package app

import (
	"context"
	"errors"

	"net/http"

	"git.farahty.com/nimer/go-mongo/models"
	"git.farahty.com/nimer/go-mongo/utils"
	"github.com/99designs/gqlgen/graphql"
	"github.com/golang-jwt/jwt/v4"
)

// Middleware injects dataloaders into context for each HTTP request
func LoaderMiddleware(loaders *Loaders, next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		ctxWithLoaders := context.WithValue(r.Context(), LoadersKey, loaders)
		next.ServeHTTP(w, r.WithContext(ctxWithLoaders))
	})
}

// ExpiryMiddleware checks for expired tokens in GraphQL resolvers
func ExpiryMiddleware(ctx context.Context, next graphql.ResponseHandler) *graphql.Response {

	if IsTokenExpired(ctx) {
		return graphql.ErrorResponse(ctx, "token expired")
	}
	return next(ctx)
}

// add response writer to context for GraphQL resolvers
func WriterMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
		ctx := context.WithValue(r.Context(), WriterKye, &rw)
		next.ServeHTTP(rw, r.WithContext(ctx))
	})
}

// add request to context for GraphQL resolvers
func RequestMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
		ctx := context.WithValue(r.Context(), RequestKey, r)
		next.ServeHTTP(rw, r.WithContext(ctx))
	})
}

// AuthMiddleware parses JWT token and injects user context for HTTP requests
func AuthMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {

		headerToken, headerErr := utils.GetTokenFromHeader(r)
		cookieToken, cookieErr := utils.GetTokenFromCookie(r)

		if headerErr != nil && cookieErr != nil {
			ctx := SetStatus(r.Context(), headerErr.Error())
			next.ServeHTTP(rw, r.WithContext(ctx))
			return
		}

		token := headerToken
		if token == "" {
			token = cookieToken
		}

		user, err := utils.GetUserFromToken[models.UserJWT](token, Config.AccessSecret)
		ctx := r.Context()

		if err != nil {
			ctx = SetStatus(ctx, err.Error())
			if errors.Is(err, jwt.ErrTokenExpired) {
				ctx = SetTokenExpired(ctx, true)
			}
			next.ServeHTTP(rw, r.WithContext(ctx))
			return
		}

		ctx = SetCurrentUser(ctx, user)
		ctx = SetStatus(ctx, "ok")
		next.ServeHTTP(rw, r.WithContext(ctx))
	})
}