using System.Linq;
using Content.Client.Guidebook.Richtext;
using Pidgin;
using Robust.Client.UserInterface;
using Robust.Shared.Reflection;
using Robust.Shared.Sandboxing;
using static Pidgin.Parser;

namespace Content.Client.Guidebook;

/// <summary>
///     This manager should be used to convert documents (shitty rich-text / pseudo-xaml) into UI Controls
/// </summary>
public sealed partial class DocumentParsingManager
{
    [Dependency] private readonly IReflectionManager _reflectionManager = default!;
    [Dependency] private readonly ISandboxHelper _sandboxHelper = default!;

    private readonly Dictionary<string, Parser<char, Control>> _tagControlParsers = new();
    private Parser<char, Control> _tagParser = default!;
    private Parser<char, Control> _controlParser = default!;
    public Parser<char, IEnumerable<Control>> ControlParser = default!;

    public void Initialize()
    {
        _tagParser = TryOpeningTag
            .Assert(_tagControlParsers.ContainsKey, tag => $"unknown tag: {tag}")
            .Bind(tag => _tagControlParsers[tag]);

        _controlParser = OneOf(_tagParser, TryHeaderControl, ListControlParser, TextControlParser).Before(SkipWhitespaces);

        foreach (var typ in _reflectionManager.GetAllChildren<IDocumentTag>())
        {
            _tagControlParsers.Add(typ.Name, CreateTagControlParser(typ.Name, typ, _sandboxHelper));
        }

        ControlParser = SkipWhitespaces.Then(_controlParser.Many());
    }

    public bool TryAddMarkup(Control control, string text, bool log = true)
    {
        try
        {
            foreach (var child in ControlParser.ParseOrThrow(text))
            {
                control.AddChild(child);
            }
        }
        catch (Exception e)
        {
            if (log)
                Logger.Error($"Encountered error while generating markup controls: {e}");
            return false;
        }

        return true;
    }

    private Parser<char, Control> CreateTagControlParser(string tagId, Type tagType, ISandboxHelper sandbox) => Map(
        (args, controls) =>
        {
            var tag = (IDocumentTag) sandbox.CreateInstance(tagType);
            if (!tag.TryParseTag(args, out var control))
            {
                Logger.Error($"Failed to parse {tagId} args");
                return new Control();
            }

            foreach (var child in controls)
            {
                control.AddChild(child);
            }
            return control;
        },
        ParseTagArgs(tagId),
        TagContentParser(tagId)).Labelled($"{tagId} control");

    // Parse a bunch of controls until we encounter a matching closing tag.
    private Parser<char, IEnumerable<Control>> TagContentParser(string tag) =>
    OneOf(
        Try(ImmediateTagEnd).ThenReturn(Enumerable.Empty<Control>()),
        TagEnd.Then(_controlParser.Until(TryTagTerminator(tag)).Labelled($"{tag} children"))
    );
}