/* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*
*  Licensed to Elasticsearch B.V. under one or more contributor
*  license agreements. See the NOTICE file distributed with
*  this work for additional information regarding copyright
*  ownership. Elasticsearch B.V. licenses this file to you under
*  the Apache License, Version 2.0 (the "License"); you may
*  not use this file except in compliance with the License.
*  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
*  Unless required by applicable law or agreed to in writing,
*  software distributed under the License is distributed on an
*  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
*  KIND, either express or implied.  See the License for the
*  specific language governing permissions and limitations
*  under the License.
*/

using System;
using System.Collections.Generic;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using ApiGenerator.Configuration;
using ApiGenerator.Domain;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using RazorLight;
using RazorLight.Generation;
using RazorLight.Razor;
using ShellProgressBar;

namespace ApiGenerator.Generator.Razor
{
    public abstract class RazorGeneratorBase
    {
        private static readonly RazorLightEngine Engine = new RazorLightEngineBuilder()
            .UseProject(new EmbeddedRazorProject(typeof(CodeTemplatePage<>).Assembly, "ApiGenerator.Views"))
			.SetOperatingAssembly(typeof(CodeTemplatePage<>).Assembly)
			.UseMemoryCachingProvider()
			.EnableDebugMode()
            .Build();

        protected async Task DoRazor<TModel>(TModel model, string viewLocation, string targetLocation, CancellationToken token)
        {
            try
            {
                token.ThrowIfCancellationRequested();
                var generated = await Engine.CompileRenderAsync(viewLocation,  model);
                WriteFormattedCsharpFile(targetLocation, generated);
            }
            catch (TemplateGenerationException e)
            {
                foreach (var d in e.Diagnostics) Console.WriteLine(d.GetMessage());
                throw;
            }
        }

        protected async Task DoRazorDependantFiles<TModel>(
            ProgressBar pbar, IReadOnlyCollection<TModel> items, string viewLocation,
            Func<TModel, string> identifier, Func<string, string> target,
            CancellationToken token
            )
        {
            using (var c = pbar.Spawn(items.Count, "Generating namespaces", new ProgressBarOptions
            {
                ProgressCharacter = '─',
                ForegroundColor = ConsoleColor.Yellow
            }))
            {
                foreach (var item in items)
                {
                    var id = identifier(item);
                    var targetLocation = target(id);
                    await DoRazor(item, viewLocation, targetLocation, token);
                    c.Tick($"{Title}: {id}");
                }
            }
        }

        protected static void WriteFormattedCsharpFile(string path, string contents)
        {
            var tree = CSharpSyntaxTree.ParseText(contents);
            var root = tree.GetRoot().NormalizeWhitespace(indentation:"\t", "\n");
            contents = root.ToFullString();

			if (Directory.GetParent(path) is { Exists: false } dir) dir.Create();

			File.WriteAllText(path, contents);
        }

        public abstract string Title { get; }
        public abstract Task Generate(RestApiSpec spec, ProgressBar progressBar, CancellationToken token);
    }
}