// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT License.
// See the LICENSE file in the project root for more information. 

<#@ template debug="false" hostspecific="false" language="C#" #>
<#@ assembly name="$(ProjectDir)\..\System.Linq.Async\bin\$(Configuration)\net46\System.Threading.Tasks.Extensions.dll" #>
<#@ assembly name="$(ProjectDir)\..\System.Linq.Async\bin\$(Configuration)\net46\System.Linq.Async.dll" #>
<#@ assembly name="System.Core" #>
<#@ assembly name="System.Runtime" #>
<#@ import namespace="System.Collections.Generic" #>
<#@ import namespace="System.Linq" #>
<#@ import namespace="System.Reflection" #>
<#@ output extension=".cs" #>
<#
Func<Type, string> toCSharp = null;
toCSharp = t =>
{
    if (t.IsGenericType)
    {
        var def = t.GetGenericTypeDefinition();
        if (def == typeof(Nullable<>))
        {
            return toCSharp(t.GetGenericArguments()[0]) + "?";
        }
        else
        {
            return def.Name.Substring(0, def.Name.IndexOf('`')) + "<" + string.Join(", ", t.GetGenericArguments().Select(toCSharp)) + ">";
        }
    }
    else if (t.IsArray)
    {
        return toCSharp(t.GetElementType()) + "[]";
    }
    else
    {
        if (t == typeof(int))
        {
            return "int";
        }
        else if (t == typeof(long))
        {
            return "long";
        }
        else if (t == typeof(float))
        {
            return "float";
        }
        else if (t == typeof(double))
        {
            return "double";
        }
        else if (t == typeof(decimal))
        {
            return "decimal";
        }
        else if (t == typeof(bool))
        {
            return "bool";
        }
        else if (t == typeof(object))
        {
            return "object";
        }

        return t.Name;
    }
};

Func<ParameterInfo, string> getOptionalSuffix = p =>
{
    if (p.IsOptional)
    {
        return " = default";
    }

    return "";
};
#>
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;

namespace System.Linq
{
    partial class AsyncEnumerable
    {
<#
var methods = typeof(AsyncEnumerable).GetMethods(BindingFlags.NonPublic | BindingFlags.Static);
var asyncMethods = methods.Where(m => m.Name.Contains("Await") && m.Name.EndsWith("Core")).OrderBy(m => m.Name).ThenBy(m => m.GetParameters().Length);
#>
#if SUPPORT_FLAT_ASYNC_API
<#
foreach (var g in asyncMethods.GroupBy(m => m.Name.Contains("WithCancellation")))
{
    if (g.Key)
    {
#>

#if !NO_DEEP_CANCELLATION
<#
    }

    foreach (var m in g)
    {
        var longName = m.Name;
        var shortName = m.Name.Replace("WithCancellation", "").Replace("Await", "").Replace("Core", "");
        var genArgs = m.IsGenericMethod ? "<" + string.Join(", ", m.GetGenericArguments().Select(t => t.Name)) + ">" : "";
        var returnType = toCSharp(m.ReturnType);
        var isExtension = m.IsDefined(typeof(System.Runtime.CompilerServices.ExtensionAttribute), true);
        var pars = (isExtension ? "this " : "") + string.Join(", ", m.GetParameters().Select(p => toCSharp(p.ParameterType) + " " + p.Name + getOptionalSuffix(p)));
        var args = string.Join(", ", m.GetParameters().Select(p => p.Name));
        var cons = m.Name.StartsWith("ToDictionary") ? " where TKey : notnull" : "";
#>
        public static <#=returnType#> <#=shortName#><#=genArgs#>(<#=pars#>)<#=cons#> => <#=longName#><#=genArgs#>(<#=args#>);
<#
    }

    if (g.Key)
    {
#>
#endif
<#
    }
}
#>
#else
<#
foreach (var g in asyncMethods.GroupBy(m => m.Name.Contains("WithCancellation")))
{
    if (g.Key)
    {
#>

#if !NO_DEEP_CANCELLATION
<#
    }

    foreach (var m in g)
    {
        var longName = m.Name;
        var shortName = m.Name.Replace("Core", "");
        var genArgs = m.IsGenericMethod ? "<" + string.Join(", ", m.GetGenericArguments().Select(t => t.Name)) + ">" : "";
        var returnType = toCSharp(m.ReturnType);
        var isExtension = m.IsDefined(typeof(System.Runtime.CompilerServices.ExtensionAttribute), true);
        var pars = (isExtension ? "this " : "") + string.Join(", ", m.GetParameters().Select(p => toCSharp(p.ParameterType) + " " + p.Name + getOptionalSuffix(p)));
        var args = string.Join(", ", m.GetParameters().Select(p => p.Name));
        var cons = m.Name.StartsWith("ToDictionary") ? " where TKey : notnull" : "";
#>
        public static <#=returnType#> <#=shortName#><#=genArgs#>(<#=pars#>)<#=cons#> => <#=longName#><#=genArgs#>(<#=args#>);
<#
    }

    if (g.Key)
    {
#>
#endif
<#
    }
}
#>
#endif
    }
}