using YamlDotNet.Core;
using YamlDotNet.Core.Events;
using YamlDotNet.Serialization;

namespace TimePasses.Model;

[Serializable]
public class WhenLevel : IWhen {
    public uint Level { get; init; }
    public int CompareResult { get; init; }
    public ReplacementText Text { get; init; }
    public bool Slowly { get; init; }

    public bool IsValid(Plugin plugin) {
        if (plugin.ClientState.LocalPlayer is not { } player) {
            return false;
        }

        var cmp = ((uint) player.Level).CompareTo(this.Level);
        return this.CompareResult switch {
            1 when cmp > 0 => true,
            0 when cmp == 0 => true,
            -1 when cmp < 0 => true,
            _ => false,
        };
    }
}

public class WhenLevelConverter : IYamlTypeConverter {
    public bool Accepts(Type type) {
        return type == typeof(WhenLevel);
    }

    public object ReadYaml(IParser parser, Type type) {
        parser.Consume<MappingStart>();

        ReplacementText? text = null;
        int? comparerResult = null;
        uint? level = null;
        var slowly = false;
        while (parser.Current is not MappingEnd) {
            var key = parser.Consume<Scalar>();
            if (!key.IsKey) {
                throw new YamlException("expected key");
            }

            if (key.Value == "text") {
                text = (ReplacementText?) ReplacementTextConverter.Instance.ReadYaml(parser, type);
                continue;
            }

            var value = parser.Consume<Scalar>();

            switch (key.Value) {
                case "greaterThan": {
                    ParseOperation(1);
                    break;
                }
                case "equalTo": {
                    ParseOperation(0);
                    break;
                }
                case "lessThan": {
                    ParseOperation(-1);
                    break;
                }
                case "slowly": {
                    if (!bool.TryParse(value.Value, out slowly)) {
                        throw new YamlException("invalid whenlevel: slowly was not a boolean");
                    }

                    break;
                }
                default: {
                    continue;
                }
            }

            continue;

            void ParseOperation(int comparer) {
                if (comparerResult != null) {
                    throw new YamlException("duplicate operations in whenlevel");
                }

                comparerResult = comparer;

                if (!uint.TryParse(value.Value, out var lvl)) {
                    throw new YamlException("invalid whenlevel: level was not numeric");
                }

                level = lvl;
            }
        }

        parser.Consume<MappingEnd>();

        if (text == null) {
            throw new YamlException("invalid whenlevel: missing text");
        }

        if (comparerResult == null) {
            throw new YamlException("invalid whenlevel: missing operation");
        }

        if (level == null) {
            throw new YamlException("invalid whenlevel: missing level");
        }

        return new WhenLevel {
            CompareResult = comparerResult.Value,
            Level = level.Value,
            Text = text,
            Slowly = slowly,
        };
    }

    public void WriteYaml(IEmitter emitter, object? value, Type type) {
        throw new NotImplementedException();
    }
}