt.Sprintf("Total installable apps: %d", len(apps)))
	output.Info("")
	output.Info("Usage:")
	output.Info("  wild app fetch <app>    # Fetch app template to project")
	output.Info("  wild app deploy <app>   # Deploy app to Kubernetes")

	return nil
}

// outputJSON displays apps in JSON format
func outputJSON(apps []AppInfo) error {
	output.Printf("{\n")
	output.Printf("  \"apps\": [\n")

	for i, app := range apps {
		output.Printf("    {\n")
		output.Printf("      \"name\": \"%s\",\n", app.Name)
		output.Printf("      \"version\": \"%s\",\n", app.Version)
		output.Printf("      \"description\": \"%s\",\n", app.Description)
		output.Printf("      \"icon\": \"%s\",\n", app.Icon)
		output.Printf("      \"requires\": [")
		for j, req := range app.Requires {
			output.Printf("\"%s\"", req)
			if j < len(app.Requires)-1 {
				output.Printf(", ")
			}
		}
		output.Printf("],\n")
		if app.Installed {
			output.Printf("      \"installed\": \"%s\",\n", app.InstalledVersion)
		} else {
			output.Printf("      \"installed\": \"NO\",\n")
		}
		output.Printf("      \"installed_version\": \"%s\"\n", app.InstalledVersion)
		output.Printf("    }")
		if i < len(apps)-1 {
			output.Printf(",")
		}
		output.Printf("\n")
	}

	output.Printf("  ],\n")
	output.Printf("  \"total\": %d\n", len(apps))
	output.Printf("}\n")

	return nil
}

// outputYAML displays apps in YAML format
func outputYAML(apps []AppInfo) error {
	output.Printf("apps:\n")

	for _, app := range apps {
		output.Printf("- name: %s\n", app.Name)
		output.Printf("  version: %s\n", app.Version)
		output.Printf("  description: %s\n", app.Description)
		if app.Installed {
			output.Printf("  installed: %s\n", app.InstalledVersion)
		} else {
			output.Printf("  installed: NO\n")
		}
		if app.InstalledVersion != "" {
			output.Printf("  installed_version: %s\n", app.InstalledVersion)
		}
		if app.Icon != "" {
			output.Printf("  icon: %s\n", app.Icon)
		}
		if len(app.Requires) > 0 {
			output.Printf("  requires:\n")
			for _, req := range app.Requires {
				output.Printf("    - %s\n", req)
			}
		}
	}

	return nil
}