"""Admin routes for the EPUB search web UI."""

from __future__ import annotations

import logging

from fastapi import APIRouter, Request
from fastapi.responses import HTMLResponse

from python.ebook_search.api.bm25_tasks import schedule_bm25_refresh
from python.ebook_search.api.dependencies import (  # noqa: TC001 FastAPI resolves these annotated dependencies at runtime
    AppConfig,
    AppHttpClient,
)
from python.ebook_search.api.web import error_response, templates
from python.ebook_search.embeddings import embed_missing_chunks, embedding_model_stats
from python.ebook_search.ingest import ingest_configured_paths
from python.ebook_search.protected_phrases.generate_ngrams import generate_candidate_phrases_for_books
from python.ebook_search.protected_phrases.judge_ngrams import judge_candidate_phrases_for_books
from python.ebook_search.protected_phrases.store import book_ids_pending_first_judgment, corpus_phrase_stats
from python.fastapi_tools import (  # noqa: TC001 FastAPI resolves these annotated dependencies at runtime
    AppAsyncEngine,
    AsyncDbSession,
)

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/admin")


@router.get("", response_class=HTMLResponse)
async def admin(request: Request, config: AppConfig, session: AsyncDbSession) -> HTMLResponse:
    """Render the admin page."""
    stats = await embedding_model_stats(session)
    phrase_stats = await corpus_phrase_stats(session)
    logger.info(
        f"ebook_admin_page_loaded models={len(stats)} {phrase_stats.candidate_phrases=} "
        f"{phrase_stats.protected_phrases=}"
    )
    return templates.TemplateResponse(
        request,
        "admin.html",
        {"config": config, "stats": stats, "phrase_stats": phrase_stats},
    )


@router.post("/scan", response_class=HTMLResponse)
async def scan_library(request: Request, config: AppConfig, session: AsyncDbSession) -> HTMLResponse:
    """Scan configured library paths for EPUB changes."""
    try:
        count = await ingest_configured_paths(session, config)
        await session.commit()
    except Exception as error:
        logger.exception("ebook_admin_scan_failed")
        return error_response(request, error)

    logger.info(f"ebook_admin_scan_complete {count=}")
    if count > 0:
        schedule_bm25_refresh(request.app)
    return templates.TemplateResponse(request, "partials/admin_status.html", {"message": f"Indexed {count} EPUBs"})


@router.post("/phrases/generate-all", response_class=HTMLResponse)
async def generate_all_phrases(request: Request, config: AppConfig, engine: AppAsyncEngine) -> HTMLResponse:
    """Regenerate candidate phrases for every indexed book without LLM judging."""
    try:
        result = await generate_candidate_phrases_for_books(engine, config)
    except Exception as error:
        logger.exception("ebook_admin_generate_phrases_failed")
        return error_response(request, error)

    logger.info(
        f"ebook_admin_generate_phrases_complete {result.books_seen=} {result.books_built=} {result.candidate_phrases=}"
    )
    return templates.TemplateResponse(
        request,
        "partials/admin_status.html",
        {
            "message": (
                f"Generated phrases for {result.books_built} of {result.books_seen} books; "
                f"{result.candidate_phrases} candidates stored"
            )
        },
    )


@router.post("/phrases/judge-all", response_class=HTMLResponse)
async def judge_all_phrases(request: Request, engine: AppAsyncEngine, config: AppConfig) -> HTMLResponse:
    """Judge unjudged candidate phrases across every indexed book."""
    return await run_phrase_judgment(request, engine, config, source_ids=None)


@router.post("/phrases/judge-missing", response_class=HTMLResponse)
async def judge_missing_phrases(
    request: Request,
    engine: AppAsyncEngine,
    config: AppConfig,
    session: AsyncDbSession,
) -> HTMLResponse:
    """Judge candidate phrases only for books where judging has never run."""
    source_ids = await book_ids_pending_first_judgment(session)
    if not source_ids:
        return templates.TemplateResponse(
            request,
            "partials/admin_status.html",
            {"message": "All books with candidate phrases have been judged"},
        )
    return await run_phrase_judgment(request, engine, config, source_ids=source_ids)


async def run_phrase_judgment(
    request: Request,
    engine: AppAsyncEngine,
    config: AppConfig,
    *,
    source_ids: list[int] | None,
) -> HTMLResponse:
    """Run LLM judging for candidate phrases and render the outcome as an admin status partial.

    Args:
        request (Request): Current request, for template rendering.
        engine (AppAsyncEngine): Engine used to open per-book judging sessions.
        config (AppConfig): Runtime phrase-tuning settings.
        source_ids (list[int] | None): Books to judge; ``None`` judges every indexed book.

    Returns:
        HTMLResponse: Status partial describing the judging outcome.
    """
    try:
        result = await judge_candidate_phrases_for_books(engine, config, source_ids=source_ids)
    except Exception as error:
        logger.exception("ebook_admin_judge_phrases_failed")
        return error_response(request, error)

    logger.info(
        f"ebook_admin_judge_phrases_complete {result.books_seen=} {result.books_judged=} {result.books_failed=} "
        f"{result.candidates_judged=} {result.protected_phrases=} {result.phrase_mentions=}"
    )
    return templates.TemplateResponse(
        request,
        "partials/admin_status.html",
        {
            "message": (
                f"Judged {result.candidates_judged} candidates across {result.books_judged} of "
                f"{result.books_seen} books; {result.protected_phrases} protected phrases, "
                f"{result.phrase_mentions} mentions"
                + (f"; {result.books_failed} books failed" if result.books_failed else "")
            )
        },
    )


@router.post("/embed-missing", response_class=HTMLResponse)
async def embed_missing(
    request: Request,
    config: AppConfig,
    session: AsyncDbSession,
    client: AppHttpClient,
) -> HTMLResponse:
    """Embed chunks missing vectors for the configured model."""
    try:
        count = await embed_missing_chunks(session, client, config)
        await session.commit()
    except Exception as error:
        logger.exception("ebook_admin_embed_missing_failed")
        return error_response(request, error)

    logger.info(f"ebook_admin_embed_missing_complete {count=}")
    return templates.TemplateResponse(
        request,
        "partials/admin_status.html",
        {"message": f"Embedded {count} chunks"},
    )


@router.post("/embed-all", response_class=HTMLResponse)
async def embed_all(
    request: Request,
    config: AppConfig,
    session: AsyncDbSession,
    client: AppHttpClient,
) -> HTMLResponse:
    """Embed all chunks missing vectors in fixed-size batches."""
    total = 0
    batches = 0
    try:
        while True:
            count = await embed_missing_chunks(session, client, config)
            if count == 0:
                break
            await session.commit()
            total += count
            batches += 1
            logger.info(f"ebook_admin_embed_all_batch_complete {batches=} {count=} {total=}")
    except Exception as error:
        logger.exception(f"ebook_admin_embed_all_failed {batches=} {total=}")
        return error_response(request, f"Embed all failed after {total} chunks in {batches} batches: {error}")

    logger.info(f"ebook_admin_embed_all_complete {batches=} {total=}")
    return templates.TemplateResponse(
        request,
        "partials/admin_status.html",
        {"message": f"Embedded {total} chunks in {batches} batches of {config.embedding_batch_size}"},
    )