#!/usr/bin/env python3
"""Vérifie que chaque fiche contient les champs prévus pour son modèle."""

import sys
import tomllib
from datetime import datetime
from pathlib import Path
from typing import Any

from _schema import (
    CONTENT_SECTIONS,
    LIST_FIELDS,
    SECTION_FIELDS,
    UPDATED_LINE_RE,
    URL_TERM_FIELDS,
    VOCABULARY_FIELDS,
)

ROOT_DIR = Path(__file__).resolve().parent.parent
CONTENT_DIR = ROOT_DIR / "src" / "content"

COMMON_FIELDS = {
    "title": str,
    "date": datetime,
    "description": str,
    "draft": bool,
}


class Validator:
    def __init__(self) -> None:
        self.errors = 0

    def error(self, path: Path | None, message: str) -> None:
        label = f"{path.relative_to(ROOT_DIR).as_posix()} : " if path else ""
        print(f"ERREUR : {label}{message}", file=sys.stderr)
        self.errors += 1

    def finish(self) -> int:
        print(f"\nRésultat : {self.errors} erreur(s).")
        return 1 if self.errors else 0


def read_front_matter(
    path: Path,
    validator: Validator,
) -> tuple[dict[str, Any], str] | None:
    try:
        lines = path.read_text(encoding="utf-8").splitlines()
    except (OSError, UnicodeError) as exc:
        validator.error(path, f"lecture impossible ({exc})")
        return None

    if not lines or lines[0] != "+++":
        validator.error(path, "front matter TOML initial absent")
        return None

    try:
        closing_index = lines.index("+++", 1)
    except ValueError:
        validator.error(path, "délimiteur final +++ absent")
        return None

    source = "\n".join(lines[1:closing_index])
    try:
        return tomllib.loads(source), source
    except tomllib.TOMLDecodeError as exc:
        validator.error(path, f"front matter TOML invalide ({exc})")
        return None


def check_type(
    value: Any,
    expected_type: type,
    label: str,
    path: Path,
    validator: Validator,
) -> bool:
    if isinstance(value, expected_type):
        return True

    validator.error(path, f"{label} doit être de type {expected_type.__name__}")
    return False


def check_string_list(
    value: Any,
    label: str,
    path: Path,
    validator: Validator,
) -> bool:
    if isinstance(value, list) and all(isinstance(item, str) for item in value):
        return True

    validator.error(path, f"{label} doit être un tableau de chaînes")
    return False


def check_fields(
    metadata: dict[str, Any],
    table_name: str,
    fields: tuple[str, ...],
    path: Path,
    validator: Validator,
) -> None:
    table = metadata.get(table_name)
    if not isinstance(table, dict):
        validator.error(path, f"{table_name} doit être une table TOML")
        return

    missing = [field for field in fields if field not in table]
    if missing:
        validator.error(path, f"champs {table_name} manquants : {', '.join(missing)}")

    for field in fields:
        if field not in table:
            continue

        label = f"{table_name}.{field}"
        if field in LIST_FIELDS:
            if check_string_list(table[field], label, path, validator) and field in URL_TERM_FIELDS:
                spaced_terms = [
                    term
                    for term in table[field]
                    if any(char.isspace() for char in term)
                ]
                if spaced_terms:
                    validator.error(
                        path,
                        f"{label} doit utiliser des tirets à la place des espaces : "
                        + ", ".join(repr(term) for term in spaced_terms),
                    )
        else:
            check_type(table[field], str, label, path, validator)


def check_common_fields(
    metadata: dict[str, Any],
    front_matter: str,
    path: Path,
    validator: Validator,
) -> None:
    for field, expected_type in COMMON_FIELDS.items():
        if field not in metadata:
            validator.error(path, f"champ manquant : {field}")
        else:
            check_type(metadata[field], expected_type, field, path, validator)

    updated_lines = len(UPDATED_LINE_RE.findall(front_matter))
    if updated_lines != 1:
        validator.error(path, "la fiche doit contenir exactement une ligne updated")

    if "updated" in metadata:
        check_type(metadata["updated"], datetime, "updated", path, validator)


def check_vocabulary(
    metadata: dict[str, Any],
    path: Path,
    validator: Validator,
) -> None:
    taxonomies = metadata.get("taxonomies")
    if not isinstance(taxonomies, dict):
        validator.error(path, "taxonomies doit être une table TOML")
        return

    if "natures" not in taxonomies:
        validator.error(path, "champ taxonomies manquant : natures")
        return

    natures = taxonomies["natures"]
    if not check_string_list(natures, "taxonomies.natures", path, validator):
        return

    if len(natures) != 1:
        validator.error(path, "taxonomies.natures doit contenir exactement une nature")
        return

    nature = natures[0]
    if nature not in VOCABULARY_FIELDS:
        validator.error(path, f"nature grammaticale inconnue : {nature!r}")
        return

    check_fields(metadata, "extra", VOCABULARY_FIELDS[nature], path, validator)


def main() -> int:
    validator = Validator()
    if not CONTENT_DIR.is_dir():
        validator.error(None, f"répertoire introuvable : {CONTENT_DIR}")
        return validator.finish()

    print("Vérification des fiches…", flush=True)
    for path in sorted(CONTENT_DIR.rglob("*.md")):
        relative_path = path.relative_to(CONTENT_DIR)
        if path.name == "_index.md" or len(relative_path.parts) == 1:
            continue

        section = relative_path.parts[0]
        if section not in CONTENT_SECTIONS:
            validator.error(path, f"section inconnue : {section}")
            continue

        result = read_front_matter(path, validator)
        if result is None:
            continue
        metadata, front_matter = result

        check_common_fields(metadata, front_matter, path, validator)

        if section == "vocabulaire":
            check_vocabulary(metadata, path, validator)
        else:
            for table_name, fields in SECTION_FIELDS[section].items():
                check_fields(metadata, table_name, fields, path, validator)

    return validator.finish()


if __name__ == "__main__":
    raise SystemExit(main())