package auth

import (
	"time"

	"github.com/golang-jwt/jwt/v5"
	"github.com/google/uuid"
)

type Claims struct {
	UserID  uuid.UUID `json:"user_id"`
	Role    string    `json:"role"`
	Regioes []string  `json:"regioes"`
	jwt.RegisteredClaims
}

func GenerateAccessToken(userID uuid.UUID, role string, regioes []string, secret string, ttlMinutes int) (string, time.Time, error) {
	// Extend TTL to 30 days specifically for RESEARCHER role to prevent session drop
	if role == "RESEARCHER" {
		ttlMinutes = 30 * 24 * 60
	}

	expirationTime := time.Now().Add(time.Duration(ttlMinutes) * time.Minute)
	claims := &Claims{
		UserID:  userID,
		Role:    role,
		Regioes: regioes,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(expirationTime),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	tokenString, err := token.SignedString([]byte(secret))
	return tokenString, expirationTime, err
}

func ValidateToken(tokenString string, secret string) (*Claims, error) {
	claims := &Claims{}
	token, err := jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
		return []byte(secret), nil
	})

	if err != nil {
		return nil, err
	}

	if !token.Valid {
		return nil, jwt.ErrSignatureInvalid
	}

	return claims, nil
}

func GenerateRefreshToken(userID uuid.UUID, secret string, ttlDays int) (string, error) {
	// Simple refresh token generation (could be improved with DB storage/validation)
	// For now, let's use a long-lived JWT or just a random string if stored in DB.
	// Since we are storing it in DB (RefreshToken table), a random string is better.
	// But the service code I wrote earlier expects a string.
	// Let's generate a random UUID string.
	return uuid.New().String(), nil
}