package services

import (
	"os"
	"path/filepath"
)

type ModInfo struct {
	ID       string   `json:"id"`
	Name     string   `json:"name"`
	Source   string   `json:"source"`
	Path     string   `json:"path"`
	Size     int64    `json:"size"`
	InUse    bool     `json:"in_use"`
	Modlists []string `json:"modlists"`
}

func ListWorkshopMods(serverfileDir string) []ModInfo {
	workshopDir := filepath.Join(serverfileDir, "steamapps", "workshop", "content", workshopAppID)
	entries, err := os.ReadDir(workshopDir)
	if err != nil {
		return nil
	}

	var mods []ModInfo
	for _, e := range entries {
		if !e.IsDir() {
			continue
		}
		id := e.Name()
		p := filepath.Join(workshopDir, id)
		size := dirSize(p)
		mods = append(mods, ModInfo{
			ID:     id,
			Name:   "",
			Source: "workshop",
			Path:   p,
			Size:   size,
		})
	}
	return mods
}

func ListLocalMods(modsDir string) []ModInfo {
	entries, err := os.ReadDir(modsDir)
	if err != nil {
		return nil
	}

	var mods []ModInfo
	for _, e := range entries {
		if !e.IsDir() {
			continue
		}
		name := e.Name()
		p := filepath.Join(modsDir, name)
		size := dirSize(p)
		displayName := name
		if len(name) > 0 && name[0] == '@' {
			displayName = name[1:]
		}
		mods = append(mods, ModInfo{
			ID:   displayName,
			Name: name,
			Source: "local",
			Path:   p,
			Size:   size,
		})
	}
	return mods
}

func BuildUsageMap(modlists *ModlistManager) (usedWorkshop map[string][]string, usedLocal map[string][]string) {
	usedWorkshop = make(map[string][]string)
	usedLocal = make(map[string][]string)

	lists, err := modlists.List()
	if err != nil {
		return
	}

	for _, li := range lists {
		ml, err := modlists.Get(li.ID)
		if err != nil {
			continue
		}
		for _, m := range ml.Mods {
			if m.ID != "" {
				usedWorkshop[m.ID] = append(usedWorkshop[m.ID], ml.Name)
			}
			if m.Name != "" {
				nameWithAt := "@" + m.Name
				usedLocal[m.Name] = append(usedLocal[m.Name], ml.Name)
				usedLocal[nameWithAt] = append(usedLocal[nameWithAt], ml.Name)
			}
		}
	}
	return
}

func RemoveMod(path string) error {
	return os.RemoveAll(path)
}

func dirSize(path string) int64 {
	var size int64
	filepath.WalkDir(path, func(_ string, d os.DirEntry, err error) error {
		if err != nil {
			return nil
		}
		if !d.IsDir() {
			fi, err := d.Info()
			if err == nil {
				size += fi.Size()
			}
		}
		return nil
	})
	return size
}