"""Tests for the managed proxy pool."""

import asyncio
import ssl
import time
from unittest.mock import AsyncMock, MagicMock, patch

import pytest

from s5p.config import ChainHop, PoolSourceConfig, ProxyPoolConfig
from s5p.pool import ProxyEntry, ProxyPool


class TestProxyEntry:
    """Test ProxyEntry defaults."""

    def test_defaults(self):
        hop = ChainHop(proto="socks5", host="1.2.3.4", port=1080)
        entry = ProxyEntry(hop=hop)
        assert entry.alive is False
        assert entry.fails == 0
        assert entry.tests == 0


class TestProxyPoolMerge:
    """Test proxy deduplication and merge."""

    def test_merge_dedup(self):
        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)
        proxies = [
            ChainHop(proto="socks5", host="1.2.3.4", port=1080),
            ChainHop(proto="socks5", host="1.2.3.4", port=1080),
            ChainHop(proto="socks5", host="5.6.7.8", port=1080),
        ]
        pool._merge(proxies)
        assert pool.count == 2

    def test_merge_updates_existing(self):
        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)
        hop = ChainHop(proto="socks5", host="1.2.3.4", port=1080)
        pool._merge([hop])
        first_seen = pool._proxies["socks5://1.2.3.4:1080"].last_seen

        # merge again -- last_seen should update
        time.sleep(0.01)
        pool._merge([hop])
        assert pool._proxies["socks5://1.2.3.4:1080"].last_seen >= first_seen
        assert pool.count == 1


class TestProxyPoolGet:
    """Test proxy selection."""

    def test_get_empty(self):
        import asyncio

        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)
        result = asyncio.run(pool.get())
        assert result is None

    def test_get_returns_alive(self):
        import asyncio

        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)
        hop = ChainHop(proto="socks5", host="1.2.3.4", port=1080)
        pool._proxies["socks5://1.2.3.4:1080"] = ProxyEntry(hop=hop, alive=True)
        pool._rebuild_alive()
        result = asyncio.run(pool.get())
        assert result is not None
        assert result.host == "1.2.3.4"


class TestProxyPoolWeight:
    """Test weighted proxy selection."""

    def test_recent_proxy_preferred(self):
        import asyncio
        from collections import Counter

        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)

        now = time.time()
        fresh = ChainHop(proto="socks5", host="10.0.0.1", port=1080)
        stale = ChainHop(proto="socks5", host="10.0.0.2", port=1080)
        pool._proxies["socks5://10.0.0.1:1080"] = ProxyEntry(
            hop=fresh, alive=True, last_ok=now,
        )
        pool._proxies["socks5://10.0.0.2:1080"] = ProxyEntry(
            hop=stale, alive=True, last_ok=now - 3600,
        )
        pool._rebuild_alive()

        counts: Counter[str] = Counter()
        for _ in range(1000):
            hop = asyncio.run(pool.get())
            counts[hop.host] += 1

        assert counts["10.0.0.1"] > counts["10.0.0.2"] * 3

    def test_weight_values(self):
        hop = ChainHop(proto="socks5", host="1.2.3.4", port=1080)
        now = 1000.0

        # just tested
        entry = ProxyEntry(hop=hop, last_ok=now)
        assert ProxyPool._weight(entry, now) == pytest.approx(1.0)

        # 5 minutes ago
        entry.last_ok = now - 300
        assert ProxyPool._weight(entry, now) == pytest.approx(0.5)

        # never tested
        entry.last_ok = 0
        assert ProxyPool._weight(entry, now) == pytest.approx(0.01)

    def test_weight_failure_penalty(self):
        hop = ChainHop(proto="socks5", host="1.2.3.4", port=1080)
        now = 1000.0

        # healthy proxy: weight ~1.0
        entry = ProxyEntry(hop=hop, last_ok=now)
        assert ProxyPool._weight(entry, now) == pytest.approx(1.0)

        # just failed: weight drops to floor (fail_age=0 -> multiplier=0)
        entry.last_fail = now
        assert ProxyPool._weight(entry, now) == pytest.approx(0.01)

        # 30s after failure: base=1/(1+30/300)=0.909, penalty=30/60=0.5 -> ~0.45
        assert ProxyPool._weight(entry, now + 30) == pytest.approx(0.4545, abs=0.05)

