// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Microsoft.AspNetCore.Builder.Extensions;
using Microsoft.AspNetCore.Http;
 
namespace Microsoft.AspNetCore.Builder;
 
/// <summary>
/// Extension methods for the <see cref="MapMiddleware"/>.
/// </summary>
public static class MapExtensions
{
    /// <summary>
    /// Branches the request pipeline based on matches of the given request path. If the request path starts with
    /// the given path, the branch is executed.
    /// </summary>
    /// <param name="app">The <see cref="IApplicationBuilder"/> instance.</param>
    /// <param name="pathMatch">The request path to match.</param>
    /// <param name="configuration">The branch to take for positive path matches.</param>
    /// <returns>The <see cref="IApplicationBuilder"/> instance.</returns>
    public static IApplicationBuilder Map(this IApplicationBuilder app, string pathMatch, Action<IApplicationBuilder> configuration)
    {
        return Map(app, pathMatch, preserveMatchedPathSegment: false, configuration);
    }
 
    /// <summary>
    /// Branches the request pipeline based on matches of the given request path. If the request path starts with
    /// the given path, the branch is executed.
    /// </summary>
    /// <param name="app">The <see cref="IApplicationBuilder"/> instance.</param>
    /// <param name="pathMatch">The request path to match.</param>
    /// <param name="configuration">The branch to take for positive path matches.</param>
    /// <returns>The <see cref="IApplicationBuilder"/> instance.</returns>
    public static IApplicationBuilder Map(this IApplicationBuilder app, PathString pathMatch, Action<IApplicationBuilder> configuration)
    {
        return Map(app, pathMatch, preserveMatchedPathSegment: false, configuration);
    }
 
    /// <summary>
    /// Branches the request pipeline based on matches of the given request path. If the request path starts with
    /// the given path, the branch is executed.
    /// </summary>
    /// <param name="app">The <see cref="IApplicationBuilder"/> instance.</param>
    /// <param name="pathMatch">The request path to match.</param>
    /// <param name="preserveMatchedPathSegment">if false, matched path would be removed from Request.Path and added to Request.PathBase.</param>
    /// <param name="configuration">The branch to take for positive path matches.</param>
    /// <returns>The <see cref="IApplicationBuilder"/> instance.</returns>
    public static IApplicationBuilder Map(this IApplicationBuilder app, PathString pathMatch, bool preserveMatchedPathSegment, Action<IApplicationBuilder> configuration)
    {
        ArgumentNullException.ThrowIfNull(app);
        ArgumentNullException.ThrowIfNull(configuration);
 
        if (pathMatch.HasValue && pathMatch.Value!.EndsWith('/'))
        {
            throw new ArgumentException("The path must not end with a '/'", nameof(pathMatch));
        }
 
        // create branch
        var branchBuilder = app.New();
        configuration(branchBuilder);
        var branch = branchBuilder.Build();
 
        var options = new MapOptions
        {
            Branch = branch,
            PathMatch = pathMatch,
            PreserveMatchedPathSegment = preserveMatchedPathSegment
        };
        return app.Use(next => new MapMiddleware(next, options).Invoke);
    }
}