package com.example.dcav2gui;

import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

import java.io.IOException;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class TickerTracker {
    private static final String BINANCE_API_BASE_URL = "https://api.binance.com/api/v3/ticker/24hr";
    private static final OkHttpClient httpClient = new OkHttpClient();
    private static final Gson gson = new Gson();

    /**
     * Retrieves price change percentages for a specific trading pair from Binance.
     *
     * @param symbol The trading pair symbol (e.g., "BTCUSDT")
     * @return PriceChangeData object containing 24h, 7d, and 30d percentage changes
     * @throws IOException If there's an error connecting to the Binance API
     */
    public static PriceChangeData getPriceChanges(String symbol) throws IOException {
        // Construct the API request URL for 24h change
        Request request24h = new Request.Builder()
                .url(BINANCE_API_BASE_URL + "?symbol=" + symbol)
                .build();

        // Send 24h request
        try (Response response24h = httpClient.newCall(request24h).execute()) {
            // Parse the JSON response
            String responseBody24h = response24h.body().string();
            JsonObject jsonResponse = JsonParser.parseString(responseBody24h).getAsJsonObject();

            // Extract current price
            double currentPrice = jsonResponse.has("lastPrice")
                    ? jsonResponse.get("lastPrice").getAsDouble()
                    : 0.0;

            // Extract 24h percentage change
            double priceChangePercent24h = jsonResponse.has("priceChangePercent")
                    ? jsonResponse.get("priceChangePercent").getAsDouble()
                    : 0.0;

            // Fetch historical data for 7d and 30d changes
            Request historicalRequest = new Request.Builder()
                    .url("https://api.binance.com/api/v3/klines?symbol=" + symbol + "&interval=1d&limit=30")
                    .build();

            // Send historical data request
            try (Response historicalResponse = httpClient.newCall(historicalRequest).execute()) {
                String historicalResponseBody = historicalResponse.body().string();

                // Calculate 7d and 30d percentage changes
                double priceChangePercent7d = calculatePercentageChange(historicalResponseBody, 7);
                double priceChangePercent30d = calculatePercentageChange(historicalResponseBody, 30);

                // Return the price change data
                return new PriceChangeData(
                        symbol,
                        currentPrice,
                        priceChangePercent24h,
                        priceChangePercent7d,
                        priceChangePercent30d
                );
            }
        }
    }

    // Calculates the percentage change
    private static double calculatePercentageChange(String jsonKlineData, int days) {
        try {
            // Parse the kline data
            JsonArray klines = JsonParser.parseString(jsonKlineData).getAsJsonArray();

            // Ensure we have enough data
            if (klines == null || klines.size() < days) {
                return 0.0;
            }

            // Get the opening price of the first day in the period
            // Kline data structure: [Open time, Open, High, Low, Close, Volume, Close time, Quote asset volume, Number of trades, Taker buy base asset volume, Taker buy quote asset volume, Ignore]
            double firstOpenPrice = klines.get(0).getAsJsonArray().get(1).getAsDouble();

            // Get the closing price of the last day in the period
            double lastClosePrice = klines.get(days - 1).getAsJsonArray().get(4).getAsDouble();

            // Calculate percentage change
            return ((lastClosePrice - firstOpenPrice) / firstOpenPrice) * 100;
        } catch (Exception e) {
            System.err.println("Error calculating percentage change: " + e.getMessage());
            return 0.0;
        }
    }

    // Class to hold price information
    public static class PriceChangeData {
        private final String symbol;
        private final double currentPrice;
        private final double priceChangePercent24h;
        private final double priceChangePercent7d;
        private final double priceChangePercent30d;

        public PriceChangeData(String symbol, double currentPrice, double priceChangePercent24h,
                               double priceChangePercent7d, double priceChangePercent30d) {
            this.symbol = symbol;
            this.currentPrice = currentPrice;
            this.priceChangePercent24h = priceChangePercent24h;
            this.priceChangePercent7d = priceChangePercent7d;
            this.priceChangePercent30d = priceChangePercent30d;
        }

        // Getters (Just in case)
        public String getSymbol() { return symbol; }
        public double getCurrentPrice() { return currentPrice; }
        public double getPriceChangePercent24h() { return priceChangePercent24h; }
        public double getPriceChangePercent7d() { return priceChangePercent7d; }
        public double getPriceChangePercent30d() { return priceChangePercent30d; }

//        @Override
//        public String toString() {
//            return String.format("Symbol: %s\nPrice: %.2f%%\n24h Change: %.2f%%\n7d Change: %.2f%%\n30d Change: %.2f%%",
//                    symbol, currentPrice, priceChangePercent24h, priceChangePercent7d, priceChangePercent30d);
//        }
    }
}