from __future__ import annotations

import shutil
from pathlib import Path

import pytest

from imagepipeline.core.pipeline import Pipeline
from imagepipeline.core.resume import materialize_external_outputs, step_outputs_complete
from imagepipeline.core.step import StepDefinition
from imagepipeline.modules.imagemagick_grayscale import ImageMagickGrayscale
from imagepipeline.modules.registry import get_module
from imagepipeline.utils.gmic import split_gmic_command
from tests.conftest import make_png


class TestGmicCommandSplit:
    def test_splits_command_and_arguments(self) -> None:
        assert split_gmic_command("-gcd_stereo_img 0,0,2.028,1,1.714,3.06,4,1,0") == [
            "-gcd_stereo_img",
            "0,0,2.028,1,1.714,3.06,4,1,0",
        ]

    def test_preserves_quoted_empty_argument(self) -> None:
        parts = split_gmic_command('-fx_custom_gradient 0,0,0,"",1,0')
        assert parts == ["-fx_custom_gradient", "0,0,0,,1,0"]


class TestPipelineResume:
    @pytest.mark.skipif(not shutil.which("magick"), reason="ImageMagick not installed")
    def test_continue_skips_completed_steps(self, input_dir: Path, output_base: Path, capsys) -> None:
        with Pipeline(
            name="resume_test",
            input_dir=input_dir,
            output_base=output_base,
            verbose=True,
        ) as p:
            first = p.step("imagemagick_grayscale", inputs="input")
            p.step("imagemagick_grayscale", inputs=first)
            root = p.run()

        capsys.readouterr()

        with Pipeline(
            name="resume_test",
            input_dir=input_dir,
            output_base=output_base,
            verbose=True,
            continue_from=root,
        ) as p:
            step_a = p.step("imagemagick_grayscale", inputs="input")
            p.step("imagemagick_grayscale", inputs=step_a)
            resumed_root = p.run()

        assert resumed_root == root
        output = capsys.readouterr().out
        assert "Skipped step imagemagick_grayscale_01" in output
        assert "Skipped step imagemagick_grayscale_02" in output

    @pytest.mark.skipif(not shutil.which("magick"), reason="ImageMagick not installed")
    def test_existing_outputs_reuse_external_folder(
        self, input_dir: Path, output_base: Path, tmp_path: Path, capsys
    ) -> None:
        external = tmp_path / "external_rembg"
        external.mkdir()
        for src in input_dir.iterdir():
            if src.is_file():
                make_png(external / src.name, width=4, height=4, rgb=(10, 20, 30))

        with Pipeline(
            name="external_test",
            input_dir=input_dir,
            output_base=output_base,
            verbose=True,
            existing_outputs={"imagemagick_grayscale_01": external},
        ) as p:
            reused = p.step("imagemagick_grayscale", inputs="input")
            p.step("imagemagick_grayscale", inputs=reused)
            root = p.run()

        output = capsys.readouterr().out
        assert "Reused external output for imagemagick_grayscale_01" in output
        assert (root / "imagemagick_grayscale_01" / "photo_a.png").exists()


class TestMaterializeExternal:
    def test_links_files_by_stem(self, tmp_path: Path) -> None:
        external = tmp_path / "external"
        external.mkdir()
        make_png(external / "photo_a.png")
        output_dir = tmp_path / "out"
        step = StepDefinition(
            step_id="imagemagick_grayscale_01",
            module_name="imagemagick_grayscale",
            module=ImageMagickGrayscale,
            input_refs=["input"],
            params={},
            output_dir_name="imagemagick_grayscale_01",
        )
        input_paths = [tmp_path / "photo_a.png"]
        paths = materialize_external_outputs(
            external,
            output_dir,
            step,
            matched_groups=[[path] for path in input_paths],
            input_paths=input_paths,
            params={},
        )
        assert len(paths) == 1
        assert paths[0].name == "photo_a.png"
        assert paths[0].is_symlink()

    def test_step_outputs_complete(self, tmp_path: Path) -> None:
        output_dir = tmp_path / "done"
        output_dir.mkdir()
        make_png(output_dir / "photo.png")
        assert step_outputs_complete([output_dir / "photo.png"])
        assert not step_outputs_complete([output_dir / "missing.png"])