using Application.Abstractions.Crypto;
using System.Net.Http.Json;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace Infrastructure.Crypto;

public sealed class UpbitRestClient(HttpClient http) : IUpbitClient
{
    private static readonly JsonSerializerOptions _jsonOptions = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.SnakeCaseLower,
        NumberHandling = JsonNumberHandling.AllowReadingFromString
    };

    // ─── Candle ───────────────────────────────────────────────

    public async Task<IReadOnlyList<UpbitCandle>> GetSecondCandlesAsync(string market, int count, CancellationToken ct = default)
    {
        return await FetchCandlesAsync($"candles/seconds?market={market}&count={count}", ct);
    }

    public async Task<IReadOnlyList<UpbitCandle>> GetMinuteCandlesAsync(string market, int unit, int count, CancellationToken ct = default)
    {
        return await FetchCandlesAsync($"candles/minutes/{unit}?market={market}&count={count}", ct);
    }

    public async Task<IReadOnlyList<UpbitCandle>> GetDayCandlesAsync(string market, int count, CancellationToken ct = default)
    {
        return await FetchCandlesAsync($"candles/days?market={market}&count={count}", ct);
    }

    public async Task<IReadOnlyList<UpbitCandle>> GetWeekCandlesAsync(string market, int count, CancellationToken ct = default)
    {
        return await FetchCandlesAsync($"candles/weeks?market={market}&count={count}", ct);
    }

    public async Task<IReadOnlyList<UpbitCandle>> GetMonthCandlesAsync(string market, int count, CancellationToken ct = default)
    {
        return await FetchCandlesAsync($"candles/months?market={market}&count={count}", ct);
    }

    public async Task<IReadOnlyList<UpbitCandle>> GetYearCandlesAsync(string market, int count, CancellationToken ct = default)
    {
        return await FetchCandlesAsync($"candles/years?market={market}&count={count}", ct);
    }

    // ─── Market ───────────────────────────────────────────────

    public async Task<IReadOnlyList<UpbitMarket>> GetMarketsAsync(CancellationToken ct = default)
    {
        var items = await http.GetFromJsonAsync<List<UpbitMarketDto>>("market/all?is_details=true", _jsonOptions, ct) ?? [];

        return [..items.Select(m => new UpbitMarket(
            m.Market,
            m.KoreanName,
            m.EnglishName,
            m.MarketWarning
        ))];
    }

    // ─── Ticker ───────────────────────────────────────────────

    public async Task<IReadOnlyList<UpbitTickerDetail>> GetTickersAsync(string[] markets, CancellationToken ct = default)
    {
        var query = string.Join(",", markets);
        var items = await http.GetFromJsonAsync<List<UpbitTickerDetailDto>>($"ticker?markets={query}", _jsonOptions, ct) ?? [];

        return [..items.Select(t => new UpbitTickerDetail(
            t.Market,
            t.TradePrice,
            t.Change,
            t.SignedChangePrice,
            t.SignedChangeRate,
            t.OpeningPrice,
            t.HighPrice,
            t.LowPrice,
            t.PrevClosingPrice,
            t.AccTradePrice,
            t.AccTradePrice24h,
            t.AccTradeVolume,
            t.AccTradeVolume24h,
            t.Highest52WeekPrice,
            t.Highest52WeekDate,
            t.Lowest52WeekPrice,
            t.Lowest52WeekDate,
            t.Timestamp
        ))];
    }

    // ─── Trade ────────────────────────────────────────────────

    public async Task<IReadOnlyList<UpbitTrade>> GetTradesAsync(string market, int count, CancellationToken ct = default)
    {
        var items = await http.GetFromJsonAsync<List<UpbitTradeDto>>($"trades/ticks?market={market}&count={count}", _jsonOptions, ct) ?? [];

        return [..items.Select(t => new UpbitTrade(
            t.Market,
            t.TradeDate,
            t.TradeTime,
            t.Timestamp,
            t.TradePrice,
            t.TradeVolume,
            t.PrevClosingPrice,
            t.AskBid,
            t.SequentialId
        ))];
    }

