"""받은 예정노선 원본 꼭짓점(635-2 · 요구 546) — B05 「예정노선 수정」이 고칠 선.

계산 자리 ③ 서버 단독 · 읽기만(파일 안 만듦). 원본 = 올린(받은) 노선 파일 꼭짓점을 사업지 좌표로 ·
사용 범위(`projects.route_start_m · route_end_m`) · 지표면 트림까지 — 체인 예정노선
(`load_design_route`)과 같은 차례에서 **조밀화만 뺌**. 고친 꼭짓점은 `POST /route/follow` 가
같은 간격(`spacing_m`)으로 조밀화한 뒤 추적 → 안 고친 원본 = 체인 초기선과 거리 0(`test_635_2`).

  GET /api/projects/{id}/route/plan/source
    → {status, expected_source: [[x, y], …], spacing_m}   (원본 없음 = 빈 목록)
    404 프로젝트 없음
"""

from __future__ import annotations

import asyncio
from pathlib import Path
from typing import Any
from uuid import UUID

from fastapi import APIRouter
from fastapi.responses import JSONResponse

from B05_Profile.B05_Profile_Router_Replan import _PROJECT_PATH_MISSING, _project_paths
from common_util.common_util_route_geometry import load_design_route, trim_route_to_surface
from common_util.common_util_surface_confirmation import get_surface_confirmation_params
from common_util.common_util_surface_sampler import build_surface_sampler
from config.config_db import get_db_pool
from config.config_system import (
    ROUTE_DIRECT_LINK_CELL_FACTOR,
    ROUTE_GRID_RES_M,
    ROUTE_PLANNED_DENSIFY_SAFETY,
)

router = APIRouter(prefix="/api/projects", tags=["B05 Plan Source"])

#: 체인 예정노선 조밀화 간격(`load_design_route` 와 같은 값)
SPACING_M = ROUTE_DIRECT_LINK_CELL_FACTOR * ROUTE_GRID_RES_M * ROUTE_PLANNED_DENSIFY_SAFETY


def source_vertices(
    root: Path, surface: dict[str, Any] | None, route_range: tuple | None
) -> list[list[float]]:
    """원본 꼭짓점 — 사업지 좌표 · 범위 · 지표면 트림(지표면을 못 열면 트림 없이) · 조밀화 없음."""
    planned = load_design_route(root, None, route_range)
    if planned is None:
        return []
    points = [(v.x, v.y) for v in planned.vertices]
    if surface:
        try:
            sampler = build_surface_sampler(
                root / "B04_PreProcess" / "models",
                str(surface["source_filter"]),
                str(surface["method"]),
                bool(surface["smooth"]),
            )
        except (FileNotFoundError, KeyError, OSError):
            sampler = None
        if sampler is not None:
            points = trim_route_to_surface(points, sampler)
    return [[float(x), float(y)] for x, y in points] if len(points) >= 2 else []


@router.get("/{project_id}/route/plan/source", response_model=None)
async def read_plan_source(project_id: UUID) -> dict[str, Any] | JSONResponse:
    paths = await _project_paths(project_id)
    if paths is None:
        return JSONResponse(status_code=404, content=_PROJECT_PATH_MISSING)
    async with get_db_pool().acquire() as connection:
        surface = await get_surface_confirmation_params(connection, str(project_id))
        async with connection.cursor() as cursor:
            await cursor.execute(
                "SELECT route_start_m, route_end_m FROM projects WHERE id = %s",
                (str(project_id),),
            )
            row = await cursor.fetchone()
    vertices = await asyncio.to_thread(
        source_vertices, paths[0], surface, (row[0], row[1]) if row else None
    )
    return {
        "status": "success",
        "project_id": str(project_id),
        "expected_source": vertices,
        "spacing_m": SPACING_M,
    }