package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"os"
	"time"

	_ "github.com/go-sql-driver/mysql"
)

// RecoveryMiddleware catches panics and returns 500
func RecoveryMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		defer func() {
			if err := recover(); err != nil {
				log.Printf("[PANIC] %v", err)
				http.Error(w, "Internal Server Error", http.StatusInternalServerError)
			}
		}()
		next.ServeHTTP(w, r)
	})
}

// getStepManager creates a new StepManager for the given user, loading state from DB
func getStepManager(userID string) *StepManager {
	return NewStepManager(userID)
}

func initTimezone() {
	tz := os.Getenv("TZ")
	if tz != "" {
		loc, err := time.LoadLocation(tz)
		if err != nil {
			log.Printf("Error loading timezone %s: %v. Using UTC.", tz, err)
			return
		}
		time.Local = loc
		log.Printf("Timezone set to %s", tz)
	} else {
		log.Printf("TZ environment variable not set, using system default (usually UTC)")
	}
	log.Printf("Current system time: %s", time.Now().Format(time.RFC1123Z))
}

func main() {
	// Initialize components
	initTimezone()
	InitDB()
	InitFitbit()

	// 1. Serve Static Files (Frontend)
	fs := http.FileServer(http.Dir("frontend"))
	http.Handle("/", fs)

	// 2. API Endpoints (all require authentication)
	http.HandleFunc("/api/status", RequireAuth(func(w http.ResponseWriter, r *http.Request) {
		userID, _ := getUserID(r.Context())
		sm := getStepManager(userID)

		status := sm.GetStatus()

		// Add user info to status
		user, err := GetUser(userID)
		if err == nil && user != nil {
			status["user"] = map[string]string{
				"displayName": user.DisplayName,
				"avatarUrl":   user.AvatarURL,
			}
		} else {
			fmt.Printf("[API Status] WARNING: User info not found for ID: %s (err=%v)\n", userID, err)
		}

		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(status)
	}))

	http.HandleFunc("/api/refresh", RequireAuth(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost {
			http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
			return
		}

		userID, _ := getUserID(r.Context())
		sm := getStepManager(userID)
		sm.Sync()
		w.WriteHeader(http.StatusOK)
	}))

	http.HandleFunc("/api/trip", RequireAuth(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost {
			http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
			return
		}

		userID, _ := getUserID(r.Context())
		sm := getStepManager(userID)
		sm.StartNewTrip()
		w.WriteHeader(http.StatusOK)
	}))

	http.HandleFunc("/api/drain", RequireAuth(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost {
			http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
			return
		}

		userID, _ := getUserID(r.Context())
		sm := getStepManager(userID)
		go sm.Drain() // Async so we don't block
		w.WriteHeader(http.StatusOK)
	}))

	// 3. KML Management Endpoints
	http.HandleFunc("/api/kml/upload", RequireAuth(HandleKMLUpload))
	http.HandleFunc("/api/kml/list", RequireAuth(HandleKMLList))
	http.HandleFunc("/api/kml/privacy", RequireAuth(HandleKMLPrivacyToggle))
	http.HandleFunc("/api/kml/vote", RequireAuth(HandleKMLVote))
	http.HandleFunc("/api/kml/delete", RequireAuth(HandleKMLDelete))
	http.HandleFunc("/api/kml/download", RequireAuth(HandleKMLDownload))

	// 4. Fitbit OAuth Endpoints
	http.HandleFunc("/auth/fitbit", HandleFitbitAuth)
	http.HandleFunc("/auth/callback", HandleFitbitCallback)

	// 5. Logout Endpoint
	http.HandleFunc("/auth/logout", func(w http.ResponseWriter, r *http.Request) {
		session, err := GetSessionFromRequest(r)
		if err == nil {
			DeleteSession(session.Token)
		}
		ClearSessionCookie(w)
		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
	})

	// 6. Start Server
	binding := "0.0.0.0:8080"
	fmt.Printf("Server starting on http://%s\n", binding)
	log.Fatal(http.ListenAndServe(binding, RecoveryMiddleware(http.DefaultServeMux)))
}