        # 60s after failure: penalty=1.0, only base decay -> 1/(1+60/300)=0.833
        assert ProxyPool._weight(entry, now + 60) == pytest.approx(0.833, abs=0.05)

    def test_report_failure(self):
        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)
        hop = ChainHop(proto="socks5", host="1.2.3.4", port=1080)
        pool._proxies["socks5://1.2.3.4:1080"] = ProxyEntry(
            hop=hop, alive=True, last_ok=time.time(),
        )

        assert pool._proxies["socks5://1.2.3.4:1080"].last_fail == 0.0
        pool.report_failure(hop)
        assert pool._proxies["socks5://1.2.3.4:1080"].last_fail > 0.0

    def test_report_failure_unknown_proxy(self):
        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)
        hop = ChainHop(proto="socks5", host="9.9.9.9", port=1080)
        pool.report_failure(hop)  # should not raise


class TestProxyPoolHealthTests:
    """Test selective health testing."""

    def test_selective_keys(self):
        import asyncio
        from unittest.mock import AsyncMock, patch

        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)

        now = time.time()
        hop_a = ChainHop(proto="socks5", host="10.0.0.1", port=1080)
        hop_b = ChainHop(proto="socks5", host="10.0.0.2", port=1080)
        pool._proxies["socks5://10.0.0.1:1080"] = ProxyEntry(
            hop=hop_a, alive=False, last_seen=now,
        )
        pool._proxies["socks5://10.0.0.2:1080"] = ProxyEntry(
            hop=hop_b, alive=False, last_seen=now,
        )

        # only test proxy A
        with patch.object(pool, "_test_proxy", new_callable=AsyncMock, return_value=True) as mock:
            asyncio.run(pool._run_health_tests(keys=["socks5://10.0.0.1:1080"]))
            # should only have been called for proxy A
            assert mock.call_count == 1
            assert mock.call_args[0][0] == "socks5://10.0.0.1:1080"

        assert pool._proxies["socks5://10.0.0.1:1080"].alive is True
        # proxy B untouched
        assert pool._proxies["socks5://10.0.0.2:1080"].alive is False

    def test_chain_check_skips_on_failure(self):
        import asyncio
        from unittest.mock import AsyncMock, patch

        chain_hop = ChainHop(proto="socks5", host="127.0.0.1", port=9050)
        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [chain_hop], timeout=10.0)

        now = time.time()
        hop = ChainHop(proto="socks5", host="10.0.0.1", port=1080)
        pool._proxies["socks5://10.0.0.1:1080"] = ProxyEntry(
            hop=hop, alive=True, last_seen=now, last_ok=now,
        )
        pool._rebuild_alive()

        # chain test fails -> proxy tests should be skipped
        with (
            patch.object(pool, "_test_chain", new_callable=AsyncMock, return_value=False),
            patch.object(pool, "_test_proxy", new_callable=AsyncMock) as mock_proxy,
        ):
            asyncio.run(pool._run_health_tests())
            mock_proxy.assert_not_called()

        # proxy should remain in its previous state (untouched)
        assert pool._proxies["socks5://10.0.0.1:1080"].alive is True

    def test_chain_check_passes(self):
        import asyncio
        from unittest.mock import AsyncMock, patch

        chain_hop = ChainHop(proto="socks5", host="127.0.0.1", port=9050)
        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [chain_hop], timeout=10.0)

        now = time.time()
        hop = ChainHop(proto="socks5", host="10.0.0.1", port=1080)
        pool._proxies["socks5://10.0.0.1:1080"] = ProxyEntry(
            hop=hop, alive=False, last_seen=now,
        )

        # chain test passes -> proxy tests should run
        with (
            patch.object(pool, "_test_chain", new_callable=AsyncMock, return_value=True),
            patch.object(pool, "_test_proxy", new_callable=AsyncMock, return_value=True),
        ):
            asyncio.run(pool._run_health_tests())

        assert pool._proxies["socks5://10.0.0.1:1080"].alive is True

    def test_no_chain_skips_check(self):
        import asyncio
        from unittest.mock import AsyncMock, patch

        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)  # no static chain

        now = time.time()
        hop = ChainHop(proto="socks5", host="10.0.0.1", port=1080)
        pool._proxies["socks5://10.0.0.1:1080"] = ProxyEntry(
            hop=hop, alive=False, last_seen=now,
        )

