"""Tests for exchange helpers and caching."""

import pytest

from coinhunter.services import exchange_service as es


class TestNormSymbol:
    def test_already_normalized(self):
        assert es.norm_symbol("BTC/USDT") == "BTC/USDT"

    def test_raw_symbol(self):
        assert es.norm_symbol("BTCUSDT") == "BTC/USDT"

    def test_lowercase(self):
        assert es.norm_symbol("btcusdt") == "BTC/USDT"

    def test_dash_separator(self):
        assert es.norm_symbol("BTC-USDT") == "BTC/USDT"

    def test_underscore_separator(self):
        assert es.norm_symbol("BTC_USDT") == "BTC/USDT"

    def test_unsupported_symbol(self):
        with pytest.raises(ValueError):
            es.norm_symbol("BTC")


class TestStorageSymbol:
    def test_converts_to_flat(self):
        assert es.storage_symbol("BTC/USDT") == "BTCUSDT"

    def test_raw_input(self):
        assert es.storage_symbol("ETHUSDT") == "ETHUSDT"


class TestFloorToStep:
    def test_no_step(self):
        assert es.floor_to_step(1.234, 0) == 1.234

    def test_floors_to_step(self):
        assert es.floor_to_step(1.234, 0.1) == pytest.approx(1.2)

    def test_exact_multiple(self):
        assert es.floor_to_step(12, 1) == 12


class TestGetExchangeCaching:
    def test_returns_cached_instance(self, monkeypatch):
        monkeypatch.setenv("BINANCE_API_KEY", "test_key")
        monkeypatch.setenv("BINANCE_API_SECRET", "test_secret")

        class FakeEx:
            def load_markets(self):
                pass

        # Reset cache and patch ccxt.binance
        original_cache = es._exchange_cache
        original_cached_at = es._exchange_cached_at
        try:
            es._exchange_cache = None
            es._exchange_cached_at = None
            monkeypatch.setattr(es.ccxt, "binance", lambda *a, **kw: FakeEx())

            first = es.get_exchange()
            second = es.get_exchange()
            assert first is second

            third = es.get_exchange(force_new=True)
            assert third is not first
        finally:
            es._exchange_cache = original_cache
            es._exchange_cached_at = original_cached_at

    def test_cache_expires_after_ttl(self, monkeypatch):
        monkeypatch.setenv("BINANCE_API_KEY", "test_key")
        monkeypatch.setenv("BINANCE_API_SECRET", "test_secret")

        class FakeEx:
            def load_markets(self):
                pass

        original_cache = es._exchange_cache
        original_cached_at = es._exchange_cached_at
        try:
            es._exchange_cache = None
            es._exchange_cached_at = None
            monkeypatch.setattr(es.ccxt, "binance", lambda *a, **kw: FakeEx())
            monkeypatch.setattr(es, "load_env", lambda: None)

            first = es.get_exchange()
            # Simulate time passing beyond TTL
            es._exchange_cached_at -= es.CACHE_TTL_SECONDS + 1
            second = es.get_exchange()
            assert first is not second
        finally:
            es._exchange_cache = original_cache
            es._exchange_cached_at = original_cached_at