// backend\pending_autostart.go

package main

import (
	"encoding/json"
	"errors"
	"net/http"
	"net/url"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"sync"
)

type PendingAutoStartItem struct {
	ModelKey      string `json:"modelKey"`
	URL           string `json:"url"`
	Mode          string `json:"mode,omitempty"`          // wait_public | probe_retry
	NextProbeAtMs int64  `json:"nextProbeAtMs,omitempty"` // nur bei probe_retry
	CurrentShow   string `json:"currentShow,omitempty"`   // public/private/hidden/away/offline/unknown
	ImageURL      string `json:"imageUrl,omitempty"`
}

type PendingAutoStartResponse struct {
	Items []PendingAutoStartItem `json:"items"`
}

type pendingAutoStartFile struct {
	Items []PendingAutoStartItem `json:"items"`
}

var pendingAutoStartMu sync.Mutex

func normalizePendingModeServer(v string) string {
	if strings.TrimSpace(strings.ToLower(v)) == "probe_retry" {
		return "probe_retry"
	}
	return "wait_public"
}

func normalizePendingShowServer(v string) string {
	switch strings.TrimSpace(strings.ToLower(v)) {
	case "public":
		return "public"
	case "private":
		return "private"
	case "hidden":
		return "hidden"
	case "away":
		return "away"
	case "offline":
		return "offline"
	default:
		return "unknown"
	}
}

func safeUserKeyForFile(v string) string {
	re := regexp.MustCompile(`[^a-zA-Z0-9._-]+`)
	return re.ReplaceAllString(v, "_")
}

func pendingAutoStartFilePath(userKey string) string {
	return filepath.Join("data", "pending-autostart", safeUserKeyForFile(userKey)+".json")
}

func loadPendingAutoStartItems(userKey string) ([]PendingAutoStartItem, error) {
	path := pendingAutoStartFilePath(userKey)

	raw, err := os.ReadFile(path)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			return []PendingAutoStartItem{}, nil
		}
		return nil, err
	}

	var f pendingAutoStartFile
	if err := json.Unmarshal(raw, &f); err != nil {
		// kaputte Datei => lieber leer zurückgeben statt alles zu crashen
		return []PendingAutoStartItem{}, nil
	}

	if f.Items == nil {
		f.Items = []PendingAutoStartItem{}
	}

	// noch einmal sauber normalisieren
	out := make([]PendingAutoStartItem, 0, len(f.Items))
	for _, it := range f.Items {
		key := strings.ToLower(strings.TrimSpace(it.ModelKey))
		u := strings.TrimSpace(it.URL)
		if key == "" || u == "" {
			continue
		}

		out = append(out, PendingAutoStartItem{
			ModelKey:      key,
			URL:           u,
			Mode:          normalizePendingModeServer(it.Mode),
			NextProbeAtMs: it.NextProbeAtMs,
			CurrentShow:   normalizePendingShowServer(it.CurrentShow),
			ImageURL:      strings.TrimSpace(it.ImageURL),
		})
	}

	return out, nil
}

func savePendingAutoStartItems(userKey string, items []PendingAutoStartItem) error {
	path := pendingAutoStartFilePath(userKey)

	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		return err
	}

	payload := pendingAutoStartFile{
		Items: items,
	}

	raw, err := json.MarshalIndent(payload, "", "  ")
	if err != nil {
		return err
	}

	tmp := path + ".tmp"
	if err := os.WriteFile(tmp, raw, 0o644); err != nil {
		return err
	}

	return os.Rename(tmp, path)
}

func handlePendingAutoStart(auth *AuthManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		sess, _ := auth.getSession(r)
		if sess == nil || !sess.Authed || strings.TrimSpace(sess.User) == "" {
			http.Error(w, "unauthorized", http.StatusUnauthorized)
			return
		}

		userKey := strings.ToLower(strings.TrimSpace(sess.User))

		pendingAutoStartMu.Lock()
		defer pendingAutoStartMu.Unlock()

		switch r.Method {
		case http.MethodGet:
			items, err := loadPendingAutoStartItems(userKey)
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}

			w.Header().Set("Content-Type", "application/json")
			_ = json.NewEncoder(w).Encode(PendingAutoStartResponse{
				Items: items,
			})
			return

		case http.MethodPost:
			var in PendingAutoStartItem
			if err := json.NewDecoder(r.Body).Decode(&in); err != nil {
				http.Error(w, "invalid json body", http.StatusBadRequest)
				return
			}

			in.ModelKey = strings.ToLower(strings.TrimSpace(in.ModelKey))
			in.URL = strings.TrimSpace(in.URL)
			in.Mode = normalizePendingModeServer(in.Mode)
			in.CurrentShow = normalizePendingShowServer(in.CurrentShow)
			in.ImageURL = strings.TrimSpace(in.ImageURL)

			if in.ModelKey == "" {
				http.Error(w, "missing modelKey", http.StatusBadRequest)
				return
			}
			if in.URL == "" {
				http.Error(w, "missing url", http.StatusBadRequest)
				return
			}

			u, err := url.Parse(in.URL)
			if err != nil || (u.Scheme != "http" && u.Scheme != "https") {
				http.Error(w, "invalid url", http.StatusBadRequest)
				return
			}

			items, err := loadPendingAutoStartItems(userKey)
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}

			replaced := false
			for i := range items {
				if strings.ToLower(strings.TrimSpace(items[i].ModelKey)) == in.ModelKey {
					items[i] = in
					replaced = true
					break
				}
			}

			if !replaced {
				items = append(items, in)
			}

			if err := savePendingAutoStartItems(userKey, items); err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}

			w.WriteHeader(http.StatusNoContent)
			return

		case http.MethodDelete:
			modelKey := strings.ToLower(strings.TrimSpace(r.URL.Query().Get("modelKey")))
			if modelKey == "" {
				http.Error(w, "missing modelKey", http.StatusBadRequest)
				return
			}

			items, err := loadPendingAutoStartItems(userKey)
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}

			next := make([]PendingAutoStartItem, 0, len(items))
			for _, item := range items {
				if strings.ToLower(strings.TrimSpace(item.ModelKey)) == modelKey {
					continue
				}
				next = append(next, item)
			}

			if err := savePendingAutoStartItems(userKey, next); err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}

			w.WriteHeader(http.StatusNoContent)
			return

		default:
			w.Header().Set("Allow", "GET, POST, DELETE")
			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
			return
		}
	}
}