using System;
using Microsoft.Extensions.Options;

namespace LightlessSyncServer.Configuration;

public class BroadcastConfiguration : IBroadcastConfiguration
{
    private static readonly TimeSpan DefaultEntryTtl = TimeSpan.FromMinutes(180);
    private const int DefaultMaxStatusBatchSize = 30;
    private const string DefaultNotificationTemplate = "{DisplayName} sent you a pair request. To accept, right-click them, open the context menu, and send a request back.";

    private readonly IOptionsMonitor<BroadcastOptions> _optionsMonitor;

    public BroadcastConfiguration(IOptionsMonitor<BroadcastOptions> optionsMonitor)
    {
        _optionsMonitor = optionsMonitor;
    }

    private BroadcastOptions Options => _optionsMonitor.CurrentValue ?? new BroadcastOptions();

    public string RedisKeyPrefix
    {
        get
        {
            var prefix = Options.RedisKeyPrefix;
            return string.IsNullOrWhiteSpace(prefix) ? "broadcast:" : prefix!;
        }
    }

    public TimeSpan BroadcastEntryTtl
    {
        get
        {
            var seconds = Options.EntryTtlSeconds;
            return seconds > 0 ? TimeSpan.FromSeconds(seconds) : DefaultEntryTtl;
        }
    }

    public int MaxStatusBatchSize
    {
        get
        {
            var value = Options.MaxStatusBatchSize;
            return value > 0 ? value : DefaultMaxStatusBatchSize;
        }
    }

    public bool NotifyOwnerOnPairRequest => Options.NotifyOwnerOnPairRequest;

    public bool EnableBroadcasting => Options.EnableBroadcasting;

    public bool EnableSyncshellBroadcastPayloads => Options.EnableSyncshellBroadcastPayloads;

    public string BuildRedisKey(string hashedCid)
    {
        if (string.IsNullOrEmpty(hashedCid))
            return RedisKeyPrefix;

        return string.Concat(RedisKeyPrefix, hashedCid);
    }

    public string BuildUserOwnershipKey(string userUid)
    {
        if (string.IsNullOrWhiteSpace(userUid))
            throw new ArgumentException("User UID must not be null or empty.", nameof(userUid));

        return string.Concat(RedisKeyPrefix, "owner:", userUid);
    }

    public string BuildPairRequestNotification()
    {
        var template = Options.PairRequestNotificationTemplate;
        if (string.IsNullOrWhiteSpace(template))
        {
            template = DefaultNotificationTemplate;
        }

        return template;
    }

    public int PairRequestRateLimit => Options.PairRequestRateLimit > 0 ? Options.PairRequestRateLimit : 5;
    public int PairRequestRateWindow => Options.PairRequestRateWindow > 0 ? Options.PairRequestRateWindow : 60;
}