import { showToast, showLoadingToast, closeToast } from "vant";
import useApiFetch from "@/composables/useApiFetch";

// 阿里云验证码场景 ID
const ALIYUN_CAPTCHA_SCENE_ID = "wynt39to";
// 是否启用加密模式（通过环境变量控制，非加密模式时前端不调用后端获取 EncryptedSceneId）
const ENABLE_ENCRYPTED =
    import.meta.env.VITE_ALIYUN_CAPTCHA_ENCRYPTED === "false";

let captchaInitialised = false;
/** 首次初始化后，SDK 会异步调用 getInstance，用此 Promise 在实例就绪后再 show */
let captchaReadyPromise = null;
let captchaReadyResolve = null;

async function ensureCaptchaInit() {
    if (captchaInitialised || typeof window === "undefined") return;
    if (typeof window.initAliyunCaptcha !== "function") return;

    captchaInitialised = true;
    window.captcha = null;
    window.__lastBizResponse = null;
    window.__onCaptchaBizSuccess = null;
    captchaReadyPromise = new Promise((resolve) => {
        captchaReadyResolve = resolve;
    });

    // 非加密模式：仅传 SceneId，不调用后端接口
    if (!ENABLE_ENCRYPTED) {
        window.initAliyunCaptcha({
            SceneId: ALIYUN_CAPTCHA_SCENE_ID,
            mode: "popup",
            element: "#captcha-element",
            getInstance(instance) {
                window.captcha = instance;
                if (typeof captchaReadyResolve === "function") {
                    captchaReadyResolve();
                    captchaReadyResolve = null;
                }
            },
            captchaVerifyCallback(param) {
                return typeof window.__captchaVerifyCallback === "function"
                    ? window.__captchaVerifyCallback(param)
                    : Promise.resolve({
                          captchaResult: false,
                          bizResult: false,
                      });
            },
            onBizResultCallback(bizResult) {
                if (typeof window.__onBizResultCallback === "function") {
                    window.__onBizResultCallback(bizResult);
                }
                window.__lastBizResponse = null;
                window.__onCaptchaBizSuccess = null;
            },
            slideStyle: { width: 360, height: 40 },
            language: "cn",
        });
        return;
    }

    // 加密模式：先从后端获取 EncryptedSceneId，再初始化
    const { data, error } = await useApiFetch("/captcha/encryptedSceneId")
        .post()
        .json();
    const resp = data?.value;
    const encryptedSceneId = resp?.data?.encryptedSceneId;
    if (error?.value || !encryptedSceneId) {
        showToast({ message: "获取验证码参数失败，请稍后重试" });
        captchaInitialised = false;
        captchaReadyPromise = null;
        captchaReadyResolve = null;
        return;
    }
    window.initAliyunCaptcha({
        SceneId: ALIYUN_CAPTCHA_SCENE_ID,
        EncryptedSceneId: encryptedSceneId,
        mode: "popup",
        element: "#captcha-element",
        getInstance(instance) {
            window.captcha = instance;
            if (typeof captchaReadyResolve === "function") {
                captchaReadyResolve();
                captchaReadyResolve = null;
            }
        },
        captchaVerifyCallback(param) {
            return typeof window.__captchaVerifyCallback === "function"
                ? window.__captchaVerifyCallback(param)
                : Promise.resolve({ captchaResult: false, bizResult: false });
        },
        onBizResultCallback(bizResult) {
            if (typeof window.__onBizResultCallback === "function") {
                window.__onBizResultCallback(bizResult);
            }
            window.__lastBizResponse = null;
            window.__onCaptchaBizSuccess = null;
        },
        slideStyle: { width: 360, height: 40 },
        language: "cn",
    });
}

/**
 * 阿里云滑块验证码通用封装。
 * 依赖 index.html 中已加载的 AliyunCaptcha.js；初始化在首次调起时执行。
 *
 * @param { (captchaVerifyParam: string) => Promise<{ data: Ref, error: Ref }> } bizVerify - 业务请求函数，接收滑块参数，返回 useApiFetch 的 { data, error }
 * @param { (res: any) => void } [onSuccess] - 业务成功回调（code===200 时调用，传入接口返回的 data.value）
 */
export function useAliyunCaptcha() {
    /**
     * 先弹出滑块，通过后执行 bizVerify(captchaVerifyParam)，再根据结果调用 onSuccess。
     */
    async function runWithCaptcha(bizVerify, onSuccess) {
        if (typeof window === "undefined") {
            showToast({ message: "验证码仅支持浏览器环境" });
            return;
        }

        const loading = showLoadingToast({
            message: "安全验证加载中...",
            forbidClick: true,
            duration: 0,
            loadingType: "spinner",
        });

        try {
            window.__captchaVerifyCallback = async (captchaVerifyParam) => {
                window.__lastBizResponse = null;
                const { data, error } = await bizVerify(captchaVerifyParam);
                const result = data?.value ?? data;
                if (error?.value || !result) {
                    return { captchaResult: false, bizResult: false };
                }
                window.__lastBizResponse = result;
                const captchaOk = result.captchaVerifyResult !== false;
                const bizOk = result.code === 200;
                return { captchaResult: captchaOk, bizResult: bizOk };
            };

            window.__onBizResultCallback = (bizResult) => {
                if (
                    bizResult === true &&
                    window.__lastBizResponse &&
                    typeof window.__onCaptchaBizSuccess === "function"
                ) {
                    window.__onCaptchaBizSuccess(window.__lastBizResponse);
                }
            };

            await ensureCaptchaInit();

            // 首次初始化时 SDK 会异步调用 getInstance，需等待实例就绪后再 show
            if (captchaReadyPromise) {
                await captchaReadyPromise;
                captchaReadyPromise = null;
            }
            if (!window.captcha) {
                showToast({ message: "验证码未加载，请刷新页面重试" });
                return;
            }
            window.__onCaptchaBizSuccess = onSuccess;
            window.captcha.show();
        } finally {
            closeToast();
        }
    }

    return { runWithCaptcha };
}

export default useAliyunCaptcha;