using NodaTime;
using YahooQuotesApi;
using AssetManager.Data;
using AssetManager.Models.DTOs;
using Microsoft.Extensions.Logging;
using System.Collections.Immutable;

namespace AssetManager.Infrastructure.Services;


/// <summary>
/// Yahoo财经市场数据服务接口
/// </summary>
public interface IYahooMarketService
{
    /// <summary>
    /// 获取股票实时价格
    /// </summary>
    Task<MarketPriceResponse> GetStockPriceAsync(string symbol);
    
    /// <summary>
    /// 获取股票历史K线数据
    /// </summary>
    Task<List<MarketDataResponse>> GetStockHistoricalDataAsync(string symbol, string timeframe, int limit);
}
/// <summary>
/// Yahoo财经市场数据服务实现
/// <para>⚠️ Yahoo API 有频率限制，频繁请求会触发 429 错误</para>
/// <para>建议：依赖缓存机制减少 API 调用</para>
/// </summary>
public class YahooMarketService : IYahooMarketService
{
    private readonly ILogger<YahooMarketService> _logger;
    private readonly YahooQuotes _yahooQuotes;
    private readonly SemaphoreSlim _semaphore = new(1, 1); // 限制并发请求

    public YahooMarketService(ILogger<YahooMarketService> logger)
    {
        _logger = logger;
        // 复用单个实例，设置足够长的历史范围（2年）
        // YahooQuotes 内部会缓存 cookie/crumb，避免频繁请求
        _yahooQuotes = new YahooQuotesBuilder()
            .WithHistoryStartDate(Instant.FromDateTimeUtc(DateTime.UtcNow.AddDays(-730)))
            .Build();
    }

    /// <summary>
    /// 转换股票代码为 Yahoo Finance 格式
    /// <para>BRK.B → BRK-B（伯克希尔B类股）</para>
    /// <para>BRK.A → BRK-A（伯克希尔A类股）</para>
    /// </summary>
    private string ConvertToYahooSymbol(string symbol)
    {
        if (string.IsNullOrEmpty(symbol))
            return symbol;
        
        // Yahoo Finance 用连字符表示类别股，而非点号
        // BRK.B → BRK-B, BRK.A → BRK-A
        return symbol.ToUpper().Replace(".", "-");
    }

    public async Task<MarketPriceResponse> GetStockPriceAsync(string symbol)
    {
        var yahooSymbol = ConvertToYahooSymbol(symbol);
        _logger.LogInformation("Yahoo获取股票价格: {Symbol} -> {YahooSymbol}", symbol, yahooSymbol);
        
        // 限制并发，避免触发 429
        await _semaphore.WaitAsync();
        try
        {
            Snapshot? snapshot = await _yahooQuotes.GetSnapshotAsync(yahooSymbol);
            if (snapshot is null)
                throw new InvalidOperationException($"Yahoo未知标的: {symbol}");
            
            decimal price = snapshot.RegularMarketPrice;
            if (price <= 0)
                throw new InvalidOperationException($"Yahoo获取价格失败，标的: {symbol}");
            
            decimal previousClose = snapshot.RegularMarketPreviousClose;
            if (previousClose <= 0)
                previousClose = price;
            
            _logger.LogDebug("Yahoo接口返回 {Symbol}：最新价 {CurrentPrice}，昨收价 {PrevClose}", 
                symbol, price, previousClose);

            return new MarketPriceResponse
            {
                Symbol = symbol,
                Price = price,
                PreviousClose = previousClose,
                Timestamp = DateTime.UtcNow,
                AssetType = "Stock"
            };
        }
        finally
        {
            _semaphore.Release();
        }
    }

    public async Task<List<MarketDataResponse>> GetStockHistoricalDataAsync(string symbol, string timeframe, int limit)
    {
        var yahooSymbol = ConvertToYahooSymbol(symbol);
        _logger.LogInformation("Yahoo获取历史数据: {Symbol} -> {YahooSymbol}, {Timeframe}, {Limit}", symbol, yahooSymbol, timeframe, limit);
        
        // 限制并发，避免触发 429
        await _semaphore.WaitAsync();
        try
        {
            Result<History> result = await _yahooQuotes.GetHistoryAsync(yahooSymbol);
            if (result.Value == null)
                throw new InvalidOperationException($"Yahoo获取历史数据失败，标的: {symbol}");
            
            History history = result.Value;
            var ticks = history.Ticks;
            
            var marketDataList = new List<MarketDataResponse>();
            
            foreach (var tick in ticks)
            {
                marketDataList.Add(new MarketDataResponse
                {
                    Symbol = symbol,
                    Timestamp = tick.Date.ToDateTimeUtc(),
                    Open = (decimal)tick.Open,
                    High = (decimal)tick.High,
                    Low = (decimal)tick.Low,
                    Close = (decimal)tick.Close,
                    Volume = (decimal)tick.Volume,
                    AssetType = "Stock"
                });
            }
            
            // 按时间戳排序并取最近的limit条
            var sortedData = marketDataList
                .OrderBy(x => x.Timestamp)
                .TakeLast(limit)
                .ToList();
            
            _logger.LogInformation("Yahoo获取 {Symbol} 历史数据 {Count} 条（请求 {Limit} 条）", symbol, sortedData.Count, limit);
            
            return sortedData;
        }
        finally
        {
            _semaphore.Release();
        }
    }
}