package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"os"
	"time"
	"wishlify/auth"
	"wishlify/model"
	"wishlify/router"

	"github.com/google/uuid"
	"golang.org/x/crypto/bcrypt"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
)

func main() {
	dbPath := os.Getenv("DB_PATH")
	if dbPath == "" {
		dbPath = "./sqlite.db"
	}

	db, err := gorm.Open(sqlite.Open("./sqlite.db"))
	if err != nil {
		log.Fatalf("failed to connect to db: %v\n", err)
	}

	if err := db.AutoMigrate(&model.User{}, &model.Wishlist{}); err != nil {
		log.Fatalf("failed to migrate db: %v\n", err)
	}

	router := router.New()

	router.Handle("POST /auth/register", func(w http.ResponseWriter, r *http.Request) error {
		var body struct {
			Email    string `json:"email"`
			Login    string `json:"login"`
			Password string `json:"password"`
		}
		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
			w.WriteHeader(500)
			return fmt.Errorf("failed to decode request body: %v", err)
		}

		if body.Email == "" || body.Login == "" || body.Password == "" {
			w.WriteHeader(400)
			return fmt.Errorf("invalid request; email, login and password are required")
		}

		hash, err := bcrypt.GenerateFromPassword([]byte(body.Password), 10)
		if err != nil {
			w.WriteHeader(500)
			return fmt.Errorf("failed to generate password hash: %v", err)
		}

		user := &model.User{
			Email:    body.Email,
			Login:    body.Login,
			Password: string(hash),
		}
		if tx := db.Create(user); tx.Error != nil {
			w.WriteHeader(400)
			return fmt.Errorf("failed to create user: %v", tx.Error)
		}

		expiryTime := time.Now().Add(time.Hour * 24 * 7)
		token, err := auth.GenerateUserToken(user.ID, expiryTime)
		if err != nil {
			w.WriteHeader(500)
			return fmt.Errorf("failed to generate jwt: %v", err)
		}

		auth.SetUserCookie(w, token, expiryTime)

		w.WriteHeader(201)
		return router.SendJSON(w, user)
	})

	router.Handle("POST /auth/login", func(w http.ResponseWriter, r *http.Request) error {
		var body struct {
			Login    string `json:"login"`
			Password string `json:"password"`
		}
		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
			w.WriteHeader(400)
			return fmt.Errorf("failed to decode request body: %v", err)
		}

		if body.Login == "" || body.Password == "" {
			w.WriteHeader(400)
			return fmt.Errorf("invalid request; login and password are required")
		}

		user := &model.User{}
		if tx := db.First(user, "login = ?", body.Login); tx.Error != nil {
			w.WriteHeader(404)
			return fmt.Errorf("user not found: %v", tx.Error)
		}

		if err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(body.Password)); err != nil {
			w.WriteHeader(400)
			return fmt.Errorf("invalid password: %v", err)
		}

		expiryTime := time.Now().Add(time.Hour * 24 * 7)
		token, err := auth.GenerateUserToken(user.ID, expiryTime)
		if err != nil {
			w.WriteHeader(500)
			return fmt.Errorf("failed to generate jwt: %v", err)
		}

		auth.SetUserCookie(w, token, expiryTime)

		w.WriteHeader(200)
		return router.SendJSON(w, user)
	})

	router.Handle("POST /auth/logout", func(w http.ResponseWriter, r *http.Request) error {
		auth.RemoveUserCookie(w)
		w.WriteHeader(200)
		return router.SendJSON(w, struct {
			Ok bool `json:"ok"`
		}{true})
	})

	router.Handle("GET /user", func(w http.ResponseWriter, r *http.Request) error {
		userId, err := auth.GetUserIdFromRequest(r)
		if err != nil {
			w.WriteHeader(401)
			return fmt.Errorf("unauthorized: %v", err)
		}

		user := &model.User{}
		if tx := db.First(user, "id = ?", userId); tx.Error != nil {
			w.WriteHeader(404)
			return fmt.Errorf("user not found: %v", tx.Error)
		}

		return router.SendJSON(w, user)
	})

	router.Handle("GET /user/wishlists", func(w http.ResponseWriter, r *http.Request) error {
		userId, err := auth.GetUserIdFromRequest(r)
		if err != nil {
			w.WriteHeader(401)
			return fmt.Errorf("unauthorized: %v", err)
		}

		wishlists := []model.Wishlist{}
		if tx := db.Find(&wishlists, "user_id = ?", userId); tx.Error != nil {
			w.WriteHeader(404)
			return fmt.Errorf("no wishlists found: %v", err)
		}

		w.WriteHeader(200)
		return router.SendJSON(w, wishlists)
	})

	router.Handle("POST /user/wishlists", func(w http.ResponseWriter, r *http.Request) error {
		userId, err := auth.GetUserIdFromRequest(r)
		if err != nil {
			w.WriteHeader(401)
			return fmt.Errorf("unauthorized: %v", err)
		}

		var body struct {
			Name        string `json:"name"`
			Description string `json:"description"`
		}
		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
			w.WriteHeader(400)
			return fmt.Errorf("failed to decode request body: %v", err)
		}

		if body.Name == "" {
			w.WriteHeader(400)
			return fmt.Errorf("invalid request; name is required")
		}

		uid, err := uuid.NewV7()
		if err != nil {
			w.WriteHeader(500)
			return fmt.Errorf("failed to generate uuid for new wishlist: %v", err)
		}

		wishlist := &model.Wishlist{
			UUID:        uid.String(),
			Name:        body.Name,
			Description: body.Description,
			UserID:      userId,
		}
		if tx := db.Create(wishlist); tx.Error != nil {
			w.WriteHeader(500)
			return fmt.Errorf("failed to create wishlist: %v", tx.Error)
		}

		return router.SendJSON(w, wishlist)
	})

	router.Handle("GET /wishlists/{uid}", func(w http.ResponseWriter, r *http.Request) error {
		uid := r.PathValue("uid")

		wishlist := &model.Wishlist{}
		if tx := db.First(wishlist, "uuid = ?", uid); tx.Error != nil {
			w.WriteHeader(404)
			return fmt.Errorf("wishlist not found: %v", tx.Error)
		}

		w.WriteHeader(200)
		return router.SendJSON(w, wishlist)
	})

	router.Handle("DELETE /user/wishlists/{uid}", func(w http.ResponseWriter, r *http.Request) error {
		userId, err := auth.GetUserIdFromRequest(r)
		if err != nil {
			w.WriteHeader(401)
			return fmt.Errorf("unauthorized: %v", err)
		}

		uid := r.PathValue("uid")

		if tx := db.Delete(&model.Wishlist{}, "uuid = ? AND user_id = ?", uid, userId); tx.Error != nil {
			w.WriteHeader(404)
			return fmt.Errorf("failed to delete wishlist: %v", tx.Error)
		}

		return router.SendJSON(w, struct {
			Ok bool `json:"ok"`
		}{true})
	})

	log.Println("starting http server")
	if err := http.ListenAndServe(":5000", router.Mux()); err != nil {
		log.Fatalf("failed to start http server: %v\n", err)
	}
}