"""GET /api/docs — the indexed document list (feeds the Sources page)."""
from __future__ import annotations

from fastapi import APIRouter, Depends
from sqlalchemy import func, select
from sqlalchemy.orm import Session

from app.db import get_db
from app.models import Chunk, Document
from app.schemas import DocList, DocSummary

router = APIRouter(tags=["kb"])


@router.get("/docs", response_model=DocList)
def list_documents(db: Session = Depends(get_db)) -> DocList:  # noqa: B008
    """All indexed documents with per-document chunk counts.

    An empty list means the knowledge base has not been imported yet —
    the Sources page renders its designed empty state in that case.
    """
    rows = db.execute(
        select(
            Document.id,
            Document.source,
            Document.path,
            Document.title,
            func.count(Chunk.id).label("chunks"),
            Document.indexed_at,
        )
        .outerjoin(Chunk, Chunk.document_id == Document.id)
        .group_by(Document.id, Document.source, Document.path, Document.title, Document.indexed_at)
        .order_by(Document.source, Document.path)
    ).all()
    return DocList(
        documents=[
            DocSummary(
                id=str(row.id),
                source=row.source,
                path=row.path,
                title=row.title,
                chunks=row.chunks,
                indexed_at=row.indexed_at.isoformat(),
            )
            for row in rows
        ]
    )