import java.util.List;
import java.util.ArrayList;
import java.io.IOException;
import cafe.biskuteri.hinoki.Tree;

class
TimelineWindowUpdater {

    private JKomasto
    primaire;

    private MastodonApi
    api;

//   -  -%-  -

    private List<TimelineWindow>
    updatees;

    private StringBuilder
    event, data;

//   -  -%-  -

    private Thread
    federated,
    local,
    home;

//  ---%-@-%---

    public void
    addWindow(TimelineWindow updatee)
    {
        updatees.add(updatee);

        Connection c = new Connection();
        c.type = updatee.getTimelineType();
        Thread t = new Thread(c);
        switch (c.type) {
            case FEDERATED:
                if (federated != null) return;
                federated = t; break;
            case LOCAL:
                if (local != null) return;
                local = t; break;
            case HOME:
                if (home != null) return;
                home = t; break;
            default: return;
        }
        t.start();
    }

    public void
    removeWindow(TimelineWindow updatee)
    {
        updatees.remove(updatee);
    }

//   -  -%-  -

    private void
    handle(TimelineType type, String event, String data)
    {
        assert !data.isEmpty();
        if (event.isEmpty()) return;

        boolean newPost = event.equals("update");
        boolean newNotif = event.equals("notification");
        if (!(newPost || newNotif)) return;

        for (TimelineWindow updatee: filter(type)) {
            updatee.showLatestPage();
        }
    }

    private List<TimelineWindow>
    filter(TimelineType type)
    {
        List<TimelineWindow> returnee = new ArrayList<>();
        for (TimelineWindow updatee: updatees)
            if (updatee.getTimelineType() == type)
                returnee.add(updatee);
        return returnee;
    }

//  ---%-@-%---

    private class
    Connection
    implements Runnable, ServerSideEventsListener {

        private TimelineType
        type;

//       -=-

        private StringBuilder
        event, data;

//      -=%=-

        public void
        run()
        {
            event = new StringBuilder();
            data = new StringBuilder();
            api.monitorTimeline(type, this);
            // monitorTimeline should not return
            // until the connection is closed.
        }

        public void
        lineReceived(String line)
        {
            if (line.startsWith(":")) return;

            if (line.isEmpty()) {
                handle(type, event.toString(), data.toString());
                event.delete(0, event.length());
                data.delete(0, event.length());
            }

            if (line.startsWith("data: "))
                data.append(line.substring("data: ".length()));

            if (line.startsWith("event: "))
                event.append(line.substring("event: ".length()));

            /*
            * Note that I utterly ignore https://html.spec.whatwg.org
            * /multipage/server-sent-events.html#dispatchMessage.
            * That is because I am not a browser.
            */
        }

        public void
        connectionFailed(IOException eIo)
        {
            // sais pas dois-je faire..
            eIo.printStackTrace();
        }

        public void
        requestFailed(int httpCode, Tree<String> json)
        {
            // mo shiranu
            System.err.println(httpCode + ", " + json.get("error").value);
        }

    }

//  ---%-@-%---

    TimelineWindowUpdater(JKomasto primaire)
    {
        this.primaire = primaire;
        this.api = primaire.getMastodonApi();

        this.updatees = new ArrayList<>();
    }

}