        # no chain -> _test_chain should not be called, proxy tests run
        with (
            patch.object(pool, "_test_chain", new_callable=AsyncMock) as mock_chain,
            patch.object(pool, "_test_proxy", new_callable=AsyncMock, return_value=True),
        ):
            asyncio.run(pool._run_health_tests())
            mock_chain.assert_not_called()

        assert pool._proxies["socks5://10.0.0.1:1080"].alive is True


class TestProxyPoolReport:
    """Test dead proxy reporting."""

    def test_report_called_on_eviction(self):
        import asyncio
        from unittest.mock import AsyncMock, patch

        cfg = ProxyPoolConfig(sources=[], report_url="http://api:8081/report", max_fails=1)
        pool = ProxyPool(cfg, [], timeout=10.0)

        now = time.time()
        hop = ChainHop(proto="socks5", host="10.0.0.1", port=1080)
        pool._proxies["socks5://10.0.0.1:1080"] = ProxyEntry(
            hop=hop, alive=False, last_seen=now, fails=0,
        )

        with (
            patch.object(pool, "_test_proxy", new_callable=AsyncMock, return_value=False),
            patch.object(pool, "_report_dead", new_callable=AsyncMock) as mock_report,
        ):
            asyncio.run(pool._run_health_tests())
            # proxy should be evicted (fails=1 >= max_fails=1)
            assert "socks5://10.0.0.1:1080" not in pool._proxies
            mock_report.assert_called_once()
            keys = mock_report.call_args[0][0]
            assert "socks5://10.0.0.1:1080" in keys

    def test_report_not_called_without_url(self):
        import asyncio
        from unittest.mock import AsyncMock, patch

        cfg = ProxyPoolConfig(sources=[], max_fails=1)  # no report_url
        pool = ProxyPool(cfg, [], timeout=10.0)

        now = time.time()
        hop = ChainHop(proto="socks5", host="10.0.0.1", port=1080)
        pool._proxies["socks5://10.0.0.1:1080"] = ProxyEntry(
            hop=hop, alive=False, last_seen=now, fails=0,
        )

        with (
            patch.object(pool, "_test_proxy", new_callable=AsyncMock, return_value=False),
            patch.object(pool, "_report_dead", new_callable=AsyncMock) as mock_report,
        ):
            asyncio.run(pool._run_health_tests())
            mock_report.assert_not_called()

    def test_report_async_payload(self):
        import asyncio
        from unittest.mock import AsyncMock, patch

        cfg = ProxyPoolConfig(sources=[], report_url="http://api:8081/report")
        pool = ProxyPool(cfg, [], timeout=10.0)

        with patch("s5p.pool.http_post_json", new_callable=AsyncMock) as mock_post:
            asyncio.run(pool._report_dead(["socks5://10.0.0.1:1080"]))
            mock_post.assert_called_once()
            url = mock_post.call_args[0][0]
            payload = mock_post.call_args[0][1]
            assert url == "http://api:8081/report"
            assert payload == {"dead": [{"proto": "socks5", "proxy": "10.0.0.1:1080"}]}


class TestProxyPoolStaleExpiry:
    """Test stale proxy eviction."""

    def test_stale_dead_proxy_evicted(self):
        import asyncio
        from unittest.mock import AsyncMock, patch

        cfg = ProxyPoolConfig(sources=[], refresh=300)
        pool = ProxyPool(cfg, [], timeout=10.0)

        now = time.time()
        # stale + dead: should be evicted
        stale = ChainHop(proto="socks5", host="10.0.0.1", port=1080)
        pool._proxies["socks5://10.0.0.1:1080"] = ProxyEntry(
            hop=stale, alive=False, last_seen=now - 1200,
        )
        # fresh + dead: should survive (recently seen, might recover)
        fresh_dead = ChainHop(proto="socks5", host="10.0.0.2", port=1080)
        pool._proxies["socks5://10.0.0.2:1080"] = ProxyEntry(
            hop=fresh_dead, alive=False, last_seen=now,
        )

        with patch.object(pool, "_test_proxy", new_callable=AsyncMock, return_value=False):
            asyncio.run(pool._run_health_tests())

        assert "socks5://10.0.0.1:1080" not in pool._proxies
        assert "socks5://10.0.0.2:1080" in pool._proxies

