from __future__ import annotations

from io import BytesIO

from PIL import Image

from dpg_map.providers import OSM
from dpg_map.tiles import (
    TileID,
    TileManager,
    TileResult,
    TileStatus,
    calculate_visible_tiles,
    decode_tile_image,
)


def test_visible_tile_calculation_uses_provider_namespace() -> None:
    tiles = calculate_visible_tiles(
        center=(0.0, 0.0),
        zoom=2,
        width=256,
        height=256,
        provider=OSM,
        margin=0,
    )

    assert tiles
    assert {tile.tile_id.provider_name for tile in tiles} == {"osm"}
    assert all(0 <= tile.tile_id.x <= 3 for tile in tiles)
    assert all(0 <= tile.tile_id.y <= 3 for tile in tiles)


def test_tile_manager_ignores_stale_generation_results() -> None:
    manager = TileManager()
    stale = TileResult(
        TileID("osm", 1, 0, 0),
        generation=1,
        status=TileStatus.READY,
        width=1,
        height=1,
        pixels=(1.0, 1.0, 1.0, 1.0),
        source="disk",
    )
    manager._result_queue.put(stale)

    accepted = manager.drain_results(generation=2, provider_name="osm")

    assert accepted == []
    assert manager.snapshot().stale_results == 1


def test_memory_eviction_protects_visible_tiles() -> None:
    manager = TileManager(memory_cache_max_tiles=1)
    protected = TileID("osm", 1, 0, 0)
    evictable = TileID("osm", 1, 0, 1)
    with manager._lock:
        manager._visible_tile_ids = {protected}

    for tile_id in (protected, evictable):
        manager._result_queue.put(
            TileResult(
                tile_id,
                generation=1,
                status=TileStatus.READY,
                width=1,
                height=1,
                pixels=(1.0, 1.0, 1.0, 1.0),
                source="disk",
            )
        )

    manager.drain_results(generation=1, provider_name="osm")

    assert manager.get_ready_tile(protected) is not None
    assert manager.get_ready_tile(evictable) is None


def test_decode_png_tile_image() -> None:
    image = Image.new("RGBA", (1, 1), (255, 0, 128, 255))
    buffer = BytesIO()
    image.save(buffer, format="PNG")

    width, height, pixels = decode_tile_image(buffer.getvalue())

    assert (width, height) == (1, 1)
    assert pixels == (1.0, 0.0, 128 / 255, 1.0)