"""초기 계획노선 갈래 하나 — `POST /api/projects/{id}/route/initial`(PLAN 20 · 23장).

`B05_Profile_Router_Replan`(700줄)에서 나눈 길. 같은 `router` 에 붙고 그 모듈 끝에서 불려
등록된다 — main · 시험이 `Router_Replan.router` 하나만 실어도 이 길이 함께 실림.
"""

import asyncio
import functools
import logging
import time
from typing import Any
from uuid import UUID

from fastapi.responses import JSONResponse

from B05_Profile import B05_Profile_Router_Replan as replan
from B05_Profile.B05_Profile_Engine_RouteInitial import read_initial_choice
from common_util.common_util_initial_snapshot import design_route_csv_path
from common_util.common_util_route_geometry import expected_route_csv_path
from config.config_db import get_db_pool

logger = logging.getLogger(__name__)


@replan.router.post("/{project_id}/route/initial", response_model=None)
async def initial_route(
    project_id: UUID, request: replan.RouteInitialRequest
) -> dict[str, Any] | JSONResponse:
    """초기 계획노선 갈래 하나를 만들어 비교값과 함께 돌려준다(PLAN 20장).

    **파일을 쓰지 않는다** — 화면 캐시용. 적용은 받은 `nodes` 로 `POST /route/replan`([확인]).
    """
    from B05_Profile.B05_Profile_Engine_Grade import legal_grade_limit_pct
    from B05_Profile.B05_Profile_Engine_RouteInitial import (
        generate_initial_route,
        load_terrain_and_streams,
    )
    from common_util.common_util_surface_confirmation import get_surface_confirmation_params

    weights = request.weights.model_dump() if request.weights else None
    if request.mode == "weighted" and weights and abs(sum(weights.values()) - 100.0) > 0.5:
        return JSONResponse(
            status_code=400,
            content={"status": "error", "message": "비중 세 값의 합은 100 이어야 합니다."},
        )
    try:
        paths = await replan._project_paths(project_id)
    except LookupError:  # 없는 프로젝트 — 저장소 조회가 None 대신 던짐
        paths = None
    if paths is None:
        return JSONResponse(status_code=404, content=replan._PROJECT_PATH_MISSING)
    project_root, _ = paths
    expected = await asyncio.to_thread(replan._vertices_of, expected_route_csv_path(project_root))
    if not expected:
        expected = await asyncio.to_thread(replan._vertices_of, design_route_csv_path(project_root))
    if len(expected) < 2:
        return JSONResponse(
            status_code=400,
            content={"status": "error", "message": "예상노선이 없어 초기노선을 만들 수 없습니다."},
        )
    radius_m, _, _ = await replan._plan_criteria(project_id)
    grade_class, design_speed, terrain_type = await replan._road_settings(project_id)
    # 비포장 기준 — 포장 예외(18 %)는 포장 여부가 정해진 뒤 종단 설계가 따진다(사용자 확정 대기).
    max_grade = legal_grade_limit_pct(grade_class, terrain_type, False, design_speed) / 100.0
    # 화면 제약 칸(PLAN 20장 확정) — 비운 칸은 위 프로젝트 기본값 그대로, 채운 칸만 겹쳐 쓴다.
    criteria = request.criteria
    if criteria and criteria.max_grade_pct is not None:
        max_grade = criteria.max_grade_pct / 100.0
    if criteria and criteria.min_radius_m is not None:
        radius_m = criteria.min_radius_m
    stream_offset_m = criteria.stream_offset_m if criteria else None
    grade_smooth_m = criteria.grade_smooth_m if criteria else None
    target_pct = criteria.target_grade_pct if criteria else None
    pool = get_db_pool()
    async with pool.acquire() as connection:
        selection = await get_surface_confirmation_params(connection, str(project_id))
    started = time.perf_counter()
    try:
        terrain, streams = await asyncio.to_thread(
            load_terrain_and_streams, project_root, selection
        )
        result = await asyncio.to_thread(
            functools.partial(
                generate_initial_route,
                [(x, y) for x, y in expected],
                terrain,
                streams,
                mode=request.mode,
                weights=weights,
                max_grade=max_grade,
                min_radius_m=radius_m,
                stream_offset_m=stream_offset_m,
                grade_smooth_m=grade_smooth_m,
                target_grade=None if target_pct is None else target_pct / 100.0,
            )
        )
    except (FileNotFoundError, ValueError) as error:
        return JSONResponse(status_code=409, content={"status": "error", "message": str(error)})
    logger.info(
        "초기 계획노선 %s: project_id=%s %.1fs 연장 %.0fm 이격 평균 %.1fm",
        request.mode,
        project_id,
        time.perf_counter() - started,
        result["metrics"]["length_m"],
        result["metrics"]["offset_avg_m"],
    )
    current = await asyncio.to_thread(read_initial_choice, project_root)
    return {
        "status": "success",
        "project_id": str(project_id),
        **result,
        "current_initial": current,
    }