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

from __future__ import annotations

import logging
from typing import TYPE_CHECKING

from fastapi import APIRouter, BackgroundTasks, HTTPException, Request
from fastapi.responses import HTMLResponse, RedirectResponse
from sqlalchemy import func, select

from python.ebook_search.api.dependencies import (
    AppConfig,  # noqa: TC001 FastAPI resolves this annotated dependency at runtime
)
from python.ebook_search.api.judge_tasks import is_judging_book, pop_book_judgment_outcome, start_book_phrase_judgment
from python.ebook_search.api.web import templates
from python.ebook_search.protected_phrases.generate_ngrams import recalculate_candidate_phrases_for_book
from python.ebook_search.protected_phrases.store import count_protected_phrases
from python.fastapi_tools import AsyncDbSession  # noqa: TC001 FastAPI resolves this annotated dependency at runtime
from python.orm.richie import EbookCandidatePhrase, EbookChapter, EbookChunk, EbookProtectedPhrase, EbookSource

if TYPE_CHECKING:
    from sqlalchemy.ext.asyncio import AsyncSession

logger = logging.getLogger(__name__)

router = APIRouter()


@router.get("/", response_class=HTMLResponse)
async def index(request: Request, config: AppConfig) -> HTMLResponse:
    """Render the search page."""
    return templates.TemplateResponse(request, "search.html", {"config": config})


@router.get("/books", response_class=HTMLResponse)
async def books(request: Request, session: AsyncDbSession) -> HTMLResponse:
    """Render the indexed books page."""
    sources = list((await session.scalars(select(EbookSource).order_by(EbookSource.title))).all())
    logger.info(f"ebook_books_page_loaded count={len(sources)}")
    return templates.TemplateResponse(request, "books.html", {"sources": sources})


async def get_chapter_count(session: AsyncSession, book_id: int) -> int:
    """Return the number of indexed chapters for one book."""
    return await session.scalar(select(func.count(EbookChapter.id)).where(EbookChapter.source_id == book_id)) or 0


async def get_chunk_count(session: AsyncSession, book_id: int) -> int:
    """Return the number of indexed chunks for one book."""
    return await session.scalar(select(func.count(EbookChunk.id)).where(EbookChunk.source_id == book_id)) or 0


async def get_candidate_count(session: AsyncSession, book_id: int) -> int:
    """Return the number of indexed candidates for one book."""
    return (
        await session.scalar(select(func.count(EbookCandidatePhrase.id)).where(EbookCandidatePhrase.book_id == book_id))
        or 0
    )


async def get_judged_candidate_count(session: AsyncSession, book_id: int) -> int:
    """Return the number of judged candidates for one book."""
    return (
        await session.scalar(
            select(func.count(EbookCandidatePhrase.id)).where(
                EbookCandidatePhrase.book_id == book_id,
                EbookCandidatePhrase.llm_judged.is_(True),
            )
        )
        or 0
    )


async def get_candidates(session: AsyncSession, book_id: int) -> list[EbookCandidatePhrase]:
    """Return the indexed candidates for one book."""
    return list(
        await session.scalars(
            select(EbookCandidatePhrase)
            .where(EbookCandidatePhrase.book_id == book_id)
            .order_by(EbookCandidatePhrase.candidate_score.desc())
            .limit(100)
        )
    )


async def get_protected_phrases(session: AsyncSession, book_id: int) -> list[EbookProtectedPhrase]:
    """Return the protected phrases for one book."""
    return list(
        await session.scalars(
            select(EbookProtectedPhrase)
            .where(EbookProtectedPhrase.book_id == book_id)
            .order_by(EbookProtectedPhrase.importance.desc())
            .limit(100)
        )
    )


@router.get("/books/{source_id}", response_class=HTMLResponse)
async def book_detail(source_id: int, request: Request, session: AsyncDbSession) -> HTMLResponse:
    """Render details for one indexed book."""
    source = await session.get(EbookSource, source_id)
    phrase_status_message = None
    recalculated = request.query_params.get("phrases_recalculated")
    if recalculated is not None:
        phrase_status_message = f"Recalculated phrases; {recalculated} candidates generated"
    judgment_outcome = pop_book_judgment_outcome(request.app, source_id)
    if judgment_outcome is not None:
        phrase_status_message = judgment_outcome
    judging_in_progress = is_judging_book(request.app, source_id)
    if judging_in_progress:
        phrase_status_message = "Judging candidate phrases in the background; refresh to see progress"
    if source is not None:
        chapter_count = await get_chapter_count(session, source.id)
        chunk_count = await get_chunk_count(session, source.id)
        candidate_count = await get_candidate_count(session, source.id)
        judged_candidate_count = await get_judged_candidate_count(session, source.id)
        protected_count = await count_protected_phrases(session, source.id)
        candidates = await get_candidates(session, source.id)
        protected_phrases = await get_protected_phrases(session, source.id)
    else:
        chapter_count = 0
        chunk_count = 0
        candidate_count = 0
        judged_candidate_count = 0
        protected_count = 0
        candidates = []
        protected_phrases = []
    logger.info(
        f"ebook_book_detail_loaded {source_id=} found={source is not None} {chapter_count=} {chunk_count=} "
        f"{candidate_count=} {judged_candidate_count=} {protected_count=}"
    )
    return templates.TemplateResponse(
        request,
        "book_detail.html",
        {
            "candidate_count": candidate_count,
            "candidates": candidates,
            "chapter_count": chapter_count,
            "chunk_count": chunk_count,
            "judged_candidate_count": judged_candidate_count,
            "judging_in_progress": judging_in_progress,
            "protected_count": protected_count,
            "protected_phrases": protected_phrases,
            "phrase_status_message": phrase_status_message,
            "source": source,
        },
    )


@router.post("/books/{source_id}/recalculate-phrases")
async def recalculate_book_phrases(source_id: int, config: AppConfig, session: AsyncDbSession) -> RedirectResponse:
    """Clear and regenerate candidate phrases for one indexed book."""
    source = await session.get(EbookSource, source_id)
    if source is None:
        raise HTTPException(status_code=404, detail="Book not found")

    try:
        result = await recalculate_candidate_phrases_for_book(session, source, config)
    except ValueError as error:
        raise HTTPException(status_code=409, detail=str(error)) from error
    logger.info(
        f"ebook_book_phrase_recalculation_complete {source_id=} {result.candidate_phrases=} "
        f"{result.deleted_candidates=} {result.deleted_protected_phrases=} {result.deleted_aliases=} "
        f"{result.deleted_mentions=}"
    )
    return RedirectResponse(
        url=f"/books/{source_id}?phrases_recalculated={result.candidate_phrases}",
        status_code=303,
    )


@router.post("/books/{source_id}/judge-phrases")
async def judge_book_phrases(
    source_id: int,
    request: Request,
    background_tasks: BackgroundTasks,
    session: AsyncDbSession,
) -> RedirectResponse:
    """Queue background judging of one book's candidate phrases and return immediately."""
    source = await session.get(EbookSource, source_id)
    if source is None:
        raise HTTPException(status_code=404, detail="Book not found")

    started = start_book_phrase_judgment(request.app, background_tasks, source.id)
    logger.info(f"ebook_book_phrase_judgment_requested {source_id=} {started=}")
    return RedirectResponse(url=f"/books/{source_id}", status_code=303)