/**
 * Typed API client for Chrysopedia review queue endpoints.
 *
 * All functions use fetch() with JSON handling and throw on non-OK responses.
 * Base URL is empty so requests go through the Vite dev proxy or nginx in prod.
 */

// ── Types ───────────────────────────────────────────────────────────────────

export interface KeyMomentRead {
  id: string;
  source_video_id: string;
  technique_page_id: string | null;
  title: string;
  summary: string;
  start_time: number;
  end_time: number;
  content_type: string;
  plugins: string[] | null;
  raw_transcript: string | null;
  review_status: string;
  created_at: string;
  updated_at: string;
}

export interface ReviewQueueItem extends KeyMomentRead {
  video_filename: string;
  creator_name: string;
}

export interface ReviewQueueResponse {
  items: ReviewQueueItem[];
  total: number;
  offset: number;
  limit: number;
}

export interface ReviewStatsResponse {
  pending: number;
  approved: number;
  edited: number;
  rejected: number;
}

export interface ReviewModeResponse {
  review_mode: boolean;
}

export interface MomentEditRequest {
  title?: string;
  summary?: string;
  start_time?: number;
  end_time?: number;
  content_type?: string;
  plugins?: string[];
}

export interface MomentSplitRequest {
  split_time: number;
}

export interface MomentMergeRequest {
  target_moment_id: string;
}

export interface QueueParams {
  status?: string;
  offset?: number;
  limit?: number;
}

// ── Helpers ──────────────────────────────────────────────────────────────────

const BASE = "/api/v1/review";

class ApiError extends Error {
  constructor(
    public status: number,
    public detail: string,
  ) {
    super(`API ${status}: ${detail}`);
    this.name = "ApiError";
  }
}

async function request<T>(url: string, init?: RequestInit): Promise<T> {
  const res = await fetch(url, {
    ...init,
    headers: {
      "Content-Type": "application/json",
      ...init?.headers,
    },
  });

  if (!res.ok) {
    let detail = res.statusText;
    try {
      const body = await res.json();
      detail = body.detail ?? detail;
    } catch {
      // body not JSON — keep statusText
    }
    throw new ApiError(res.status, detail);
  }

  return res.json() as Promise<T>;
}

// ── Queue ────────────────────────────────────────────────────────────────────

export async function fetchQueue(
  params: QueueParams = {},
): Promise<ReviewQueueResponse> {
  const qs = new URLSearchParams();
  if (params.status) qs.set("status", params.status);
  if (params.offset !== undefined) qs.set("offset", String(params.offset));
  if (params.limit !== undefined) qs.set("limit", String(params.limit));
  const query = qs.toString();
  return request<ReviewQueueResponse>(
    `${BASE}/queue${query ? `?${query}` : ""}`,
  );
}

export async function fetchStats(): Promise<ReviewStatsResponse> {
  return request<ReviewStatsResponse>(`${BASE}/stats`);
}

// ── Actions ──────────────────────────────────────────────────────────────────

export async function approveMoment(id: string): Promise<KeyMomentRead> {
  return request<KeyMomentRead>(`${BASE}/moments/${id}/approve`, {
    method: "POST",
  });
}

export async function rejectMoment(id: string): Promise<KeyMomentRead> {
  return request<KeyMomentRead>(`${BASE}/moments/${id}/reject`, {
    method: "POST",
  });
}

export async function editMoment(
  id: string,
  data: MomentEditRequest,
): Promise<KeyMomentRead> {
  return request<KeyMomentRead>(`${BASE}/moments/${id}`, {
    method: "PUT",
    body: JSON.stringify(data),
  });
}

export async function splitMoment(
  id: string,
  splitTime: number,
): Promise<KeyMomentRead[]> {
  const body: MomentSplitRequest = { split_time: splitTime };
  return request<KeyMomentRead[]>(`${BASE}/moments/${id}/split`, {
    method: "POST",
    body: JSON.stringify(body),
  });
}

export async function mergeMoments(
  id: string,
  targetId: string,
): Promise<KeyMomentRead> {
  const body: MomentMergeRequest = { target_moment_id: targetId };
  return request<KeyMomentRead>(`${BASE}/moments/${id}/merge`, {
    method: "POST",
    body: JSON.stringify(body),
  });
}

// ── Mode ─────────────────────────────────────────────────────────────────────

export async function getReviewMode(): Promise<ReviewModeResponse> {
  return request<ReviewModeResponse>(`${BASE}/mode`);
}

export async function setReviewMode(
  enabled: boolean,
): Promise<ReviewModeResponse> {
  return request<ReviewModeResponse>(`${BASE}/mode`, {
    method: "PUT",
    body: JSON.stringify({ review_mode: enabled }),
  });
}