import { randomUUID } from "node:crypto";
import { mkdir, readFile, rename, writeFile } from "node:fs/promises";
import path from "node:path";

import {
  cancelAgentRunChatTurn,
  describeAgentRunAdapterAvailability,
  submitAgentRunChatTurn,
} from "../cloud/code-agent-agentrun-adapter.ts";
import { agentRunJson, resolveAgentRunManagerUrl } from "../cloud/code-agent-agentrun-runtime.ts";
import { agentRunResultToCodeAgentPayload } from "../cloud/code-agent-agentrun-result.ts";
import { createCodeAgentTraceStore } from "../cloud/code-agent-trace-store.ts";
import type { WorkbenchApplication, WorkbenchTurnInput } from "./contracts.ts";

type NativeState = {
  sessions: Record<string, Record<string, any>>;
  turns: Record<string, Record<string, any>>;
};

const TERMINAL = new Set(["completed", "failed", "blocked", "cancelled", "canceled"]);

export function createNativeAgentRunWorkbenchApplication(options: {
  stateFile: string;
  env: Record<string, string | undefined>;
  fetchImpl?: typeof fetch;
  now?: () => string;
}): WorkbenchApplication {
  const env = options.env;
  const fetchImpl = options.fetchImpl ?? fetch;
  const now = options.now ?? (() => new Date().toISOString());
  const traceStore = createCodeAgentTraceStore();
  const mutate = async <T>(fn: (state: NativeState) => T | Promise<T>) => {
    const state = await load(options.stateFile);
    const result = await fn(state);
    await mkdir(path.dirname(options.stateFile), { recursive: true });
    const temporary = `${options.stateFile}.${process.pid}.tmp`;
    await writeFile(temporary, `${JSON.stringify(state, null, 2)}\n`, "utf8");
    await rename(temporary, options.stateFile);
    return result;
  };

  return {
    async snapshot() { return load(options.stateFile); },
    async health() {
      const state = await load(options.stateFile);
      const availability = describeAgentRunAdapterAvailability(env, { params: { providerProfile: env.HWLAB_CODE_AGENT_DEFAULT_PROVIDER_PROFILE } });
      return {
        serviceId: "hwlab-workbench-native-agentrun",
        status: availability.ready ? "ready" : "blocked",
        mode: "agentrun-native",
        providerProfile: text(env.HWLAB_CODE_AGENT_DEFAULT_PROVIDER_PROFILE),
        agentRun: availability.agentRun,
        sessionCount: Object.keys(state.sessions).length,
        turnCount: Object.keys(state.turns).length,
        valuesPrinted: false,
      };
    },
    async createSession({ actor, params }) {
      return mutate((state) => {
        const sessionId = validOptionalId(params.sessionId, "ses_") ?? `ses_${randomUUID()}`;
        const conversationId = validOptionalId(params.conversationId, "cnv_") ?? `cnv_${randomUUID()}`;
        const timestamp = now();
        const session = {
          sessionId,
          conversationId,
          projectId: text(params.projectId) || "pikasTech/HWLAB",
          ownerUserId: actor.id,
          ownerRole: actor.role ?? "user",
          status: "idle",
          providerProfile: text(params.providerProfile) || text(env.HWLAB_CODE_AGENT_DEFAULT_PROVIDER_PROFILE) || "gpt.pika",
          createdAt: timestamp,
          updatedAt: timestamp,
          mode: "agentrun-native",
          messages: [] as Record<string, unknown>[],
        };
        state.sessions[sessionId] = session;
        return { status: "created", session, valuesRedacted: true, secretMaterialStored: false };
      });
    },
    async admitTurn(input) {
      return mutate((state) => {
        const session = ownedSession(state, input.sessionId, input.actor.id);
        const timestamp = now();
        const message = requiredText(input.params.message, "message");
        state.turns[input.traceId] = {
          traceId: input.traceId,
          sessionId: input.sessionId,
          conversationId: session.conversationId,
          ownerUserId: input.actor.id,
          status: "admitted",
          message,
          createdAt: timestamp,
          updatedAt: timestamp,
          terminal: false,
        };
        session.messages.push({ messageId: `msg_user_${input.traceId.slice(4)}`, role: "user", content: message, traceId: input.traceId, status: "completed", createdAt: timestamp });
        session.status = "running";
        session.lastTraceId = input.traceId;
        session.updatedAt = timestamp;
        return { ...input, params: { ...input.params, message, providerProfile: text(input.params.providerProfile) || session.providerProfile } };
      });
    },
    async dispatchTurn(input: WorkbenchTurnInput) {
      try {
        const state = await load(options.stateFile);
        const session = ownedSession(state, input.sessionId, input.actor.id);
        const params = {
          ...input.params,
          sessionId: input.sessionId,
          conversationId: session.conversationId,
          projectId: session.projectId,
          ownerUserId: input.actor.id,
          ownerRole: input.actor.role ?? "user",
          providerProfile: text(input.params.providerProfile) || session.providerProfile,
          shortConnection: true,
        };
        const admitted = await submitAgentRunChatTurn({ traceId: input.traceId, params, options: { env, fetchImpl }, traceStore });
        await projectRunning(admitted, input.traceId);
        const terminal = await waitForTerminal(admitted, input.traceId);
        await projectTerminal(terminal, input.traceId);
        return terminal;
      } catch (error: any) {
        const failed = {
          status: "failed",
          terminal: true,
          error: { code: text(error?.code) || "agentrun_native_dispatch_failed", message: text(error?.message) || String(error) },
          valuesPrinted: false,
        };
        await projectTerminal(failed, input.traceId);
        return failed;
      }
    },
    async cancelTurn(input) {
      const state = await load(options.stateFile);
      const turn = state.turns[input.traceId];
      if (!turn || turn.ownerUserId !== input.actor.id) throw codedError("turn_not_found", "turn is not visible to the actor");
      const canceled = await cancelAgentRunChatTurn({ traceId: input.traceId, currentResult: turn.result ?? null, options: { env, fetchImpl }, traceStore });
      if (!canceled) throw codedError("turn_not_running", "turn has no active AgentRun command");
      await projectTerminal(canceled, input.traceId);
      return canceled;
    },
  };

