"""Unit tests for the slack_notifier handler."""

import sys
import os
from datetime import datetime
from decimal import Decimal
from unittest.mock import patch
from zoneinfo import ZoneInfo

# ---------------------------------------------------------------------------
# Ensure the handler module can be imported.  The shared layer lives under
# src/shared/ and the handler lives under functions/slack_notifier/.
# ---------------------------------------------------------------------------
import importlib.util

_repo = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
sys.path.insert(0, os.path.join(_repo, "src", "shared"))

_handler_path = os.path.join(_repo, "functions", "slack_notifier", "handler.py")
_spec = importlib.util.spec_from_file_location("slack_notifier_handler", _handler_path)
handler = importlib.util.module_from_spec(_spec)
sys.modules["slack_notifier_handler"] = handler
_spec.loader.exec_module(handler)

ET = ZoneInfo("America/New_York")


# ────────────────────────────────────────────────────────────────────────────
# Helpers
# ────────────────────────────────────────────────────────────────────────────


def _make_datetime(year, month, day, hour, minute=0):
    """Return a timezone-aware datetime in America/New_York."""
    return datetime(year, month, day, hour, minute, tzinfo=ET)


def _thursday_10am():
    """2026-05-14 is a Thursday."""
    return _make_datetime(2026, 5, 14, 10)


def _thursday_11am():
    return _make_datetime(2026, 5, 14, 11)


def _wednesday_10am():
    """2026-05-13 is a Wednesday."""
    return _make_datetime(2026, 5, 13, 10)


# ────────────────────────────────────────────────────────────────────────────
# Reminder Dedup Guard (Critical)
# ────────────────────────────────────────────────────────────────────────────


class TestReminderDedupGuard:
    @patch("slack_notifier_handler.datetime")
    def test_reminder_skipped_wrong_hour(self, mock_dt):
        """Invoked at 11am Thursday ET -> returns skipped."""
        mock_dt.now.return_value = _thursday_11am()

        result = handler.handle_reminder({"event": "reminder"})

        assert result["status"] == "skipped", "Should skip when hour is not 10"
        assert "outside reminder window" in result["reason"]

    @patch("slack_notifier_handler.datetime")
    def test_reminder_skipped_wrong_day(self, mock_dt):
        """Invoked at 10am Wednesday ET -> returns skipped."""
        mock_dt.now.return_value = _wednesday_10am()

        result = handler.handle_reminder({"event": "reminder"})

        assert result["status"] == "skipped", "Should skip when day is not Thursday"
        assert "outside reminder window" in result["reason"]

    @patch("slack_notifier_handler.send_dm")
    @patch("slack_notifier_handler.get_orders", return_value=[])
    @patch("slack_notifier_handler.get_roster", return_value=[])
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    @patch("slack_notifier_handler.datetime")
    def test_reminder_runs_at_correct_time(
        self, mock_dt, mock_week, mock_roster, mock_orders, mock_dm
    ):
        """Invoked at 10am Thursday ET -> proceeds (does not skip)."""
        mock_dt.now.return_value = _thursday_10am()

        result = handler.handle_reminder({"event": "reminder"})

        assert result["status"] != "skipped", "Should not skip at 10am Thursday"

    @patch("slack_notifier_handler.datetime")
    def test_lambda_handler_reminder_guard(self, mock_dt):
        """lambda_handler lines 32-34 also return skipped for wrong time."""
        mock_dt.now.return_value = _thursday_11am()

        result = handler.lambda_handler({"event": "reminder"}, None)

        assert result["status"] == "skipped", (
            "lambda_handler should short-circuit before calling handle_reminder"
        )
        assert "outside reminder window" in result["reason"]


