import { randomUUID } from "node:crypto";
import cors from "cors";
import express from "express";

import { SessionTranscriptStore } from "./sessions/transcriptStore.js";
import { ChatSessionBridge } from "./chat/sessionBridge.js";
import { config } from "./config.js";
import { SessionUiStateStore } from "./sessions/uiStateStore.js";
import { SessionMetadataStore } from "./sessions/metadataStore.js";
import { logger } from "./logger.js";
import { LearningOrchestrator } from "./learning/orchestrator.js";
import { MemoryStore } from "./memory/store.js";
import { ResultReferenceResolver } from "./results/resolver.js";
import { ResultReferenceStore } from "./results/store.js";
import { buildChatRouter } from "./routes/chat.js";
import { FrontendActionCoordinator, FrontendActionError } from "./frontendAction/coordinator.js";
import { opencodeRuntime } from "./runtime/opencode.js";
import { getRuntimeSessionContext } from "./runtime/sessionContext.js";

const app = express();

// 这里集中组装 Agent 服务的运行期依赖，路由层只通过接口调用，便于测试时替换实现。
const sessionBridge = new ChatSessionBridge(opencodeRuntime);
const sessionMetadataStore = new SessionMetadataStore();
const sessionUiStateStore = new SessionUiStateStore();
const memoryStore = new MemoryStore();
const sessionTranscriptStore = new SessionTranscriptStore();
const learningOrchestrator = new LearningOrchestrator(
  opencodeRuntime,
  memoryStore,
  sessionTranscriptStore,
);
const resultReferenceStore = new ResultReferenceStore();
const resultReferenceResolver = new ResultReferenceResolver(resultReferenceStore);
const internalToken = config.AGENT_INTERNAL_TOKEN ?? randomUUID();
const frontendActionCoordinator = new FrontendActionCoordinator();

process.env.TJWATER_AGENT_INTERNAL_TOKEN = internalToken;

app.use(cors());
app.use(express.json({ limit: "1mb" }));

app.post("/internal/frontend-actions/request", async (req, res) => {
  if (req.header("x-agent-internal-token") !== internalToken) {
    res.status(403).json({ message: "forbidden" });
    return;
  }
  const runtimeSessionId = typeof req.body?.session_id === "string" ? req.body.session_id.trim() : "";
  const context = runtimeSessionId ? getRuntimeSessionContext(runtimeSessionId) : null;
  if (!context) {
    res.status(404).json({ message: "session context not found" });
    return;
  }
  if (!context.capabilities?.includes("frontend-action@1")) {
    // Legacy clients still execute the existing UIEnvelope emitted from the tool call.
    res.json({
      version: "frontend-action-result@1",
      status: "succeeded",
      output: { legacy: true },
      detail: "legacy client executes the action from its UIEnvelope",
    });
    return;
  }
  try {
    const result = await frontendActionCoordinator.request({
      sessionId: context.clientSessionId,
      toolCallId: typeof req.body?.call_id === "string" ? req.body.call_id : "",
      name: typeof req.body?.name === "string" ? req.body.name : "",
      params: req.body?.params,
      fallbackText: typeof req.body?.fallback_text === "string" ? req.body.fallback_text : undefined,
    });
    res.json(result);
  } catch (error) {
    const status = error instanceof FrontendActionError ? error.status : 500;
    res.status(status).json({ message: error instanceof Error ? error.message : String(error) });
  }
});

app.get("/health", async (_req, res) => {
  try {
    const runtime = await opencodeRuntime.health();
    res.json({
      ok: true,
      runtime,
      sessions: sessionBridge.count(),
    });
  } catch (error) {
    const detail = error instanceof Error ? error.message : String(error);
    res.status(503).json({
      ok: false,
      message: "opencode runtime unavailable",
      detail,
      sessions: sessionBridge.count(),
    });
  }
});

app.post("/internal/tools/session-search", async (req, res) => {
  if (req.header("x-agent-internal-token") !== internalToken) {
    res.status(403).json({ message: "forbidden" });
    return;
  }

  const sessionId =
    typeof req.body?.session_id === "string" ? req.body.session_id.trim() : "";
  const query = typeof req.body?.query === "string" ? req.body.query : "";
  const context = sessionId ? getRuntimeSessionContext(sessionId) : null;
  if (!context) {
    res.status(404).json({
      message: "session context not found",
      detail: sessionId,
    });
    return;
  }
  if (!query.trim()) {
    res.status(400).json({ message: "query is required" });
    return;
  }
  const hits = await sessionTranscriptStore.search(
    {
      actorKey: context.actorKey,
      projectKey: context.projectKey,
    },
    query,
    typeof req.body?.max_results === "number" ? req.body.max_results : undefined,
  );
  res.json({
    hits,
    query,
  });
});

app.use(
  "/api/v1/agent/chat",
  buildChatRouter(
    sessionBridge,
    opencodeRuntime,
    sessionMetadataStore,
    sessionUiStateStore,
    memoryStore,
    sessionTranscriptStore,
    learningOrchestrator,
    resultReferenceResolver,
    frontendActionCoordinator,
  ),
);

const bootstrap = async () => {
  await Promise.all([
    sessionMetadataStore.initialize(),
    sessionUiStateStore.initialize(),
    learningOrchestrator.initialize(),
    memoryStore.initialize(),
    resultReferenceStore.initialize(),
    sessionTranscriptStore.initialize(),
  ]);
  resultReferenceStore.startCleanupLoop();
};

await bootstrap();

const server = app.listen(config.PORT, config.HOST, () => {
  logger.info(
    { host: config.HOST, port: config.PORT },
    "TJWaterAgent listening",
  );
  void warmupOpencodeRuntime();
});

const warmupOpencodeRuntime = async () => {
  const startedAt = Date.now();
  try {
    await opencodeRuntime.ensureClient();
    logger.info(
      {
        elapsedMs: Math.max(0, Date.now() - startedAt),
        mode: config.OPENCODE_MODE,
      },
      "opencode runtime warmed up",
    );
  } catch (error) {
    logger.error(
      {
        err: error,
        elapsedMs: Math.max(0, Date.now() - startedAt),
        mode: config.OPENCODE_MODE,
      },
      "failed to warm up opencode runtime",
    );
  }
};

const shutdown = async () => {
  logger.info("shutting down TJWaterAgent");
  server.close();
  resultReferenceStore.stopCleanupLoop();
  // 同步关闭 embedded opencode server，避免本服务退出后留下孤儿进程。
  await opencodeRuntime.dispose();
};

process.on("SIGINT", () => {
  void shutdown();
});

process.on("SIGTERM", () => {
  void shutdown();
});