using StellaOps.SbomService.Models;
using System.Text.Json;

namespace StellaOps.SbomService.Repositories;

public sealed class FileComponentLookupRepository : IComponentLookupRepository
{
    private readonly IReadOnlyList<ComponentLookupRecord> _items;

    public FileComponentLookupRepository(string path)
    {
        if (!File.Exists(path))
        {
            _items = Array.Empty<ComponentLookupRecord>();
            return;
        }

        using var stream = File.OpenRead(path);
        var items = JsonSerializer.Deserialize<List<ComponentLookupRecord>>(stream, new JsonSerializerOptions
        {
            PropertyNameCaseInsensitive = true
        });

        _items = items ?? new List<ComponentLookupRecord>();
    }

    public Task<(IReadOnlyList<ComponentLookupRecord> Items, int Total)> QueryAsync(ComponentLookupQuery query, CancellationToken cancellationToken)
    {
        var filtered = _items
            .Where(c => c.Purl.Equals(query.Purl, StringComparison.OrdinalIgnoreCase))
            .Where(c => query.Artifact is null || c.Artifact.Equals(query.Artifact, StringComparison.OrdinalIgnoreCase))
            .OrderBy(c => c.Artifact)
            .ThenBy(c => c.Purl)
            .ToList();

        var page = filtered
            .Skip(query.Offset)
            .Take(query.Limit)
            .ToList();

        return Task.FromResult<(IReadOnlyList<ComponentLookupRecord> Items, int Total)>((page, filtered.Count));
    }
}