"""
Unit tests for supervisor.py and proxy.py.

Tests cover pure-Python logic only — no DB, no subprocesses, no network.
DB-dependent functions (is_due, _get_last_success_time) are tested via mocks.

supervisor.py lives in src/padelnomics/ (not a uv workspace package), so we
add src/ to sys.path before importing.
"""

import sys
import textwrap
import tomllib
from datetime import UTC, datetime, timedelta
from pathlib import Path
from unittest.mock import MagicMock, patch

import pytest

# Load supervisor.py directly by path — avoids clashing with the web app's
# 'padelnomics' namespace (which is the installed web package).
import importlib.util as _ilu

_SUP_PATH = Path(__file__).parent.parent.parent / "src" / "padelnomics" / "supervisor.py"
_spec = _ilu.spec_from_file_location("padelnomics_supervisor", _SUP_PATH)
sup = _ilu.module_from_spec(_spec)
_spec.loader.exec_module(sup)

from padelnomics_extract.proxy import (
    load_proxy_urls,
    make_round_robin_cycler,
    make_sticky_selector,
)


# ── load_workflows ────────────────────────────────────────────────


class TestLoadWorkflows:
    def test_loads_all_fields(self, tmp_path):
        toml = tmp_path / "workflows.toml"
        toml.write_text(textwrap.dedent("""\
            [extract_a]
            module = "mypkg.extract_a"
            schedule = "daily"

            [extract_b]
            module = "mypkg.extract_b"
            schedule = "weekly"
            entry = "run"
            depends_on = ["extract_a"]
            proxy_mode = "sticky"
        """))
        wfs = sup.load_workflows(toml)
        assert len(wfs) == 2

        a = next(w for w in wfs if w["name"] == "extract_a")
        assert a["module"] == "mypkg.extract_a"
        assert a["schedule"] == "daily"
        assert a["entry"] == "main"         # default
        assert a["depends_on"] == []         # default
        assert a["proxy_mode"] == "round-robin"  # default

        b = next(w for w in wfs if w["name"] == "extract_b")
        assert b["entry"] == "run"
        assert b["depends_on"] == ["extract_a"]
        assert b["proxy_mode"] == "sticky"

    def test_raises_on_missing_module(self, tmp_path):
        toml = tmp_path / "bad.toml"
        toml.write_text("[wf]\nschedule = 'daily'\n")
        with pytest.raises(AssertionError, match="missing 'module'"):
            sup.load_workflows(toml)

    def test_raises_on_missing_schedule(self, tmp_path):
        toml = tmp_path / "bad.toml"
        toml.write_text("[wf]\nmodule = 'mypkg.wf'\n")
        with pytest.raises(AssertionError, match="missing 'schedule'"):
            sup.load_workflows(toml)

    def test_raises_if_file_missing(self, tmp_path):
        with pytest.raises(AssertionError, match="not found"):
            sup.load_workflows(tmp_path / "nonexistent.toml")


# ── resolve_schedule ──────────────────────────────────────────────


class TestResolveSchedule:
    def test_maps_named_presets(self):
        assert sup.resolve_schedule("hourly") == "0 * * * *"
        assert sup.resolve_schedule("daily") == "0 5 * * *"
        assert sup.resolve_schedule("weekly") == "0 3 * * 1"
        assert sup.resolve_schedule("monthly") == "0 4 1 * *"

    def test_passes_through_raw_cron(self):
        expr = "0 6-23 * * *"
        assert sup.resolve_schedule(expr) == expr

    def test_unknown_name_passes_through(self):
        assert sup.resolve_schedule("quarterly") == "quarterly"


# ── is_due ────────────────────────────────────────────────────────


class TestIsDue:
    def _wf(self, schedule="daily", name="test_wf"):
        return {"name": name, "schedule": schedule}

    def test_never_ran_is_due(self):
        conn = MagicMock()
        with patch.object(sup, "_get_last_success_time", return_value=None):
            assert sup.is_due(conn, self._wf()) is True

    def test_ran_after_last_trigger_is_not_due(self):
        """Last run was AFTER the most recent trigger — not due."""
        conn = MagicMock()
        # Use a daily schedule — trigger fires at 05:00 UTC
        # Simulate last success = today at 06:00, so trigger already covered
        now = datetime.now(UTC)
        last_success = now.replace(hour=6, minute=0, second=0, microsecond=0)
        with patch.object(sup, "_get_last_success_time", return_value=last_success):
            assert sup.is_due(conn, self._wf(schedule="daily")) is False

    def test_ran_before_last_trigger_is_due(self):
        """Last run was BEFORE the most recent trigger — due again."""
        conn = MagicMock()
        # Monthly fires on the 1st at 04:00 — simulate running last month
        last_success = datetime.now(UTC) - timedelta(days=35)
        with patch.object(sup, "_get_last_success_time", return_value=last_success):
            assert sup.is_due(conn, self._wf(schedule="monthly")) is True


