package services

import (
	"encoding/json"
	"os"
	"path/filepath"
	"strings"

	"sproutclaw-web/internal/models"
)

// ListExtensions reads the extensions directory and returns metadata.
func ListExtensions(agentDir string) []models.ExtensionInfo {
	extDir := filepath.Join(agentDir, "extensions")
	entries, err := os.ReadDir(extDir)
	if err != nil {
		return nil
	}

	var exts []models.ExtensionInfo
	for _, e := range entries {
		if !e.IsDir() {
			continue
		}
		ext := buildExtensionInfo(filepath.Join(extDir, e.Name()), e.Name())
		exts = append(exts, ext)
	}
	return exts
}

func buildExtensionInfo(path, id string) models.ExtensionInfo {
	info := models.ExtensionInfo{
		ID:      id,
		Name:    id,
		Enabled: true, // assume enabled unless configured otherwise
		Source:  "local",
	}

	// try package.json for version/name
	pkgPath := filepath.Join(path, "package.json")
	if data, err := os.ReadFile(pkgPath); err == nil {
		var pkg struct {
			Name    string `json:"name"`
			Version string `json:"version"`
		}
		if json.Unmarshal(data, &pkg) == nil {
			if pkg.Name != "" {
				info.Name = pkg.Name
			}
			info.Version = pkg.Version
			// detect npm packages
			if strings.Contains(pkg.Name, "/") || strings.HasPrefix(pkg.Name, "@") {
				info.Source = "npm"
			}
		}
	}
	return info
}

// ToggleExtension is a placeholder – full implementation requires settings.json management.
func ToggleExtension(agentDir, id string, enable bool) error {
	return updateSettingsExtensions(filepath.Join(agentDir, "settings.json"), id, enable)
}

func updateSettingsExtensions(settingsPath, id string, enable bool) error {
	data, err := os.ReadFile(settingsPath)
	if err != nil && !os.IsNotExist(err) {
		return err
	}

	var settings map[string]any
	if len(data) > 0 {
		if err := json.Unmarshal(data, &settings); err != nil {
			settings = map[string]any{}
		}
	} else {
		settings = map[string]any{}
	}

	// extensions is a list of enabled extension IDs
	extList, _ := settings["extensions"].([]any)
	set := map[string]bool{}
	for _, e := range extList {
		if s, ok := e.(string); ok {
			set[s] = true
		}
	}
	if enable {
		set[id] = true
	} else {
		delete(set, id)
	}

	newList := make([]string, 0, len(set))
	for k := range set {
		newList = append(newList, k)
	}
	settings["extensions"] = newList

	out, err := json.MarshalIndent(settings, "", "  ")
	if err != nil {
		return err
	}
	return os.WriteFile(settingsPath, append(out, '\n'), 0o644)
}