using System.Collections;
using YamlDotNet.Core;
using YamlDotNet.Core.Events;
using YamlDotNet.Serialization;

namespace TimePasses.Model;

[Serializable]
public class ReplacementText : IReadOnlyList<string> {
    private IReadOnlyList<string> List { get; }

    internal ReplacementText(IReadOnlyList<string> list) {
        this.List = list;
    }

    public string this[int index] => this.List[index];

    public int Count => this.List.Count;

    public IEnumerator<string> GetEnumerator() {
        return this.List.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator() {
        return this.List.GetEnumerator();
    }
}

internal class ReplacementTextConverter : IYamlTypeConverter {
    internal static readonly ReplacementTextConverter Instance = new();

    public bool Accepts(Type type) {
        return type == typeof(ReplacementText);
    }

    public object? ReadYaml(IParser parser, Type type) {
        var list = new List<string>();
        if (parser.Current is Scalar) {
            AddItem();
        } else if (parser.Current is SequenceStart) {
            parser.Consume<SequenceStart>();
            while (parser.Current is not SequenceEnd) {
                AddItem();
            }

            parser.Consume<SequenceEnd>();
        } else {
            throw new YamlException("expected string or list of strings");
        }

        return new ReplacementText(list);

        void AddItem() {
            var scalar = parser.Consume<Scalar>();
            if (scalar.IsKey) {
                throw new YamlException("invalid key found: expected string or list of strings");
            }

            list.Add(scalar.Value);
        }
    }

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