[移动开发]第五课作业

import Iter "mo:base/Iter";
import List "mo:base/List";
import Principal "mo:base/Principal";
import Time "mo:base/Time";
import Buffer "mo:base/Buffer";
import Array "mo:base/Array";
import Int "mo:base/Int";

actor {
    public type Message = {
        text: Text;
        time: Time.Time;//该时间为从1970-01-01到现在经历的秒数
        author: Text;
    };

    public type FollowInfo = {
        name: Text;
        id : Text;
    };

    public type Microblog = actor {
        follow: shared(Principal) -> async ();
        follows: shared query () -> async [Principal];

        post: shared (Text,Text) -> async ();
        posts: shared query () -> async [Message];

        timeline: shared () -> async [Message];

        set_name : shared (Text) -> async ();
        get_name : shared query () -> async (?Text);
    };

    var authors: ?Text = null;
    public shared func set_name(text2: Text) : async () {
        authors := ?text2;
    };

    public query func get_name() : async ?Text {
        authors
    };

    var followed : List.List<Principal> = List.nil();

    public shared func follow(id: Principal) : async (){
        followed := List.push(id,followed);
    };

    public shared query func follows() : async [FollowInfo] {
        var all : List.List<FollowInfo> = List.nil();

        for(id in Iter.fromList(followed)){
            ignore do ? {
                let canister : Microblog = actor(Principal.toText(id));
                let name = (await canister.get_name()) !;
                let tmp : FollowInfo = {name = name;id =Principal.toText(id)};
                all := List.push<FollowInfo>(tmp, all);

            }
        };
        return List.toArray(all);
    }; 

    var messages : List.List<Message> = List.nil();

    public shared func post(otp:Text, text1: Text) : async () {
        assert(otp == "123456");
        let _author = switch (auth) {
            case (?a) { a };
            case (null) { "" };
        };

        let message1 = {
            text = text1;
            time = Time.now();
            author=_author;
        };
        
        messages := List.push(message1,messages)
    };

    public shared query func posts() : async [Message] {
        List.toArray(messages);
    };

    public shared func timeline() : async [Message] {
        var all : List.List<Message> = List.nil();

        for (id in Iter.fromList(followed)) {
            let canister : Microblog = actor(Principal.toText(id));
            let msgs = await canister.posts();
            for (msg in Iter.fromArray(msgs)) {
                all := List.push(msg,all);
            };
        };

        List.toArray(all);
    };
};