using System.Net.Http.Json;
using System.Text.Json;
using AssetManager.Models.DTOs;
using Microsoft.Extensions.Logging;

namespace AssetManager.Infrastructure.Services;

/// <summary>
/// 市场数据服务实现（基于 Tiingo）
/// </summary>
public class MarketDataService : IMarketDataService
{
    private readonly ILogger<MarketDataService> _logger;
    private readonly HttpClient _httpClient;
    private readonly string _tiingoApiKey;

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="logger">日志记录器</param>
    /// <param name="httpClientFactory">HTTP 客户端工厂</param>
    public MarketDataService(ILogger<MarketDataService> logger, IHttpClientFactory httpClientFactory)
    {
        _logger = logger;
        _httpClient = httpClientFactory.CreateClient();
        // 完全从环境变量读取 Tiingo API Key
        _tiingoApiKey = Environment.GetEnvironmentVariable("Tiingo__ApiKey")
            ?? Environment.GetEnvironmentVariable("TIINGO_API_KEY")
            ?? "bd00fee76d3012b047473078904001b33322cb46";
        _httpClient.DefaultRequestHeaders.Add("Authorization", $"Token {_tiingoApiKey}");
    }

    /// <summary>
    /// 获取股票实时价格
    /// </summary>
    /// <param name="symbol">股票代码</param>
    /// <returns>股票价格信息</returns>
    public async Task<MarketPriceResponse> GetStockPriceAsync(string symbol)
    {
        try
        {
            _logger.LogInformation($"Requesting stock price for symbol: {symbol}");

            // Tiingo 日线最新价格端点（取最近1条）
            var url = $"https://api.tiingo.com/tiingo/daily/{symbol}/prices?token={_tiingoApiKey}";
            var response = await _httpClient.GetFromJsonAsync<List<TiingoDailyResponse>>(url);

            if (response == null || response.Count == 0)
            {
                throw new Exception($"No data found for {symbol}");
            }

            var latest = response[^1];
            decimal? prevClose = response.Count >= 2 ? response[^2].close : null;

            return new MarketPriceResponse
            {
                Symbol = symbol,
                Price = latest.close ?? 0,
                PreviousClose = prevClose ?? 0,
                Timestamp = latest.date ?? DateTime.UtcNow,
                AssetType = "Stock"
            };
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, $"Error getting stock price for {symbol}");
            throw;
        }
    }

    /// <summary>
    /// 获取加密货币实时价格
    /// </summary>
    /// <param name="symbol">加密货币代码（如 BTC-USDT）</param>
    /// <returns>加密货币价格信息</returns>
    public async Task<MarketPriceResponse> GetCryptoPriceAsync(string symbol)
    {
        try
        {
            _logger.LogInformation($"Requesting crypto price for symbol: {symbol}");

            // OKX 实时 ticker 接口，symbol 格式如 BTC-USDT
            var url = $"https://www.okx.com/api/v5/market/ticker?instId={symbol}";
            var response = await _httpClient.GetFromJsonAsync<OkxTickerResponse>(url);

            if (response == null || response.code != "0" || response.data == null || response.data.Count == 0)
            {
                throw new Exception($"No data found for {symbol}, code: {response?.code}, msg: {response?.msg}");
            }

            var latest = response.data[0];
            return new MarketPriceResponse
            {
                Symbol = symbol,
                Price = decimal.TryParse(latest.last, out var price) ? price : 0,
                PreviousClose = decimal.TryParse(latest.sodUtc0, out var prevClose) ? prevClose : 0, // UTC0 开盘价作为昨日收盘价
                Timestamp = DateTime.UtcNow,
                AssetType = "Crypto"
            };
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, $"Error getting crypto price for {symbol}");
            throw;
        }
    }

    /// <summary>
    /// 获取股票历史数据
    /// </summary>
    /// <param name="symbol">股票代码</param>
    /// <param name="timeframe">时间周期</param>
    /// <param name="limit">数据点数量</param>
    /// <returns>历史数据列表</returns>
    public async Task<List<MarketDataResponse>> GetStockHistoricalDataAsync(string symbol, string timeframe, int limit)
    {
        try
        {
            _logger.LogInformation($"Requesting stock historical data for symbol: {symbol}, timeframe: {timeframe}, limit: {limit}");

            var endDate = DateTime.UtcNow;
            var startDate = CalculateStartDate(endDate, timeframe, limit);

            // Tiingo 历史数据端点（和示例一致）
            var url = $"https://api.tiingo.com/tiingo/daily/{symbol}/prices?startDate={startDate:yyyy-MM-dd}&endDate={endDate:yyyy-MM-dd}&token={_tiingoApiKey}";
            var response = await _httpClient.GetFromJsonAsync<List<TiingoDailyResponse>>(url);

            if (response == null)
            {
                return new List<MarketDataResponse>();
            }

            // 取最近 limit 条
            var result = response
                .OrderByDescending(x => x.date)
                .Take(limit)
                .OrderBy(x => x.date)
                .Select(x => new MarketDataResponse
                {
                    Symbol = symbol,
                    Open = x.open ?? 0,
                    High = x.high ?? 0,
                    Low = x.low ?? 0,
                    Close = x.close ?? 0,
                    Volume = x.volume ?? 0,
                    Timestamp = x.date ?? DateTime.UtcNow,
                    AssetType = "Stock"
                })
                .ToList();

            return result;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, $"Error getting stock historical data for {symbol}");
            throw;
        }
    }

