package cognitoauth

import (
	"context"
	"fmt"
	"net/http"
	"os"

	"queryorchestration/internal/serviceconfig/auth"

	"strings"

	"github.com/labstack/echo/v4"
	"github.com/lestrrat-go/jwx/v2/jwt"
)

// RegisterRoutes registers all authentication-related routes to the Echo engine.
// It configures login and callback endpoints, and applies JWT authentication middleware.
// If the DISABLE_AUTH environment variable is set to "true", authentication is bypassed.
//
// Parameters:
//   - e: The Echo instance to register routes on
//   - config: Configuration provider for authentication settings
func RegisterRoutes(e *echo.Echo, config auth.ConfigProvider) {
	// check the auth feature flag
	fmt.Println("Registering routes for Auth.")
	disableAuth := os.Getenv("DISABLE_AUTH")
	if strings.ToLower(disableAuth) == "true" {
		fmt.Println("Auth is disabled. Skipping auth routes.")
		return // Do nothing if auth is not enabled
	}

	// Register the login route - the middleware will handle this
	e.GET(config.GetAuthLoginPath(), func(c echo.Context) error {
		// This is handled by the middleware
		return nil
	})

	// Register callback route - the middleware will handle this
	e.GET(config.GetAuthCallbackPath(), func(c echo.Context) error {
		// This handler will only be called for requests that don't have a code parameter
		// (those are handled directly in the middleware)

		// Get user info from context
		userClaims, _ := c.Get("user_claims").(map[string]interface{})
		userGroups, _ := c.Get("user_groups").([]string)

		return c.JSON(http.StatusOK, map[string]interface{}{
			"authenticated": true,
			"username":      userClaims["cognito:username"],
			"email":         userClaims["email"],
			"groups":        userGroups,
		})
	})

	// Apply the JWT Auth middleware first
	e.Use(JWTAuthMiddleware(config))

	// Then apply the token validation middleware
	e.Use(TokenValidationMiddleware(config))
}

// GetTokenFromRequest extracts the JWT token from the HTTP request.
// It first attempts to retrieve the token from the Authorization header
// in Bearer token format. If not found, it then tries to retrieve the token
// from the "auth_token" cookie. Returns an empty string if no token is found.
//
// Parameters:
//   - c: The Echo context containing the HTTP request
//
// Returns:
//   - string: The extracted JWT token, or an empty string if not found
func GetTokenFromRequest(c echo.Context) string {
	// First try from Authorization header
	authHeader := c.Request().Header.Get("Authorization")
	if authHeader != "" && strings.HasPrefix(authHeader, "Bearer ") {
		return authHeader[7:]
	}

	// Then try from cookie
	tokenCookie, err := c.Cookie("auth_token")
	if err == nil && tokenCookie.Value != "" {
		return tokenCookie.Value
	}

	return ""
}

// GetUserInfo retrieves user information from the Echo context.
// It first attempts to retrieve user info directly from the context.
// If not found there, it tries to extract and parse the JWT token,
// then extract user information from the token claims.
//
// Parameters:
//   - c: The Echo context containing the HTTP request and context values
//
// Returns:
//   - UserInfo: Structure containing username, email, and groups
//   - bool: True if user information was successfully retrieved, false otherwise
func GetUserInfo(c echo.Context) (UserInfo, bool) {
	// Try to get user info from context
	userInfo, ok := c.Get("user_info").(UserInfo)
	if ok {
		return userInfo, true
	}

	// Try to get token and extract user info
	token := GetTokenFromRequest(c)
	if token == "" {
		return UserInfo{}, false
	}

	// Parse token to extract claims
	parsedToken, err := jwt.Parse([]byte(token), jwt.WithVerify(false))
	if err != nil {
		return UserInfo{}, false
	}

	claims, err := parsedToken.AsMap(context.Background())
	if err != nil {
		return UserInfo{}, false
	}

	// Extract user info
	userInfo = ExtractUserInfo(claims)
	return userInfo, true
}

// RequireGroups creates a middleware that enforces group-based authorization.
// It checks if the authenticated user belongs to at least one of the specified groups.
// If the user is not authenticated, it returns a 401 Unauthorized response.
// If the user is authenticated but doesn't belong to any of the required groups,
// it returns a 403 Forbidden response with detailed information.
//
// Parameters:
//   - groups: Variable number of group names that grant access
//
// Returns:
//   - echo.MiddlewareFunc: Middleware function for Echo framework
func RequireGroups(groups ...string) echo.MiddlewareFunc {
	return func(next echo.HandlerFunc) echo.HandlerFunc {
		return func(c echo.Context) error {
			userInfo, ok := GetUserInfo(c)
			if !ok {
				return c.JSON(http.StatusUnauthorized, map[string]string{
					"error": "Authentication required",
				})
			}

			// Check if user has any of the required groups
			for _, requiredGroup := range groups {
				for _, userGroup := range userInfo.Groups {
					if userGroup == requiredGroup {
						return next(c)
					}
				}
			}

			return c.JSON(http.StatusForbidden, map[string]interface{}{
				"error":           "Insufficient permissions",
				"message":         "User doesn't have the required group membership",
				"username":        userInfo.Username,
				"groups":          userInfo.Groups,
				"required_groups": groups,
			})
		}
	}
}