from __future__ import annotations

from pathlib import Path

from PIL import Image

from copienator import atomic_write_json, configuration, read_json, utils
from copienator.filesystem import staged_directory
from copienator.platform import safe_filename


def publish_answer_returns(root: Path, source: Path, destination: Path) -> None:
    """Publish individual reviewed answers and per-question information."""
    scores = read_json(source / "score.json")
    if not isinstance(scores, dict):
        raise ValueError(f"Expected a score object in {source}")
    info_path = source / "info.json"
    if not info_path.is_file():
        raise ValueError(f"Missing {info_path}; recompile annotations before giving-names")
    info = read_json(info_path)
    if not isinstance(info, dict) or set(info) != set(scores):
        raise ValueError(f"Invalid question information in {info_path}; recompile annotations")
    for label, entry in info.items():
        if (
            not isinstance(entry, dict)
            or set(entry) != {"present", "not_empty", "touched", "score"}
            or any(type(entry[key]) is not bool for key in ("present", "not_empty", "touched"))
            or (entry["not_empty"] and not entry["present"])
            or (entry["touched"] and not entry["not_empty"])
        ):
            raise ValueError(f"Invalid question information in {info_path}; recompile annotations")
        # Match score.json, including manual score edits awaiting recompilation.
        entry["score"] = scores[label]

    answers_dir = destination / "answers"
    if answers_dir.is_symlink():
        raise ValueError(f"Expected a real answer directory: {answers_dir}")
    if configuration.RETURN_ANSWERS_ENABLED:
        labels = [label for label, entry in info.items() if entry["present"] and entry["not_empty"]]

        # Import the rendering backend only when individual images are requested.
        from copienator.commands.annotating import make_base_image
        from copienator.commands.reading_annotations import concatenate

        all_labels = utils.read_all_labels(root)
        with staged_directory(answers_dir) as staging:
            for index, label in enumerate(sorted(labels, key=utils.natural_key), 1):
                paths = []
                if configuration.RETURN_ANSWERS_CONTEXT:
                    paths.extend(utils.pdf_images_of_contexts(root, label, all_labels))
                if configuration.RETURN_ANSWERS_QUESTION:
                    paths.append(utils.pdf_image_of_enonce(root, label))
                if configuration.RETURN_ANSWERS_SOLUTION:
                    paths.append(utils.pdf_image_of_solution(root, label))
                images = []
                for path in paths:
                    if path:
                        supplement, _, _ = make_base_image(path)
                        if supplement is None:
                            raise ValueError(f"Could not render {path}")
                        images.append(supplement)
                with Image.open(source / f"{label}.jpg") as answer:
                    images.append(answer.convert("RGB"))
                image = concatenate(images)
                # Numbering avoids collisions between sanitized label filenames.
                image.save(staging / f"{index:03d} - {safe_filename(label)}.jpg")
    elif answers_dir.exists():
        # Replace the managed directory with an empty one to remove stale exports.
        with staged_directory(answers_dir):
            pass
    atomic_write_json(destination / "info.json", info)
    (destination / "touched.json").unlink(missing_ok=True)