using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Newtonsoft.Json.Linq;

namespace Pf2e.Scrapper.Importers.Implementations.FoundryEn.Compendium;

/// <summary>
/// Загрузчик данных компендиума.
/// </summary>
/// <param name="repository"><inheritdoc cref="FoundryEnRepository"/></param>
public sealed class FoundryEnCompendium(FoundryEnRepository repository) : AbstractCompendium
{
    /// <inheritdoc/>
    public override FoundryEnRepository Repository { get; } = repository;

    /// <summary>
    /// Коллекция всех записей компендиума.
    /// </summary>
    public ConcurrentBag<FoundryEnCompendiumItem> Items { get; } = [];

    /// <inheritdoc/>
    public override int Count(params ICollection<string> types) =>
        types.Count == 0 ? Items.Count : Items.Count(i => types.Contains(i.Type));

    /// <inheritdoc/>
    public override IEnumerable<Tuple<AbstractCompendiumItem, JObject>> Iterate(
        params ICollection<string> types
    )
    {
        IEnumerable<string> files =
            types.Count == 0
                ? Items.Select(item => item.File).Distinct()
                : Items
                    .Where(item => types.Contains(item.Type))
                    .Select(item => item.File)
                    .Distinct();

        foreach (string file in files)
        {
            Dictionary<string, FoundryEnCompendiumItem> fileReferences = Items
                .Where(i => i.File == file)
                .ToDictionary(i => i.Id);

            using StreamReader fileReader = new(file);
            JArray array = JArray.Parse(fileReader.ReadToEnd());

            foreach (JToken item in array)
            {
                string? id = item.SelectToken("_id")?.ToString();

                if (
                    id is null
                    || !fileReferences.TryGetValue(id, out FoundryEnCompendiumItem? reference)
                    || (types.Count > 0 && !types.Contains(reference.Type))
                )
                {
                    continue;
                }

                yield return new(reference, (JObject)item);
            }
        }
    }
}