package handlers

import (
	"database/sql"
	"encoding/json"
	"log"
	"net/http"
	"time"

	"github.com/go-chi/chi/v5"
	"github.com/golang-jwt/jwt/v5"
)

// GET current finalize time
func (app *App) HandleGetFinalizeTime(w http.ResponseWriter, r *http.Request) {
	var t string
	err := app.DB.QueryRow("SELECT value FROM settings WHERE key = 'finalize_time'").Scan(&t)
	if err == sql.ErrNoRows {
		t = "10:30" // default if not set
	}
	writeJSON(w, map[string]string{"time": t})
}

// Handle User Registration
func (app *App) HandleRegister(w http.ResponseWriter, r *http.Request) {
	var req registerRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "invalid request", http.StatusBadRequest)
		return
	}

	if req.Username == "" || req.Password == "" {
		http.Error(w, "username and password required", http.StatusBadRequest)
		return
	}

	res, err := app.DB.Exec(
		"INSERT INTO users (username, password, role) VALUES (?, ?, ?)",
		req.Username, req.Password, 100,
	)
	if err != nil {
		http.Error(w, "username already exists", http.StatusBadRequest)
		return
	}
	id, _ := res.LastInsertId()

	token, err := generateToken(int(id), req.Username)
	if err != nil {
		http.Error(w, "could not generate token", http.StatusInternalServerError)
		return
	}

	writeJSON(w, map[string]string{
		"token":    token,
		"username": req.Username,
	})
}

// Handle User Login
func (app *App) HandleLogin(w http.ResponseWriter, r *http.Request) {
	var req loginRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "invalid request", http.StatusBadRequest)
		return
	}

	var id int
	var storedPassword string
	err := app.DB.QueryRow("SELECT id, password FROM users WHERE username = ?", req.Username).Scan(&id, &storedPassword)
	if err != nil {
		http.Error(w, "invalid username or password", http.StatusUnauthorized)
		return
	}

	if storedPassword != req.Password {
		http.Error(w, "invalid username or password", http.StatusUnauthorized)
		return
	}

	token, err := generateToken(id, req.Username)
	if err != nil {
		http.Error(w, "could not generate token", http.StatusInternalServerError)
		return
	}

	writeJSON(w, map[string]string{
		"token":    token,
		"username": req.Username,
	})
}

// Get Menu Options from DB
func (app *App) HandleOptions(w http.ResponseWriter, r *http.Request) {
	rows, err := app.DB.Query("SELECT category, name FROM menu_items ORDER BY id ASC")
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	defer rows.Close()

	valasztek := Valasztek{
		Levesek:  []Leves{},
		Foetelek: []Foetel{},
		Koretek:  []Koret{},
	}

	for rows.Next() {
		var category, name string
		if err := rows.Scan(&category, &name); err == nil {
			switch category {
			case "soup":
				valasztek.Levesek = append(valasztek.Levesek, name)
			case "main":
				valasztek.Foetelek = append(valasztek.Foetelek, name)
			case "side":
				valasztek.Koretek = append(valasztek.Koretek, name)
			}
		}
	}

	writeJSON(w, valasztek)
}

// Handle User Saved Selection
func (app *App) HandleSaveSelection(w http.ResponseWriter, r *http.Request) {
	tokenStr := r.Header.Get("Authorization")
	if tokenStr == "" {
		http.Error(w, "missing token", http.StatusUnauthorized)
		return
	}

	// Strip "Bearer " prefix
	if len(tokenStr) > 7 && tokenStr[:7] == "Bearer " {
		tokenStr = tokenStr[7:]
	}

	token, err := jwt.Parse(tokenStr, func(t *jwt.Token) (interface{}, error) {
		return jwtSecret, nil
	})
	if err != nil || !token.Valid {
		http.Error(w, "invalid token", http.StatusUnauthorized)
		return
	}

	claims := token.Claims.(jwt.MapClaims)
	userID := int(claims["user_id"].(float64))

	var req selectionRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "invalid request", http.StatusBadRequest)
		return
	}

	now := time.Now().Format(time.RFC3339)

	// Insert or update selection (simple approach: delete old one, insert new)
	_, _ = app.DB.Exec("DELETE FROM selections WHERE user_id = ?", userID)
	_, err = app.DB.Exec(
		"INSERT INTO selections (user_id, main, side, soup, created_at) VALUES (?, ?, ?, ?, ?)",
		userID, req.Main, req.Side, req.Soup, now,
	)
	if err != nil {
		http.Error(w, "failed to save selection", http.StatusInternalServerError)
		return
	}

	writeJSON(w, map[string]string{
		"status": "ok",
		"main":   req.Main,
		"side":   req.Side,
		"soup":   req.Soup,
	})
}

