"""FlowDeck — OPML importer (v5.6.0, Phase 4).

Imports an OPML outline (RSS readers, feed lists) as a collection of feeds.
"""
from __future__ import annotations

import xml.etree.ElementTree as ET
from typing import Any

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

_SCHEMA = [
    {"name": "Title", "type": "title"},
    {"name": "Feed URL", "type": "url"},
    {"name": "Site URL", "type": "url"},
    {"name": "Type", "type": "select", "options": [
        {"name": "rss", "color": "orange"},
        {"name": "folder", "color": "gray"},
    ]},
    {"name": "Folder", "type": "text"},
]


@register_importer
class OpmlImporter(Importer):
    source_id = "opml"
    label = "OPML (flux RSS)"
    description = "Outline OPML → collection de flux (titre, URL, dossier)."
    extensions = (".opml", ".xml")
    order = 34

    def detect(self, filename: str, data: bytes) -> bool:
        if filename.lower().endswith(".opml"):
            return True
        head = decode_text(data)[:1000].lower()
        return "<opml" in head and "<outline" in head

    def parse(self, filename: str, data: bytes) -> ImportResult:
        result = ImportResult(source=self.source_id)
        rows: list[dict] = []
        try:
            root = ET.fromstring(decode_text(data))
        except ET.ParseError as exc:
            result.warn(f"OPML invalide : {exc}")
            return result.finalize()
        for outline in root.iter("outline"):
            attrs = {k.lower(): v for k, v in outline.attrib.items()}
            feed = attrs.get("xmlurl")
            title = attrs.get("title") or attrs.get("text") or feed or ""
            if not feed and not title:
                continue
            props: dict[str, Any] = {}
            if feed:
                props["Feed URL"] = feed
                props["Type"] = "rss"
            else:
                props["Type"] = "folder"
            if attrs.get("htmlurl"):
                props["Site URL"] = attrs["htmlurl"]
            folder = _folder_of(outline, root)
            if folder:
                props["Folder"] = folder
            rows.append({"title": title[:200] or "Feed", "properties": props})
        result.pages.append(make_collection("OPML feeds", _SCHEMA, rows, source_path=filename))
        result.stats["rows"] = len(rows)
        return result.finalize()


def _folder_of(node: ET.Element, root: ET.Element) -> str:
    parents = {child: parent for parent in root.iter() for child in parent}
    parts: list[str] = []
    current = parents.get(node)
    while current is not None:
        attrs = {k.lower(): v for k, v in current.attrib.items()}
        if not attrs.get("xmlurl"):
            label = attrs.get("title") or attrs.get("text")
            if label:
                parts.append(label)
        current = parents.get(current)
    return " / ".join(reversed(parts))