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

from __future__ import annotations

import logging
from dataclasses import replace
from time import perf_counter
from typing import TYPE_CHECKING, Annotated

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

from python.ebook_search.answer import answer_query
from python.ebook_search.api.web import templates
from python.ebook_search.search import search_ebooks
from python.ebook_search.timing import runtime_step_from_start

if TYPE_CHECKING:
    from fastapi import FastAPI

logger = logging.getLogger(__name__)

router = APIRouter()


def register_search_routes(app: FastAPI) -> None:
    """Register search routes on the app."""
    app.include_router(router)


@router.post("/search", response_class=HTMLResponse)
def search(
    request: Request,
    query: Annotated[str, Form()],
    rerank: Annotated[str | None, Form()] = None,
) -> HTMLResponse:
    """Run a search and render HTMX results."""
    try:
        response = search_ebooks(request.app.state.engine, query, request.app.state.config, rerank=rerank == "true")
    except Exception as error:
        logger.exception("ebook_search_request_failed")
        return templates.TemplateResponse(request, "partials/error.html", {"message": str(error)}, status_code=500)

    answer_start = perf_counter()
    if request.app.state.config.answer_enabled:
        try:
            answer = answer_query(query, response.results, request.app.state.config)
        except RuntimeError as error:
            logger.warning("ebook_answer_request_failed_falling_back error=%s", error)
            answer = "Answer generation failed. Source chunks are still shown below."
    else:
        logger.info("ebook_answer_skipped_disabled")
        answer = "Answer generation is disabled. Source chunks are shown below."
    answer_step_name = "Answer generation" if request.app.state.config.answer_enabled else "Answer skipped"
    response = replace(
        response,
        timings=(*response.timings, runtime_step_from_start(answer_step_name, answer_start)),
    )

    logger.info(
        "ebook_search_request_complete results=%s rank_label=%s runtime_ms=%.1f",
        len(response.results),
        response.rank_label,
        response.total_runtime_ms,
    )
    return templates.TemplateResponse(request, "partials/results.html", {"answer": answer, "response": response})