import { BackendAsset, CanvasDocument, CanvasTemplate } from '../types';
import { apiUrl, ensureOk } from './api';
import { cloneDocument, normalizeDocument } from './canvasDocument';

export function templateId(template: CanvasTemplate) {
  return template.template_id || template.id || '';
}

export function templateCreatedAt(template: CanvasTemplate) {
  return template.created_at || template.createdAt || '';
}

export function templateUpdatedAt(template: CanvasTemplate) {
  return template.updated_at || template.updatedAt || '';
}

export function templateReferenceIds(template: CanvasTemplate) {
  return template.reference_asset_ids || template.referenceAssetIds || [];
}

export function templateCoverId(template: CanvasTemplate) {
  return template.cover_asset_id || template.coverAssetId || templateReferenceIds(template)[0] || '';
}

export async function listDesignTemplates(): Promise<CanvasTemplate[]> {
  const res = await ensureOk(await fetch(apiUrl('/api/design-templates')), '读取模板库失败');
  const items = (await res.json()) as CanvasTemplate[];
  return items.map(item => ({ ...item, document: normalizeDocument(item.document) }));
}

export async function createCanvasTemplate(input: {
  name: string;
  description: string;
  document: CanvasDocument;
  referenceAssetIds?: string[];
  coverAssetId?: string;
}): Promise<CanvasTemplate> {
  const fd = new FormData();
  fd.append('name', input.name.trim() || '未命名模板');
  fd.append('description', input.description.trim());
  fd.append('document', JSON.stringify(normalizeDocument(input.document)));
  fd.append('reference_asset_ids', JSON.stringify(input.referenceAssetIds || []));
  fd.append('cover_asset_id', input.coverAssetId || input.referenceAssetIds?.[0] || '');
  const res = await ensureOk(await fetch(apiUrl('/api/design-templates'), { method: 'POST', body: fd }), '保存模板失败');
  const template = (await res.json()) as CanvasTemplate;
  return { ...template, document: normalizeDocument(template.document) };
}

export async function importCanvasTemplate(
  file: File,
  name = '',
  description = '',
): Promise<CanvasTemplate> {
  const fd = new FormData();
  fd.append('file', file);
  if (name) fd.append('name', name.trim());
  if (description) fd.append('description', description.trim());
  const res = await ensureOk(await fetch(apiUrl('/api/design-templates/import'), { method: 'POST', body: fd }), '导入设计包失败');
  const template = (await res.json()) as CanvasTemplate;
  return { ...template, document: normalizeDocument(template.document) };
}

export async function updateCanvasTemplate(
  id: string,
  partial: {
    name?: string;
    description?: string;
    document?: CanvasDocument;
    referenceAssetIds?: string[];
    coverAssetId?: string;
  },
): Promise<CanvasTemplate> {
  const fd = new FormData();
  if (partial.name !== undefined) fd.append('name', partial.name.trim() || '未命名模板');
  if (partial.description !== undefined) fd.append('description', partial.description.trim());
  if (partial.document) fd.append('document', JSON.stringify(normalizeDocument(partial.document)));
  if (partial.referenceAssetIds) fd.append('reference_asset_ids', JSON.stringify(partial.referenceAssetIds));
  if (partial.coverAssetId !== undefined) fd.append('cover_asset_id', partial.coverAssetId);
  const res = await ensureOk(await fetch(apiUrl(`/api/design-templates/${id}`), { method: 'PATCH', body: fd }), '更新模板失败');
  const template = (await res.json()) as CanvasTemplate;
  return { ...template, document: normalizeDocument(template.document) };
}

export async function deleteCanvasTemplate(id: string) {
  await ensureOk(await fetch(apiUrl(`/api/design-templates/${id}`), { method: 'DELETE' }), '删除模板失败');
}

export async function listAssets(type = ''): Promise<BackendAsset[]> {
  const query = type ? `?type=${encodeURIComponent(type)}` : '';
  const res = await ensureOk(await fetch(apiUrl(`/api/assets${query}`)), '读取素材失败');
  return (await res.json()) as BackendAsset[];
}

export async function uploadAsset(file: File, type = 'reference'): Promise<BackendAsset> {
  const fd = new FormData();
  fd.append('file', file);
  fd.append('name', file.name.replace(/\.(svg|png|jpe?g)$/i, ''));
  fd.append('type', type);
  const res = await ensureOk(await fetch(apiUrl('/api/assets'), { method: 'POST', body: fd }), '上传参考图失败');
  return (await res.json()) as BackendAsset;
}

export function assetUrl(assetOrPath?: BackendAsset | string) {
  if (!assetOrPath) return '';
  const raw = typeof assetOrPath === 'string' ? assetOrPath : assetOrPath.file_url;
  if (!raw) return '';
  return apiUrl(raw);
}

export function duplicateDocument(document: CanvasDocument): CanvasDocument {
  return cloneDocument(document);
}