/* =============================================================================
 * D03_PlanAnalysis_Api.ts
 * D03 분석 화면 서버 요청(PLAN 530-3) — 지점 정본(D02) · 지형 받기 · 분석 · 진행 · 저장본 · [저장] ·
 *   연도별 지형면(모델 행 · 격자). 끈 지점은 `points`(작업 좌표계 m)로 실어 보냄.
 * ========================================================================== */

import { API_BASE_URL } from "@config/config_frontend";
import { fetchCachedBytes } from "../A00_Common/b_asset_cache";
import { listSurfaceModels } from "../B04_PreProcess/B04_PreProcess_Api_Fetch";
import { type DtmGrid, parseDtmGrid } from "../common_util/common_util_surface_sampler";
import type { ChainRow, Vertex, YearAnalysis } from "./logic/D03_PlanAnalysis_Plan";

export interface PlanPointsView {
  year_start: number;
  year_end: number;
  epsg: number | null;
  years: Array<{
    year: number;
    start: { x: number; y: number } | null;
    end: { x: number; y: number } | null;
  }>;
}

export interface PlanJob {
  running: boolean;
  percent: number;
  message: string | null;
  error: string | null;
}

export interface PlanAnalysisView {
  years: Array<{ year: number; start: Vertex; end: Vertex; analysis: YearAnalysis | null }>;
  chain: ChainRow[] | null;
  /** 등록 노선 시작 누가(m). */
  start_chainage_m: number;
  /** 등록 노선 종료 누가(계획 목표 · m) — 없으면 null. */
  end_chainage_target_m?: number | null;
}

export type PlanPoints = Array<{ year: number; start: Vertex; end: Vertex }>;

async function request<T>(path: string, init: RequestInit = {}): Promise<T> {
  const response = await fetch(`${API_BASE_URL}${path}`, {
    ...init,
    credentials: "include",
    headers: { "Content-Type": "application/json", ...(init.headers ?? {}) },
  });
  const body = (await response.json().catch(() => ({}))) as T & { detail?: unknown };
  if (!response.ok) {
    const detail = typeof body.detail === "string" ? body.detail : `HTTP ${response.status}`;
    throw new Error(detail);
  }
  return body;
}

const base = (projectId: string): string => `/projects/${projectId}/plan`;
const pointsBody = (points: PlanPoints | null): string => JSON.stringify(points ? { points } : {});

export const fetchPlanPoints = (projectId: string): Promise<PlanPointsView> =>
  request(`${base(projectId)}/points`);

export const startPlanJob = (
  projectId: string,
  kind: "terrain" | "analyze",
  points: PlanPoints | null,
): Promise<PlanJob> =>
  request(`${base(projectId)}/${kind}`, { method: "POST", body: pointsBody(points) });

export const fetchPlanProgress = (
  projectId: string,
): Promise<{ terrain: PlanJob; analyze: PlanJob }> => request(`${base(projectId)}/progress`);

export const fetchPlanAnalysis = (
  projectId: string,
  points: PlanPoints | null,
): Promise<PlanAnalysisView> =>
  request(
    `${base(projectId)}/analysis` +
      (points ? `?points=${encodeURIComponent(JSON.stringify(points))}` : ""),
  );

export const savePlanAnalysis = (
  projectId: string,
  choices: Record<number, string>,
  points: PlanPoints | null,
): Promise<{ chain: ChainRow[] }> =>
  request(`${base(projectId)}/analysis`, {
    method: "PUT",
    body: JSON.stringify(points ? { choices, points } : { choices }),
  });

export interface YearSurface {
  modelId: number;
  grid: DtmGrid;
}

/** 연도별 지형면 — 모델 행 경로 `…/models_<연도>/…` · 격자 = 분석과 같은 평활본. */
export async function fetchYearSurfaces(projectId: string): Promise<Map<number, YearSurface>> {
  const { models } = await listSurfaceModels(projectId);
  const out = new Map<number, YearSurface>();
  for (const model of models) {
    const year = Number(/models_(\d+)\//.exec(model.model_file_path ?? "")?.[1]);
    if (!year || out.has(year)) continue;
    const stamp = String(model.generation_params?.file_stamp ?? "");
    const url =
      `${API_BASE_URL}/projects/${projectId}/surface/models/${model.id}/grid` +
      `?smooth=true&sig=${encodeURIComponent(stamp)}`;
    out.set(year, {
      modelId: model.id,
      grid: parseDtmGrid(await fetchCachedBytes(projectId, url)),
    });
  }
  return out;
}