/* =============================================================================
 * M02_MasterTemplete_Api_Fetch.ts
 * 마스터 템플릿 서버 호출 — 계약 `6_계약.md` 서버 길 · 시스템 층은 시스템 관리자만
 * ========================================================================== */

import { API_BASE_URL } from "@config/config_frontend";

/** 층 이름 — 서버와 같은 글 */
export type Layer = "system" | "company" | "personal" | "project";
/** 서버 종류 — 화면의 「표 양식」 = table · 「도면 양식」 = drawing */
export type Kind = "table" | "drawing";

export interface TemplateInfo {
  종류: Kind;
  이름: string;
  판: string;
  수정일: string;
}

export interface TemplateDoc {
  종류: Kind;
  이름: string;
  /** 프로젝트 층에서 작업본이 아직 없으면(옛 프로젝트) 시스템 양식이 와서 null */
  판: string | null;
  문서: unknown;
}

/** 서버가 판 불일치로 막았을 때 */
export class StaleError extends Error {}

async function call<T>(path: string, init: RequestInit = {}): Promise<T> {
  const response = await fetch(`${API_BASE_URL}/m02${path}`, {
    credentials: "include",
    headers: { "Content-Type": "application/json" },
    ...init,
  });
  const body = (await response.json().catch(() => ({}))) as { detail?: unknown } & T;
  if (response.status === 409) throw new StaleError(String(body.detail ?? "409"));
  if (!response.ok) {
    const detail = body.detail;
    throw new Error(typeof detail === "string" ? detail : `HTTP ${response.status}`);
  }
  return body;
}

const enc = encodeURIComponent;
const q = (projectId: string | null): string => (projectId ? `?project_id=${enc(projectId)}` : "");
const head = (layer: Layer): string =>
  layer === "system" ? "/templates" : `/layers/${layer}/templates`;
const item = (layer: Layer, kind: Kind, name: string, projectId: string | null): string =>
  `${head(layer)}/${kind}/${enc(name)}${layer === "system" ? "" : q(projectId)}`;

/** 시스템 길은 배열 · 층 길은 `{층, 양식: [...]}` — 둘 다 목록으로 */
export const listTemplates = async (
  layer: Layer,
  projectId: string | null,
): Promise<TemplateInfo[]> => {
  const got = await call<TemplateInfo[] | { 양식: TemplateInfo[] }>(
    layer === "system" ? head(layer) : `${head(layer)}${q(projectId)}`,
  );
  return Array.isArray(got) ? got : got.양식;
};

export const readTemplate = (
  layer: Layer,
  kind: Kind,
  name: string,
  projectId: string | null,
): Promise<TemplateDoc> => call(item(layer, kind, name, projectId));

export const saveTemplate = (
  layer: Layer,
  kind: Kind,
  name: string,
  projectId: string | null,
  판: string,
  문서: unknown,
): Promise<TemplateInfo> =>
  call(item(layer, kind, name, projectId), { method: "PUT", body: JSON.stringify({ 판, 문서 }) });

/** 시스템 층만 지움 */
export const deleteTemplate = (kind: Kind, name: string, 판: string): Promise<{ ok: boolean }> =>
  call(`/templates/${kind}/${enc(name)}?판=${enc(판)}`, { method: "DELETE" });

/* --- 프로젝트 층 단추 다섯 --- */
const project = (id: string, tail: string): string => `/projects/${enc(id)}/templates/${tail}`;
const post = (path: string, body: object = {}): Promise<unknown> =>
  call(path, { method: "POST", body: JSON.stringify(body) });

export const resetProject = (id: string): Promise<unknown> => post(project(id, "reset"));

export const applyToProject = (
  id: string,
  from: { from: Layer; user_id?: string; project_id?: string; 종류?: Kind; 이름?: string },
): Promise<unknown> => post(project(id, "apply"), from);

export const saveProjectAs = (
  id: string,
  to: "personal" | "company",
  종류: Kind,
  이름: string,
): Promise<unknown> => post(project(id, "save-as"), { to, 종류, 이름 });

export const fetchSources = (id: string): Promise<unknown> => call(`/projects/${enc(id)}/sources`);

/** 설계값을 채운 표 문서 — 서버가 그때그때 채움 · 저장 안 함 */
export const readFilled = (id: string, name: string): Promise<TemplateDoc> =>
  call(`/projects/${enc(id)}/tables/${enc(name)}/filled`);