import { API, graphqlOperation } from 'aws-amplify';
import Observable from 'zen-observable-ts';
import { App } from '../config';

export interface SyncMessage {
    stage: string,
    type: string,
    topic: string,
    key: string,
    body: {
        version: string | number,
        account: string | number,
        time: string | number,
        region: string,
        resources: string[],
        detail: {
            [key: string]: any
        }
    }
}

export function subscribeToNotifications(topic: string, callback: (message: SyncMessage) => void) {
    const env = App.Environment;
    const appsync = env && env['APP SYNC'];
    const envStage = App.IsLocalhost || !env
        ? 'dev'
        : env.stage;
    const syncStage = appsync && appsync.stages && appsync.stages[envStage]
        ? appsync.stages[envStage]
        : envStage;
    const operation: Observable<object> = API.graphql(
        graphqlOperation(
            `
                subscription ListenMessage($stage: String!, $topic: String!) {
                    listenMessage(stage: $stage, topic: $topic) {
                        stage
                        body
                        key
                        topic
                    }
                }
            `,
            { stage: syncStage, topic }
        )
    ) as any;

    return operation.subscribe({
        next: ({ value }: any) => {
            const message = {
                ...value.data.listenMessage,
                body: JSON.parse(value.data.listenMessage.body)
            }
            callback(message);
        },
        error: (error: any) => console.warn(error)
    })
}

export async function sendNotification(topic: string, key: string, body: any) {
    const env = App.Environment;
    const appsync = env && env['APP SYNC'];
    const envStage = App.IsLocalhost || !env
        ? 'dev'
        : env.stage;
    const syncStage = appsync && appsync.stages && appsync.stages[envStage]
        ? appsync.stages[envStage]
        : envStage;
    const operation = await API.graphql(
        graphqlOperation(
            `
            mutation SendMessage($message: MessageInput!) {
                sendMessage(message: $message) {
                    stage
                    topic
                    key
                    body
                }
            }
            `,
            {
                stage: syncStage,
                topic,
                key,
                body: JSON.stringify({
                    version: '1.0.0',
                    time: Date.now(),
                    region: 'us-east-2',
                    resources: ['appsync.amazon.com'],
                    detail: body,
                }, null, '')
            }
        )
    );
    operation
}