using System.Text.Json;

namespace VideoDownloader.Browser;

/// <summary>T3-1: 도메인 → 워크스페이스 자동 라우팅 규칙(Vivaldi 규칙/Arc ATC).
/// 주소창 이동 시 매칭되면 해당 워크스페이스로 자동 전환한다. JSON 영속.</summary>
public sealed class WorkspaceRoutingRules
{
    private readonly string _path;
    private Dictionary<string, string> _map = new(StringComparer.OrdinalIgnoreCase);

    public WorkspaceRoutingRules(string path)
    {
        _path = path;
        try
        {
            if (File.Exists(path))
                _map = JsonSerializer.Deserialize<Dictionary<string, string>>(File.ReadAllText(path)) ?? new();
        }
        catch { }
        _map ??= new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
    }

    public IReadOnlyDictionary<string, string> Rules => _map;

    public void Add(string domain, string workspaceName)
    {
        var d = domain.Trim().TrimStart('.', 'w', 'w', 'w', '.');
        _map[d] = workspaceName;
        Save();
    }

    public void Remove(string domain)
    {
        _map.Remove(domain.Trim());
        Save();
    }

    /// <summary>URL 이 매칭되는 워크스페이스명(없으면 null). www/서브도메인 허용.</summary>
    public string? Match(string? url)
    {
        if (string.IsNullOrWhiteSpace(url)) return null;
        if (!Uri.TryCreate(url, UriKind.Absolute, out var u) ||
            (u.Scheme != Uri.UriSchemeHttp && u.Scheme != Uri.UriSchemeHttps)) return null;
        var host = u.Host;
        if (host.StartsWith("www.", StringComparison.OrdinalIgnoreCase)) host = host[4..];
        foreach (var (domain, ws) in _map)
        {
            if (host.Equals(domain, StringComparison.OrdinalIgnoreCase) ||
                host.EndsWith("." + domain, StringComparison.OrdinalIgnoreCase))
                return ws;
        }
        return null;
    }

    private void Save()
    {
        try
        {
            Directory.CreateDirectory(Path.GetDirectoryName(_path)!);
            File.WriteAllText(_path, JsonSerializer.Serialize(_map));
        }
        catch { }
    }
}