/// SPDX-License-Identifier: GPL-3.0-or-later
/// SPDX-FileCopyrightText: Copyright © 2016-2021 Tony Garnock-Jones <tonyg@leastfixedpoint.com>

import { Dataspace, Ref, Sturdy, AnyValue, Reader, Schemas, isEmbedded } from "@syndicate-lang/core";
import { boot as bootHtml, Anchor, template as html, HtmlFragments, GlobalEvent, UIAttribute, UIChangeableProperty } from "@syndicate-lang/html";
import { boot as bootWakeDetector, WakeEvent } from "./wake-detector";
import { boot as bootWsRelay, ForceRelayDisconnect, fromRelayAddress, RelayAddress, fromForceRelayDisconnect, Resolved } from "./wsRelay";
import { fromSays, fromPresent, Present, Says } from './gen/simpleChatProtocol';

const Transport = Schemas.transportAddress;

export function main() {
    document.getElementById('chat_form')!.onsubmit = e => { e.preventDefault(); return false; };
    document.getElementById('nym_form')!.onsubmit = e => { e.preventDefault(); return false; };
    setWsurl();
    setUsernameIfUnset();
    document.getElementById('chat_input')!.focus();

    Dataspace.boot(ds => {
        bootHtml(ds);
        bootWakeDetector(ds);
        bootWsRelay(ds, true);
        bootChat(ds);
    });
}

function bootChat(ds: Ref) {
    spawn named 'chat' {
        at ds {
            field nym: string = '';
            on asserted UIChangeableProperty('#nym', 'value', $v: string) => nym.value = v;

            during UIChangeableProperty('#wsurl', 'value', $wsurl: string) =>
                during UIChangeableProperty('#servercap', 'value', $servercapText: string) => {
                    let servercap: AnyValue | null = null;
                    try {
                        const a = new Reader<Ref>(servercapText).next();
                        Sturdy.asSturdyRef(a); // throws if invalid
                        servercap = a;
                    } catch (e) {
                        console.error(e);
                    }
                    assert UIAttribute('#servercap', 'class', 'invalid') when (!servercap);
                    if (wsurl && servercap) {
                        contactRemote(wsurl, servercap);
                    }
                }

            function contactRemote(wsurl: string, servercap: AnyValue) {
                during Resolved({
                    "addr": RelayAddress(Transport.WebSocket(wsurl)),
                    "sturdyref": servercap,
                    "resolved": $remoteDs_e,
                }) => {
                    if (!isEmbedded(remoteDs_e)) return;
                    const remoteDs = remoteDs_e.embeddedValue;

                    on message WakeEvent() =>
                        send message fromForceRelayDisconnect(ForceRelayDisconnect(
                            RelayAddress(Transport.WebSocket(wsurl))));

                    outputState('connected', 'connected to ' + wsurl);
                    on stop outputState('disconnected', 'disconnected from ' + wsurl);

                    on message GlobalEvent('#send_chat', 'click', _) => {
                        const inp = document.getElementById("chat_input") as HTMLInputElement;
                        var utterance = inp.value;
                        inp.value = '';
                        if (utterance) {
                            at remoteDs {
                                send message fromSays(Says({ who: nym.value, what: utterance }));
                            }
                        }
                    }

                    at remoteDs {
                        assert fromPresent(Present(nym.value));

                        const ui = new Anchor();
                        during Present($who: string) => at ds {
                            assert ui.context(who).html('#nymlist', html`<li>${who}</li>`);
                        }

                        on message Says({ "who": $who: string, "what": $what: string }) => {
                            outputUtterance(who, what);
                        }
                    }
                }
            }
        }
    }
}

function setWsurl() {
    const wsurl = document.getElementById('wsurl')! as HTMLInputElement;
    if (wsurl.value === '') {
        wsurl.value = `ws://${document.location.host}:9001/`;
    }
}

function setUsernameIfUnset() {
    const nym = document.getElementById('nym')! as HTMLInputElement;
    if (nym.value === '') {
        nym.value = "nym" + Math.floor(Math.random() * 65536);
    }
}

function outputItem(cls: string, item0: HtmlFragments): ChildNode {
    const stamp = html`<span class="timestamp">${(new Date()).toUTCString()}</span>`;
    const item = html`<div class="${cls}">${stamp}${item0}</div>`;
    const n = item.node();
    const o = document.getElementById('chat_output')!;
    o.appendChild(n);
    o.scrollTop = o.scrollHeight;
    return n;
}

function outputState(cls: string, state: string) {
    outputItem(`state_${cls}`, html`<span class="state ${cls}">${state}</span>`)
}

function outputUtterance(who: string, what: string) {
    outputItem('utterance',
               html`<span class="nym">${who}</span><span class="utterance">${what}</span>`);
}