using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using BTCPayServer.Abstractions.Contracts;
using BTCPayServer.Configuration;
using BTCPayServer.Services;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace BTCPayServer.Plugins
{
    public class PluginService
    {
        private readonly IOptions<DataDirectories> _dataDirectories;
        private readonly PoliciesSettings _policiesSettings;
        private readonly PluginBuilderClient _pluginBuilderClient;
        public PluginService(
            IEnumerable<IBTCPayServerPlugin> btcPayServerPlugins,
            PluginBuilderClient pluginBuilderClient,
            IOptions<DataDirectories> dataDirectories,
            PoliciesSettings policiesSettings,
            BTCPayServerEnvironment env)
        {
            LoadedPlugins = btcPayServerPlugins;
            _pluginBuilderClient = pluginBuilderClient;
            _dataDirectories = dataDirectories;
            _policiesSettings = policiesSettings;
            Env = env;
        }

        public IEnumerable<IBTCPayServerPlugin> LoadedPlugins { get; }
        public BTCPayServerEnvironment Env { get; }
        
        public Version GetVersionOfPendingInstall(string plugin)
        {
            var dirName = Path.Combine(_dataDirectories.Value.PluginDir, plugin);
            var manifestFileName = dirName + ".json";
            if (!File.Exists(manifestFileName)) return null;
            var pluginManifest =  JObject.Parse(File.ReadAllText(manifestFileName)).ToObject<AvailablePlugin>();
            return pluginManifest.Version;
        }

        public async Task<AvailablePlugin[]> GetRemotePlugins()
        {
            var versions = await _pluginBuilderClient.GetPublishedVersions(null, _policiesSettings.PluginPreReleases);
            return versions.Select(v =>
            {
                var p = v.ManifestInfo.ToObject<AvailablePlugin>();
                p.Documentation = v.Documentation;
                var github = v.BuildInfo.GetGithubRepository();
                if (github != null)
                {
                    p.Source = github.GetSourceUrl(v.BuildInfo.gitCommit, v.BuildInfo.pluginDir);
                    p.Author = github.Owner;
                    p.AuthorLink = $"https://github.com/{github.Owner}";
                }
                p.SystemPlugin = false;
                return p;
            }).ToArray();
        }

        public async Task DownloadRemotePlugin(string pluginIdentifier, string version)
        {
            var dest = _dataDirectories.Value.PluginDir;
            var filedest = Path.Join(dest, pluginIdentifier + ".btcpay");
            var filemanifestdest = Path.Join(dest, pluginIdentifier + ".json");
            Directory.CreateDirectory(Path.GetDirectoryName(filedest));
            var url = $"api/v1/plugins/[{Uri.EscapeDataString(pluginIdentifier)}]/versions/{Uri.EscapeDataString(version)}/download";
            var manifest = (await _pluginBuilderClient.GetPublishedVersions(null, true)).Select(v => v.ManifestInfo.ToObject<AvailablePlugin>()).FirstOrDefault(p => p.Identifier == pluginIdentifier);
            await File.WriteAllTextAsync(filemanifestdest, JsonConvert.SerializeObject(manifest, Formatting.Indented));
            using var resp2 = await _pluginBuilderClient.HttpClient.GetAsync(url);
            await using var fs = new FileStream(filedest, FileMode.Create, FileAccess.ReadWrite);
            await resp2.Content.CopyToAsync(fs);
            await fs.FlushAsync();
        }

        public void InstallPlugin(string plugin)
        {
            var dest = _dataDirectories.Value.PluginDir;
            UninstallPlugin(plugin);
            PluginManager.QueueCommands(dest, ("install", plugin));
        }

        public void UpdatePlugin(string plugin)
        {
            var dest = _dataDirectories.Value.PluginDir;
            PluginManager.QueueCommands(dest, ("update", plugin));
        }

        public async Task UploadPlugin(IFormFile plugin)
        {
            var dest = _dataDirectories.Value.PluginDir;
            var filedest = Path.Combine(dest, plugin.FileName);
            Directory.CreateDirectory(Path.GetDirectoryName(filedest));
            if (Path.GetExtension(filedest) == PluginManager.BTCPayPluginSuffix)
            {
                await using var stream = new FileStream(filedest, FileMode.Create);
                await plugin.CopyToAsync(stream);
            }
        }

        public void UninstallPlugin(string plugin)
        {
            var dest = _dataDirectories.Value.PluginDir;
            PluginManager.CancelCommands(dest, plugin);
            PluginManager.QueueCommands(dest, ("delete", plugin));
        }

        public class AvailablePlugin
        {
            public string Identifier { get; set; }
            public string Name { get; set; }
            public Version Version { get; set; }
            public string Description { get; set; }
            public bool SystemPlugin { get; set; } = false;

            public IBTCPayServerPlugin.PluginDependency[] Dependencies { get; set; } = Array.Empty<IBTCPayServerPlugin.PluginDependency>();
            public string Documentation { get; set; }
            public string Source { get; set; }
            public string Author { get; set; }
            public string AuthorLink { get; set; }

            public void Execute(IApplicationBuilder applicationBuilder, IServiceProvider applicationBuilderApplicationServices)
            {
            }

            public void Execute(IServiceCollection applicationBuilder)
            {
            }
        }

        class GithubFile
        {
            [JsonProperty("name")] public string Name { get; set; }

            [JsonProperty("sha")] public string Sha { get; set; }
            [JsonProperty("type")] public string Type { get; set; }
            [JsonProperty("path")] public string Path { get; set; }

            [JsonProperty("download_url")] public string DownloadUrl { get; set; }
        }

        public (string command, string plugin)[] GetPendingCommands()
        {
            return PluginManager.GetPendingCommands(_dataDirectories.Value.PluginDir);
        }

        public void CancelCommands(string plugin)
        {
            PluginManager.CancelCommands(_dataDirectories.Value.PluginDir, plugin);
        }

        public Dictionary<string, Version> GetDisabledPlugins()
        {
            return PluginManager.GetDisabledPlugins(_dataDirectories.Value.PluginDir);
        }
    }
}