"""B05 경로 설계 FastAPI 라우터."""

import asyncio
import logging
from pathlib import Path
from uuid import UUID

from fastapi import APIRouter
from fastapi.responses import JSONResponse

from B03_FileInput.B03_FileInput_Repository import get_project_storage_relative_path
from B05_wf2_Route.B05_wf2_Route_Engine import run_route_design
from B05_wf2_Route.B05_wf2_Route_Repository import (
    confirm_route,
    create_route,
    create_route_statistics,
    get_latest_route,
    insert_route_points,
)
from B05_wf2_Route.B05_wf2_Route_Schema import (
    RouteConfirmResponse,
    RouteSolveRequest,
    RouteSolveResponse,
)
from common_util.common_util_storage import resolve_stored_project_path
from common_util.common_util_workflow_state import complete_stage, fail_stage, start_stage
from config.config_db import get_db_pool

logger = logging.getLogger(__name__)
router = APIRouter(prefix="/api/projects", tags=["B05 Route Design"])


@router.post("/{project_id}/route/solve", response_model=RouteSolveResponse)
async def solve_route(
    project_id: UUID, request: RouteSolveRequest
) -> RouteSolveResponse | JSONResponse:
    """경로 탐색을 실행하고 결과를 GeoJSON 저장 + DB 기록한다."""
    pool = get_db_pool()
    try:
        params = {
            "filter_key": request.filter_key,
            "method": request.method,
            "smooth": request.smooth,
            "points": request.points,
            "options": request.options(),
            "algorithm": request.algorithm,
            "surface_model_id": request.surface_model_id,
        }
        async with pool.acquire() as connection:
            async with connection.cursor() as cursor:
                await start_stage(cursor, str(project_id), 2, params)
                await connection.commit()

            stored_path = await get_project_storage_relative_path(connection, project_id)
            project_root = Path(resolve_stored_project_path(stored_path))

            # 무거운 경로 탐색은 이벤트 루프를 막지 않도록 별도 스레드에서 실행.
            design = await asyncio.to_thread(
                run_route_design,
                project_root,
                request.filter_key,
                request.method,
                request.smooth,
                request.points_data(),
                request.options(),
                request.algorithm,
            )
            solver = design["solver_result"]
            metrics = solver["metrics"]

            await connection.begin()
            try:
                route_id = await create_route(
                    connection,
                    project_id=project_id,
                    surface_model_id=request.surface_model_id,
                    total_length_m=metrics.get("length_m"),
                    start_chainage_m=0.0,
                    end_chainage_m=metrics.get("length_m"),
                    grade_percent=design["grade_percent"],
                    constraints=design["constraints"],
                    algorithm_params=design["algorithm_params"],
                    route_data_path=design["route_data_path"],
                )
                await insert_route_points(connection, route_id, design["render_points"])
                stats = design["statistics"]
                await create_route_statistics(
                    connection,
                    route_id=route_id,
                    min_slope=stats["min_slope"],
                    max_slope=stats["max_slope"],
                    mean_slope=stats["mean_slope"],
                    cost_score=stats["cost_score"],
                )
                async with connection.cursor() as cursor:
                    await complete_stage(cursor, str(project_id), 2)
                await connection.commit()
            except Exception:
                await connection.rollback()
                raise

        return RouteSolveResponse(
            project_id=str(project_id),
            route_id=route_id,
            total_length_m=metrics.get("length_m", 0.0),
            metrics=metrics,
            required_points_ok=solver["required_points_ok"],
            route_data_path=design["route_data_path"],
        )
    except LookupError as exc:
        async with pool.acquire() as connection, connection.cursor() as cursor:
            await fail_stage(cursor, str(project_id), 2, str(exc))
            await connection.commit()
        return JSONResponse(status_code=404, content={"status": "error", "message": str(exc)})
    except FileNotFoundError as exc:
        async with pool.acquire() as connection, connection.cursor() as cursor:
            await fail_stage(cursor, str(project_id), 2, str(exc))
            await connection.commit()
        return JSONResponse(status_code=404, content={"status": "error", "message": str(exc)})
    except (OSError, ValueError) as exc:
        async with pool.acquire() as connection, connection.cursor() as cursor:
            await fail_stage(cursor, str(project_id), 2, str(exc))
            await connection.commit()
        return JSONResponse(status_code=400, content={"status": "error", "message": str(exc)})
    except Exception as exc:
        logger.exception("B05 경로 탐색 실패: project_id=%s", project_id)
        async with pool.acquire() as connection, connection.cursor() as cursor:
            await fail_stage(cursor, str(project_id), 2, str(exc))
            await connection.commit()
        return JSONResponse(
            status_code=500,
            content={"status": "error", "message": "경로 탐색 처리 중 오류가 발생했습니다."},
        )


@router.post("/{project_id}/route/confirm", response_model=RouteConfirmResponse)
async def confirm_latest_route(project_id: UUID) -> RouteConfirmResponse | JSONResponse:
    """프로젝트의 최신 경로를 확정(CONFIRMED)한다."""
    pool = get_db_pool()
    try:
        async with pool.acquire() as connection:
            latest = await get_latest_route(connection, project_id)
            if not latest:
                return JSONResponse(
                    status_code=404,
                    content={"status": "error", "message": "확정할 경로가 없습니다."},
                )
            await connection.begin()
            try:
                await confirm_route(connection, latest["id"])
                async with connection.cursor() as cursor:
                    await complete_stage(cursor, str(project_id), 2)
                await connection.commit()
            except Exception:
                await connection.rollback()
                raise
        return RouteConfirmResponse(project_id=str(project_id), route_id=latest["id"])
    except Exception:
        logger.exception("B05 경로 확정 실패: project_id=%s", project_id)
        return JSONResponse(
            status_code=500,
            content={"status": "error", "message": "경로 확정 처리 중 오류가 발생했습니다."},
        )