package handlers

import (
	"bookhoard/internal/database"
	"context"
	"errors"
	"fmt"
	"net/http"
	"time"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgtype"
	"github.com/labstack/echo/v5"
)

type RefreshTokenRequest struct {
	RefreshToken string `json:"refresh_token" validate:"required"`
}

func parseTokenUUID(tokenStr string) (pgtype.UUID, error) {
	tokenUUID, err := uuid.Parse(tokenStr)
	if err != nil {
		return pgtype.UUID{}, err
	}
	return pgtype.UUID{Bytes: tokenUUID, Valid: true}, nil
}

type RefreshTokenResponse struct {
	AccessToken string `json:"access_token"`
	TokenType   string `json:"token_type"`
	ExpiresIn   int    `json:"expires_in"` // seconds
}

// RefreshAccessToken handles POST /api/auth/refresh
func (h *AuthHandler) RefreshAccessToken(c *echo.Context) error {
	var req RefreshTokenRequest
	if err := c.Bind(&req); err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid request"})
	}
	if err := c.Validate(&req); err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": err.Error()})
	}

	tokenUUID, err := parseTokenUUID(req.RefreshToken)
	if err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid refresh token format"})
	}

	tokenInfo, err := h.db.GetRefreshToken(c.Request().Context(), tokenUUID)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return c.JSON(http.StatusUnauthorized, map[string]string{"error": "invalid or expired refresh token"})
		}
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to validate refresh token"})
	}

	accessToken, err := h.generateJWTWithAllClaims(
		uuid.UUID(tokenInfo.UserID.Bytes).String(),
		tokenInfo.Role,
		tokenInfo.Email,
		tokenInfo.Username,
	)
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to generate access token"})
	}

	return c.JSON(http.StatusOK, RefreshTokenResponse{
		AccessToken: accessToken,
		TokenType:   "Bearer",
		ExpiresIn:   int(h.refreshTokenTTL().Seconds()),
	})
}

// Logout handles POST /api/auth/logout
func (h *AuthHandler) Logout(c *echo.Context) error {
	var req RefreshTokenRequest
	if err := c.Bind(&req); err != nil {
		return c.JSON(http.StatusOK, map[string]string{"message": "logged out successfully"})
	}

	tokenUUID, err := parseTokenUUID(req.RefreshToken)
	if err != nil {
		return c.JSON(http.StatusOK, map[string]string{"message": "logged out successfully"})
	}

	err = h.db.RevokeRefreshToken(c.Request().Context(), tokenUUID)
	if err != nil && !errors.Is(err, pgx.ErrNoRows) {
		return c.JSON(http.StatusInternalServerError, map[string]string{"error": "failed to revoke refresh token"})
	}

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

// CreateRefreshToken creates a new refresh token for a user
func (h *AuthHandler) CreateRefreshToken(userID uuid.UUID) (string, string, error) {
	tokenUUID := uuid.New()
	refreshToken := tokenUUID.String()

	expiresAt := time.Now().Add(h.refreshTokenTTL())
	_, err := h.db.CreateRefreshToken(context.Background(), database.CreateRefreshTokenParams{
		UserID:    pgtype.UUID{Bytes: userID, Valid: true},
		Token:     pgtype.UUID{Bytes: tokenUUID, Valid: true},
		ExpiresAt: pgtype.Timestamptz{Time: expiresAt, Valid: true},
	})
	if err != nil {
		fmt.Printf("ERROR storing refresh token: %v\n", err)
		return "", "", err
	}
	fmt.Printf("DEBUG: refreshToken generated: '%s'\n", refreshToken)

	accessToken, err := h.generateJWT(userID.String())
	if err != nil {
		return "", "", err
	}

	return accessToken, refreshToken, nil
}