/* B03 다중 파일 업로드 API 클라이언트 */

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

export interface UploadedFileResult {
  input_file_id: number;
  original_filename: string;
  file_type: string;
  relative_path: string;
  size_bytes: number;
  metadata: Record<string, unknown>;
}

export interface FileUploadResponse {
  status: string;
  project_id: string;
  files: UploadedFileResult[];
}

export interface ChunkSessionCreateResponse {
  status: string;
  project_id: string;
  upload_session_id: string;
  original_filename: string;
  file_size_bytes: number;
  chunk_size_bytes: number;
  total_chunks: number;
  completed_chunks: number;
  /** 같은 내용이 이미 올라와 있어 전송을 건너뛰어도 되는지. */
  already_uploaded?: boolean;
}

export interface ChunkUploadResponse {
  status: string;
  upload_session_id: string;
  chunk_index: number;
  completed_chunks: number;
  total_chunks: number;
  chunk_hash: string;
}

export interface UploadStatusResponse {
  status: string;
  upload_session_id: string;
  upload_status: string;
  original_filename: string;
  file_size_bytes: number;
  chunk_size_bytes: number;
  total_chunks: number;
  completed_chunks: number;
  completed_chunk_indexes: number[];
}

/**
 * 「지우고 진행할까?」를 물어야 하는 상태(409). 서버가 무엇이 지워지는지 함께 준다.
 * 되돌릴 수 없는 삭제라 사람이 한 번 보고 정한다(2026-09-08 사용자 지시).
 */
export class ReplaceOutputsConfirmRequired extends Error {
  readonly targets: string[];

  constructor(message: string, targets: string[]) {
    super(message);
    this.name = "ReplaceOutputsConfirmRequired";
    this.targets = targets;
  }
}

async function readJsonOrThrow<T>(response: Response): Promise<T> {
  const payload = (await response.json()) as T & {
    message?: string;
    confirm?: string;
    targets?: string[];
  };
  if (!response.ok) {
    if (response.status === 409 && payload.confirm === "replace_outputs") {
      throw new ReplaceOutputsConfirmRequired(
        payload.message ?? "이미 만들어 둔 결과가 지워집니다.",
        payload.targets ?? [],
      );
    }
    throw new Error(payload.message ?? `HTTP ${response.status}`);
  }
  return payload;
}

export async function uploadProjectFiles(
  projectId: string,
  files: readonly File[],
  confirmReplace = false,
): Promise<FileUploadResponse> {
  const formData = new FormData();
  for (const file of files) formData.append("files", file, file.name);
  if (confirmReplace) formData.append("confirm_replace", "true");

  const controller = new AbortController();
  const timeoutId = window.setTimeout(() => controller.abort(), API_TIMEOUT_MS);
  try {
    const response = await fetch(`${API_BASE_URL}/projects/${projectId}/files`, {
      method: "POST",
      credentials: "include",
      body: formData,
      signal: controller.signal,
    });
    return await readJsonOrThrow<FileUploadResponse>(response);
  } finally {
    window.clearTimeout(timeoutId);
  }
}

export async function createUploadSession(
  projectId: string,
  file: File,
  chunkSizeBytes: number,
  fingerprint?: string | null,
  completeUpload = false,
  lasFree = false,
  confirmReplace = false,
): Promise<ChunkSessionCreateResponse> {
  const response = await fetch(`${API_BASE_URL}/projects/${projectId}/upload-sessions`, {
    method: "POST",
    credentials: "include",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      original_filename: file.name,
      size_bytes: file.size,
      chunk_size_bytes: chunkSizeBytes,
      fingerprint: fingerprint ?? null,
      complete_upload: completeUpload,
      las_free: lasFree,
      confirm_replace: confirmReplace,
    }),
  });
  return await readJsonOrThrow<ChunkSessionCreateResponse>(response);
}

