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

import { fromJS, Bytes, Dataspace, Ref, Sturdy, AnyValue, Reader, Schemas, Embedded, stringify } 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 } from "@syndicate-lang/ws-relay";
import { Present, Says } from './gen/simpleChatProtocol';
import G = Schemas.gatekeeper;
import N = Schemas.noise;

export function main() {
    document.getElementById('chat_form')!.onsubmit = e => { e.preventDefault(); return false; };
    document.getElementById('nym_form')!.onsubmit = e => { e.preventDefault(); return false; };
    setDataspaceAddress();
    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('#route', 'value', $routeText: string) => {
                let route: G.Route<Ref> | null = null;
                try {
                    route = G.asRoute(new Reader<Ref>(routeText).next());
                } catch (e) {
                    console.error(e);
                }
                assert UIAttribute('#route', 'class', 'invalid') when (!route);
                if (route) contactRemote(route);
            }

            function contactRemote(route: G.Route<Ref>) {
                console.log('contactRemote', route);
                during G.ResolvePath({
                    "route": route,
                    "addr": $addr,
                    "control": $control_e: Embedded,
                    "resolved": G.Resolved.accepted($remoteDs_e: Embedded),
                }) => {
                    const remoteDs = remoteDs_e.embeddedValue;
                    const control = control_e.embeddedValue;

                    on message WakeEvent() => at control {
                        send message G.ForceDisconnect();
                    }

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

                    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 Says({ who: nym.value, what: utterance });
                            }
                        }
                    }

                    at remoteDs {
                        assert 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 setDataspaceAddress() {
    const route = document.getElementById('route')! as HTMLInputElement;
    if (route.value === '') {
        const isSecure = (document.location.protocol ?? '').toLowerCase().endsWith('s:');
        const localWs = isSecure ? 'wss' : 'ws';
        const wsurls = [
            `wss://generic-dataspace.demo.leastfixedpoint.com/`,
            `${localWs}://${document.location.hostname}:9001/`,
        ];
        const transports: AnyValue[] =
            wsurls.map(u => fromJS(Schemas.transportAddress.WebSocket(u)));

        route.value = stringify(G.Route<Ref>({
            "transports": transports,
            "pathSteps": [G.PathStep({
                "stepType": N.$noise,
                "detail": fromJS(N.NoiseSpec({
                    "service": "syndicate",
                    "key": Bytes.fromHex("21f6cd4e11e7e37711d6b3084ff18cded8fc8abf293aa47d43e8bb86dda65516"),
                    "protocol": N.NoiseProtocol.absent(),
                    "preSharedKeys": N.NoisePreSharedKeys.absent(),
                })),
            })],
        }));

        // To use a sturdyref instead:
        //
        // route.value = stringify(G.Route<Ref>({
        //     "transports": transports,
        //     "pathSteps": [G.PathStep({
        //         "stepType": Sturdy.$ref,
        //         "detail": fromJS(Sturdy.Parameters({
        //             "oid": "syndicate",
        //             "sig": Bytes.fromHex('69ca300c1dbfa08fba692102dd82311a'),
        //             "caveats": Sturdy.CaveatsField.absent(),
        //         })),
        //     })],
        // }));
        //
        // ... and of course you can chain these things, depending on server setup.
    }
}

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>`);
}