# ────────────────────────────────────────────────────────────────────────────
# Reminder DMs (High)
# ────────────────────────────────────────────────────────────────────────────


class TestReminderDMs:
    @patch("slack_notifier_handler.send_dm")
    @patch("slack_notifier_handler.get_orders")
    @patch("slack_notifier_handler.get_roster")
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    @patch("slack_notifier_handler.datetime")
    def test_reminder_sends_to_non_ordered(
        self, mock_dt, mock_week, mock_roster, mock_orders, mock_dm
    ):
        """Roster of 3, 1 has ordered -> DMs sent to 2 others."""
        mock_dt.now.return_value = _thursday_10am()
        mock_roster.return_value = [
            {"email": "alice@x.com", "name": "Alice A", "slack_user_id": "U001"},
            {"email": "bob@x.com", "name": "Bob B", "slack_user_id": "U002"},
            {"email": "carol@x.com", "name": "Carol C", "slack_user_id": "U003"},
        ]
        mock_orders.return_value = [
            {"employee_email": "alice@x.com"},
        ]

        result = handler.handle_reminder({"event": "reminder"})

        assert result["dm_count"] == 2, "Should DM the 2 employees who haven't ordered"
        assert result["missing_count"] == 2
        assert mock_dm.call_count == 2

        dm_user_ids = {call.args[0] for call in mock_dm.call_args_list}
        assert dm_user_ids == {"U002", "U003"}, "Should DM Bob and Carol, not Alice"

    @patch("slack_notifier_handler.send_dm")
    @patch("slack_notifier_handler.get_orders", return_value=[])
    @patch("slack_notifier_handler.get_roster")
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    @patch("slack_notifier_handler.datetime")
    def test_reminder_skips_no_slack_id(
        self, mock_dt, mock_week, mock_roster, mock_orders, mock_dm
    ):
        """Employee without slack_user_id is counted as missing but not DM'd."""
        mock_dt.now.return_value = _thursday_10am()
        mock_roster.return_value = [
            {"email": "dave@x.com", "name": "Dave D"},  # no slack_user_id
            {"email": "eve@x.com", "name": "Eve E", "slack_user_id": "U005"},
        ]

        result = handler.handle_reminder({"event": "reminder"})

        assert result["missing_count"] == 2, "Both are missing (no orders at all)"
        assert result["dm_count"] == 1, "Only Eve should be DM'd (Dave has no Slack ID)"
        mock_dm.assert_called_once()
        assert mock_dm.call_args.args[0] == "U005"

    @patch("slack_notifier_handler.send_dm")
    @patch("slack_notifier_handler.get_orders")
    @patch("slack_notifier_handler.get_roster")
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    @patch("slack_notifier_handler.datetime")
    def test_reminder_case_insensitive_email(
        self, mock_dt, mock_week, mock_roster, mock_orders, mock_dm
    ):
        """'Adam@x.com' in roster matches 'adam@x.com' in orders."""
        mock_dt.now.return_value = _thursday_10am()
        mock_roster.return_value = [
            {"email": "Adam@x.com", "name": "Adam M", "slack_user_id": "U010"},
        ]
        mock_orders.return_value = [
            {"employee_email": "adam@x.com"},
        ]

        result = handler.handle_reminder({"event": "reminder"})

        assert result["dm_count"] == 0, (
            "Adam already ordered (case-insensitive match) — no DM expected"
        )
        mock_dm.assert_not_called()


# ────────────────────────────────────────────────────────────────────────────
# Order Confirmed (High)
# ────────────────────────────────────────────────────────────────────────────


class TestOrderConfirmed:
    @patch("slack_notifier_handler.send_dm")
    @patch("slack_notifier_handler.get_roster")
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    def test_order_confirmed_dm_format(self, mock_week, mock_roster, mock_dm):
        """DM contains item breakdown with 'your cost' labels and payroll total."""
        mock_roster.return_value = [
            {"email": "alice@x.com", "name": "Alice Adams", "slack_user_id": "U001"},
        ]

        event = {
            "event": "order_confirmed",
            "employee_email": "alice@x.com",
            "employee_name": "Alice Adams",
            "items": [
                {"name": "Grilled Chicken", "quantity": 2, "price": 8.50},
                {"name": "Caesar Salad", "quantity": 1, "price": 6.00},
            ],
            "total": 23.00,
            "week": "2026-W19",
        }

