chemenu/tools/chemenu/commands/cite_cmd.py

"""`wikitool cite ...` - real GFM footnote citations.

A citation marker is `[^cite-id]` in a page's prose, resolved by a
`[^cite-id]: [[Source - X]]` (or `[[Source - X|file.md]]`) definition line in
the page's trailing Footnotes block (see chemenu.provenance for the
regexes and cite_id() derivation). AGENTS.md invariant 1 forbids hand-writing
generated structure, and a cite-id is exactly that - an author must never
compute or paste one by hand. `cite add` is the only way to get one onto a
page; `cite sync` is the only way to reconcile a page's block after prose
edits changed which ids are actually referenced.

None of this writes the inline `[^cite-id]` reference into prose: where a
citation belongs in a sentence is an editorial call, same as the prose itself
(see tools/CONTRACT.md's design notes). `cite add` prints the marker to paste
in; the LLM places it.
"""
from __future__ import annotations

from typing import Optional

import typer

from chemenu import config
from chemenu.commands._util import fail, rel_path, success
from chemenu.frontmatter_io import write_page
from chemenu.page import Page
from chemenu.kb_scan import load_kb_pages
from chemenu.provenance import (
    CITE_REF_RE,
    cite_id,
    render_page_body,
    split_cite_block,
    unique_cite_id,
)

app = typer.Typer(help="Manage [^cite-id] footnote citations and their Footnotes definition blocks.")


def _find_page(pages: dict[str, Page], title: str) -> Page:
    if title not in pages:
        fail(f"No page titled '{title}' found under wiki/.")
    return pages[title]


@app.command("id")
def cite_id_command(
    title: str = typer.Option(..., "--title", help="Source page title, e.g. 'Source - Docker Cheatsheet'"),
    file: Optional[str] = typer.Option(None, "--file", help="Qualifier for a multi-file source, e.g. 'storage-model.md'"),
):
    """Print the deterministic id cite_id() would derive for (--title, --file).

    Read-only preview - does not check the id is actually free on any given
    page (two pages, or two distinct pairs on one page, can share this base
    id; `cite add`/`cite sync` are what apply the real -2/-3 suffixing).
    """
    typer.echo(cite_id(title, file))


def upsert_citation(page: Page, source_title: str, qualifier: Optional[str]) -> tuple[str, str, bool]:
    """Ensure `page` has a Footnotes definition for (source_title, qualifier)
    and that source_title is in its frontmatter `sources:`. Returns
    (cite_id_to_use, new_body, changed) - reuses an existing definition for
    the same pair instead of minting a duplicate id."""
    head, definitions = split_cite_block(page.body)

    existing_id = next(
        (cid for cid, pair in definitions.items() if pair == (source_title, qualifier)),
        None,
    )
    if existing_id is not None:
        marker_id = existing_id
        block_changed = False
    else:
        marker_id = unique_cite_id(set(definitions), source_title, qualifier)
        definitions[marker_id] = (source_title, qualifier)
        block_changed = True

    sources = page.frontmatter.setdefault("sources", [])
    sources_changed = source_title not in sources
    if sources_changed:
        sources.append(source_title)

    new_body = render_page_body(head, definitions)
    changed = block_changed or sources_changed or new_body != page.body
    return marker_id, new_body, changed


@app.command("add")
def cite_add(
    page_title: str = typer.Option(..., "--page", help="Exact title of the page to add a citation on"),
    source: str = typer.Option(..., "--source", help="Exact title of the source page being cited, e.g. 'Source - X'"),
    file: Optional[str] = typer.Option(None, "--file", help="Qualifier for a multi-file source, e.g. 'storage-model.md'"),
    dry_run: bool = typer.Option(False, "--dry-run", help="Preview instead of writing"),
):
    """Upsert a Footnotes definition for `--source` (reusing it if the page
    already cites the same source/file pair) and ensure `--source` is in the
    page's frontmatter `sources:`. Prints the `[^cite-id]` marker to paste
    into the prose - placing it is still the caller's job.
    """
    pages = load_kb_pages(config.KB_DIR)
    page = _find_page(pages, page_title)
    if source not in pages:
        fail(f"No page titled '{source}' found under wiki/ - citing a page that doesn't exist would be a dangling reference.")

