const PROFILE_API_BASE_URL = (import.meta.env.VITE_LAUNCHER_API_BASE_URL ?? 'http://localhost:4200/api').replace(/\/+$/, '');
const AVATAR_MAX_BYTES = 80 * 1024;

export async function fetchProfileAvatar(accessToken: string, version: number): Promise<Blob | null> {
  const response = await fetch(`${PROFILE_API_BASE_URL}/auth/profile/avatar?v=${version}`, {
    headers: {
      Authorization: `Bearer ${accessToken}`,
    },
    credentials: 'include',
  });

  if (response.status === 404) return null;
  if (!response.ok) throw new Error('avatar_load_failed');
  return response.blob();
}

export async function uploadProfileAvatar(accessToken: string, imageBlob: Blob): Promise<void> {
  const response = await fetch(`${PROFILE_API_BASE_URL}/auth/profile/avatar`, {
    method: 'PUT',
    headers: {
      Authorization: `Bearer ${accessToken}`,
      'Content-Type': imageBlob.type,
    },
    credentials: 'include',
    body: imageBlob,
  });

  if (!response.ok) throw new Error('avatar_upload_failed');
}

export async function deleteProfileAvatar(accessToken: string): Promise<void> {
  const response = await fetch(`${PROFILE_API_BASE_URL}/auth/profile/avatar`, {
    method: 'DELETE',
    headers: {
      Authorization: `Bearer ${accessToken}`,
    },
    credentials: 'include',
  });

  if (!response.ok) throw new Error('avatar_delete_failed');
}

export async function resizeImageToWebp(file: File, size = 128): Promise<Blob> {
  if (!file.type.startsWith('image/')) throw new Error('이미지 파일만 등록할 수 있습니다.');

  const dataUrl = await new Promise<string>((resolve, reject) => {
    const reader = new FileReader();
    reader.onload = () => resolve(String(reader.result));
    reader.onerror = () => reject(new Error('이미지를 읽을 수 없습니다.'));
    reader.readAsDataURL(file);
  });

  const image = await new Promise<HTMLImageElement>((resolve, reject) => {
    const img = new Image();
    img.onload = () => resolve(img);
    img.onerror = () => reject(new Error('이미지를 불러올 수 없습니다.'));
    img.src = dataUrl;
  });

  const sourceSize = Math.min(image.naturalWidth, image.naturalHeight);
  const sourceX = Math.max(0, (image.naturalWidth - sourceSize) / 2);
  const sourceY = Math.max(0, (image.naturalHeight - sourceSize) / 2);
  const canvas = document.createElement('canvas');
  canvas.width = size;
  canvas.height = size;
  const context = canvas.getContext('2d');
  if (!context) throw new Error('이미지를 처리할 수 없습니다.');

  context.drawImage(image, sourceX, sourceY, sourceSize, sourceSize, 0, 0, size, size);

  const blob = await new Promise<Blob | null>((resolve) => {
    canvas.toBlob(resolve, 'image/webp', 0.82);
  });

  if (!blob) throw new Error('이미지를 압축할 수 없습니다.');
  if (blob.size > AVATAR_MAX_BYTES) throw new Error('이미지 용량이 너무 큽니다.');
  return blob;
}

export function notifyProfileAvatarUpdated(): void {
  window.dispatchEvent(new Event('profile-avatar-updated'));
}

export function notifyProfileAvatarDeleted(): void {
  window.dispatchEvent(new Event('profile-avatar-deleted'));
}