"""Every renderer that produces a device-facing frame must return
exactly EPD_WIDTH*EPD_HEIGHT/2 bytes (the panel's packed 2px/byte
format) -- firmware writes this straight to the display with no length
checking of its own, so a renderer that's off by even one byte is a
silent on-device corruption bug, not a clean error. This is a cheap,
high-value regression guard: pure PIL rendering, no DB/HTTP/Node."""

from __future__ import annotations

import pytest

from app.calendar_render import CALENDAR_VIEWS, render_calendar
from app.image_pipeline import EPD_HEIGHT, EPD_WIDTH, render_placeholder

EXPECTED_BYTES = EPD_WIDTH * EPD_HEIGHT // 2
ORIENTATIONS = ["landscape", "landscape_flipped", "portrait", "portrait_flipped"]

_SAMPLE_EVENTS = [
    {
        "summary": "Dentist", "start": "2026-08-01T14:00:00+00:00", "end": "2026-08-01T15:00:00+00:00",
        "all_day": False, "sources": [{"owner_display_name": "Alice", "color_index": None}],
    },
    {
        "summary": "Team Offsite", "start": "2026-08-03T00:00:00", "end": "2026-08-04T00:00:00",
        "all_day": True, "sources": [{"owner_display_name": "Bob", "color_index": 2}],
    },
]


@pytest.mark.parametrize("orientation", ORIENTATIONS)
def test_placeholder_render_size(orientation):
    data = render_placeholder(["Not configured yet"], orientation=orientation)
    assert len(data) == EXPECTED_BYTES


@pytest.mark.parametrize("view", CALENDAR_VIEWS)
def test_calendar_render_size_across_views(view):
    data = render_calendar(_SAMPLE_EVENTS, view, browse_offset=0, orientation="landscape",
                           palette_rgb=None, timezone="UTC")
    assert len(data) == EXPECTED_BYTES


@pytest.mark.parametrize("orientation", ORIENTATIONS)
def test_calendar_render_size_across_orientations(orientation):
    data = render_calendar(_SAMPLE_EVENTS, "agenda", browse_offset=0, orientation=orientation,
                           palette_rgb=None, timezone="UTC")
    assert len(data) == EXPECTED_BYTES


def test_calendar_render_size_empty_events():
    data = render_calendar([], "week", browse_offset=0, orientation="landscape",
                           palette_rgb=None, timezone="UTC")
    assert len(data) == EXPECTED_BYTES


def test_calendar_render_size_with_fetch_summary_and_tasks():
    tasks = [{"summary": "Buy milk", "completed": False}, {"summary": "Walk the dog", "completed": True}]
    data = render_calendar(_SAMPLE_EVENTS, "week", browse_offset=0, orientation="landscape",
                           palette_rgb=None, timezone="UTC", fetch_summary="1 of 2 calendars unavailable",
                           week_days=5, week_layout="vertical", tasks=tasks)
    assert len(data) == EXPECTED_BYTES


def test_calendar_render_size_with_week_start_offset():
    data = render_calendar(_SAMPLE_EVENTS, "week", browse_offset=0, orientation="landscape",
                           palette_rgb=None, timezone="UTC", week_days=3, week_start_offset=2)
    assert len(data) == EXPECTED_BYTES