// Handle User's selected Menu
func (app *App) HandleGetSelection(w http.ResponseWriter, r *http.Request) {
	tokenStr := r.Header.Get("Authorization")
	if tokenStr == "" {
		http.Error(w, "missing token", http.StatusUnauthorized)
		return
	}
	if len(tokenStr) > 7 && tokenStr[:7] == "Bearer " {
		tokenStr = tokenStr[7:]
	}

	token, err := jwt.Parse(tokenStr, func(t *jwt.Token) (interface{}, error) {
		return jwtSecret, nil
	})
	if err != nil || !token.Valid {
		http.Error(w, "invalid token", http.StatusUnauthorized)
		return
	}

	claims := token.Claims.(jwt.MapClaims)
	userID := int(claims["user_id"].(float64))

	row := app.DB.QueryRow("SELECT main, side, soup, created_at FROM selections WHERE user_id = ?", userID)
	var main, side, soup, createdAt string
	err = row.Scan(&main, &side, &soup, &createdAt)
	if err == sql.ErrNoRows {
		writeJSON(w, map[string]string{"status": "none"})
		return
	} else if err != nil {
		http.Error(w, "db error", http.StatusInternalServerError)
		return
	}

	writeJSON(w, map[string]string{
		"main":       main,
		"side":       side,
		"soup":       soup,
		"created_at": createdAt,
	})
}

// Get all active Orders
func (app *App) HandleGetOrders(w http.ResponseWriter, r *http.Request) {
	rows, err := app.DB.Query("SELECT id, username, soup, main, side, created_at, status FROM orders WHERE status = 'active' ORDER BY id DESC")
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	defer rows.Close()

	var out []Order
	for rows.Next() {
		var o Order
		if err := rows.Scan(&o.ID, &o.Username, &o.Soup, &o.Main, &o.Side, &o.CreatedAt, &o.Status); err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		out = append(out, o)
	}
	writeJSON(w, out)
}

// Handle new Order
func (app *App) HandleAddOrder(w http.ResponseWriter, r *http.Request) {
	var in struct{ Soup, Main, Side string }
	if err := json.NewDecoder(r.Body).Decode(&in); err != nil || in.Main == "" || in.Side == "" {
		http.Error(w, "invalid order", http.StatusBadRequest)
		return
	}
	username, err := usernameFromJWT(r)
	if err != nil || username == "" {
		http.Error(w, "unauthorized", http.StatusUnauthorized)
		return
	}

	now := time.Now().Format(time.RFC3339)

	// // Step 1: mark any previous active orders for this user as history
	// _, _ = app.DB.Exec("UPDATE orders SET status = 'history' WHERE username = ? AND status = 'active'", username)

	// Step 2: insert new active order
	res, err := app.DB.Exec(
		"INSERT INTO orders (username, soup, main, side, created_at, status) VALUES (?, ?, ?, ?, ?, ?)",
		username, in.Soup, in.Main, in.Side, now, "active",
	)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	id, _ := res.LastInsertId()
	ord := Order{
		ID:        int(id),
		Username:  username,
		Soup:      in.Soup,
		Main:      in.Main,
		Side:      in.Side,
		CreatedAt: now,
		Status:    "active",
	}

	// broadcast to SSE clients
	if data, err := json.Marshal(ord); err == nil {
		log.Printf("Broadcasting active order via SSE: %+v", ord)
		app.Broker.broadcast <- data
	}

	writeJSON(w, ord)
}

// Handle Order deletion
func (app *App) HandleDeleteOrder(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")
	username, err := usernameFromJWT(r)
	if err != nil || username == "" {
		http.Error(w, "unauthorized", http.StatusUnauthorized)
		return
	}

	res, err := app.DB.Exec("UPDATE orders SET status = 'history' WHERE id = ? AND username = ?", id, username)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	n, _ := res.RowsAffected()
	if n == 0 {
		http.Error(w, "order not found", http.StatusNotFound)
		return
	}

	// broadcast deletion (tell clients to refresh)
	msg := map[string]any{"id": id, "status": "history", "event": "deleted"}
	if data, err := json.Marshal(msg); err == nil {
		app.Broker.broadcast <- data
	}

	writeJSON(w, map[string]string{"status": "archived"})
}

// Send Orders over SSE to client
func (app *App) HandleOrdersStream(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/event-stream")
	w.Header().Set("Cache-Control", "no-cache")
	w.Header().Set("Connection", "keep-alive")
	w.Header().Del("Content-Encoding")
	w.Header().Set("X-Accel-Buffering", "no")

	flusher, ok := w.(http.Flusher)
	if !ok {
		http.Error(w, "stream unsupported", http.StatusInternalServerError)
		return
	}

	ch := make(chan []byte, 1)
	app.Broker.add <- ch
	defer func() { app.Broker.remove <- ch }()

	// open the stream
	w.Write([]byte(":ok\n\n"))
	flusher.Flush()

	ticker := time.NewTicker(15 * time.Second)
	defer ticker.Stop()

	for {
		select {
		case <-r.Context().Done():
			log.Println("SSE client disconnected")
			return
		case msg := <-ch:
			log.Printf("SSE send: %s", string(msg))
			w.Write([]byte("data: "))
			w.Write(msg)
			w.Write([]byte("\n\n"))
			flusher.Flush()
		case <-ticker.C:
			// log.Println("SSE heartbeat -> :ping")
			w.Write([]byte(":ping\n\n"))
			flusher.Flush()
		}
	}
}

// Get User's information and Role
func (app *App) HandleWhoAmI(w http.ResponseWriter, r *http.Request) {
	username, err := usernameFromJWT(r)
	if err != nil || username == "" {
		http.Error(w, "unauthorized", http.StatusUnauthorized)
		return
	}

	role, err := app.getUserRole(username)
	if err != nil {
		http.Error(w, "db error", http.StatusInternalServerError)
		return
	}

	writeJSON(w, map[string]any{
		"username": username,
		"role":     role,
	})
}