using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using PLib.Desktop.Imaging;
using PLib.Desktop.Services;
using PLib.Desktop.Settings;
using PLib.Desktop.ViewModels;
using PLib.Infrastructure;
using PLib.Infrastructure.Storage;
using Serilog;

namespace PLib.Desktop;

/// <summary>
/// Composition root. Everything the application is made of is wired up here and nowhere else.
/// </summary>
internal static class AppHost
{
    public static IHost Create(string[] args)
    {
        // The paths are needed to locate the user settings file, which is itself a
        // configuration source — so they are built before the container exists and then
        // handed to it as an instance.
        var paths = new AppPaths();

        // A desktop app is launched from arbitrary working directories, so the content root
        // has to be the folder the executable lives in rather than Environment.CurrentDirectory.
        var builder = Host.CreateApplicationBuilder(new HostApplicationBuilderSettings
        {
            Args = args,
            ContentRootPath = AppContext.BaseDirectory,
        });

        builder.Configuration.AddJsonFile(
            Path.Combine(paths.DataDirectory, "settings.json"),
            optional: true,
            reloadOnChange: true);

        ConfigureLogging(builder, paths);

        builder.Services.AddSingleton<IAppPaths>(paths);

        builder.Services.AddOptions<AppearanceOptions>()
            .Bind(builder.Configuration.GetSection(AppearanceOptions.SectionName));

        builder.Services.AddOptions<PlaybackOptions>()
            .Bind(builder.Configuration.GetSection(PlaybackOptions.SectionName))
            .ValidateDataAnnotations();
        builder.Services.AddPLibInfrastructure(builder.Configuration);

        builder.Services.AddSingleton<ThumbnailCache>();
        builder.Services.AddSingleton<IThumbnailLoader>(sp => sp.GetRequiredService<ThumbnailCache>());
        builder.Services.AddSingleton<IAppSettingsStore, JsonAppSettingsStore>();
        builder.Services.AddSingleton<IFolderPicker, StorageProviderFolderPicker>();
        builder.Services.AddSingleton<ISystemShell, SystemShell>();
        builder.Services.AddSingleton<IThemeService, ThemeService>();
        builder.Services.AddSingleton<RemoteImageLoader>();
        builder.Services.AddSingleton<MainWindowViewModel>();

        // Scoped, not singleton: the settings dialog edits a working copy, so each opening
        // gets its own model and a cancelled edit never leaks into the next one.
        builder.Services.AddScoped<SettingsViewModel>();

        return builder.Build();
    }

    private static void ConfigureLogging(HostApplicationBuilder builder, IAppPaths paths)
    {
        Log.Logger = new LoggerConfiguration()
            .MinimumLevel.Information()
            .WriteTo.Console()
            .WriteTo.File(
                Path.Combine(paths.DataDirectory, "logs", "plib-.log"),
                rollingInterval: RollingInterval.Day,
                retainedFileCountLimit: 7)
            .CreateLogger();

        builder.Logging.ClearProviders();
        builder.Logging.AddSerilog(Log.Logger, dispose: true);
    }
}