// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Diagnostics;
using System.Linq;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Abstractions;
using Microsoft.AspNetCore.Mvc.Infrastructure;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.Routing;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
 
namespace Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure;
 
internal sealed class PageRequestDelegateFactory : IRequestDelegateFactory
{
    private readonly PageActionInvokerCache _cache;
    private readonly IReadOnlyList<IValueProviderFactory> _valueProviderFactories;
    private readonly IModelMetadataProvider _modelMetadataProvider;
    private readonly ITempDataDictionaryFactory _tempDataFactory;
    private readonly MvcViewOptions _mvcViewOptions;
    private readonly IPageHandlerMethodSelector _selector;
    private readonly DiagnosticListener _diagnosticListener;
    private readonly ILogger<PageActionInvoker> _logger;
    private readonly IActionResultTypeMapper _mapper;
    private readonly IActionContextAccessor _actionContextAccessor;
    private readonly bool _enableActionInvokers;
 
    public PageRequestDelegateFactory(
        PageActionInvokerCache cache,
        IModelMetadataProvider modelMetadataProvider,
        ITempDataDictionaryFactory tempDataFactory,
        IOptions<MvcOptions> mvcOptions,
        IOptions<MvcViewOptions> mvcViewOptions,
        IPageHandlerMethodSelector selector,
        DiagnosticListener diagnosticListener,
        ILoggerFactory loggerFactory,
        IActionResultTypeMapper mapper)
        : this(cache, modelMetadataProvider, tempDataFactory, mvcOptions, mvcViewOptions, selector, diagnosticListener, loggerFactory, mapper, null)
    {
    }
 
    public PageRequestDelegateFactory(
        PageActionInvokerCache cache,
        IModelMetadataProvider modelMetadataProvider,
        ITempDataDictionaryFactory tempDataFactory,
        IOptions<MvcOptions> mvcOptions,
        IOptions<MvcViewOptions> mvcViewOptions,
        IPageHandlerMethodSelector selector,
        DiagnosticListener diagnosticListener,
        ILoggerFactory loggerFactory,
        IActionResultTypeMapper mapper,
        IActionContextAccessor? actionContextAccessor)
    {
        _cache = cache;
        _valueProviderFactories = mvcOptions.Value.ValueProviderFactories.ToArray();
        _modelMetadataProvider = modelMetadataProvider;
        _tempDataFactory = tempDataFactory;
        _mvcViewOptions = mvcViewOptions.Value;
        _enableActionInvokers = mvcOptions.Value.EnableActionInvokers;
        _selector = selector;
        _diagnosticListener = diagnosticListener;
        _logger = loggerFactory.CreateLogger<PageActionInvoker>();
        _mapper = mapper;
        _actionContextAccessor = actionContextAccessor ?? ActionContextAccessor.Null;
    }
 
    public RequestDelegate? CreateRequestDelegate(ActionDescriptor actionDescriptor, RouteValueDictionary? dataTokens)
    {
        if (_enableActionInvokers || actionDescriptor is not CompiledPageActionDescriptor page)
        {
            return null;
        }
 
        // Compiled pages are the only ones that run
 
        return context =>
        {
            RouteData? routeData = null;
 
            if (dataTokens is null or { Count: 0 })
            {
                routeData = new RouteData(context.Request.RouteValues);
            }
            else
            {
                routeData = new RouteData();
                routeData.PushState(router: null, context.Request.RouteValues, dataTokens);
            }
 
            var pageContext = new PageContext(context, routeData, page);
 
            var (cacheEntry, filters) = _cache.GetCachedResult(pageContext);
 
            pageContext.ValueProviderFactories = new CopyOnWriteList<IValueProviderFactory>(_valueProviderFactories);
            pageContext.ViewData = cacheEntry.ViewDataFactory(_modelMetadataProvider, pageContext.ModelState);
            pageContext.ViewStartFactories = cacheEntry.ViewStartFactories.ToList();
 
            var pageInvoker = new PageActionInvoker(
                _selector,
                _diagnosticListener,
                _logger,
                _actionContextAccessor,
                _mapper,
                pageContext,
                filters,
                cacheEntry,
                _tempDataFactory,
                _mvcViewOptions.HtmlHelperOptions);
 
            return pageInvoker.InvokeAsync();
        };
    }
}