"""generator config + content ingestion.

Per BR1.1/BR1.2, US5/US7: reads config.json (MastheadConfig) and the content/
folder, parsing markdown/text into Article entities with fidelity (NFR7).
"""

from __future__ import annotations

import json
import re
from pathlib import Path

from .model import Article, MastheadConfig

META_KEYS = {"title", "couple_names", "date_line", "issue_number", "volume"}


def load_config(path: Path) -> MastheadConfig:
    """Read and validate config.json (BR1.1/BR1.2)."""
    data = json.loads(path.read_text(encoding="utf-8"))
    return MastheadConfig(
        title=str(data.get("title", "The Wedding Times")),
        couple_names=str(data.get("couple_names", "The Happy Couple")),
        date_line=str(data.get("date_line", "")),
        issue_number=str(data.get("issue_number", "1")),
        volume=str(data.get("volume", "1")),
    )


def _read_frontmatter(text: str) -> dict[str, str]:
    """Very light front-matter parse: ---key: value--- lines at the top."""
    meta: dict[str, str] = {}
    if text.startswith("---"):
        m = re.match(r"^---\s*\n(.*?)\n---", text, re.S)
        if m:
            for line in m.group(1).splitlines():
                if ":" in line:
                    k, _, v = line.partition(":")
                    if k.strip() in META_KEYS:
                        meta[k.strip()] = v.strip()
            return meta
    return meta


def _strip_frontmatter(text: str) -> str:
    if text.startswith("---"):
        m = re.match(r"^---\s*\n.*?\n---\s*\n?", text, re.S)
        if m:
            return text[m.end():]
    return text


def parse_article(path: Path, article_id: str) -> Article:
    """Parse one .md/.txt content file into an Article (BR1.1, NFR7 fidelity)."""
    raw = path.read_text(encoding="utf-8")
    meta = _read_frontmatter(raw)
    body = _strip_frontmatter(raw)
    first_line = next((ln for ln in body.splitlines() if ln.strip()), "")
    type_ = meta.get("type", "article")
    section = meta.get("section", "News")
    return Article(
        article_id=article_id,
        type=type_,
        headline=meta.get("headline", first_line.strip(" #")),
        body=body.strip(),
        byline=meta.get("byline", ""),
        section=section,
    )


def load_content(content_dir: Path) -> list[Article]:
    """Read every .md/.txt file in the folder, in sorted order (US5)."""
    articles: list[Article] = []
    files = sorted(
        p for p in content_dir.rglob("*")
        if p.is_file() and p.suffix.lower() in {".md", ".txt"}
    )
    for i, path in enumerate(files, start=1):
        articles.append(parse_article(path, f"article-{i}"))
    return articles