"""Unit tests for slot generation and calendar logic — no HTTP involved."""
import asyncio
from datetime import date, time, timedelta
from unittest.mock import AsyncMock, MagicMock

import pytest

from app.services.slot_service import generate_slots, _fmt_time  # type: ignore
from app.exceptions import AppError


def make_mock_db(schedule=None, blocked=None):
    db = AsyncMock()
    db.transaction = MagicMock(return_value=_TxCtx())
    db.fetch = AsyncMock(side_effect=lambda q, *a: _route_fetch(q, schedule, blocked))
    db.fetchval = AsyncMock(return_value=None)
    db.execute = AsyncMock(return_value="INSERT 1")
    return db


def _route_fetch(query, schedule, blocked):
    if "weekly_schedule" in query:
        return schedule or []
    if "blocked_dates" in query:
        return blocked or []
    return []


class _TxCtx:
    async def __aenter__(self): return self
    async def __aexit__(self, *a): return False


MONDAY = 0  # weekday() value for Monday

SCHED_ROW = {
    "day_of_week": MONDAY,
    "start_time": time(9, 0),
    "end_time": time(11, 0),
    "slot_duration_minutes": 60,
}


async def test_generate_slots_creates_correct_count():
    """Mon 09:00–11:00 with 60-min slots → 2 slots per Monday."""
    db = make_mock_db(schedule=[SCHED_ROW])

    # Find the next Monday
    today = date.today()
    days_ahead = (7 - today.weekday()) % 7 or 7
    next_monday = today + timedelta(days=days_ahead)

    db.fetchval = AsyncMock(return_value=None)  # no existing slots

    created = await generate_slots(db, next_monday, next_monday)
    assert created == 2


async def test_generate_slots_skips_blocked_dates():
    """A blocked Monday produces 0 slots."""
    today = date.today()
    days_ahead = (7 - today.weekday()) % 7 or 7
    next_monday = today + timedelta(days=days_ahead)

    blocked = [{"date": next_monday}]
    db = make_mock_db(schedule=[SCHED_ROW], blocked=blocked)
    db.fetchval = AsyncMock(return_value=None)

    created = await generate_slots(db, next_monday, next_monday)
    assert created == 0


async def test_generate_slots_skips_existing_slots():
    """If a slot already exists, it is not duplicated."""
    today = date.today()
    days_ahead = (7 - today.weekday()) % 7 or 7
    next_monday = today + timedelta(days=days_ahead)

    db = make_mock_db(schedule=[SCHED_ROW])
    db.fetchval = AsyncMock(return_value=1)  # all slots already exist

    created = await generate_slots(db, next_monday, next_monday)
    assert created == 0


async def test_generate_slots_range_over_90_days_rejected():
    with pytest.raises(AppError) as exc_info:
        db = AsyncMock()
        await generate_slots(db, date(2026, 1, 1), date(2026, 5, 1))
    assert exc_info.value.code == "RANGE_TOO_LARGE"


async def test_generate_slots_no_schedule_raises():
    db = make_mock_db(schedule=[])
    with pytest.raises(AppError) as exc_info:
        await generate_slots(db, date(2026, 6, 1), date(2026, 6, 7))
    assert exc_info.value.code == "NO_SCHEDULE"


# ── Time formatting ───────────────────────────────────────────────────────────

def test_fmt_time_strips_seconds():
    from datetime import time as t
    assert _fmt_time(t(10, 0, 0)) == "10:00"
    assert _fmt_time(t(9, 30)) == "09:30"


def test_fmt_time_string_input():
    assert _fmt_time("14:30:00") == "14:30"
    assert _fmt_time("08:00") == "08:00"


def test_fmt_time_none():
    assert _fmt_time(None) == ""