using System.Text.Json;
using Remora.Discord.API;
using Remora.Discord.API.Abstractions.Objects;
using Remora.Discord.API.Objects;
using Remora.Rest.Json;
using StackExchange.Redis;

namespace Catalogger.Backend.Database.Redis;

public class RedisService(Config config)
{
    private readonly ConnectionMultiplexer _multiplexer = ConnectionMultiplexer.Connect(config.Database.Redis!);

    private readonly JsonSerializerOptions _options = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.SnakeCaseLower
    };

    public IDatabase GetDatabase(int db = -1) => _multiplexer.GetDatabase(db);

    public async Task SetAsync<T>(string key, T value, TimeSpan? expiry = null)
    {
        var json = JsonSerializer.Serialize(value, _options);
        await GetDatabase().StringSetAsync(key, json, expiry);
    }

    public async Task<T?> GetAsync<T>(string key)
    {
        var value = await GetDatabase().StringGetAsync(key);
        return value.IsNull ? default : JsonSerializer.Deserialize<T>(value!, _options);
    }

    public async Task SetHashAsync<T>(string hashKey, string fieldKey, T value)
    {
        var json = JsonSerializer.Serialize(value, _options);
        await GetDatabase().HashSetAsync(hashKey, fieldKey, json);
    }

    public async Task SetHashAsync<T>(string hashKey, IEnumerable<T> values, Func<T, string> keySelector)
    {
        var hashEntries = values
            .Select(v => new { Key = keySelector(v), Value = JsonSerializer.Serialize(v, _options) })
            .Select(v => new HashEntry(v.Key, v.Value));
        await GetDatabase().HashSetAsync(hashKey, hashEntries.ToArray());
    }

    public async Task<T?> GetHashAsync<T>(string hashKey, string fieldKey)
    {
        var value = await GetDatabase().HashGetAsync(hashKey, fieldKey);
        return value.IsNull ? default : JsonSerializer.Deserialize<T>(value!, _options);
    }
}