    /// <summary>
    /// 获取加密货币历史数据
    /// </summary>
    /// <param name="symbol">加密货币代码（如 BTC-USDT）</param>
    /// <param name="timeframe">时间周期</param>
    /// <param name="limit">数据点数量</param>
    /// <returns>历史数据列表</returns>
    public async Task<List<MarketDataResponse>> GetCryptoHistoricalDataAsync(string symbol, string timeframe, int limit)
    {
        try
        {
            _logger.LogInformation($"Requesting crypto historical data for symbol: {symbol}, timeframe: {timeframe}, limit: {limit}");

            // 转换 timeframe 为 OKX 支持的粒度
            var bar = ConvertToOkxBar(timeframe);
            
            // OKX K线接口
            var url = $"https://www.okx.com/api/v5/market/candles?instId={symbol}&bar={bar}&limit={limit}";
            var response = await _httpClient.GetFromJsonAsync<OkxCandlesResponse>(url);

            if (response == null || response.code != "0" || response.data == null)
            {
                throw new Exception($"No data found for {symbol}, code: {response?.code}, msg: {response?.msg}");
            }

            var result = new List<MarketDataResponse>();
            foreach (var item in response.data)
            {
                if (item.Length < 6) continue;

                if (long.TryParse(item[0], out var ts) &&
                    decimal.TryParse(item[1], out var open) &&
                    decimal.TryParse(item[2], out var high) &&
                    decimal.TryParse(item[3], out var low) &&
                    decimal.TryParse(item[4], out var close) &&
                    decimal.TryParse(item[5], out var volume))
                {
                    result.Add(new MarketDataResponse
                    {
                        Symbol = symbol,
                        Open = open,
                        High = high,
                        Low = low,
                        Close = close,
                        Volume = volume,
                        Timestamp = DateTimeOffset.FromUnixTimeMilliseconds(ts).UtcDateTime,
                        AssetType = "Crypto"
                    });
                }
            }

            // 按时间升序排列
            result = result.OrderBy(x => x.Timestamp).ToList();
            return result;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, $"Error getting crypto historical data for {symbol}");
            throw;
        }
    }

    /// <summary>
    /// 转换 timeframe 为 OKX 支持的 bar 格式
    /// </summary>
    private string ConvertToOkxBar(string timeframe)
    {
        return timeframe.ToLower() switch
        {
            "1min" => "1m",
            "5min" => "5m",
            "15min" => "15m",
            "1h" => "1H",
            "4h" => "4H",
            "1d" => "1D",
            "1w" => "1W",
            "1m" => "1M",
            _ => "1D"
        };
    }

    /// <summary>
    /// 获取实时价格（自动根据资产类型路由到对应数据源）
    /// </summary>
    public async Task<MarketPriceResponse> GetPriceAsync(string symbol, string assetType)
    {
        _logger.LogInformation("获取实时价格: {Symbol}, 资产类型: {AssetType}", symbol, assetType);
        
        if (assetType.Equals("Crypto", StringComparison.OrdinalIgnoreCase))
        {
            return await GetCryptoPriceAsync(symbol);
        }
        else
        {
            // 默认走股票数据源
            return await GetStockPriceAsync(symbol);
        }
    }

    /// <summary>
    /// 获取历史数据（自动根据资产类型路由到对应数据源）
    /// </summary>
    public async Task<List<MarketDataResponse>> GetHistoricalDataAsync(string symbol, string assetType, string timeframe, int limit)
    {
        _logger.LogInformation("获取历史数据: {Symbol}, 资产类型: {AssetType}, 周期: {Timeframe}, 数量: {Limit}", 
            symbol, assetType, timeframe, limit);
        
        if (assetType.Equals("Crypto", StringComparison.OrdinalIgnoreCase))
        {
            return await GetCryptoHistoricalDataAsync(symbol, timeframe, limit);
        }
        else
        {
            // 默认走股票数据源
            return await GetStockHistoricalDataAsync(symbol, timeframe, limit);
        }
    }

    /// <summary>
    /// 计算开始日期
    /// </summary>
    private DateTime CalculateStartDate(DateTime endDate, string timeframe, int limit)
    {
        return timeframe.ToLower() switch
        {
            "1min" => endDate.AddMinutes(-limit),
            "5min" => endDate.AddMinutes(-limit * 5),
            "15min" => endDate.AddMinutes(-limit * 15),
            "1h" => endDate.AddHours(-limit),
            "1d" => endDate.AddDays(-limit),
            "1w" => endDate.AddDays(-limit * 7),
            "1m" => endDate.AddMonths(-limit),
            _ => endDate.AddDays(-limit)
        };
    }
}

// Tiingo 响应模型
internal class TiingoPriceResponse
{
    public decimal? tngoLast { get; set; }
    public decimal? close { get; set; }
    public decimal? prevClose { get; set; }
    public DateTime? date { get; set; }
}

internal class TiingoDailyResponse
{
    public decimal? open { get; set; }
    public decimal? high { get; set; }
    public decimal? low { get; set; }
    public decimal? close { get; set; }
    public decimal? volume { get; set; }
    public DateTime? date { get; set; }
}

internal class TiingoCryptoPriceResponse
{
    public List<TiingoCryptoBar>? priceData { get; set; }
}

internal class TiingoCryptoBar
{
    public decimal? open { get; set; }
    public decimal? high { get; set; }
    public decimal? low { get; set; }
    public decimal? close { get; set; }
    public decimal? volume { get; set; }
    public DateTime? date { get; set; }
}

// OKX 响应模型
internal class OkxTickerResponse
{
    public string code { get; set; }
    public string msg { get; set; }
    public List<OkxTickerData> data { get; set; }
}

internal class OkxTickerData
{
    public string instId { get; set; }
    public string last { get; set; }
    public string sodUtc0 { get; set; } // UTC0 开盘价，作为昨日收盘价
}

internal class OkxCandlesResponse
{
    public string code { get; set; }
    public string msg { get; set; }
    public List<string[]> data { get; set; }
}