using System.Diagnostics;
using AVSCartonShipmentVerifier.Configuration;
using Microsoft.AspNetCore.Hosting.Server;
using Microsoft.AspNetCore.Hosting.Server.Features;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;

namespace AVSCartonShipmentVerifier.Hosting;

/// <summary>
/// Opens the default browser once the web server has started (Windows desktop-style launch).
/// </summary>
internal sealed class LaunchBrowserHostedService : IHostedService
{
    private readonly IHostApplicationLifetime _lifetime;
    private readonly IOptions<DesktopHostOptions> _options;
    private readonly IServer _server;
    private readonly ILogger<LaunchBrowserHostedService> _logger;

    public LaunchBrowserHostedService(
        IServer server,
        IHostApplicationLifetime lifetime,
        IOptions<DesktopHostOptions> options,
        ILogger<LaunchBrowserHostedService> logger)
    {
        _server = server;
        _lifetime = lifetime;
        _options = options;
        _logger = logger;
    }

    public Task StartAsync(CancellationToken cancellationToken)
    {
        var opts = _options.Value;
        if (!opts.LaunchBrowser)
            return Task.CompletedTask;

        _lifetime.ApplicationStarted.Register(OpenBrowser);
        return Task.CompletedTask;
    }

    private void OpenBrowser()
    {
        try
        {
            var url = ResolveUrl();
            if (string.IsNullOrWhiteSpace(url))
            {
                _logger.LogWarning("Could not determine URL to open in the browser.");
                return;
            }

            if (OperatingSystem.IsWindows())
            {
                Process.Start(new ProcessStartInfo(url) { UseShellExecute = true });
            }
            else if (OperatingSystem.IsMacOS())
            {
                Process.Start("open", url);
            }
            else
            {
                Process.Start(new ProcessStartInfo("xdg-open", url) { UseShellExecute = true });
            }
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "Failed to launch the default browser.");
        }
    }

    private string? ResolveUrl()
    {
        var configured = _options.Value.BrowserUrl;
        if (!string.IsNullOrWhiteSpace(configured))
            return configured;

        var addresses = _server.Features.Get<IServerAddressesFeature>()?.Addresses;
        if (addresses is null || addresses.Count == 0)
            return null;

        return addresses.FirstOrDefault(static a => a.StartsWith("http://", StringComparison.OrdinalIgnoreCase))
            ?? addresses.FirstOrDefault(static a => a.StartsWith("https://", StringComparison.OrdinalIgnoreCase))
            ?? addresses.FirstOrDefault();
    }

    public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
}