using System.Collections.ObjectModel;
using System.IO;
using System.Text.Json;

namespace VideoDownloader.App.Browser.Features;

/// <summary>팔레트 명령(T2-1, Arc Command Bar / Vivaldi Quick Commands 패턴).</summary>
public sealed record PaletteCommand(string Title, string Keywords, Action Execute, string? Category = null);

/// <summary>명령 등록·검색·실행. 동적 소스(탭/기록/북마크)는 검색 시점에 평가.</summary>
public sealed class CommandPalette
{
    private readonly List<PaletteCommand> _static = new();
    private readonly List<Func<IEnumerable<PaletteCommand>>> _dynamic = new();
    private readonly List<PaletteCommand> _separators = new(); // 빈질의 표시용 구분자(Title="\u2015")

    public IReadOnlyList<PaletteCommand> Register(string title, string keywords, Action execute, string? category = null)
    {
        var cmd = new PaletteCommand(title, keywords, execute, category);
        _static.Add(cmd);
        return new[] { cmd };
    }

    public void RegisterDynamic(Func<List<PaletteCommand>> source) => _dynamic.Add(source);

    public void RegisterSeparator() => _separators.Add(new PaletteCommand("\u2015", "", () => { }));

    /// <summary>검색: 정적+동적 통합, 시작-일치 우선, 대소문자 무시. 빈 질의는 정적 전체(등록순).</summary>
    public List<PaletteCommand> Search(string? query)
    {
        query = query?.Trim();
        if (string.IsNullOrEmpty(query))
            return _static.ToList();

        var low = query.ToLowerInvariant();
        var pool = _static.Concat(_dynamic.SelectMany(d => d())).ToList();

        return pool
            .Select(c => new { Cmd = c, Hay = (c.Title + " " + c.Keywords).ToLowerInvariant() })
            .Where(x => x.Hay.Contains(low))
            .OrderByDescending(x => x.Hay.StartsWith(low) ? 1 : 0)
            .ThenBy(_ => 0) // 안정 정렬 유지(등록순)
            .Select(x => x.Cmd)
            .Take(12)
            .ToList();
    }

    public void Execute(PaletteCommand command) => command.Execute();
}

/// <summary>사이트별 부스트 설정(T2-7, Zen/Arc Boosts 패턴).</summary>
public sealed record BoostSettings(bool ForceDark, string CustomCss);

/// <summary>도메인별 부스트 영속 저장.</summary>
public sealed class BoostStore
{
    private readonly string _path;
    private Dictionary<string, BoostSettings> _map = new(StringComparer.OrdinalIgnoreCase);

    public BoostStore(string path)
    {
        _path = path;
        try
        {
            if (File.Exists(path))
            {
                var loaded = JsonSerializer.Deserialize<Dictionary<string, BoostSettings>>(File.ReadAllText(path));
                if (loaded != null) _map = loaded;
            }
        }
        catch { _map = new(); }
    }

    public BoostSettings Get(string? url)
    {
        var host = Normalize(url);
        return host != null && _map.TryGetValue(host, out var v) ? v : new BoostSettings(false, "");
    }

    public void Set(string? url, bool forceDark, string css)
    {
        var host = Normalize(url);
        if (host == null) return;
        _map[host] = new BoostSettings(forceDark, css);
        try
        {
            Directory.CreateDirectory(Path.GetDirectoryName(_path)!);
            var tmp = _path + ".tmp";
            File.WriteAllText(tmp, JsonSerializer.Serialize(_map));
            File.Move(tmp, _path, overwrite: true);
        }
        catch { }
    }

    private static string? Normalize(string? url)
    {
        if (string.IsNullOrWhiteSpace(url)) return null;
        var raw = url.Trim();
        Uri? uri = null;
        if (Uri.TryCreate(raw, UriKind.Absolute, out var parsed) && !string.IsNullOrEmpty(parsed.Host)) uri = parsed;
        else Uri.TryCreate("https://" + raw, UriKind.Absolute, out uri); // 스킴 없는 호스트 허용
        if (uri == null) return null;
        var host = uri.Host;
        return host.StartsWith("www.", StringComparison.OrdinalIgnoreCase) ? host[4..] : host;
    }
}

/// <summary>부스트 → 문서 생성 시점 주입 JS 생성(강제 다크: 반전 필터 + 미디어 보호).</summary>
public static class BoostCssBuilder
{
    public static string BuildScript(string? url, BoostSettings settings)
    {
        if (!settings.ForceDark && string.IsNullOrWhiteSpace(settings.CustomCss)) return "";
        var css = "";
        if (settings.ForceDark)
        {
            css += """
html { filter: invert(1) hue-rotate(180deg); background: #fff; }
img, video, picture, canvas, svg, iframe, embed, object { filter: invert(1) hue-rotate(180deg); }
""";
        }
        if (!string.IsNullOrWhiteSpace(settings.CustomCss)) css += settings.CustomCss + "\n";
        var js = $$"""
(function(){ try { var s = document.createElement('style'); s.id = 'vd-boost'; s.textContent = {{JsonSerializer.Serialize(css)}}; (document.head || document.documentElement).appendChild(s); } catch(e){} })();
""";
        return js;
    }
}