# ── topological_waves ─────────────────────────────────────────────


class TestTopologicalWaves:
    def _wf(self, name, depends_on=None):
        return {"name": name, "depends_on": depends_on or []}

    def test_no_deps_single_wave(self):
        wfs = [self._wf("a"), self._wf("b"), self._wf("c")]
        waves = sup.topological_waves(wfs)
        assert len(waves) == 1
        assert {w["name"] for w in waves[0]} == {"a", "b", "c"}

    def test_simple_chain_two_waves(self):
        wfs = [self._wf("a"), self._wf("b", depends_on=["a"])]
        waves = sup.topological_waves(wfs)
        assert len(waves) == 2
        assert waves[0][0]["name"] == "a"
        assert waves[1][0]["name"] == "b"

    def test_diamond_three_waves(self):
        """a → b,c → d"""
        wfs = [
            self._wf("a"),
            self._wf("b", depends_on=["a"]),
            self._wf("c", depends_on=["a"]),
            self._wf("d", depends_on=["b", "c"]),
        ]
        waves = sup.topological_waves(wfs)
        assert len(waves) == 3
        assert waves[0][0]["name"] == "a"
        assert {w["name"] for w in waves[1]} == {"b", "c"}
        assert waves[2][0]["name"] == "d"

    def test_dep_outside_due_set_ignored(self):
        """Dependency not in the due set is treated as satisfied."""
        wfs = [self._wf("b", depends_on=["a"])]  # "a" not in due set
        waves = sup.topological_waves(wfs)
        assert len(waves) == 1
        assert waves[0][0]["name"] == "b"

    def test_circular_dep_raises(self):
        wfs = [
            self._wf("a", depends_on=["b"]),
            self._wf("b", depends_on=["a"]),
        ]
        with pytest.raises(AssertionError, match="Circular dependency"):
            sup.topological_waves(wfs)

    def test_empty_list_returns_empty(self):
        assert sup.topological_waves([]) == []

    def test_real_workflows_toml(self):
        """The actual workflows.toml in the repo parses and produces valid waves."""
        repo_root = Path(__file__).parent.parent.parent
        wf_path = repo_root / "infra" / "supervisor" / "workflows.toml"
        if not wf_path.exists():
            pytest.skip("workflows.toml not found")
        wfs = sup.load_workflows(wf_path)
        waves = sup.topological_waves(wfs)
        # playtomic_availability must come after playtomic_tenants
        all_names = [w["name"] for wave in waves for w in wave]
        tenants_idx = all_names.index("playtomic_tenants")
        avail_idx = all_names.index("playtomic_availability")
        assert tenants_idx < avail_idx


# ── proxy.py ─────────────────────────────────────────────────────


class TestLoadProxyUrls:
    def test_returns_empty_when_unset(self, monkeypatch):
        monkeypatch.delenv("PROXY_URLS", raising=False)
        assert load_proxy_urls() == []

    def test_parses_comma_separated_urls(self, monkeypatch):
        monkeypatch.setenv(
            "PROXY_URLS",
            "http://p1:8080,http://p2:8080,http://p3:8080",
        )
        urls = load_proxy_urls()
        assert urls == ["http://p1:8080", "http://p2:8080", "http://p3:8080"]

    def test_strips_whitespace(self, monkeypatch):
        monkeypatch.setenv("PROXY_URLS", " http://p1:8080 , http://p2:8080 ")
        urls = load_proxy_urls()
        assert urls == ["http://p1:8080", "http://p2:8080"]

    def test_ignores_empty_segments(self, monkeypatch):
        monkeypatch.setenv("PROXY_URLS", "http://p1:8080,,http://p2:8080,")
        urls = load_proxy_urls()
        assert urls == ["http://p1:8080", "http://p2:8080"]


class TestRoundRobinCycler:
    def test_returns_none_callable_when_no_proxies(self):
        fn = make_round_robin_cycler([])
        assert fn() is None

    def test_cycles_through_proxies(self):
        urls = ["http://p1", "http://p2", "http://p3"]
        fn = make_round_robin_cycler(urls)
        results = [fn() for _ in range(6)]
        assert results == ["http://p1", "http://p2", "http://p3"] * 2

    def test_thread_safe_independent_calls(self):
        """Concurrent calls each get a proxy — no exceptions."""
        import threading
        urls = ["http://p1", "http://p2"]
        fn = make_round_robin_cycler(urls)
        results = []
        lock = threading.Lock()

        def worker():
            proxy = fn()
            with lock:
                results.append(proxy)

        threads = [threading.Thread(target=worker) for _ in range(10)]
        for t in threads:
            t.start()
        for t in threads:
            t.join()

        assert len(results) == 10
        assert all(r in urls for r in results)


class TestStickySelectorProxy:
    def test_returns_none_callable_when_no_proxies(self):
        fn = make_sticky_selector([])
        assert fn("any_key") is None

    def test_same_key_always_same_proxy(self):
        urls = ["http://p1", "http://p2", "http://p3"]
        fn = make_sticky_selector(urls)
        proxy = fn("tenant_abc")
        for _ in range(10):
            assert fn("tenant_abc") == proxy

    def test_different_keys_can_map_to_different_proxies(self):
        urls = ["http://p1", "http://p2", "http://p3"]
        fn = make_sticky_selector(urls)
        results = {fn(f"key_{i}") for i in range(30)}
        assert len(results) > 1  # distribution across proxies

    def test_all_results_are_valid_proxies(self):
        urls = ["http://p1", "http://p2"]
        fn = make_sticky_selector(urls)
        for i in range(20):
            assert fn(f"key_{i}") in urls