from pathlib import Path

import numpy as np
import pytest

from bookmark.capture_strategies.manual_button import ManualButtonStrategy
from bookmark.catalogue import Catalogue
from bookmark.session import IntakeSession, IntakeState
from bookmark.sizing import MarkerRegion


def make_reference(size=100, color=200):
    return np.full((size, size, 3), color, dtype=np.uint8)


def make_book_frame(size=100, ref_color=200, book_color=50, box=(20, 20, 40, 40)):
    frame = np.full((size, size, 3), ref_color, dtype=np.uint8)
    x, y, w, h = box
    frame[y:y + h, x:x + w] = book_color
    return frame


@pytest.fixture
def session(tmp_path):
    catalogue = Catalogue(tmp_path / "catalogue.csv")
    strategy = ManualButtonStrategy()
    reference = make_reference()
    markers = [
        MarkerRegion(name="small_boundary", bucket="small", x=0, y=0, width=10, height=10),
        MarkerRegion(name="medium_boundary", bucket="medium", x=90, y=0, width=10, height=10),
        MarkerRegion(name="large_boundary", bucket="large", x=0, y=90, width=10, height=10),
    ]
    return IntakeSession(
        catalogue=catalogue,
        strategy=strategy,
        reference_frame=reference,
        markers=markers,
        captures_dir=tmp_path / "captures",
    )


def test_session_starts_waiting_for_front(session):
    assert session.state == IntakeState.WAITING_FRONT


def test_front_capture_advances_to_waiting_back_and_writes_catalogue_row(session):
    session.strategy.trigger()
    fired = session.observe_frame(make_book_frame())

    assert fired is True
    assert session.state == IntakeState.WAITING_BACK
    assert session.current_book_id is not None

    rows = session.catalogue.read_all()
    assert len(rows) == 1
    assert rows[0]["book_id"] == session.current_book_id
    assert rows[0]["status"] == "captured"
    assert Path(rows[0]["front_wide_path"]).exists()
    assert Path(rows[0]["front_cropped_path"]).exists()


def test_back_capture_completes_book_and_updates_row(session):
    session.strategy.trigger()
    session.observe_frame(make_book_frame())
    book_id = session.current_book_id

    session.strategy.trigger()
    fired = session.observe_frame(make_book_frame())

    assert fired is True
    assert session.state == IntakeState.BOOK_COMPLETE
    rows = session.catalogue.read_all()
    assert rows[0]["book_id"] == book_id
    assert Path(rows[0]["back_wide_path"]).exists()
    assert Path(rows[0]["back_cropped_path"]).exists()


def test_start_next_book_resets_state_and_assigns_new_id(session):
    session.strategy.trigger()
    session.observe_frame(make_book_frame())
    session.strategy.trigger()
    session.observe_frame(make_book_frame())
    first_book_id = session.current_book_id

    session.start_next_book()
    assert session.state == IntakeState.WAITING_FRONT
    assert session.current_book_id is None

    session.strategy.trigger()
    session.observe_frame(make_book_frame())
    assert session.current_book_id != first_book_id


def test_start_next_book_raises_if_book_not_complete(session):
    with pytest.raises(RuntimeError):
        session.start_next_book()


def test_empty_platform_capture_does_not_corrupt_state_or_files(session):
    """Feeding the unchanged reference frame (nothing on the platform) should not
    crash, should not create a catalogue row, should not leave an orphan file on
    disk, should leave the strategy un-armed, and should not advance state."""
    session.strategy.trigger()

    fired = session.observe_frame(session.reference_frame)

    assert fired is False
    assert session.last_error is not None
    assert session.state == IntakeState.WAITING_FRONT
    assert session.current_book_id is None
    assert session.catalogue.read_all() == []
    assert session.strategy.observe(make_book_frame()) is False  # not left armed
    assert not (session.captures_dir).exists() or not any(session.captures_dir.rglob("*.jpg"))


def test_empty_platform_capture_on_back_step_does_not_advance_or_corrupt(session):
    """Same failure mode, but triggered on the back-capture step: the front row
    must survive untouched, and state must stay at WAITING_BACK."""
    session.strategy.trigger()
    session.observe_frame(make_book_frame())
    book_id = session.current_book_id
    assert session.state == IntakeState.WAITING_BACK

    session.strategy.trigger()
    fired = session.observe_frame(session.reference_frame)

    assert fired is False
    assert session.last_error is not None
    assert session.state == IntakeState.WAITING_BACK
    assert session.current_book_id == book_id
    rows = session.catalogue.read_all()
    assert len(rows) == 1
    assert rows[0]["back_wide_path"] == ""
    assert rows[0]["back_cropped_path"] == ""
    back_files = list((session.captures_dir / book_id).glob("back_*.jpg"))
    assert back_files == []


def test_book_complete_no_op_fire_does_not_return_true(session):
    """A strategy re-firing while the session is already BOOK_COMPLETE (e.g. an
    auto-strategy re-satisfying stability while a finished book sits on the
    platform) must not report a capture and must not stay armed."""
    session.strategy.trigger()
    session.observe_frame(make_book_frame())
    session.strategy.trigger()
    session.observe_frame(make_book_frame())
    assert session.state == IntakeState.BOOK_COMPLETE

    session.strategy.trigger()
    fired = session.observe_frame(make_book_frame())

    assert fired is False
    assert session.state == IntakeState.BOOK_COMPLETE
    assert session.strategy.observe(make_book_frame()) is False  # reset, not left armed