    // ─── Orderbook ────────────────────────────────────────────

    public async Task<IReadOnlyList<UpbitOrderbook>> GetOrderbookAsync(string[] markets, CancellationToken ct = default)
    {
        var query = string.Join(",", markets);
        var items = await http.GetFromJsonAsync<List<UpbitOrderbookDto>>($"orderbook?markets={query}", _jsonOptions, ct) ?? [];

        return [..items.Select(o => new UpbitOrderbook(
            o.Market,
            o.TotalAskSize,
            o.TotalBidSize,
            [..o.OrderbookUnits.Select(u => new UpbitOrderbookUnit(
                u.AskPrice,
                u.BidPrice,
                u.AskSize,
                u.BidSize
            ))],
            o.Timestamp
        ))];
    }

    // ─── Private helpers ──────────────────────────────────────

    private async Task<IReadOnlyList<UpbitCandle>> FetchCandlesAsync(string url, CancellationToken ct)
    {
        var items = await http.GetFromJsonAsync<List<UpbitCandleDto>>(url, _jsonOptions, ct) ?? [];

        return [..items.Select(c => new UpbitCandle(
            c.Market,
            c.CandleDateTimeUtc,
            c.OpeningPrice,
            c.HighPrice,
            c.LowPrice,
            c.TradePrice,
            c.Timestamp,
            c.CandleAccTradePrice,
            c.CandleAccTradeVolume,
            c.FirstDayOfPeriod
        ))];
    }

    // ─── Internal DTOs ────────────────────────────────────────

    private sealed class UpbitCandleDto
    {
        public string Market { get; set; } = default!;
        public DateTime CandleDateTimeUtc { get; set; }
        public decimal OpeningPrice { get; set; }
        public decimal HighPrice { get; set; }
        public decimal LowPrice { get; set; }
        public decimal TradePrice { get; set; }
        public long Timestamp { get; set; }
        public decimal CandleAccTradePrice { get; set; }
        public decimal CandleAccTradeVolume { get; set; }
        public string? FirstDayOfPeriod { get; set; }
    }

    private sealed class UpbitMarketDto
    {
        public string Market { get; set; } = default!;
        public string KoreanName { get; set; } = default!;
        public string EnglishName { get; set; } = default!;
        public string? MarketWarning { get; set; }
    }

    private sealed class UpbitTickerDetailDto
    {
        public string Market { get; set; } = default!;
        public decimal TradePrice { get; set; }
        public string Change { get; set; } = default!;
        public decimal SignedChangePrice { get; set; }
        public decimal SignedChangeRate { get; set; }
        public decimal OpeningPrice { get; set; }
        public decimal HighPrice { get; set; }
        public decimal LowPrice { get; set; }
        public decimal PrevClosingPrice { get; set; }
        public decimal AccTradePrice { get; set; }
        public decimal AccTradePrice24h { get; set; }
        public decimal AccTradeVolume { get; set; }
        public decimal AccTradeVolume24h { get; set; }
        public decimal Highest52WeekPrice { get; set; }
        public string Highest52WeekDate { get; set; } = default!;
        public decimal Lowest52WeekPrice { get; set; }
        public string Lowest52WeekDate { get; set; } = default!;
        public long Timestamp { get; set; }
    }

    private sealed class UpbitTradeDto
    {
        public string Market { get; set; } = default!;
        public string TradeDate { get; set; } = default!;
        public string TradeTime { get; set; } = default!;
        public long Timestamp { get; set; }
        public decimal TradePrice { get; set; }
        public decimal TradeVolume { get; set; }
        public decimal PrevClosingPrice { get; set; }
        public string AskBid { get; set; } = default!;
        public long SequentialId { get; set; }
    }

    private sealed class UpbitOrderbookDto
    {
        public string Market { get; set; } = default!;
        public decimal TotalAskSize { get; set; }
        public decimal TotalBidSize { get; set; }
        public List<UpbitOrderbookUnitDto> OrderbookUnits { get; set; } = [];
        public long Timestamp { get; set; }
    }

    private sealed class UpbitOrderbookUnitDto
    {
        public decimal AskPrice { get; set; }
        public decimal BidPrice { get; set; }
        public decimal AskSize { get; set; }
        public decimal BidSize { get; set; }
    }
}