import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
import { Env } from "../types.js";
import { kbdbFetch } from "../lib/kbdb-client.js";

interface ActionLogSlots {
  org_namespace?: string;
  action_type?: string;
  payload?: string;
  occurred_at?: string;
}

interface ActionLogRecord {
  id: string;
  slots?: ActionLogSlots;
}

export function registerGetGuiContext(server: McpServer, env: Env, orgNamespace: string) {
  server.tool(
    "u6u_get_gui_context",
    "查詢用戶在 GUI 上的最近操作記錄，了解用戶的當前意圖與操作上下文。" +
    "回傳最近 N 條操作記錄（從新到舊），以及用戶當前所在頁面和正在編輯的 Workflow ID。",
    {
      limit: z.number().int().min(1).max(100).default(20)
        .describe("要取回的最近操作數量（預設 20，最大 100）"),
    },
    async ({ limit }) => {
      try {
        if (!env.KBDB) {
          return {
            content: [{ type: "text", text: "Error: KBDB service binding unavailable" }],
            isError: true,
          };
        }

        const resp = await kbdbFetch(
          env,
          `/records/search?template_id=tpl-action-log&user_id=${encodeURIComponent(orgNamespace)}&limit=${limit ?? 20}`
        );

        if (!resp.ok) {
          return {
            content: [{ type: "text", text: `Error querying action log: ${await resp.text()}` }],
            isError: true,
          };
        }

        const data = await resp.json<{ records: ActionLogRecord[] }>();
        const records = data.records ?? [];

        // 按 occurred_at 降序排列（最新在前）
        const sorted = records
          .map(r => ({
            action_type: r.slots?.action_type ?? '',
            payload: (() => {
              try { return JSON.parse(r.slots?.payload ?? '{}'); } catch { return {}; }
            })(),
            occurred_at: r.slots?.occurred_at ?? '',
          }))
          .sort((a, b) => b.occurred_at.localeCompare(a.occurred_at))
          .slice(0, limit ?? 20);

        // 提取當前頁面和正在操作的 Workflow
        const lastNavigate = sorted.find(a => a.action_type === 'NAVIGATE');
        const lastOpenWorkflow = sorted.find(a => a.action_type === 'OPEN_WORKFLOW');

        const context = {
          recent_actions: sorted,
          current_page: (lastNavigate?.payload as { page?: string })?.page ?? null,
          open_workflow_id: (lastOpenWorkflow?.payload as { workflow_id?: string })?.workflow_id ?? null,
        };

        return {
          content: [{ type: "text", text: JSON.stringify(context, null, 2) }],
        };
      } catch (error) {
        return {
          content: [{ type: "text", text: `Internal Error: ${error instanceof Error ? error.message : String(error)}` }],
          isError: true,
        };
      }
    }
  );
}