import type { VerificationIssueStage } from './verificationBoardStages';

const API_BASE = import.meta.env.VITE_API_BASE_URL ?? 'http://localhost:8080/api';

export interface VerificationIssueDto {
  id?: number;
  title: string;
  content: string;
  reproductionPath?: string;
  stage: VerificationIssueStage;
  createdAt?: string;
  updatedAt?: string;
}

function getDeviceId(): string {
  let id = localStorage.getItem('gc_device_id');
  if (!id) {
    id = crypto.randomUUID();
    localStorage.setItem('gc_device_id', id);
  }
  return id;
}

function authHeaders(): Record<string, string> {
  const headers: Record<string, string> = {
    'Content-Type': 'application/json',
    'x-device-id': getDeviceId(),
  };
  const userId = localStorage.getItem('gc_user_id');
  if (userId) headers['x-user-id'] = userId;
  return headers;
}

function authHeadersMultipart(): Record<string, string> {
  const headers: Record<string, string> = {
    'x-device-id': getDeviceId(),
  };
  const userId = localStorage.getItem('gc_user_id');
  if (userId) headers['x-user-id'] = userId;
  return headers;
}

export function verificationIssueImageUrl(issueId: number, imageId: number): string {
  return `${API_BASE}/verification-issues/${issueId}/images/${imageId}/file`;
}

async function apiGet<T>(path: string): Promise<T | null> {
  try {
    const res = await fetch(`${API_BASE}${path}`, { headers: authHeaders() });
    if (!res.ok) return null;
    return (await res.json()) as T;
  } catch {
    return null;
  }
}

async function mutateOrThrow<T>(path: string, init: RequestInit): Promise<T> {
  const res = await fetch(`${API_BASE}${path}`, {
    ...init,
    headers: { ...authHeaders(), ...(init.headers ?? {}) },
  });
  const text = await res.text().catch(() => '');
  if (!res.ok) {
    throw new Error(text ? text.slice(0, 200) : `요청 실패 (${res.status})`);
  }
  if (res.status === 204 || !text) return undefined as T;
  return JSON.parse(text) as T;
}

export async function loadVerificationIssues(
  stage?: VerificationIssueStage | '',
): Promise<VerificationIssueDto[]> {
  const qs = stage ? `?stage=${encodeURIComponent(stage)}` : '';
  return (await apiGet<VerificationIssueDto[]>(`/verification-issues${qs}`)) ?? [];
}

export async function loadVerificationIssue(id: number): Promise<VerificationIssueDto | null> {
  return apiGet<VerificationIssueDto>(`/verification-issues/${id}`);
}

export async function saveVerificationIssue(dto: VerificationIssueDto): Promise<VerificationIssueDto> {
  return mutateOrThrow<VerificationIssueDto>('/verification-issues', {
    method: 'POST',
    body: JSON.stringify(dto),
  });
}

export async function deleteVerificationIssue(id: number): Promise<void> {
  await mutateOrThrow<void>(`/verification-issues/${id}`, { method: 'DELETE' });
}

// ── 댓글 ─────────────────────────────────────────────────────────────────────

export interface VerificationIssueCommentDto {
  id?: number;
  issueId?: number;
  content: string;
  authorName?: string;
  createdAt?: string;
  updatedAt?: string;
}

export async function loadVerificationIssueComments(
  issueId: number,
): Promise<VerificationIssueCommentDto[]> {
  return (await apiGet<VerificationIssueCommentDto[]>(
    `/verification-issues/${issueId}/comments`,
  )) ?? [];
}

export async function createVerificationIssueComment(
  issueId: number,
  dto: Pick<VerificationIssueCommentDto, 'content' | 'authorName'>,
): Promise<VerificationIssueCommentDto> {
  return mutateOrThrow<VerificationIssueCommentDto>(
    `/verification-issues/${issueId}/comments`,
    { method: 'POST', body: JSON.stringify(dto) },
  );
}

export async function updateVerificationIssueComment(
  issueId: number,
  commentId: number,
  dto: Pick<VerificationIssueCommentDto, 'content'>,
): Promise<VerificationIssueCommentDto> {
  return mutateOrThrow<VerificationIssueCommentDto>(
    `/verification-issues/${issueId}/comments/${commentId}`,
    { method: 'PUT', body: JSON.stringify(dto) },
  );
}

export async function deleteVerificationIssueComment(
  issueId: number,
  commentId: number,
): Promise<void> {
  await mutateOrThrow<void>(
    `/verification-issues/${issueId}/comments/${commentId}`,
    { method: 'DELETE' },
  );
}

// ── 첨부 이미지 ─────────────────────────────────────────────────────────────

export interface VerificationIssueImageDto {
  id?: number;
  issueId?: number;
  fileName?: string;
  contentType?: string;
  fileSize?: number;
  sortOrder?: number;
  url?: string;
  createdAt?: string;
}

export async function loadVerificationIssueImages(
  issueId: number,
): Promise<VerificationIssueImageDto[]> {
  return (await apiGet<VerificationIssueImageDto[]>(
    `/verification-issues/${issueId}/images`,
  )) ?? [];
}

export async function uploadVerificationIssueImages(
  issueId: number,
  files: File[],
): Promise<VerificationIssueImageDto[]> {
  const form = new FormData();
  files.forEach(f => form.append('files', f, f.name));
  const res = await fetch(`${API_BASE}/verification-issues/${issueId}/images`, {
    method: 'POST',
    headers: authHeadersMultipart(),
    body: form,
  });
  const text = await res.text().catch(() => '');
  if (!res.ok) {
    throw new Error(parseVerificationUploadError(res.status, text));
  }
  return JSON.parse(text) as VerificationIssueImageDto[];
}

function parseVerificationUploadError(status: number, text: string): string {
  if (text) {
    try {
      const json = JSON.parse(text) as { message?: string };
      if (json.message) return json.message;
    } catch {
      if (text.includes('413') || text.toLowerCase().includes('too large')) {
        return '업로드 용량이 너무 큽니다. 이미지를 줄이거나 5MB 이하 파일을 사용하세요.';
      }
      if (!text.trimStart().startsWith('<')) {
        return text.slice(0, 200);
      }
    }
  }
  if (status === 413) {
    return '업로드 용량이 너무 큽니다. 이미지를 줄이거나 5MB 이하 파일을 사용하세요.';
  }
  if (status === 400) return '파일 형식 또는 크기를 확인하세요. (jpeg, png, gif, webp, bmp, zip, hwp, hwpx · 파일당 5MB)';
  return `이미지 업로드에 실패했습니다. (${status})`;
}

export async function deleteVerificationIssueImage(
  issueId: number,
  imageId: number,
): Promise<void> {
  const res = await fetch(
    `${API_BASE}/verification-issues/${issueId}/images/${imageId}`,
    { method: 'DELETE', headers: authHeadersMultipart() },
  );
  if (!res.ok && res.status !== 204) {
    throw new Error(`삭제 실패 (${res.status})`);
  }
}