"""FlowDeck — generic Markdown / text importer (v5.6.0, Phase 1)."""
from __future__ import annotations

import io
import zipfile

from app.services.importers.base import (
    Importer,
    ImportPage,
    ImportResult,
    decode_text,
    register_importer,
)

_MD_EXTS = (".md", ".markdown", ".txt", ".mdx")


def _title_from_name(name: str) -> str:
    base = name.replace("\\", "/").rsplit("/", 1)[-1]
    for ext in (".markdown", ".markdown", ".mdx", ".md", ".txt"):
        if base.lower().endswith(ext):
            base = base[: -len(ext)]
            break
    return base.strip() or "Untitled"


@register_importer
class MarkdownImporter(Importer):
    source_id = "markdown"
    label = "Markdown / texte"
    description = "Fichiers .md/.markdown/.txt ou archive .zip de fichiers Markdown."
    extensions = (".md", ".markdown", ".txt", ".zip")
    order = 90

    def detect(self, filename: str, data: bytes) -> bool:
        low = filename.lower()
        if low.endswith(_MD_EXTS):
            return True
        if low.endswith(".zip"):
            try:
                zf = zipfile.ZipFile(io.BytesIO(data))
            except (zipfile.BadZipFile, OSError):
                return False
            names = [n for n in zf.namelist() if not n.endswith("/")]
            return bool(names) and all(n.lower().endswith(_MD_EXTS) for n in names)
        return False

    def parse(self, filename: str, data: bytes) -> ImportResult:
        result = ImportResult(source=self.source_id)
        if filename.lower().endswith(".zip"):
            try:
                zf = zipfile.ZipFile(io.BytesIO(data))
            except (zipfile.BadZipFile, OSError) as exc:
                result.warn(f"Archive invalide : {exc}")
                return result.finalize()
            entries = sorted(
                (n for n in zf.namelist()
                 if not n.endswith("/") and n.lower().endswith(_MD_EXTS)),
                key=lambda n: (n.count("/"), n.lower()),
            )
            if not entries:
                result.warn("Aucun fichier Markdown trouvé dans l'archive")
                return result.finalize()
            for name in entries:
                try:
                    text = decode_text(zf.read(name))
                except Exception as exc:  # noqa: BLE001
                    result.warn(f"Lecture impossible : {name} ({exc})")
                    continue
                parts = name.replace("\\", "/").split("/")
                result.pages.append(ImportPage(
                    title=_title_from_name(name),
                    markdown=text,
                    source_path=name,
                    parent_path="/".join(parts[:-1]),
                    external_id=name,
                ))
            return result.finalize()

        text = decode_text(data)
        result.pages.append(ImportPage(
            title=_title_from_name(filename),
            markdown=text,
            source_path=filename,
            external_id=filename,
        ))
        return result.finalize()