#!/usr/bin/env python3
"""Songs pipeline — validates, renders, and publishes song .md files to MediaWiki."""

import argparse
import hashlib
import io
import os
import sys
from datetime import datetime
from pathlib import Path

import frontmatter
import mwclient

sys.path.insert(0, str(Path(__file__).resolve().parent.parent.parent))
from lib.wiki import AUTO_BANNER_PREFIX, connect_wiki, markdown_to_wikitext, strip_first_h1


def validate(fm: dict, path: Path) -> None:
    errors = []

    val = fm.get("title")
    if not val or not str(val).strip():
        errors.append("missing or empty 'title'")

    if not isinstance(fm.get("wiki", {}).get("publish"), bool):
        errors.append("'wiki.publish' must be a boolean (true/false), not a string")

    if "release_date" in fm and fm["release_date"]:
        try:
            datetime.strptime(str(fm["release_date"]), "%Y-%m-%d")
        except ValueError:
            errors.append("'release_date' must be YYYY-MM-DD")

    if "categories" in fm and not isinstance(fm["categories"], list):
        errors.append("'categories' must be a list")

    for i, sib in enumerate(fm.get("wiki", {}).get("siblings") or []):
        if not isinstance(sib, dict):
            errors.append(f"wiki.siblings[{i}] must be a mapping")
            continue
        sib_path = sib.get("path")
        sib_tag = sib.get("tag")
        if sib_path and sib_tag:
            if not (path.parent / str(sib_path)).resolve().exists():
                errors.append(f"wiki.siblings[{i}]: path '{sib_path}' not found")

    if errors:
        raise ValueError(f"{path}: " + "; ".join(errors))


def build_sibling_map(posts: dict) -> dict[str, str]:
    """Map abs_path_str → wiki_title for all published posts."""
    return {str(path): str(post.metadata["title"]) for path, post in posts.items()}


def apply_sibling_substitutions(wikitext: str, this_path: Path, fm_wiki: dict, sibling_map: dict[str, str]) -> str:
    """Replace [[TAG]] placeholders using the declared sibling bill of materials."""
    for sib in (fm_wiki.get("siblings") or []):
        if not isinstance(sib, dict):
            continue
        tag = sib.get("tag")
        path = sib.get("path")
        if not tag or not path:
            continue
        label = (sib.get("label") or "").strip()
        abs_sib = str((this_path.parent / str(path)).resolve())
        title = sibling_map.get(abs_sib)
        if title and label:
            replacement = f"[[{title}|{label}]]"
        elif title:
            replacement = f"[[{title}]]"
        elif label:
            replacement = label
        else:
            replacement = tag
        wikitext = wikitext.replace(tag, replacement)
    return wikitext


def build_wikitext(fm: dict, body_wikitext: str, source_url: str, source_ref: str, lrc_filename: str | None = None) -> str:
    banner = f"{{{{Auto-generated|source={source_url}|commit={source_ref}}}}}"
    lrc_line = f"[[Media:{lrc_filename}|Synced lyrics (.lrc)]]\n" if lrc_filename else ""

    cat_parts = []
    if fm.get("album"):
        cat_parts.append(f"[[Category:Songs]]")
        cat_parts.append(f"[[Category:Album:{fm['album']}]]")
    for cat in (fm.get("categories") or []):
        cat_parts.append(f"[[Category:{cat}]]")
    categories = "\n".join(cat_parts) + "\n" if cat_parts else ""

    return f"{banner}\n\n{body_wikitext}{lrc_line}{categories}"


def upload_lrc(lrc_path: Path, title: str, site: mwclient.Site) -> bool:
    """Upload LRC file to wiki if content has changed. Returns True if uploaded."""
    if not lrc_path.exists():
        print(f"  warn: LRC file not found: {lrc_path}", file=sys.stderr)
        return False

    content = lrc_path.read_bytes()
    try:
        content.decode("utf-8")
    except UnicodeDecodeError:
        print(f"  warn: {lrc_path} is not valid UTF-8 text, skipping LRC upload", file=sys.stderr)
        return False

    wiki_filename = f"{title}.lrc"
    local_sha1 = hashlib.sha1(content).hexdigest()

    if site.images[wiki_filename].imageinfo.get("sha1") == local_sha1:
        return False

