package provider

import (
	"context"
	"time"

	"gitea.computernetthings.ru/yash/crypto_alert_bot/internal/entities"
)

type Provider interface {
	// Price returns the current price of the pair (base currency / quote currency).
	// e.g. BTC/USDT.
	Price(ctx context.Context, instrument entities.Instrument) (*entities.Price, error)

	// Candles returns OHLC candles for the given interval in the [from, to) range.
	// interval is a provider-specific string (e.g. "1", "5", "60", "D", "W" for Bybit).
	// The implementation handles pagination automatically when the range exceeds one
	// request's capacity.
	Candles(ctx context.Context, instrument entities.Instrument, from, to time.Time, interval KlineInterval) ([]entities.Candle, error)

	// InstrumentExists reports whether the trading pair base/quote is listed on this provider.
	// Returns (false, nil) when the symbol is simply not found (as opposed to a network error).
	InstrumentExists(ctx context.Context, base, quote string) (bool, error)
}

type KlineInterval string

const (
	Kline1m  = "1"
	Kline3m  = "3"
	Kline5m  = "5"
	Kline15m = "15"
	Kline30m = "30"
	Kline1H  = "1h"
	Kline4H  = "4h"
	Kline6H  = "6h"
	Kline12H = "12h"
	Kline1D  = "1d"
	Kline1W  = "1w"
)

func (k KlineInterval) ToDuration() time.Duration {
	switch k {
	case Kline1m:
		return time.Minute
	case Kline3m:
		return 3 * time.Minute
	case Kline5m:
		return 5 * time.Minute
	case Kline15m:
		return 15 * time.Minute
	case Kline30m:
		return 30 * time.Minute
	case Kline1H:
		return time.Hour
	case Kline4H:
		return 4 * time.Hour
	case Kline6H:
		return 6 * time.Hour
	case Kline12H:
		return 12 * time.Hour
	case Kline1D:
		return 24 * time.Hour
	case Kline1W:
		return 7 * 24 * time.Hour
	default:
		return time.Minute
	}
}