    def test_stale_alive_proxy_kept(self):
        import asyncio
        from unittest.mock import AsyncMock, patch

        cfg = ProxyPoolConfig(sources=[], refresh=300)
        pool = ProxyPool(cfg, [], timeout=10.0)

        now = time.time()
        # stale but alive: should survive (still passing health tests)
        hop = ChainHop(proto="socks5", host="10.0.0.1", port=1080)
        pool._proxies["socks5://10.0.0.1:1080"] = ProxyEntry(
            hop=hop, alive=True, last_seen=now - 1200, last_ok=now,
        )

        with patch.object(pool, "_test_proxy", new_callable=AsyncMock, return_value=True):
            asyncio.run(pool._run_health_tests())

        assert "socks5://10.0.0.1:1080" in pool._proxies


class TestProxyPoolFetchFile:
    """Test file source parsing."""

    def test_parse_file(self, tmp_path):
        proxy_file = tmp_path / "proxies.txt"
        proxy_file.write_text(
            "# comment\n"
            "socks5://1.2.3.4:1080\n"
            "socks5://user:pass@5.6.7.8:1080\n"
            "http://proxy.example.com:8080\n"
            "\n"
            "  # another comment\n"
        )
        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)
        src = PoolSourceConfig(file=str(proxy_file))
        result = pool._fetch_file_sync(src)
        assert len(result) == 3
        assert result[0].proto == "socks5"
        assert result[0].host == "1.2.3.4"
        assert result[1].username == "user"
        assert result[1].password == "pass"
        assert result[2].proto == "http"

    def test_parse_file_with_proto_filter(self, tmp_path):
        proxy_file = tmp_path / "proxies.txt"
        proxy_file.write_text(
            "socks5://1.2.3.4:1080\n"
            "http://proxy.example.com:8080\n"
        )
        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)
        src = PoolSourceConfig(file=str(proxy_file), proto="socks5")
        result = pool._fetch_file_sync(src)
        assert len(result) == 1
        assert result[0].proto == "socks5"

    def test_missing_file(self, tmp_path):
        cfg = ProxyPoolConfig(sources=[])
        pool = ProxyPool(cfg, [], timeout=10.0)
        src = PoolSourceConfig(file=str(tmp_path / "nonexistent.txt"))
        result = pool._fetch_file_sync(src)
        assert result == []


class TestProxyPoolPersistence:
    """Test state save/load."""

    def test_save_and_load(self, tmp_path):
        state_file = str(tmp_path / "pool.json")
        cfg = ProxyPoolConfig(sources=[], state_file=state_file)
        pool = ProxyPool(cfg, [], timeout=10.0)

        hop = ChainHop(proto="socks5", host="1.2.3.4", port=1080)
        pool._proxies["socks5://1.2.3.4:1080"] = ProxyEntry(
            hop=hop, alive=True, fails=0, tests=5, last_ok=1000.0,
        )
        pool._rebuild_alive()
        pool._save_state()

        # load into a fresh pool
        pool2 = ProxyPool(cfg, [], timeout=10.0)
        pool2._load_state()
        assert pool2.count == 1
        assert pool2.alive_count == 1
        entry = pool2._proxies["socks5://1.2.3.4:1080"]
        assert entry.hop.host == "1.2.3.4"
        assert entry.tests == 5
        assert entry.alive is True

    def test_corrupt_state(self, tmp_path):
        state_file = tmp_path / "pool.json"
        state_file.write_text("{invalid json")
        cfg = ProxyPoolConfig(sources=[], state_file=str(state_file))
        pool = ProxyPool(cfg, [], timeout=10.0)
        pool._load_state()
        assert pool.count == 0

    def test_missing_state(self, tmp_path):
        cfg = ProxyPoolConfig(sources=[], state_file=str(tmp_path / "missing.json"))
        pool = ProxyPool(cfg, [], timeout=10.0)
        pool._load_state()  # should not raise
        assert pool.count == 0

    def test_state_with_auth(self, tmp_path):
        state_file = str(tmp_path / "pool.json")
        cfg = ProxyPoolConfig(sources=[], state_file=state_file)
        pool = ProxyPool(cfg, [], timeout=10.0)

        hop = ChainHop(
            proto="socks5", host="1.2.3.4", port=1080,
            username="user", password="pass",
        )
        pool._proxies["socks5://1.2.3.4:1080"] = ProxyEntry(hop=hop, alive=True)
        pool._save_state()

        pool2 = ProxyPool(cfg, [], timeout=10.0)
        pool2._load_state()
        entry = pool2._proxies["socks5://1.2.3.4:1080"]
        assert entry.hop.username == "user"
        assert entry.hop.password == "pass"


class TestTlsCheck:
    """Test TLS handshake health check."""

