using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using MongoDB.Driver;
using PolyTraderSharp.Extensions;
using PolyTraderSharp.Models;
using PolyTraderSharp.Services;

namespace PolyTraderSharp.Services
{
    public class MarketSyncService : BackgroundService
    {
        private readonly PolymarketApiService _apiService;
        private readonly IMongoDatabase _db;
        private readonly TerminalLogger _logger;
        private readonly JobStatusRow _jobStatus;
        private readonly TradingState _state;

        public MarketSyncService(PolymarketApiService apiService, IMongoDatabase db, TerminalLogger logger, JobManager jobManager, TradingState state)
        {
            _apiService = apiService;
            _db = db;
            _logger = logger;
            _state = state;

            _jobStatus = new JobStatusRow
            {
                JobName = "Market Data Sync",
                Description = "Polls Polymarket Gamma API for the 1000 newest markets.",
                StatusText = "Pending Initial Delay..."
            };
            
            _jobStatus.ManualTriggerAction = async () => 
            {
                string oldStatus = _jobStatus.StatusText;
                _jobStatus.StatusText = "Running (Manual)...";
                await SyncMarketsAsync();
                _jobStatus.StatusText = "Idle";
            };

            jobManager.RegisterJob(_jobStatus);
        }

        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            _logger.Info("MarketSyncService started. Will sync markets every 1 hour.");

            // Give the app some time to start up before initial sync
            await Task.Delay(TimeSpan.FromSeconds(10), stoppingToken);
            _jobStatus.StatusText = "Idle";

            while (!stoppingToken.IsCancellationRequested)
            {
                if (_jobStatus.IsEnabled)
                {
                    try
                    {
                        _jobStatus.StatusText = "Running (Scheduled)...";
                        await SyncMarketsAsync();
                        _jobStatus.LastRun = DateTime.Now;
                    }
                    catch (Exception ex)
                    {
                        _logger.Error($"MarketSyncService loop error: {ex.Message}");
                        _jobStatus.StatusText = "Error!";
                    }
                    finally
                    {
                        if (_jobStatus.StatusText != "Error!")
                            _jobStatus.StatusText = "Idle";
                    }
                }
                else
                {
                    _jobStatus.StatusText = "Paused";
                }
                
                // Sleep for 3 minutes to keep the Cache extremely fresh against high-frequency listings
                _jobStatus.NextRun = DateTime.Now.AddMinutes(3);
                await Task.Delay(TimeSpan.FromMinutes(3), stoppingToken);
            }
        }

        private async Task SyncMarketsAsync()
        {
            _logger.Info("Syncing newest markets from Polymarket API...");
            var newMarkets = await _apiService.GetRecentMarketsAsync(1000);
            
            if (newMarkets.Count == 0)
            {
                _logger.Warning("No markets returned from Polymarket API during sync.");
                return;
            }

            var col = _db.GetCollection<MarketData>("markets");
            col.EnsureIndex(x => x.Id);
            
            int inserted = 0;
            int updated = 0;
            
            foreach (var market in newMarkets)
            {
                var existing = col.LiteFindOne(x => x.Id == market.Id);
                if (existing == null)
                {
                    col.Insert(market);
                    inserted++;
                    
                    // NEW: Hot-Load active markets directly into RAM Cache
                    if (!market.Closed && !string.IsNullOrEmpty(market.ClobTokenIds))
                    {
                        try 
                        {
                            var tokenIds = System.Text.Json.JsonSerializer.Deserialize<List<string>>(market.ClobTokenIds);
                            if (tokenIds != null)
                            {
                                foreach(var t in tokenIds) 
                                {
                                    _state.MarketCache[t] = market;
                                }
                            }
                        } catch { } // Ignore JSON parse error if malformed
                    }
                }
                else
                {
                    // Update dynamic fields like EndDate, Active, Closed
                    existing.EndDate = market.EndDate;
                    existing.Active = market.Active;
                    existing.Closed = market.Closed;
                    existing.NegRisk = market.NegRisk;
                    
                    // The API can sometimes be slow to assign ClobTokenIds. Update them if we got new ones.
                    if (string.IsNullOrEmpty(existing.ClobTokenIds) && !string.IsNullOrEmpty(market.ClobTokenIds))
                    {
                        existing.ClobTokenIds = market.ClobTokenIds;
                    }
                    
                    col.Update(existing);
                    updated++;
                    
                    // Keep RAM cache synchronized to prevent using stale active/closed flags
                    if (!string.IsNullOrEmpty(existing.ClobTokenIds))
                    {
                        try 
                        {
                            var tokenIds = System.Text.Json.JsonSerializer.Deserialize<List<string>>(existing.ClobTokenIds);
                            if (tokenIds != null)
                            {
                                foreach(var t in tokenIds) 
                                {
                                    if (!existing.Closed)
                                    {
                                        // Unconditionally keep active markets hot in the cache
                                        _state.MarketCache[t] = existing;
                                    }
                                    else
                                    {
                                        // Only update if it is already there (e.g. to flag it as closed for running logic)
                                        if (_state.MarketCache.ContainsKey(t))
                                            _state.MarketCache[t] = existing;
                                    }
                                }
                            }
                        } catch { } // Ignore JSON parse error if malformed
                    }
                }
            }
            
            _logger.Info($"Market Sync Complete: {inserted} new markets, {updated} updated.");
        }
    }
}