import { GatewayOpcodes } from '../../types/shared.ts';
import { Shard, ShardSocketCloseCodes, ShardState } from './types.ts';

export async function identify(shard: Shard): Promise<void> {
    // A new identify has been requested even though there is already a connection open.
    // Therefore we need to close the old connection and heartbeating before creating a new one.
    if (shard.state === ShardState.Connected) {
        // console.log("CLOSING EXISTING SHARD: #" + shard.id);
        shard.close(ShardSocketCloseCodes.ReIdentifying, 'Re-identifying closure of old connection.');
    }

    shard.state = ShardState.Identifying;
    shard.events.identifying?.(shard);

    // It is possible that the shard is in Heartbeating state but not identified,
    // so check whether there is already a gateway connection existing.
    // If not we need to create one before we identify.
    if (!shard.isOpen()) {
        await shard.connect();
    }

    // Wait until an identify is free for this shard.
    await shard.requestIdentify();

    shard.send({
        op: GatewayOpcodes.Identify,
        d: {
            token: `Bot ${shard.gatewayConfig.token}`,
            compress: shard.gatewayConfig.compress,
            properties: shard.gatewayConfig.properties,
            intents: shard.gatewayConfig.intents,
            shard: [shard.id, shard.totalShards],
            presence: await shard.makePresence?.(shard.id),
        },
    }, true);

    return new Promise((resolve) => {
        shard.resolves.set('READY', () => {
            shard.events.identified?.(shard);
            resolve();
        });
        // When identifying too fast,
        // Discord sends an invalid session payload.
        // This can safely be ignored though and the shard starts a new identify action.
        shard.resolves.set('INVALID_SESSION', () => {
            shard.resolves.delete('READY');
            resolve();
        });
    });
}