// 参考文献
// https://redis.io/topics/notifications
// https://medium.com/@micah1powell/using-redis-keyspace-notifications-for-a-reminder-service-with-node-c05047befec3
const Redis = require('ioredis');

//#region Redis测试

// subscriber
let RedisSubTester = new Redis({
    port: 6379, // Redis port
    host: "127.0.0.1", // Redis host
    db: 0
});

// publisher
let RedisPubTester = new Redis({
    port: 6379, // Redis port
    host: "127.0.0.1", // Redis host
    db: 0
});

// event handler
let RedisEventsHandler = new Redis({
    port: 6379, // Redis port
    host: "127.0.0.1", // Redis host
    db: 0
});

RedisEventsHandler.on('ready', function () {
    // https://redis.io/topics/notifications#configuration
    RedisEventsHandler.config("SET", "notify-keyspace-events", "KEA");

    RedisEventsHandler.setex('myKey', 5, 'Hello World');
    // RedisEventsHandler.set('myKey', 'Hello World', 'Ex', 5);
});

let PubSub = {
    publish(channel, message) {
        RedisPubTester.publish(channel, message);
    },
    subscribe(channel) {
        RedisSubTester.subscribe(channel);
    },
    psubscribe(channel) {
        RedisSubTester.psubscribe(channel);
    },
    on(event, callback) {
        RedisSubTester.on(event, (channel, message) => {
            callback(channel, message);
        });
    }
};

// PubSub.subscribe("__keyevent@0__:expired"); // normal subscriber
PubSub.psubscribe("__key*__:*"); // pattern subscriber
PubSub.psubscribe("news");
PubSub.psubscribe("music");
PubSub.publish("news", "Hello world!");
PubSub.publish("music", "Hello again!");


PubSub.on("message", async (channel, message) => {
    // Handle event
    console.log(`channel: ${channel}, message: ${message}`);
});

PubSub.on("pmessage", async (pattern, channel, message) => {
    // Handle event
    console.log(`pattern: ${pattern}, channel: ${channel}, message: ${message}`);
});

//#endregion