"""Ordered copy-level remarks and their generated LaTeX image."""
from pathlib import Path

from PIL import Image

from copienator import atomic_update_json, read_json
from copienator.custom_remarks import copy_key

FILENAME = "general_remarks.json"
IMAGE_FILENAME = "Remarques_generales.jpg"


def validate(data):
    if not isinstance(data, dict) or any(
        not isinstance(key, str) or copy_key(key) != key
        or not isinstance(remarks, list)
        or any(not isinstance(text, str) for text in remarks)
        for key, remarks in data.items()
    ):
        raise ValueError(f"Format invalide dans {FILENAME}.")


def load_remarks(root: Path) -> dict[str, list[str]]:
    data = read_json(root / FILENAME, default={})
    validate(data)
    return data


def remarks_for_copy(root: Path, copy_id: str) -> list[str]:
    return load_remarks(root).get(copy_key(copy_id), [])


def set_remarks(root: Path, copy_id: str, remarks: list[str]) -> list[str]:
    key = copy_key(copy_id)
    current = [text.strip() for text in remarks if text.strip()]
    previous = []

    def update(data):
        nonlocal previous
        validate(data)
        previous = data.get(key, [])
        if current:
            data[key] = current
        else:
            data.pop(key, None)

    atomic_update_json(root / FILENAME, update, default_factory=dict)
    return previous


def render(root: Path, copy_id: str, width: int) -> Image.Image | None:
    remarks = remarks_for_copy(root, copy_id)
    if not remarks:
        return None
    from copienator.commands.annotating import render_real_latex_text
    text = r"\textbf{Remarques générales}\par\medskip " + r"\par\medskip ".join(remarks)
    content = render_real_latex_text(text, max(100, width - 40)).convert("RGB")
    image = Image.new("RGB", (max(width, content.width + 40), content.height + 40), "white")
    image.paste(content, (20, 20))
    return image


def existing(directory: Path) -> Image.Image | None:
    path = directory / IMAGE_FILENAME
    if path.is_file():
        with Image.open(path) as image:
            return image.convert("RGB")
    return None