from __future__ import annotations

from pathlib import Path

from core.models import Scene
from perception.ocr import OCRBox
from perception.provider import DefaultPerceptionProvider, NullPerceptionProvider
from perception.scene_builder import build_scene as build_fused_scene
from perception.scene_builder import infer_png_size
from perception.ui_parser import parse_ui_tree

PNG_10X20 = b"\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR\x00\x00\x00\x0a\x00\x00\x00\x14"

TREE_XML = """
<AppiumAUT x="0" y="0" width="10" height="20">
  <XCUIElementTypeButton name="Search" label="Search" x="1" y="2" width="4" height="4" />
  <XCUIElementTypeImage name="Settings" label="Settings" x="6" y="2" width="3" height="3" />
</AppiumAUT>
"""


class FakeOCREngine:
    """Stand-in for PaddleOCREngine that never touches the real dependency."""

    def __init__(self, boxes: list[OCRBox]) -> None:
        self._boxes = boxes
        self.calls: list[object] = []

    def extract(self, image: bytes | str | Path) -> list[OCRBox]:
        self.calls.append(image)
        return self._boxes


def test_null_perception_provider_returns_empty_scene_without_ocr() -> None:
    provider = NullPerceptionProvider()

    scene = provider.build_scene(PNG_10X20, TREE_XML)

    width, height = infer_png_size(PNG_10X20)
    assert scene == Scene(width=width, height=height, elements=[])
    assert width == 10
    assert height == 20
    assert scene.elements == []


def test_null_perception_provider_infers_zero_size_for_non_png() -> None:
    provider = NullPerceptionProvider()

    scene = provider.build_scene(b"not-a-png", None)

    assert scene == Scene(width=0, height=0, elements=[])


def test_default_perception_provider_degrades_when_ui_tree_parsing_fails() -> None:
    fake_boxes = [
        OCRBox(text="Search", bounds=parse_ui_tree(TREE_XML)[0].bounds, confidence=0.9),
    ]
    fake_engine = FakeOCREngine(fake_boxes)
    provider = DefaultPerceptionProvider(ocr_engine=fake_engine)  # type: ignore[arg-type]

    scene = provider.build_scene(PNG_10X20, "<unclosed-tag")

    width, height = infer_png_size(PNG_10X20)
    expected = build_fused_scene(
        screen_width=width,
        screen_height=height,
        ui_elements=[],
        ocr_elements=[fake_boxes[0].to_scene_element("ocr-000")],
    )

    assert scene == expected
    assert scene.elements == [fake_boxes[0].to_scene_element("ocr-000")]


def test_default_perception_provider_wires_through_scene_builder() -> None:
    fake_boxes = [
        OCRBox(text="Search", bounds=parse_ui_tree(TREE_XML)[0].bounds, confidence=0.9),
    ]
    fake_engine = FakeOCREngine(fake_boxes)
    provider = DefaultPerceptionProvider(ocr_engine=fake_engine)  # type: ignore[arg-type]

    scene = provider.build_scene(PNG_10X20, TREE_XML)

    width, height = infer_png_size(PNG_10X20)
    expected = build_fused_scene(
        screen_width=width,
        screen_height=height,
        ui_elements=parse_ui_tree(TREE_XML),
        ocr_elements=[fake_boxes[0].to_scene_element("ocr-000")],
    )

    assert scene == expected
    assert len(scene.elements) == len(parse_ui_tree(TREE_XML))
    assert fake_engine.calls == [PNG_10X20]