/**
 * 自由文档 (Freeform Document) 前端 API 客户端
 * 提供单条回复保存、私密列表、详情获取、编辑保存、共享流转及回收站接口
 */

import { getBearerAuthHeaders } from './authHeaders';
import { projectSettingsErrorFromResponse } from './projectSettingsError';
import { apiFetch } from './client';

export interface FreeformDocSummary {
  doc_id: string;
  project_id: number;
  owner_user_id: number;
  title: string;
  space: 'my_private' | 'project_shared' | 'trash';
  current_version_id: number;
  current_sha256: string;
  /** 上传附件注册时持久化的源文件元数据；非上传文档缺省。 */
  source_filename?: string;
  source_mime_type?: string;
  source_size_bytes?: number;
  source_asset_id?: number;
  created_at: string;
  updated_at: string;
}

export interface FreeformDocDetail {
  document: {
    doc_id: string;
    project_id: number;
    owner_user_id: number;
    source_message_id?: number;
    source_content_sha256: string;
    title: string;
    governance_mode: 'freeform';
    space: 'my_private' | 'project_shared' | 'trash';
    current_version_id: number;
    current_sha256: string;
    /** 上传附件注册时持久化的源文件元数据；非上传文档缺省。 */
    source_filename?: string;
    source_mime_type?: string;
    source_size_bytes?: number;
    source_asset_id?: number;
    is_deleted: boolean;
    created_at: string;
    updated_at: string;
  };
  content_markdown: string;
}

export interface CreateFromMessageResponse {
  code: number;
  message: string;
  is_existing: boolean;
  data: FreeformDocDetail;
}

/**
 * 直接创建自由文档（上传附件即时注册服务端事实源）
 */
export async function createFreeformDoc(payload: {
  projectId: number;
  title: string;
  contentMarkdown: string;
  space?: 'my_private' | 'project_shared';
  clientKey?: string;
  sourceFilename?: string;
  sourceMimeType?: string;
  sourceSizeBytes?: number;
  sourceAssetId?: number;
}): Promise<FreeformDocDetail> {
  const res = await apiFetch('/api/v1/freeform-documents', {
    method: 'POST',
    headers: getBearerAuthHeaders('application/json'),
    body: JSON.stringify({
      project_id: payload.projectId,
      title: payload.title,
      content_markdown: payload.contentMarkdown,
      space: payload.space || 'my_private',
      client_key: payload.clientKey || undefined,
      source_filename: payload.sourceFilename || undefined,
      source_mime_type: payload.sourceMimeType || undefined,
      source_size_bytes: payload.sourceSizeBytes || undefined,
      source_asset_id: payload.sourceAssetId || undefined,
    }),
  });
  if (!res.ok) {
    const errData = await res.json().catch(() => ({}));
    const msg = errData.message || errData.error_code || `创建失败 (${res.status})`;
    throw new Error(typeof msg === 'string' ? msg : `创建失败 (${res.status})`);
  }
  const body = await res.json();
  return body.data;
}

/**
 * 从单条智能体回复保存为我的私密文档（幂等）
 */
export async function saveMessageToPrivate(
  messageId: number,
  projectId: number = 1,
  title?: string,
  expectedSha256?: string,
): Promise<CreateFromMessageResponse> {
  const res = await apiFetch('/api/v1/freeform-documents/from-message', {
    method: 'POST',
    headers: getBearerAuthHeaders('application/json'),
    body: JSON.stringify({
      message_id: messageId,
      project_id: projectId,
      title: title || undefined,
      expected_sha256: expectedSha256 || undefined,
    }),
  });

  if (!res.ok) {
    const errData = await res.json().catch(() => ({}));
    throw new Error(errData.message || `保存失败 (${res.status})`);
  }

  return res.json();
}

/**
 * 按空间获取自由文档概要列表
 */
export async function listFreeformDocs(
  space: 'my_private' | 'project_shared' | 'trash' = 'my_private',
  projectId?: number,
): Promise<FreeformDocSummary[]> {
  let url = `/api/v1/freeform-documents?space=${encodeURIComponent(space)}`;
  if (projectId) {
    url += `&project_id=${projectId}`;
  }

  const res = await apiFetch(url, { headers: getBearerAuthHeaders() });
  if (!res.ok) {
    throw new Error(`获取列表失败 (${res.status})`);
  }
  const body = await res.json();
  return body.data || [];
}

/**
 * 获取自由文档详情与 Markdown 正文
 */
export async function fetchFreeformDoc(docId: string): Promise<FreeformDocDetail> {
  const res = await apiFetch(`/api/v1/freeform-documents/${encodeURIComponent(docId)}`, {
    headers: getBearerAuthHeaders(),
  });
  if (!res.ok) {
    if (res.status === 403) {
      throw new Error('该文档为他人私密文档，严格禁止跨用户访问');
    }
    if (res.status === 404) {
      throw new Error('文档不存在或已被删除');
    }
    throw new Error(`读取文档失败 (${res.status})`);
  }
  const body = await res.json();
  return body.data;
}

/**
 * 更新自由文档正文或标题（支持 If-Match 乐观锁）
 */
export async function updateFreeformDoc(
  docId: string,
  payload: {
    title?: string;
    contentMarkdown?: string;
    changeSummary?: string;
    expectedVersion?: number;
    expectedSha256?: string;
  }
): Promise<FreeformDocDetail> {
  const headers = getBearerAuthHeaders('application/json');
  if (payload.expectedVersion !== undefined) {
    headers['If-Match'] = `"${payload.expectedVersion}"`;
  } else if (payload.expectedSha256) {
    headers['If-Match'] = `"${payload.expectedSha256}"`;
  }

  const res = await apiFetch(`/api/v1/freeform-documents/${encodeURIComponent(docId)}`, {
    method: 'PUT',
    headers,
    body: JSON.stringify({
      title: payload.title,
      content_markdown: payload.contentMarkdown,
      change_summary: payload.changeSummary,
      expected_version: payload.expectedVersion,
      expected_sha256: payload.expectedSha256,
    }),
  });

  if (!res.ok) {
    const text = await res.text();
    throw projectSettingsErrorFromResponse(res.status, text, `保存失败 (${res.status})`);
  }
  const body = await res.json();
  return body.data;
}

/**
 * 一键共享至项目参考库
 */
export async function shareFreeformDoc(docId: string): Promise<void> {
  const res = await apiFetch(`/api/v1/freeform-documents/${encodeURIComponent(docId)}/share`, {
    method: 'POST',
    headers: getBearerAuthHeaders(),
  });
  if (!res.ok) {
    const errData = await res.json().catch(() => ({}));
    throw new Error(errData.message || `共享失败 (${res.status})`);
  }
}

/**
 * 撤回共享，恢复为个人私密
 */
export async function unshareFreeformDoc(docId: string): Promise<void> {
  const res = await apiFetch(`/api/v1/freeform-documents/${encodeURIComponent(docId)}/unshare`, {
    method: 'POST',
    headers: getBearerAuthHeaders(),
  });
  if (!res.ok) {
    const errData = await res.json().catch(() => ({}));
    throw new Error(errData.message || `撤回失败 (${res.status})`);
  }
}

/**
 * 软删除文档移至回收站
 */
export async function deleteFreeformDoc(docId: string): Promise<void> {
  const res = await apiFetch(`/api/v1/freeform-documents/${encodeURIComponent(docId)}`, {
    method: 'DELETE',
    headers: getBearerAuthHeaders(),
  });
  if (!res.ok) {
    const errData = await res.json().catch(() => ({}));
    throw new Error(errData.message || `删除失败 (${res.status})`);
  }
}