/**
 * Harness 环境的飞书配置向导（终端一问一答版）。
 * 与 Pi 的 /feishu setup 问同样的问题；写 Harness 自己的 config.harness.json，
 * 与 Pi 的配置完全独立。
 */
import { CONFIG_HARNESS_PATH, DEFAULT_CONFIG, ensureRoot, loadConfig, mask, writeJson } from "../../feishu/config.ts";
import { registerFeishuApp } from "../../feishu/app-register.ts";
import type { Domain, FeishuConfig, GroupPolicy } from "../../feishu/types.ts";

/**
 * 终端问答器：直接监听 stdin 的行输入（不依赖 readline，管道/终端都可靠）。
 * 回车即提交；Ctrl+C 由进程默认 SIGINT 处理直接退出。
 */
function createPrompter() {
  let buffer = "";
  const pendingLines: string[] = [];
  const queue: Array<(line: string) => void> = [];
  process.stdin.setEncoding("utf8");
  process.stdin.resume();
  const onData = (chunk: string) => {
    buffer += chunk;
    let newlineIndex = buffer.indexOf("\n");
    while (newlineIndex >= 0) {
      const line = buffer.slice(0, newlineIndex).replace(/\r$/, "");
      buffer = buffer.slice(newlineIndex + 1);
      const resolve = queue.shift();
      // 管道输入可能早于提问到达：没有等待者时先缓存，提问时再取
      if (resolve) resolve(line);
      else pendingLines.push(line);
      newlineIndex = buffer.indexOf("\n");
    }
  };
  process.stdin.on("data", onData);
  return {
    question(prompt: string): Promise<string> {
      process.stdout.write(prompt);
      return new Promise((resolve) => {
        const cached = pendingLines.shift();
        if (cached !== undefined) resolve(cached);
        else queue.push(resolve);
      });
    },
    /** 移除 stdin 监听：向导可被 /feishu setup 反复触发，不关闭会叠加多个监听器互相抢输入 */
    close() {
      process.stdin.removeListener("data", onData);
    },
  };
}

type Prompter = ReturnType<typeof createPrompter>;

function select<T extends string>(
  prompter: Prompter,
  title: string,
  options: Array<{ value: T; label: string }>,
  initialValue?: T,
): Promise<T> {
  console.log(`\n${title}`);
  options.forEach((option, index) => {
    console.log(`  ${index + 1}) ${option.label}`);
  });
  const initialIndex = options.findIndex((option) => option.value === initialValue);
  const defaultLabel = initialIndex >= 0 ? String(initialIndex + 1) : "";
  return (async () => {
    for (;;) {
      const answer = (await prompter.question(`请输入序号${defaultLabel ? `（默认 ${defaultLabel}）` : ""}: `)).trim();
      const selectedIndex = answer === "" && defaultLabel
        ? initialIndex
        : Number.parseInt(answer, 10) - 1;
      if (selectedIndex >= 0 && selectedIndex < options.length) {
        return options[selectedIndex]!.value;
      }
      console.log("无效输入，请重新选择。 / Invalid input, please try again.");
    }
  })();
}

/**
 * 运行配置向导。成功返回配置（已落盘 config.json），用户中途退出返回 undefined。
 * confirmOverwrite：已有配置时先确认（/feishu setup 重新配置场景），默认不询问（首次启动场景）。
 */
export async function runHarnessSetup(options?: { confirmOverwrite?: boolean }): Promise<FeishuConfig | undefined> {
  ensureRoot();
  const prompter = createPrompter();
  try {
    if (options?.confirmOverwrite) {
      const existing = loadConfig();
      if (existing) {
        const answer = (await prompter.question(
          `检测到已有配置（App ID: ${mask(existing.appId)}）。覆盖将替换当前机器人，继续？(y/N): `,
        )).trim().toLowerCase();
        if (answer !== "y" && answer !== "yes") {
          console.log("已取消，现有配置未改动。 / Cancelled; existing config unchanged.");
          return undefined;
        }
      }
    }
    console.log("=== 飞书 / Lark 机器人配置向导 / Setup wizard ===");
    const mode = await select(
      prompter,
      "配置方式 / Setup method",
      [
        { value: "auto", label: "扫码自动创建飞书助手 / Create by QR code" },
        { value: "manual", label: "手动填写已有应用 / Configure existing app" },
      ],
      "auto",
    );

    let appId = "";
    let appSecret = "";
    let domain: Domain = "feishu";

    if (mode === "auto") {
      console.log();
      const created = await registerFeishuApp();
      appId = created.appId;
      appSecret = created.appSecret;
      domain = created.domain;
    } else {
      domain = await select(
        prompter,
        "应用区域 / App region",
        [
          { value: "feishu", label: "Feishu 中国 / Feishu China" },
          { value: "lark", label: "Lark 国际 / Lark Global" },
        ],
        "feishu",
      );
      appId = (await prompter.question("App ID / 应用 ID: ")).trim();
      appSecret = (await prompter.question("App Secret / 应用密钥: ")).trim();
    }

    if (!appId || !appSecret) {
      console.log("App ID 和 App Secret 不能为空，配置未保存。 / App ID and App Secret are required; config not saved.");
      return undefined;
    }

    const groupPolicy = await select<GroupPolicy>(
      prompter,
      "群聊策略 / Group policy",
      [
        { value: "open", label: "open：不需要 @，群/话题消息自动回复 / auto reply without @ in groups/topics" },
        { value: "mention", label: "mention：只有 @ 机器人才回复 / reply only when mentioned" },
      ],
      "open",
    );

    const config: FeishuConfig = {
      appId,
      appSecret,
      domain,
      groupPolicy,
      language: "zh",
      reactEmoji: DEFAULT_CONFIG.reactEmoji,
      autoStart: true,
    };
    writeJson(CONFIG_HARNESS_PATH, config);
    console.log(`\n飞书配置已保存 / Feishu config saved\nPath: ${CONFIG_HARNESS_PATH}\nApp ID: ${mask(appId)}\n群聊策略 / Group policy: ${groupPolicy}`);
    return config;
  } finally {
    prompter.close();
  }
}