// Memory V2 API 客户端。对应后端 /api/memory/v2 系列端点。

import { apiFetch } from "../api";
import { getBackendBaseURL } from "../config";
import { OptType, writeYLog } from "../log/y-log";

import type {
  MemorySearchMode,
  MemorySearchResult,
  MemoryTarget,
  MemoryV2ConfigResponse,
  MemoryV2Data,
} from "./types";

/** 从响应里提取后端的错误详情文本。 */
function formatErrorDetail(detail: unknown): string | null {
  if (typeof detail === "string") {
    return detail;
  }
  if (Array.isArray(detail)) {
    const parts = detail
      .map((item) => {
        if (typeof item === "string") return item;
        if (item && typeof item === "object") {
          const record = item as Record<string, unknown>;
          if (typeof record.msg === "string") return record.msg;
        }
        return null;
      })
      .filter(Boolean);
    return parts.length > 0 ? parts.join("; ") : null;
  }
  return null;
}

async function readJson<T>(response: Response, fallbackMessage: string): Promise<T> {
  if (!response.ok) {
    const errorData = (await response.json().catch(() => ({}))) as {
      detail?: unknown;
    };
    const detailMessage = formatErrorDetail(errorData.detail);
    throw new Error(detailMessage ?? `${fallbackMessage}: ${response.statusText}`);
  }
  return response.json() as Promise<T>;
}

/** 拼接可选的 ?agent= 查询串。 */
function agentQuery(agent?: string): string {
  return agent ? `?agent=${encodeURIComponent(agent)}` : "";
}

// --- 本地记忆数据 (USER.md / MEMORY.md) ---

export async function loadMemoryV2(agent?: string): Promise<MemoryV2Data> {
  const response = await apiFetch(
    `${getBackendBaseURL()}/api/memory/v2${agentQuery(agent)}`,
  );
  const data = await readJson<MemoryV2Data>(response, "Failed to fetch memory");
  writeYLog({
    optType: OptType.view,
    optDetail: "CM助手-全量-记忆-查看",
    url: `/api/memory/v2${agentQuery(agent)}`,
    reqParam: { agent },
    returnParam: data,
  });
  return data;
}

export async function addMemoryEntry(
  target: MemoryTarget,
  content: string,
  agent?: string,
): Promise<MemoryV2Data> {
  const response = await apiFetch(
    `${getBackendBaseURL()}/api/memory/v2/entries${agentQuery(agent)}`,
    {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ target, content }),
    },
  );
  const data = await readJson<MemoryV2Data>(response, "Failed to add memory entry");
  writeYLog({
    optType: OptType.create,
    optDetail: "CM助手-全量-记忆-新增",
    url: `/api/memory/v2/entries${agentQuery(agent)}`,
    reqParam: { target, content, agent },
    returnParam: data,
  });
  return data;
}

export async function replaceMemoryEntry(
  target: MemoryTarget,
  oldText: string,
  content: string,
  agent?: string,
): Promise<MemoryV2Data> {
  const response = await apiFetch(
    `${getBackendBaseURL()}/api/memory/v2/entries${agentQuery(agent)}`,
    {
      method: "PUT",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ target, old_text: oldText, content }),
    },
  );
  const data = await readJson<MemoryV2Data>(response, "Failed to replace memory entry");
  writeYLog({
    optType: OptType.edit,
    optDetail: "CM助手-全量-记忆-编辑",
    url: `/api/memory/v2/entries${agentQuery(agent)}`,
    reqParam: { target, old_text: oldText, content, agent },
    returnParam: data,
  });
  return data;
}

export async function deleteMemoryEntry(
  target: MemoryTarget,
  oldText: string,
  agent?: string,
): Promise<MemoryV2Data> {
  const params = new URLSearchParams({ target, old_text: oldText });
  if (agent) {
    params.set("agent", agent);
  }
  const response = await apiFetch(
    `${getBackendBaseURL()}/api/memory/v2/entries?${params.toString()}`,
    { method: "DELETE" },
  );
  const data = await readJson<MemoryV2Data>(response, "Failed to delete memory entry");
  writeYLog({
    optType: OptType.delete,
    optDetail: "CM助手-全量-记忆-删除",
    url: `/api/memory/v2/entries?${params.toString()}`,
    reqParam: { target, old_text: oldText, agent },
    returnParam: data,
  });
  return data;
}

// --- 配置 ---

export async function loadMemoryConfig(): Promise<MemoryV2ConfigResponse> {
  const response = await apiFetch(`${getBackendBaseURL()}/api/memory/v2/config`);
  const data = await readJson<MemoryV2ConfigResponse>(response, "Failed to fetch memory config");
  writeYLog({
    optType: OptType.view,
    optDetail: "CM助手-全量-记忆-配置查看",
    url: "/api/memory/v2/config",
    returnParam: data,
  });
  return data;
}

export async function patchMemoryConfig(
  overrides: Record<string, unknown>,
): Promise<MemoryV2ConfigResponse> {
  const response = await apiFetch(`${getBackendBaseURL()}/api/memory/v2/config`, {
    method: "PATCH",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ overrides }),
  });
  const data = await readJson<MemoryV2ConfigResponse>(response, "Failed to update memory config");
  writeYLog({
    optType: OptType.edit,
    optDetail: "CM助手-全量-记忆-配置编辑",
    url: "/api/memory/v2/config",
    reqParam: { overrides },
    returnParam: data,
  });
  return data;
}

// --- Hindsight 检索 ---

export async function searchMemory(
  query: string,
  mode: MemorySearchMode = "recall",
  agent?: string,
): Promise<MemorySearchResult> {
  const response = await apiFetch(
    `${getBackendBaseURL()}/api/memory/v2/search${agentQuery(agent)}`,
    {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ query, mode }),
    },
  );
  const data = await readJson<MemorySearchResult>(response, "Failed to search memory");
  writeYLog({
    optType: OptType.search,
    optDetail: "CM助手-全量-记忆-检索",
    url: `/api/memory/v2/search${agentQuery(agent)}`,
    reqParam: { query, mode, agent },
    returnParam: data,
  });
  return data;
}