export async function uploadFileChunk(
  projectId: string,
  sessionId: string,
  chunkIndex: number,
  chunk: Blob,
): Promise<ChunkUploadResponse> {
  const formData = new FormData();
  formData.append("session_id", sessionId);
  formData.append("chunk_index", String(chunkIndex));
  formData.append("chunk_data", chunk, `${sessionId}-${chunkIndex}.chunk`);

  const response = await fetch(`${API_BASE_URL}/projects/${projectId}/chunks`, {
    method: "POST",
    credentials: "include",
    body: formData,
  });
  return await readJsonOrThrow<ChunkUploadResponse>(response);
}

export async function finalizeUploadSession(
  projectId: string,
  sessionId: string,
  totalChunks: number,
  completeUpload: boolean,
  fingerprint?: string | null,
  lasFree = false,
  confirmReplace = false,
): Promise<FileUploadResponse> {
  const response = await fetch(`${API_BASE_URL}/projects/${projectId}/finalize`, {
    method: "POST",
    credentials: "include",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      session_id: sessionId,
      total_chunks: totalChunks,
      complete_upload: completeUpload,
      fingerprint: fingerprint ?? null,
      las_free: lasFree,
      confirm_replace: confirmReplace,
    }),
  });
  return await readJsonOrThrow<FileUploadResponse>(response);
}

export async function fetchUploadStatus(
  projectId: string,
  sessionId: string,
): Promise<UploadStatusResponse> {
  const response = await fetch(`${API_BASE_URL}/projects/${projectId}/upload-status/${sessionId}`, {
    method: "GET",
    credentials: "include",
  });
  return await readJsonOrThrow<UploadStatusResponse>(response);
}

export interface UploadOverviewFile {
  input_file_id: number;
  file_type: string;
  original_filename: string;
  file_size_mb: number;
  status: string;
  uploaded_at: string | null;
  /** 저장 경로 — PRJ 두 장(노선/지형)을 카드에 되돌릴 때 이것으로 가린다. */
  relative_path: string | null;
  /** 업로드 분석 결과 — 카드 미리보기(범위 사각형·노선 선)의 재료. */
  metadata?: Record<string, unknown> | null;
}

export interface UploadOverviewSession {
  upload_session_id: string;
  original_filename: string;
  file_size_bytes: number;
  total_chunks: number;
  completed_chunks: number;
  progress_percent: number;
  updated_at: string | null;
}

/** 지금 분석이 도는 중이면 **누가 시작했는지**. 도는 중이 아니면 `null`. */
export interface UploadLockInfo {
  running: boolean;
  user_id: number | null;
  name: string | null;
  email: string | null;
  started_at: string | null;
}

export interface UploadOverviewResponse {
  status: string;
  files: UploadOverviewFile[];
  pending_sessions: UploadOverviewSession[];
  required_complete: boolean;
  analysis_complete: boolean;
  /** 서버가 새 자료를 막는 동안 **왜·누구 때문에** 막혔는지(2026-09-09, 계획서 0-8). */
  analysis_lock?: UploadLockInfo | null;
}

/** 재접속 시 업로드 현황(정본) — 완료 파일 목록 + 중단 세션 + 완료 여부. */
export async function fetchUploadOverview(projectId: string): Promise<UploadOverviewResponse> {
  const response = await fetch(`${API_BASE_URL}/projects/${projectId}/upload-overview`, {
    method: "GET",
    credentials: "include",
  });
  return await readJsonOrThrow<UploadOverviewResponse>(response);
}

export interface WF1AnalysisStatus {
  project_id: string;
  status: "pending" | "in_progress" | "completed" | "failed";
  model_count: number;
  progress_percent: number;
  current_stage: string;
  message: string;
  error?: string;
}

export async function checkWF1AnalysisStatus(projectId: string): Promise<WF1AnalysisStatus> {
  const response = await fetch(`${API_BASE_URL}/projects/${projectId}/surface/status`, {
    method: "GET",
    credentials: "include",
  });
  return await readJsonOrThrow<WF1AnalysisStatus>(response);
}