  async function projectRunning(result: any, traceId: string) {
    return mutate((state) => {
      const turn = state.turns[traceId];
      if (!turn) throw codedError("turn_not_admitted", "turn must be admitted before dispatch");
      Object.assign(turn, {
        status: "running",
        updatedAt: now(),
        runId: result.agentRun?.runId ?? null,
        commandId: result.agentRun?.commandId ?? null,
        runnerJobId: result.agentRun?.runnerJobId ?? null,
        result,
      });
    });
  }

  async function waitForTerminal(base: any, traceId: string) {
    const managerUrl = resolveAgentRunManagerUrl(env, base.agentRun?.managerUrl);
    const runId = requiredText(base.agentRun?.runId, "agentRun.runId");
    const commandId = requiredText(base.agentRun?.commandId, "agentRun.commandId");
    const timeoutMs = positiveInteger(env.WORKBENCH_AGENTRUN_TERMINAL_TIMEOUT_MS, 600_000);
    const intervalMs = positiveInteger(env.WORKBENCH_AGENTRUN_POLL_INTERVAL_MS, 1_000);
    const deadline = Date.now() + timeoutMs;
    while (Date.now() < deadline) {
      const result = await agentRunJson(fetchImpl, managerUrl, `/api/v1/runs/${encodeURIComponent(runId)}/commands/${encodeURIComponent(commandId)}/result`, {
        timeoutMs: Math.min(20_000, Math.max(1_000, deadline - Date.now())),
        env,
      });
      const mapped = agentRunResultToCodeAgentPayload({ base, result, traceStore, traceId });
      if (TERMINAL.has(normalizeStatus(mapped.status)) && (mapped.finalResponse || mapped.status !== "completed")) return mapped;
      await Bun.sleep(intervalMs);
    }
    throw codedError("agentrun_terminal_timeout", `AgentRun command did not reach a terminal result within ${timeoutMs}ms`);
  }

  async function projectTerminal(result: any, traceId: string) {
    return mutate((state) => {
      const turn = state.turns[traceId];
      if (!turn) throw codedError("turn_not_found", "turn was not found for terminal projection");
      const session = state.sessions[turn.sessionId];
      const status = normalizeStatus(result.status);
      const timestamp = now();
      Object.assign(turn, {
        status,
        terminal: TERMINAL.has(status),
        updatedAt: timestamp,
        finishedAt: timestamp,
        runId: result.agentRun?.runId ?? turn.runId ?? null,
        commandId: result.agentRun?.commandId ?? turn.commandId ?? null,
        runnerJobId: result.agentRun?.runnerJobId ?? turn.runnerJobId ?? null,
        finalResponse: result.finalResponse ?? null,
        error: result.error ?? null,
        result,
      });
      if (session) {
        session.status = status === "completed" ? "idle" : status;
        session.updatedAt = timestamp;
        if (result.finalResponse?.text && !session.messages.some((message: any) => message.traceId === traceId && message.role === "assistant")) {
          session.messages.push({ ...result.finalResponse, role: "assistant", content: result.finalResponse.text, traceId, status });
        }
      }
    });
  }
}

async function load(stateFile: string): Promise<NativeState> {
  const parsed = JSON.parse(await readFile(stateFile, "utf8").catch(() => '{"sessions":{},"turns":{}}'));
  return { sessions: object(parsed.sessions), turns: object(parsed.turns) };
}
function object(value: unknown) { return value && typeof value === "object" && !Array.isArray(value) ? value as Record<string, Record<string, any>> : {}; }
function text(value: unknown) { return String(value ?? "").trim(); }
function requiredText(value: unknown, field: string) { const result = text(value); if (!result) throw codedError("invalid_input", `${field} is required`); return result; }
function validOptionalId(value: unknown, prefix: string) { const id = text(value); if (!id) return null; if (!id.startsWith(prefix)) throw codedError("invalid_input", `${prefix.slice(0, -1)} id is invalid`); return id; }
function ownedSession(state: NativeState, sessionId: string, ownerUserId: string) { const session = state.sessions[sessionId]; if (!session || session.ownerUserId !== ownerUserId) throw codedError("session_not_found", "session is not visible to the actor"); return session; }
function normalizeStatus(value: unknown) { const status = text(value).toLowerCase().replaceAll("_", "-"); return status === "cancelled" ? "canceled" : status; }
function positiveInteger(value: unknown, fallback: number) { const parsed = Number.parseInt(text(value), 10); return Number.isSafeInteger(parsed) && parsed > 0 ? parsed : fallback; }
function codedError(code: string, message: string) { return Object.assign(new Error(message), { code }); }