        handler.handle_order_confirmed(event)

        mock_dm.assert_called_once()
        call_kwargs = mock_dm.call_args
        blocks = call_kwargs.kwargs.get("blocks") or call_kwargs[1].get("blocks")
        body_text = blocks[1]["text"]["text"]

        assert "your cost: $17.00" in body_text, "Should show Grilled Chicken x2 cost"
        assert "your cost: $6.00" in body_text, "Should show Caesar Salad x1 cost"
        assert "$23.00" in body_text, "Should show payroll deduction total"
        assert "payroll deduction" in body_text.lower()

    @patch("slack_notifier_handler.send_dm")
    @patch("slack_notifier_handler.get_roster")
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    def test_order_confirmed_no_slack_id(self, mock_week, mock_roster, mock_dm):
        """Employee not in roster -> returns {'status': 'no_slack_id'}."""
        mock_roster.return_value = []  # empty roster

        event = {
            "event": "order_confirmed",
            "employee_email": "nobody@x.com",
            "employee_name": "Nobody",
            "items": [],
            "total": 0,
        }

        result = handler.handle_order_confirmed(event)

        assert result["status"] == "no_slack_id"
        mock_dm.assert_not_called()

    @patch("slack_notifier_handler.send_dm")
    @patch("slack_notifier_handler.get_roster")
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    def test_order_confirmed_empty_name(self, mock_week, mock_roster, mock_dm):
        """Empty name -> greeting says 'Hey there!' not crash."""
        mock_roster.return_value = [
            {"email": "anon@x.com", "name": "", "slack_user_id": "U099"},
        ]

        event = {
            "event": "order_confirmed",
            "employee_email": "anon@x.com",
            "employee_name": "",
            "items": [{"name": "Soup", "quantity": 1, "price": 5.00}],
            "total": 5.00,
        }

        result = handler.handle_order_confirmed(event)

        assert result["status"] == "confirmed", "Should not crash on empty name"

        blocks = mock_dm.call_args.kwargs.get("blocks") or mock_dm.call_args[1].get(
            "blocks"
        )
        body_text = blocks[1]["text"]["text"]
        assert "Hey there!" in body_text, (
            "Should greet with 'Hey there!' when name is empty"
        )


# ────────────────────────────────────────────────────────────────────────────
# Orders Aggregated (High)
# ────────────────────────────────────────────────────────────────────────────


class TestOrdersAggregated:
    @patch("slack_notifier_handler.send_dm")
    @patch("slack_notifier_handler.get_roster")
    @patch("slack_notifier_handler.get_settings")
    @patch("slack_notifier_handler.get_summary")
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    def test_orders_aggregated_with_subsidy(
        self, mock_week, mock_summary, mock_settings, mock_roster, mock_dm
    ):
        """employee_total < grand_total -> admin DM includes company subsidy line."""
        mock_summary.return_value = {
            "total_employees": 5,
            "total_meals": 12,
            "grand_total": Decimal("150.00"),
            "employee_total": Decimal("120.00"),
            "meals": [
                {"meal": "Grilled Chicken", "quantity": Decimal("7")},
                {"meal": "Veggie Bowl", "quantity": Decimal("5")},
            ],
        }
        mock_settings.return_value = {"admin_emails": ["admin@x.com"]}
        mock_roster.return_value = [
            {"email": "admin@x.com", "name": "Admin A", "slack_user_id": "U100"},
        ]

        result = handler.handle_orders_aggregated({"event": "orders_aggregated"})

        assert result["status"] == "notified"
        mock_dm.assert_called_once()

        blocks = mock_dm.call_args.args[2]
        section_text = blocks[1]["text"]["text"]

        assert "$150.00" in section_text, "Should show grand total"
        assert "$120.00" in section_text, "Should show employee payroll deductions"
        assert "$30.00" in section_text, "Should show company subsidy amount"
        assert "company subsidy" in section_text.lower()

