// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.DependencyInjection;

namespace Microsoft.AspNetCore.Builder
{
    /// <summary>
    /// Provides extension methods for <see cref="IRouteBuilder"/> to add routes.
    /// </summary>
    public static class MapRouteRouteBuilderExtensions
    {
        /// <summary>
        /// Adds a route to the <see cref="IRouteBuilder"/> with the specified name and template.
        /// </summary>
        /// <param name="routeBuilder">The <see cref="IRouteBuilder"/> to add the route to.</param>
        /// <param name="name">The name of the route.</param>
        /// <param name="template">The URL pattern of the route.</param>
        /// <returns>A reference to this instance after the operation has completed.</returns>
        public static IRouteBuilder MapRoute(
            this IRouteBuilder routeBuilder,
            string name,
            string template)
        {
            MapRoute(routeBuilder, name, template, defaults: null);
            return routeBuilder;
        }

        /// <summary>
        /// Adds a route to the <see cref="IRouteBuilder"/> with the specified name, template, and default values.
        /// </summary>
        /// <param name="routeBuilder">The <see cref="IRouteBuilder"/> to add the route to.</param>
        /// <param name="name">The name of the route.</param>
        /// <param name="template">The URL pattern of the route.</param>
        /// <param name="defaults">
        /// An object that contains default values for route parameters. The object's properties represent the names
        /// and values of the default values.
        /// </param>
        /// <returns>A reference to this instance after the operation has completed.</returns>
        public static IRouteBuilder MapRoute(
            this IRouteBuilder routeBuilder,
            string name,
            string template,
            object defaults)
        {
            return MapRoute(routeBuilder, name, template, defaults, constraints: null);
        }

        /// <summary>
        /// Adds a route to the <see cref="IRouteBuilder"/> with the specified name, template, default values, and
        /// constraints.
        /// </summary>
        /// <param name="routeBuilder">The <see cref="IRouteBuilder"/> to add the route to.</param>
        /// <param name="name">The name of the route.</param>
        /// <param name="template">The URL pattern of the route.</param>
        /// <param name="defaults">
        /// An object that contains default values for route parameters. The object's properties represent the names
        /// and values of the default values.
        /// </param>
        /// <param name="constraints">
        /// An object that contains constraints for the route. The object's properties represent the names and values
        /// of the constraints.
        /// </param>
        /// <returns>A reference to this instance after the operation has completed.</returns>
        public static IRouteBuilder MapRoute(
            this IRouteBuilder routeBuilder,
            string name,
            string template,
            object defaults,
            object constraints)
        {
            return MapRoute(routeBuilder, name, template, defaults, constraints, dataTokens: null);
        }

        /// <summary>
        /// Adds a route to the <see cref="IRouteBuilder"/> with the specified name, template, default values, and
        /// data tokens.
        /// </summary>
        /// <param name="routeBuilder">The <see cref="IRouteBuilder"/> to add the route to.</param>
        /// <param name="name">The name of the route.</param>
        /// <param name="template">The URL pattern of the route.</param>
        /// <param name="defaults">
        /// An object that contains default values for route parameters. The object's properties represent the names
        /// and values of the default values.
        /// </param>
        /// <param name="constraints">
        /// An object that contains constraints for the route. The object's properties represent the names and values
        /// of the constraints.
        /// </param>
        /// <param name="dataTokens">
        /// An object that contains data tokens for the route. The object's properties represent the names and values
        /// of the data tokens.
        /// </param>
        /// <returns>A reference to this instance after the operation has completed.</returns>
        public static IRouteBuilder MapRoute(
            this IRouteBuilder routeBuilder,
            string name,
            string template,
            object defaults,
            object constraints,
            object dataTokens)
        {
            if (routeBuilder.DefaultHandler == null)
            {
                throw new RouteCreationException(Resources.FormatDefaultHandler_MustBeSet(nameof(IRouteBuilder)));
            }

            var inlineConstraintResolver = routeBuilder
                .ServiceProvider
                .GetRequiredService<IInlineConstraintResolver>();

            routeBuilder.Routes.Add(new Route(
                routeBuilder.DefaultHandler,
                name,
                template,
                new RouteValueDictionary(defaults),
                new RouteValueDictionary(constraints),
                new RouteValueDictionary(dataTokens),
                inlineConstraintResolver));

            return routeBuilder;
        }
    }
}