using System.IO.Compression;
using Dapper;
using ScrapperAPI.Dtos;
using ScrapperAPI.Interfaces;
using ScrapperAPI.Records;
using ScrapperAPI.Utils;

namespace ScrapperAPI.Repositories;

public sealed class ContentRepository : IContentRepository
{
    private readonly IDbConnectionFactory _db;

    public ContentRepository(IDbConnectionFactory db) => _db = db;

    public async Task<int> SaveAsync(int queueId, string content, CancellationToken ct)
    {
        var compressed = CompressionUtils.GzipCompressUtf8(content, CompressionLevel.Fastest);

        const string sql = """
                           insert into content(queue_id, content_encoding, content_bytes, original_length, compressed_length)
                           values (@queueId, 'gzip', @bytes, @origLen, @compLen)
                           returning id;
                           """;

        using var conn = await _db.CreateOpenConnectionAsync(ct);
        return await conn.ExecuteScalarAsync<int>(new CommandDefinition(sql, new
        {
            queueId,
            bytes = compressed,
            origLen = content.Length,            // chars (ok)
            compLen = compressed.Length          // bytes
        }, cancellationToken: ct));
    }

    public async Task<ContentRow?> GetByQueueIdAsync(int queueId, CancellationToken ct)
    {
        const string sql = """
                           select id, queue_id as QueueId, content, created_date as CreatedDate
                           from content
                           where queue_id = @queueId
                           order by id desc
                           limit 1;
                           """;

        using var conn = await _db.CreateOpenConnectionAsync(ct);
        return await conn.QuerySingleOrDefaultAsync<ContentRow>(
            new CommandDefinition(sql, new { queueId }, cancellationToken: ct));
    }

    public async Task<CompressedContent?> GetCompressedByQueueIdAsync(
        int queueId,
        CancellationToken ct
    )
    {
        const string sql = """
                           select
                               id,
                               queue_id as QueueId,
                               content_encoding as ContentEncoding,
                               content_bytes as ContentBytes,
                               original_length as OriginalLength,
                               compressed_length as CompressedLength,
                               created_date as CreatedDate
                           from content
                           where queue_id = @queueId
                           order by id desc
                           limit 1;
                           """;

        using var conn = await _db.CreateOpenConnectionAsync(ct);

        return await conn.QuerySingleOrDefaultAsync<CompressedContent>(
            new CommandDefinition(
                sql,
                new { queueId },
                cancellationToken: ct
            )
        );
    }
}