    @patch("slack_notifier_handler.send_dm")
    @patch("slack_notifier_handler.get_roster")
    @patch("slack_notifier_handler.get_settings")
    @patch("slack_notifier_handler.get_summary")
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    def test_orders_aggregated_without_subsidy(
        self, mock_week, mock_summary, mock_settings, mock_roster, mock_dm
    ):
        """Equal totals -> no subsidy line."""
        mock_summary.return_value = {
            "total_employees": 3,
            "total_meals": 6,
            "grand_total": Decimal("90.00"),
            "employee_total": Decimal("90.00"),
            "meals": [
                {"meal": "Pasta Primavera", "quantity": Decimal("6")},
            ],
        }
        mock_settings.return_value = {"admin_emails": ["admin@x.com"]}
        mock_roster.return_value = [
            {"email": "admin@x.com", "name": "Admin A", "slack_user_id": "U100"},
        ]

        result = handler.handle_orders_aggregated({"event": "orders_aggregated"})

        assert result["status"] == "notified"
        blocks = mock_dm.call_args.args[2]
        section_text = blocks[1]["text"]["text"]

        assert "company subsidy" not in section_text.lower(), (
            "Should not mention subsidy when employee_total == grand_total"
        )

    @patch("slack_notifier_handler.post_channel_message")
    @patch("slack_notifier_handler.get_summary")
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    def test_orders_aggregated_no_summary(self, mock_week, mock_summary, mock_post):
        """No summary in DB -> returns {'status': 'no_summary'}."""
        mock_summary.return_value = None

        result = handler.handle_orders_aggregated({"event": "orders_aggregated"})

        assert result["status"] == "no_summary"
        mock_post.assert_not_called()

    @patch("slack_notifier_handler.send_dm")
    @patch("slack_notifier_handler.get_roster")
    @patch("slack_notifier_handler.get_settings")
    @patch("slack_notifier_handler.post_channel_message")
    @patch("slack_notifier_handler.get_summary")
    @patch("slack_notifier_handler.current_week", return_value="2026-W19")
    def test_orders_aggregated_dms_admins(
        self, mock_week, mock_summary, mock_post, mock_settings, mock_roster, mock_dm
    ):
        """Admins with a Slack ID get DM'd the summary; others are skipped."""
        mock_summary.return_value = {
            "total_employees": 2,
            "total_meals": 4,
            "grand_total": Decimal("60.00"),
            "employee_total": Decimal("60.00"),
            "meals": [
                {"meal": "Grilled Chicken", "quantity": Decimal("4")},
            ],
        }
        mock_settings.return_value = {
            "admin_emails": ["Admin@x.com", "noslack@x.com", "missing@x.com"],
        }
        mock_roster.return_value = [
            {"email": "admin@x.com", "name": "Admin A", "slack_user_id": "U100"},
            {"email": "noslack@x.com", "name": "No Slack"},  # no slack_user_id
        ]

        result = handler.handle_orders_aggregated({"event": "orders_aggregated"})

        assert result["status"] == "notified"
        assert result["admin_dm_count"] == 1, "Only the admin with a Slack ID is DM'd"
        mock_dm.assert_called_once()
        assert mock_dm.call_args.args[0] == "U100"


# ────────────────────────────────────────────────────────────────────────────
# Escaping (Low)
# ────────────────────────────────────────────────────────────────────────────


class TestEscaping:
    def test_escape_mrkdwn(self):
        """'A & B <C>' -> 'A &amp; B &lt;C&gt;'."""
        assert handler._escape_mrkdwn("A & B <C>") == "A &amp; B &lt;C&gt;"


# ────────────────────────────────────────────────────────────────────────────
# Routing
# ────────────────────────────────────────────────────────────────────────────


class TestRouting:
    def test_unknown_event_type(self):
        """Unknown event type returns error message."""
        result = handler.lambda_handler({"event": "bogus_event"}, None)

        assert "error" in result, "Should return an error key for unknown event type"
        assert "bogus_event" in result["error"], (
            "Error message should include the unrecognised event type"
        )