"""B05 경로 설계 결과의 aiomysql Raw SQL 접근.

routes(경로), route_points(렌더링 샘플), route_statistics(통계) 테이블에
메타데이터와 상대 경로를 기록한다. 전체 폴리라인은 route_data_path의
GeoJSON 파일에 저장하고 DB에는 경로만 기록한다.
"""

import json
from pathlib import PurePosixPath
from typing import Any
from uuid import UUID

import aiomysql

_STAGE_ROOT = "B05_wf2_Route"


def _validate_stage_path(relative_path: str) -> str:
    normalized = PurePosixPath(relative_path.replace("\\", "/"))
    if normalized.is_absolute() or ".." in normalized.parts:
        raise ValueError("DB에는 프로젝트 루트 기준 상대 경로만 저장할 수 있습니다.")
    if not normalized.parts or normalized.parts[0] != _STAGE_ROOT:
        raise ValueError(f"B05 산출물 경로는 {_STAGE_ROOT} 아래여야 합니다.")
    return normalized.as_posix()


async def create_route(
    connection: aiomysql.Connection,
    *,
    project_id: UUID,
    surface_model_id: int | None,
    total_length_m: float | None,
    start_chainage_m: float | None,
    end_chainage_m: float | None,
    grade_percent: list[float] | None,
    constraints: dict[str, Any] | None,
    algorithm_params: dict[str, Any] | None,
    route_data_path: str,
    status: str = "DRAFT",
) -> int:
    """경로 메타데이터를 저장하고 생성된 ID를 반환한다."""
    route_rel = _validate_stage_path(route_data_path)
    async with connection.cursor() as cursor:
        await cursor.execute(
            """
            INSERT INTO routes (
                project_id, surface_model_id, status,
                start_chainage_m, end_chainage_m, total_length_m,
                grade_percent, constraints, algorithm_params,
                route_data_path, computed_at
            )
            VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, CURRENT_TIMESTAMP)
            """,
            (
                str(project_id),
                surface_model_id,
                status,
                start_chainage_m,
                end_chainage_m,
                total_length_m,
                json.dumps(grade_percent) if grade_percent is not None else None,
                json.dumps(constraints, ensure_ascii=False) if constraints is not None else None,
                json.dumps(algorithm_params, ensure_ascii=False)
                if algorithm_params is not None
                else None,
                route_rel,
            ),
        )
        route_id = cursor.lastrowid
    if not route_id:
        raise RuntimeError("routes 레코드 생성 결과에 ID가 없습니다.")
    return int(route_id)


async def insert_route_points(
    connection: aiomysql.Connection,
    route_id: int,
    points: list[dict[str, Any]],
) -> int:
    """경로 렌더링 샘플 포인트를 일괄 저장하고 저장 건수를 반환한다.

    각 point dict: {chainage_m, elevation_m, slope_percent, sequence_num}
    """
    if not points:
        return 0
    rows = [
        (
            route_id,
            point.get("chainage_m"),
            point.get("elevation_m"),
            point.get("slope_percent"),
            point.get("sequence_num"),
        )
        for point in points
    ]
    async with connection.cursor() as cursor:
        await cursor.executemany(
            """
            INSERT INTO route_points (
                route_id, chainage_m, elevation_m, slope_percent, sequence_num
            )
            VALUES (%s, %s, %s, %s, %s)
            """,
            rows,
        )
    return len(rows)


async def create_route_statistics(
    connection: aiomysql.Connection,
    *,
    route_id: int,
    min_slope: float | None,
    max_slope: float | None,
    mean_slope: float | None,
    cut_volume_m3: float | None = None,
    fill_volume_m3: float | None = None,
    tree_cutting_volume: float | None = None,
    cost_score: float | None = None,
) -> int:
    """경로 통계를 저장하고 생성된 ID를 반환한다."""
    async with connection.cursor() as cursor:
        await cursor.execute(
            """
            INSERT INTO route_statistics (
                route_id, min_slope, max_slope, mean_slope,
                cut_volume_m3, fill_volume_m3, tree_cutting_volume, cost_score
            )
            VALUES (%s, %s, %s, %s, %s, %s, %s, %s)
            """,
            (
                route_id,
                min_slope,
                max_slope,
                mean_slope,
                cut_volume_m3,
                fill_volume_m3,
                tree_cutting_volume,
                cost_score,
            ),
        )
        stat_id = cursor.lastrowid
    if not stat_id:
        raise RuntimeError("route_statistics 레코드 생성 결과에 ID가 없습니다.")
    return int(stat_id)


async def get_latest_route(
    connection: aiomysql.Connection, project_id: UUID
) -> dict[str, Any] | None:
    """프로젝트의 최신 경로를 조회한다 (없으면 None)."""
    async with connection.cursor() as cursor:
        await cursor.execute(
            """
            SELECT id, status, total_length_m, route_data_path, computed_at
            FROM routes
            WHERE project_id = %s
            ORDER BY computed_at DESC, id DESC
            LIMIT 1
            """,
            (str(project_id),),
        )
        row = await cursor.fetchone()
    if not row:
        return None
    return {
        "id": int(row[0]),
        "status": row[1],
        "total_length_m": row[2],
        "route_data_path": row[3],
        "computed_at": row[4].isoformat() if row[4] else None,
    }


async def confirm_route(connection: aiomysql.Connection, route_id: int) -> None:
    """경로 상태를 CONFIRMED로 변경한다."""
    async with connection.cursor() as cursor:
        await cursor.execute(
            "UPDATE routes SET status = 'CONFIRMED' WHERE id = %s",
            (route_id,),
        )