    def _make_pool(self, **kwargs):
        cfg = ProxyPoolConfig(sources=[], **kwargs)
        return ProxyPool(cfg, [], timeout=10.0)

    def test_success(self):
        pool = self._make_pool(test_targets=["www.example.com"])

        mock_writer = MagicMock()
        mock_writer.is_closing.return_value = False
        mock_transport = MagicMock()
        mock_protocol = MagicMock()
        mock_transport.get_protocol.return_value = mock_protocol
        mock_writer.transport = mock_transport

        new_transport = MagicMock()

        chain_ret = (MagicMock(), mock_writer)
        with (
            patch("s5p.pool.build_chain", new_callable=AsyncMock, return_value=chain_ret),
            patch("asyncio.get_running_loop") as mock_loop_fn,
        ):
            mock_loop = MagicMock()
            mock_loop.start_tls = AsyncMock(return_value=new_transport)
            mock_loop_fn.return_value = mock_loop

            result = asyncio.run(pool._tls_check([]))

        assert result is True
        mock_loop.start_tls.assert_called_once_with(
            mock_transport, mock_protocol, pool._ssl_ctx,
            server_hostname="www.example.com",
        )
        new_transport.close.assert_called_once()

    def test_build_chain_failure(self):
        pool = self._make_pool(test_targets=["www.example.com"])

        with patch(
            "s5p.pool.build_chain", new_callable=AsyncMock,
            side_effect=ConnectionError("refused"),
        ):
            result = asyncio.run(pool._tls_check([]))

        assert result is False

    def test_handshake_failure(self):
        pool = self._make_pool(test_targets=["www.example.com"])

        mock_writer = MagicMock()
        mock_writer.is_closing.return_value = False
        mock_transport = MagicMock()
        mock_transport.get_protocol.return_value = MagicMock()
        mock_writer.transport = mock_transport

        chain_ret = (MagicMock(), mock_writer)
        with (
            patch("s5p.pool.build_chain", new_callable=AsyncMock, return_value=chain_ret),
            patch("asyncio.get_running_loop") as mock_loop_fn,
        ):
            mock_loop = MagicMock()
            mock_loop.start_tls = AsyncMock(
                side_effect=ssl.SSLError("handshake failed"),
            )
            mock_loop_fn.return_value = mock_loop

            result = asyncio.run(pool._tls_check([]))

        assert result is False

    def test_round_robin_rotation(self):
        targets = ["host-a.example.com", "host-b.example.com", "host-c.example.com"]
        pool = self._make_pool(test_targets=targets)

        selected: list[str] = []

        async def fake_build_chain(chain, host, port, timeout=None):
            selected.append(host)
            raise ConnectionError("test")

        with patch("s5p.pool.build_chain", side_effect=fake_build_chain):
            for _ in range(6):
                asyncio.run(pool._tls_check([]))

        assert selected == ["host-a.example.com", "host-b.example.com", "host-c.example.com",
                            "host-a.example.com", "host-b.example.com", "host-c.example.com"]

    def test_empty_targets(self):
        pool = self._make_pool(test_targets=[])
        result = asyncio.run(pool._tls_check([]))
        assert result is False


class TestProxyPoolConfigCompat:
    """Test backward compatibility for test_url -> test_targets."""

    def test_legacy_test_url_converts(self):
        cfg = ProxyPoolConfig(test_url="http://httpbin.org/ip")
        assert cfg.test_targets == ["httpbin.org"]

    def test_explicit_test_targets_wins(self):
        cfg = ProxyPoolConfig(
            test_url="http://httpbin.org/ip",
            test_targets=["custom.example.com"],
        )
        assert cfg.test_targets == ["custom.example.com"]

    def test_defaults_when_neither_set(self):
        cfg = ProxyPoolConfig()
        assert cfg.test_targets == ["www.google.com", "www.cloudflare.com", "www.amazon.com"]
        assert cfg.test_url == ""