"""Génération des feuilles de poste (module pur, sans base)."""

import base64
import datetime as dt
import io

from app.sheets.pdf import (
    PositionDaySheet,
    SheetArtist,
    SheetShift,
    SheetVolunteer,
    generate_position_sheets_pdf,
)

# PNG 1×1 valide (transparent), le plus petit possible.
_PNG = base64.b64decode(
    "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNk+A8AAQUBAScY"
    "42YAAAAASUVORK5CYII="
)


def _sheet(volunteers=(), min_staff=1, ideal_staff=2) -> PositionDaySheet:
    return PositionDaySheet(
        position_name="Bar central",
        position_location="Chapiteau",
        date=dt.date(2026, 7, 10),
        shifts=(
            SheetShift(
                starts_at=dt.datetime(2026, 7, 10, 19, 0),
                ends_at=dt.datetime(2026, 7, 10, 22, 0),
                min_staff=min_staff,
                ideal_staff=ideal_staff,
                volunteers=volunteers,
            ),
        ),
    )


def test_shift_is_understaffed_when_below_min_staff():
    fully_staffed = _sheet(
        volunteers=(SheetVolunteer(name="Alex Martin", phone="0600000000"),),
        min_staff=1,
    )
    assert fully_staffed.shifts[0].understaffed is False

    understaffed = _sheet(volunteers=(), min_staff=1)
    assert understaffed.shifts[0].understaffed is True


def test_generates_a_valid_pdf_with_volunteers():
    sheet = _sheet(
        volunteers=(
            SheetVolunteer(name="Alex Martin", phone="0600000000"),
            SheetVolunteer(name="Sam Nuit", phone=None),
        )
    )
    pdf = generate_position_sheets_pdf([sheet])
    assert pdf.startswith(b"%PDF")
    assert pdf.rstrip().endswith(b"%%EOF")


def test_generates_a_valid_pdf_with_no_volunteers_assigned():
    pdf = generate_position_sheets_pdf([_sheet(volunteers=())])
    assert pdf.startswith(b"%PDF")


def test_generates_a_valid_pdf_with_no_shifts_that_day():
    sheet = PositionDaySheet(
        position_name="Bar central", position_location=None,
        date=dt.date(2026, 7, 10), shifts=(),
    )
    pdf = generate_position_sheets_pdf([sheet])
    assert pdf.startswith(b"%PDF")


def test_multiple_sheets_produce_a_larger_pdf():
    one = generate_position_sheets_pdf([_sheet()])
    two = generate_position_sheets_pdf([_sheet(), _sheet()])
    assert len(two) > len(one)


def test_generates_a_valid_pdf_with_a_referent():
    sheet = PositionDaySheet(
        position_name="Bar central", position_location="Chapiteau",
        date=dt.date(2026, 7, 10), shifts=(),
        referent_name="Sam Nuit", referent_phone="0600000000",
    )
    pdf = generate_position_sheets_pdf([sheet])
    assert pdf.startswith(b"%PDF")


def test_generates_a_valid_pdf_without_a_referent():
    sheet = PositionDaySheet(
        position_name="Bar central", position_location="Chapiteau",
        date=dt.date(2026, 7, 10), shifts=(),
    )
    assert sheet.referent_name is None
    pdf = generate_position_sheets_pdf([sheet])
    assert pdf.startswith(b"%PDF")


def test_generates_a_valid_pdf_with_volunteer_photos():
    sheet = _sheet(
        volunteers=(
            SheetVolunteer(name="Alex Martin", phone="0600000000", photo=_PNG),
            SheetVolunteer(name="Sam Nuit", phone=None, photo=None),
        )
    )
    assert sheet.shifts[0].volunteers[0].photo == _PNG
    assert sheet.shifts[0].volunteers[1].photo is None
    pdf = generate_position_sheets_pdf([sheet])
    assert pdf.startswith(b"%PDF")


def test_a_volunteer_photo_makes_the_pdf_larger():
    without_photo = generate_position_sheets_pdf(
        [_sheet(volunteers=(SheetVolunteer(name="Alex Martin", phone=None, photo=None),))]
    )
    with_photo = generate_position_sheets_pdf(
        [_sheet(volunteers=(SheetVolunteer(name="Alex Martin", phone=None, photo=_PNG),))]
    )
    assert len(with_photo) > len(without_photo)


def test_generates_a_valid_pdf_with_the_day_lineup():
    sheet = PositionDaySheet(
        position_name="Bar central", position_location="Chapiteau",
        date=dt.date(2026, 7, 10), shifts=(),
        artists=(
            SheetArtist(name="Chilla", start_time=dt.time(20, 0), end_time=dt.time(21, 0)),
            SheetArtist(name="XYZ", start_time=dt.time(21, 30), end_time=dt.time(23, 0)),
        ),
    )
    pdf = generate_position_sheets_pdf([sheet])
    assert pdf.startswith(b"%PDF")


def test_generates_a_valid_pdf_without_a_lineup():
    sheet = PositionDaySheet(
        position_name="Bar central", position_location="Chapiteau",
        date=dt.date(2026, 7, 10), shifts=(),
    )
    assert sheet.artists == ()
    pdf = generate_position_sheets_pdf([sheet])
    assert pdf.startswith(b"%PDF")


def _phone_photo(seed: int) -> bytes:
    """Photo de téléphone : 3000 × 4000 px, plusieurs Mo."""
    from PIL import Image as PILImage

    img = PILImage.new("RGB", (3000, 4000), (seed * 40 % 255, 120, 60))
    img.paste(PILImage.effect_noise((800, 800), 80).convert("RGB"), (seed * 100, 200))
    out = io.BytesIO()
    img.save(out, format="JPEG", quality=92)
    return out.getvalue()


def test_large_photos_are_shrunk_to_the_thumbnail():
    # Régression : la photo d'origine était intégrée telle quelle pour
    # chaque bénévole de chaque créneau — génération interminable, PDF
    # énorme, puis erreur.
    photos = [_phone_photo(i) for i in range(5)]
    volunteers = tuple(
        SheetVolunteer(name=f"Bénévole {i}", phone=None, photo=p) for i, p in enumerate(photos)
    )
    pdf = generate_position_sheets_pdf([_sheet(volunteers=volunteers)])
    assert sum(len(p) for p in photos) > 2_000_000
    assert len(pdf) < 200_000


def test_unreadable_photo_does_not_break_the_sheet():
    pdf = generate_position_sheets_pdf(
        [_sheet(volunteers=(SheetVolunteer(name="Alex", phone=None, photo=b"pas une image"),))]
    )
    assert pdf.startswith(b"%PDF")