#!/usr/bin/env python3
"""Crée un brouillon Markdown adapté à une section du site."""

import argparse
import json
import re
import sys
import unicodedata
from datetime import datetime
from pathlib import Path
from zoneinfo import ZoneInfo, ZoneInfoNotFoundError

from _schema import LIST_FIELDS, SECTION_ALIASES, SECTION_FIELDS, VOCABULARY_FIELDS

ROOT_DIR = Path(__file__).resolve().parent.parent
CONTENT_DIR = ROOT_DIR / "src" / "content"
MZL_RE = re.compile(r"(?:mzl-)?([0-9]{1,3})")

FieldValue = str | list[str]


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(
        description="Créer un brouillon Markdown horodaté et prêt à compléter."
    )
    parser.add_argument(
        "section",
        choices=sorted(SECTION_ALIASES),
        help="section de destination",
    )
    parser.add_argument(
        "identifiant",
        help="nom du fichier sans .md ; pour un signe, numéro MZL ou mzl-XXX",
    )
    parser.add_argument(
        "--title",
        help="titre initial ; déduit de l’identifiant par défaut",
    )
    parser.add_argument(
        "--nature",
        choices=tuple(VOCABULARY_FIELDS),
        help="nature grammaticale d’une fiche de vocabulaire",
    )
    return parser.parse_args()


def normalize(value: str) -> str:
    return unicodedata.normalize("NFC", value.strip())


def validate_identifier(identifier: str, allow_leading_hyphen: bool) -> str:
    value = normalize(identifier)
    body = value[1:] if value.startswith("-") else value

    if value.startswith("-") and not allow_leading_hyphen:
        raise ValueError(
            "seul le vocabulaire accepte un identifiant commençant par un tiret"
        )
    if (
        not body
        or value in {".", "..", "_index"}
        or value != value.lower()
        or value.endswith("-")
        or "--" in value
        or not all(character.isalnum() or character == "-" for character in body)
    ):
        raise ValueError("identifiant de fichier invalide")

    return value


def parse_mzl(identifier: str) -> tuple[str, str]:
    match = MZL_RE.fullmatch(normalize(identifier))
    if match is None or not 1 <= int(match.group(1)) <= 999:
        raise ValueError("le numéro MZL doit être compris entre 1 et 999")

    mzl = f"{int(match.group(1)):03d}"
    return f"mzl-{mzl}", mzl


def choose_nature(nature: str | None) -> str:
    if nature:
        return nature
    if not sys.stdin.isatty():
        raise ValueError("--nature est requis pour une fiche de vocabulaire")

    choices = tuple(VOCABULARY_FIELDS)
    print("Nature grammaticale :")
    for index, choice in enumerate(choices, start=1):
        print(f"  {index}. {choice}")

    try:
        answer = input("Choix : ").strip()
    except (EOFError, KeyboardInterrupt) as exc:
        raise ValueError("sélection interrompue") from exc

    if not answer.isdigit() or not 1 <= int(answer) <= len(choices):
        raise ValueError("nature grammaticale invalide")
    return choices[int(answer) - 1]


def title_from_identifier(identifier: str) -> str:
    title = identifier.replace("-", " ")
    return title[:1].upper() + title[1:]


def empty_fields(fields: tuple[str, ...]) -> dict[str, FieldValue]:
    return {field: [] if field in LIST_FIELDS else "" for field in fields}


def content_tables(
    section: str,
    nature: str | None = None,
    mzl: str | None = None,
) -> dict[str, dict[str, FieldValue]]:
    if section == "vocabulaire":
        assert nature is not None
        return {
            "extra": empty_fields(VOCABULARY_FIELDS[nature]),
            "taxonomies": {"natures": [nature]},
        }

    tables = {
        table: empty_fields(fields)
        for table, fields in SECTION_FIELDS[section].items()
    }
    if section == "signes":
        assert mzl is not None
        tables["extra"]["mzl"] = mzl
    return tables


def build_content(
    title: str,
    timestamp: str,
    tables: dict[str, dict[str, FieldValue]],
) -> str:
    lines = [
        "+++",
        f"title = {json.dumps(title, ensure_ascii=False)}",
        f"date = {timestamp}",
        "# updated = YYYY-MM-DDTHH:MM:SS+HH:MM",
        'description = ""',
        "draft = true",
    ]

    for table, fields in tables.items():
        lines.extend(("", f"[{table}]"))
        lines.extend(
            f"{field} = {json.dumps(value, ensure_ascii=False)}"
            for field, value in fields.items()
        )

    lines.extend(("+++", ""))
    return "\n".join(lines)


def main() -> int:
    args = parse_args()
    section = SECTION_ALIASES[args.section]

    try:
        if section != "vocabulaire" and args.nature is not None:
            raise ValueError("--nature est réservé aux fiches de vocabulaire")

        custom_title = normalize(args.title) if args.title is not None else None
        nature = None
        mzl = None

        if section == "signes":
            filename, mzl = parse_mzl(args.identifiant)
            title = custom_title if custom_title is not None else ""
        else:
            filename = validate_identifier(
                args.identifiant,
                allow_leading_hyphen=section == "vocabulaire",
            )
            if section == "vocabulaire":
                nature = choose_nature(args.nature)
                title = custom_title if custom_title is not None else filename
            else:
                title = (
                    custom_title
                    if custom_title is not None
                    else title_from_identifier(filename)
                )

        timestamp = datetime.now(ZoneInfo("Europe/Paris")).isoformat(
            timespec="seconds"
        )
        content = build_content(
            title,
            timestamp,
            content_tables(section, nature, mzl),
        )
    except (ValueError, ZoneInfoNotFoundError) as exc:
        print(f"Erreur : {exc}", file=sys.stderr)
        return 2

    destination = CONTENT_DIR / section / f"{filename}.md"
    try:
        with destination.open("x", encoding="utf-8") as stream:
            stream.write(content)
    except FileExistsError:
        print(
            f"Erreur : le fichier existe déjà : {destination.relative_to(ROOT_DIR)}",
            file=sys.stderr,
        )
        return 1
    except OSError as exc:
        print(f"Erreur : impossible de créer la fiche ({exc})", file=sys.stderr)
        return 1

    print(f"Brouillon créé : {destination.relative_to(ROOT_DIR)}")
    return 0


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