package handlers

import (
	"net/http"
	"os"
	"strings"
	"time"

	"git.keircn.com/keiran/termbox/internal/db"
	"git.keircn.com/keiran/termbox/internal/email"
	"github.com/golang-jwt/jwt/v5"
	"github.com/labstack/echo/v4"
)

var emailService *email.Service

func InitEmailService() {
	emailService = email.NewService()
}

func generateToken(userID int, username string) (string, error) {
	claims := jwt.MapClaims{
		"user_id":  userID,
		"username": username,
		"exp":      time.Now().Add(time.Hour * 24 * 7).Unix(),
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString([]byte(os.Getenv("JWT_SECRET")))
}

func HandleRoot(c echo.Context) error {
	return c.String(http.StatusOK, "Hello, World!")
}

func HandleRegister(c echo.Context) error {
	if err := db.CleanupUnverifiedUsers(c.Request().Context()); err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to cleanup old accounts"})
	}

	var req db.CreateUserRequest
	if err := c.Bind(&req); err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "Invalid request body"})
	}

	if req.Username == "" || req.Email == "" || req.Password == "" {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "Username, email, and password are required"})
	}

	user, err := db.CreateUser(c.Request().Context(), req)
	if err != nil {
		if strings.Contains(err.Error(), "duplicate") || strings.Contains(err.Error(), "unique") {
			return c.JSON(http.StatusConflict, map[string]string{"error": "Username or email already exists"})
		}
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to create user: " + err.Error()})
	}

	verificationCode, err := db.CreateVerificationCode(c.Request().Context(), user.ID)
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to create verification code"})
	}

	err = emailService.SendVerificationCode(c.Request().Context(), user.Email, user.Username, verificationCode.Code)
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to send verification email"})
	}

	return c.JSON(http.StatusCreated, map[string]any{
		"message": "User created successfully. Please check your email for verification code.",
		"user":    user,
	})
}

func HandleVerifyCode(c echo.Context) error {
	var req db.VerifyCodeRequest
	if err := c.Bind(&req); err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "Invalid request body"})
	}

	if req.Email == "" || req.Code == "" {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "Email and code are required"})
	}

	err := db.VerifyCode(c.Request().Context(), req.Email, req.Code)
	if err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": err.Error()})
	}

	return c.JSON(http.StatusOK, map[string]string{"message": "Account verified successfully"})
}

func HandleLogin(c echo.Context) error {
	var req db.LoginRequest
	if err := c.Bind(&req); err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "Invalid request body"})
	}

	if req.Username == "" || req.Password == "" {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "Username and password are required"})
	}

	user, err := db.ValidateUserCredentials(c.Request().Context(), req.Username, req.Password)
	if err != nil {
		return c.JSON(http.StatusUnauthorized, map[string]string{"error": "Invalid credentials or account not verified"})
	}

	token, err := generateToken(user.ID, user.Username)
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to generate token"})
	}

	return c.JSON(http.StatusOK, map[string]any{
		"message": "Login successful",
		"user":    user,
		"token":   token,
	})
}