"""Tests for BE-AGT-003 — multi-slot competition handling.

Covers:
  - Winner selection (highest priority)
  - Remaining slots marked Deferred with priority += 1
  - Priority capping at MAX_PRIORITY (99)
  - Empty input edge case
  - Single slot (no competition)
  - defer_all_slots when agent is not idle
"""

import pytest
from datetime import date, time

from app.models.calendar import SlotStatus, SlotType, TimeSlot
from app.services.slot_competition import (
    CompetitionResult,
    MAX_PRIORITY,
    defer_all_slots,
    resolve_slot_competition,
)


def _make_slot(db, user_id: int, *, priority: int, status=SlotStatus.NOT_STARTED) -> TimeSlot:
    """Helper — create a minimal TimeSlot in the test DB."""
    slot = TimeSlot(
        user_id=user_id,
        date=date(2026, 4, 1),
        slot_type=SlotType.WORK,
        estimated_duration=30,
        scheduled_at=time(9, 0),
        priority=priority,
        status=status,
    )
    db.add(slot)
    db.flush()
    return slot


# ---------------------------------------------------------------------------
# resolve_slot_competition
# ---------------------------------------------------------------------------

class TestResolveSlotCompetition:
    """Tests for resolve_slot_competition."""

    def test_empty_input(self, db, seed):
        result = resolve_slot_competition(db, [])
        assert result.winner is None
        assert result.deferred == []

    def test_single_slot_no_competition(self, db, seed):
        slot = _make_slot(db, 1, priority=50)
        result = resolve_slot_competition(db, [slot])

        assert result.winner is slot
        assert result.deferred == []
        # Winner should NOT be modified
        assert slot.status == SlotStatus.NOT_STARTED
        assert slot.priority == 50

    def test_winner_is_first_slot(self, db, seed):
        """Input is pre-sorted by priority desc; first slot wins."""
        high = _make_slot(db, 1, priority=80)
        mid = _make_slot(db, 1, priority=50)
        low = _make_slot(db, 1, priority=10)
        slots = [high, mid, low]

        result = resolve_slot_competition(db, slots)

        assert result.winner is high
        assert len(result.deferred) == 2
        assert mid in result.deferred
        assert low in result.deferred

    def test_deferred_slots_status_and_priority(self, db, seed):
        """Deferred slots get status=DEFERRED and priority += 1."""
        winner = _make_slot(db, 1, priority=80)
        loser1 = _make_slot(db, 1, priority=50)
        loser2 = _make_slot(db, 1, priority=10)

        resolve_slot_competition(db, [winner, loser1, loser2])

        # Winner untouched
        assert winner.status == SlotStatus.NOT_STARTED
        assert winner.priority == 80

        # Losers deferred + bumped
        assert loser1.status == SlotStatus.DEFERRED
        assert loser1.priority == 51

        assert loser2.status == SlotStatus.DEFERRED
        assert loser2.priority == 11

    def test_priority_capped_at_max(self, db, seed):
        """Priority bump should not exceed MAX_PRIORITY."""
        winner = _make_slot(db, 1, priority=99)
        at_cap = _make_slot(db, 1, priority=99)

        resolve_slot_competition(db, [winner, at_cap])

        assert at_cap.status == SlotStatus.DEFERRED
        assert at_cap.priority == MAX_PRIORITY  # stays at 99, not 100

    def test_already_deferred_slots_get_bumped(self, db, seed):
        """Slots that were already DEFERRED still get priority bumped."""
        winner = _make_slot(db, 1, priority=90)
        already_deferred = _make_slot(db, 1, priority=40, status=SlotStatus.DEFERRED)

        result = resolve_slot_competition(db, [winner, already_deferred])

        assert already_deferred.status == SlotStatus.DEFERRED
        assert already_deferred.priority == 41

    def test_tie_breaking_first_wins(self, db, seed):
        """When priorities are equal, the first in the list wins."""
        a = _make_slot(db, 1, priority=50)
        b = _make_slot(db, 1, priority=50)

        result = resolve_slot_competition(db, [a, b])

        assert result.winner is a
        assert b in result.deferred
        assert b.status == SlotStatus.DEFERRED


# ---------------------------------------------------------------------------
# defer_all_slots
# ---------------------------------------------------------------------------

class TestDeferAllSlots:
    """Tests for defer_all_slots (agent not idle)."""

    def test_empty_input(self, db, seed):
        result = defer_all_slots(db, [])
        assert result == []

    def test_all_slots_deferred(self, db, seed):
        s1 = _make_slot(db, 1, priority=70)
        s2 = _make_slot(db, 1, priority=30)

        result = defer_all_slots(db, [s1, s2])

        assert len(result) == 2
        assert s1.status == SlotStatus.DEFERRED
        assert s1.priority == 71
        assert s2.status == SlotStatus.DEFERRED
        assert s2.priority == 31

    def test_priority_cap_in_defer_all(self, db, seed):
        s = _make_slot(db, 1, priority=99)

        defer_all_slots(db, [s])

        assert s.priority == MAX_PRIORITY

    def test_already_deferred_still_bumped(self, db, seed):
        """Even if already DEFERRED, priority still increases."""
        s = _make_slot(db, 1, priority=45, status=SlotStatus.DEFERRED)

        defer_all_slots(db, [s])

        assert s.status == SlotStatus.DEFERRED
        assert s.priority == 46