const cloud = require('wx-server-sdk');
cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV });

const db = cloud.database();

exports.main = async (event, context) => {
    const wxContext = cloud.getWXContext();
    const openid = wxContext.OPENID;
    const unionid = wxContext.UNIONID || null;

    const { action } = event;

    switch (action) {
        case 'updateProfile':
            return await handleUpdateProfile(event, openid);
        default:
            return await handleSilentLogin(openid, unionid);
    }
};

async function handleSilentLogin(openid, unionid) {
    const usersCollection = db.collection('users');

    const { data } = await usersCollection.where({ openid }).limit(1).get();

    const now = db.serverDate();

    if (data.length > 0) {
        const user = data[0];
        const updateData = { lastActiveAt: now };
        if (unionid && !user.unionid) {
            updateData.unionid = unionid;
        }
        await usersCollection.doc(user._id).update({ data: updateData });

        return {
            code: 0,
            data: { ...user, ...updateData, lastActiveAt: new Date() },
        };
    } else {
        const newUser = {
            openid,
            unionid,
            nickName: null,
            avatarUrl: null,
            totalDownloads: 0,
            createdAt: now,
            lastActiveAt: now,
        };
        const { _id } = await usersCollection.add({ data: newUser });

        return {
            code: 0,
            data: {
                _id,
                ...newUser,
                createdAt: new Date(),
                lastActiveAt: new Date(),
            },
        };
    }
}

async function handleUpdateProfile(event, openid) {
    const { nickName, avatarUrl } = event;
    const usersCollection = db.collection('users');

    const { data } = await usersCollection.where({ openid }).limit(1).get();

    if (data.length === 0) {
        return { code: -1, message: '用户不存在' };
    }

    const updateData = {};
    if (nickName !== undefined) updateData.nickName = nickName;
    if (avatarUrl !== undefined) updateData.avatarUrl = avatarUrl;

    await usersCollection.doc(data[0]._id).update({ data: updateData });

    return {
        code: 0,
        data: { ...data[0], ...updateData },
    };
}