    marker_id, new_body, changed = upsert_citation(page, source, file)
    marker = f"[^{marker_id}]"

    if dry_run:
        state = "would update" if changed else "already up to date"
        typer.echo(f"[dry-run] '{page_title}': {state}")
        typer.echo(f"marker: {marker}")
        typer.echo("No files written (--dry-run).")
        return

    if changed:
        write_page(page.path, page.frontmatter, new_body)
    typer.echo(f"marker: {marker}")
    success(
        f"{'Updated' if changed else 'Already up to date:'} '{page_title}' cites '{source}'"
        + (f" ({file})" if file else "")
        + f". Paste {marker} at the point in the prose the fact appears."
    )


def sync_page(page: Page) -> tuple[str, bool, list[str], list[str]]:
    """Reconcile one page's Footnotes block against its actual `[^id]`
    references: prune definitions nothing references any more, and re-render
    the block in first-reference order. Never mints or recomputes an id from
    a title - a reference with no definition is reported, not guessed at.

    Returns (new_body, changed, pruned_ids, undefined_ref_ids).
    """
    head, definitions = split_cite_block(page.body)
    referenced_ids = [m.group(1) for m in CITE_REF_RE.finditer(head)]
    referenced_set = set(referenced_ids)

    if not definitions and not referenced_ids:
        # No citation content at all - leave the page's whitespace exactly as
        # it is. Without this, re-rendering an empty block still normalizes
        # trailing newlines, which would make `cite sync --all` rewrite every
        # page in the wiki instead of just the ones it actually has work to do.
        return page.body, False, [], []

    pruned = [cid for cid in definitions if cid not in referenced_set]
    undefined = sorted({cid for cid in referenced_ids if cid not in definitions})

    ordered: dict[str, tuple[str, Optional[str]]] = {}
    seen: set[str] = set()
    for cid in referenced_ids:
        if cid in definitions and cid not in seen:
            ordered[cid] = definitions[cid]
            seen.add(cid)

    new_body = render_page_body(head, ordered)
    changed = new_body != page.body
    return new_body, changed, pruned, undefined


@app.command("sync")
def cite_sync(
    page_title: Optional[str] = typer.Option(None, "--page", help="Sync just this page"),
    all_pages: bool = typer.Option(False, "--all", help="Sync every page under wiki/"),
    dry_run: bool = typer.Option(False, "--dry-run", help="Report what would change instead of writing"),
):
    """Prune orphan Footnotes definitions and re-render each page's block in
    first-reference order. Reports any `[^id]` reference left with no
    definition - that is an editorial gap (a citation whose `cite add` never
    ran, or a hand-typed id), not something this command can fix."""
    if bool(page_title) == bool(all_pages):
        fail("Provide exactly one of --page or --all")

    pages = load_kb_pages(config.KB_DIR)
    targets = [_find_page(pages, page_title)] if page_title else sorted(pages.values(), key=lambda p: p.path)

    touched: list[str] = []
    undefined_report: dict[str, list[str]] = {}
    failed: list[str] = []

    for page in targets:
        new_body, changed, pruned, undefined = sync_page(page)
        title = page.path.stem
        if undefined:
            undefined_report[title] = undefined
        if not changed:
            continue
        touched.append(title)
        if dry_run:
            continue
        try:
            write_page(page.path, page.frontmatter, new_body)
        except OSError as exc:
            failed.append(f"{title} ({exc})")

    if failed:
        fail(
            f"Synced {len(touched) - len(failed)}/{len(touched)} page(s) before a write failed: "
            f"{', '.join(failed)}. Safe to retry - each page's re-render is idempotent."
        )

    verb = "Would update" if dry_run else "Updated"
    if touched:
        typer.echo(f"{verb} {len(touched)} page(s):")
        for title in touched:
            typer.echo(f"  - {title}")
    else:
        typer.echo("No pages needed a Footnotes block change.")

    if undefined_report:
        typer.echo("")
        typer.echo("Undefined [^id] reference(s) - run `cite add` for these, or fix the typo:")
        for title, ids in undefined_report.items():
            typer.echo(f"  - {title}: {', '.join(ids)}")

    if dry_run:
        typer.echo("No files written (--dry-run).")
        return

    if not touched and not undefined_report:
        success("Every Footnotes block already matches its page's references.")