    site.upload(
        file=io.BytesIO(content),
        filename=wiki_filename,
        description=f"Synced lyrics for [[{title}]] (auto-published)",
        ignore=True,
    )
    return True


def publish_one(abs_path: Path, source_dir: Path, post, site: mwclient.Site, source_ref: str, gitea_repo_url: str, sibling_map: dict[str, str]) -> str:
    """Returns 'published', 'noop', or 'skipped-manual'."""
    rel = abs_path.relative_to(source_dir)
    fm = post.metadata
    title = str(fm["title"])

    body_wikitext = markdown_to_wikitext(strip_first_h1(post.content))
    body_wikitext = apply_sibling_substitutions(body_wikitext, abs_path, fm.get("wiki", {}), sibling_map)
    source_url = f"{gitea_repo_url}/src/commit/{source_ref}/{rel}"

    lrc_filename = None
    lrc_rel = fm.get("lrc")
    if lrc_rel:
        lrc_uploaded = upload_lrc(abs_path.parent / str(lrc_rel), title, site)
        lrc_filename = f"{title}.lrc"
        if lrc_uploaded:
            print(f"  [lrc-uploaded] {lrc_filename}")

    page_content = build_wikitext(fm, body_wikitext, source_url, source_ref, lrc_filename)

    page = site.pages[title]
    existing = page.text()

    if existing and not existing.startswith(AUTO_BANNER_PREFIX):
        return "skipped-manual"

    if existing == page_content:
        return "noop"

    ref_short = source_ref[:8] if source_ref else "unknown"
    page.save(page_content, summary=f"Auto-published from {ref_short} (songs pipeline)")
    return "published"


def load_and_validate(files: list[Path], source_dir: Path) -> dict[Path, object]:
    posts = {}
    titles: dict[str, Path] = {}

    for path in files:
        if not path.exists():
            print(f"  warn: {path} not found, skipping", file=sys.stderr)
            continue

        post = frontmatter.load(str(path))

        wiki = post.metadata.get("wiki")
        if not isinstance(wiki, dict) or not wiki.get("publish"):
            continue

        validate(post.metadata, path)

        title = str(post.metadata["title"])
        if title in titles:
            raise ValueError(
                f"Duplicate wiki title '{title}': {path} and {titles[title]}"
            )
        titles[title] = path
        posts[path] = post

    return posts


def main() -> None:
    parser = argparse.ArgumentParser(description="Publish song .md files to MediaWiki.")
    parser.add_argument("--source-dir", required=True, type=Path)
    parser.add_argument("--files", nargs="*", default=[], help="Relative paths within source-dir")
    parser.add_argument("--all", action="store_true", help="Publish all publishable files")
    args = parser.parse_args()

    source_dir = args.source_dir.resolve()
    source_ref = os.environ.get("SOURCE_REF", "")
    gitea_repo_url = os.environ.get("GITEA_REPO_URL", "").rstrip("/")

    if args.all:
        candidates = list(source_dir.rglob("*.md"))
    elif args.files:
        candidates = [source_dir / f for f in args.files]
    else:
        print("Nothing to do: pass --files or --all.")
        return

    files = [
        p for p in candidates
        if p.exists()
        and p.suffix == ".md"
        and "wip" not in p.relative_to(source_dir).parts
        and p.name != "README.md"
    ]

    if not files:
        print("No publishable candidates after filtering.")
        return

    print(f"Validating {len(files)} file(s)...")
    posts = load_and_validate(files, source_dir)
    sibling_map = build_sibling_map(posts)
    print("Validation passed.")

    site = connect_wiki()

    counts = {"published": 0, "noop": 0, "skipped-manual": 0}
    for abs_path, post in posts.items():
        rel = abs_path.relative_to(source_dir)
        outcome = publish_one(abs_path, source_dir, post, site, source_ref, gitea_repo_url, sibling_map)
        counts[outcome] += 1
        if outcome == "skipped-manual":
            print(f"  [skipped-manual] {rel}  ← page exists without auto-gen banner; delete or add banner to hand over to bot", file=sys.stderr)
        else:
            print(f"  [{outcome}] {rel}")

    print(
        f"\nDone: {counts['published']} published, {counts['noop']} unchanged, "
        f"{counts['skipped-manual']} skipped (existing manual pages)."
    )


if __name__ == "__main__":
    try:
        main()
    except Exception as e:
        print(f"ERROR: {e}", file=sys.stderr)
        sys.exit(1)