import {
	IHookFunctions,
	IWebhookFunctions,
} from 'n8n-core';

import {
	IDataObject,
	ILoadOptionsFunctions,
	INodePropertyOptions,
	INodeTypeDescription,
	INodeType,
	IWebhookResponseData,
} from 'n8n-workflow';

import {
	asanaApiRequest,
	getWorkspaces,
} from './GenericFunctions';

import {
	createHmac,
} from 'crypto';

export class AsanaTrigger implements INodeType {
	description: INodeTypeDescription = {
		displayName: 'Asana Trigger',
		name: 'asanaTrigger',
		icon: 'file:asana.png',
		group: ['trigger'],
		version: 1,
		description: 'Starts the workflow when Asana events occure.',
		defaults: {
			name: 'Asana-Trigger',
			color: '#FC636B',
		},
		inputs: [],
		outputs: ['main'],
		credentials: [
			{
				name: 'asanaApi',
				required: true,
				displayOptions: {
					show: {
						authentication: [
							'accessToken',
						],
					},
				},
			},
			{
				name: 'asanaOAuth2Api',
				required: true,
				displayOptions: {
					show: {
						authentication: [
							'oAuth2',
						],
					},
				},
			},
		],
		webhooks: [
			{
				name: 'default',
				httpMethod: 'POST',
				responseMode: 'onReceived',
				path: 'webhook',
			},
		],
		properties: [
			{
				displayName: 'Authentication',
				name: 'authentication',
				type: 'options',
				options: [
					{
						name: 'Access Token',
						value: 'accessToken',
					},
					{
						name: 'OAuth2',
						value: 'oAuth2',
					},
				],
				default: 'accessToken',
				description: 'The resource to operate on.',
			},
			{
				displayName: 'Resource',
				name: 'resource',
				type: 'string',
				default: '',
				required: true,
				description: 'The resource ID to subscribe to. The resource can be a task or project.',
			},
			{
				displayName: 'Workspace',
				name: 'workspace',
				type: 'options',
				typeOptions: {
					loadOptionsMethod: 'getWorkspaces',
				},
				options: [],
				default: '',
				required: false,
				description: 'The workspace ID the resource is registered under. This is only required if you want to allow overriding existing webhooks.',
			},
		],
	};

	methods = {
		loadOptions: {
			// Get all the available workspaces to display them to user so that he can
			// select them easily
			async getWorkspaces(this: ILoadOptionsFunctions): Promise<INodePropertyOptions[]> {
				const workspaces = await getWorkspaces.call(this);
				workspaces.unshift({
					name: '',
					value: '',
				});
				return workspaces;
			},
		},
	};

	// @ts-ignore (because of request)
	webhookMethods = {
		default: {
			async checkExists(this: IHookFunctions): Promise<boolean> {
				const webhookData = this.getWorkflowStaticData('node');

				const webhookUrl = this.getNodeWebhookUrl('default') as string;

				const resource = this.getNodeParameter('resource') as string;

				const workspace = this.getNodeParameter('workspace') as string;

				const endpoint = '/webhooks';

				const { data } = await asanaApiRequest.call(this, 'GET', endpoint, {}, { workspace });

				for (const webhook of data) {
					if (webhook.resource.gid === resource && webhook.target === webhookUrl) {
						webhookData.webhookId = webhook.gid;
						return true;
					}
				}

				// If it did not error then the webhook exists
				return false;
			},
			async create(this: IHookFunctions): Promise<boolean> {
				const webhookData = this.getWorkflowStaticData('node');

				const webhookUrl = this.getNodeWebhookUrl('default') as string;

				if (webhookUrl.includes('%20')) {
					throw new Error('The name of the Asana Trigger Node is not allowed to contain any spaces!');
				}

				const resource = this.getNodeParameter('resource') as string;

				const endpoint = `/webhooks`;

				const body = {
					resource,
					target: webhookUrl,
				};

				let responseData;

				responseData = await asanaApiRequest.call(this, 'POST', endpoint, body);

				if (responseData.data === undefined || responseData.data.gid === undefined) {
					// Required data is missing so was not successful
					return false;
				}

				webhookData.webhookId = responseData.data.gid as string;

				return true;
			},
			async delete(this: IHookFunctions): Promise<boolean> {
				const webhookData = this.getWorkflowStaticData('node');

				if (webhookData.webhookId !== undefined) {
					const endpoint = `/webhooks/${webhookData.webhookId}`;
					const body = {};

					try {
						await asanaApiRequest.call(this, 'DELETE', endpoint, body);
					} catch (e) {
						return false;
					}

					// Remove from the static workflow data so that it is clear
					// that no webhooks are registred anymore
					delete webhookData.webhookId;
					delete webhookData.webhookEvents;
					delete webhookData.hookSecret;
				}

				return true;
			},
		},
	};

	async webhook(this: IWebhookFunctions): Promise<IWebhookResponseData> {
		const bodyData = this.getBodyData() as IDataObject;
		const headerData = this.getHeaderData() as IDataObject;
		const req = this.getRequestObject();

		const webhookData = this.getWorkflowStaticData('node');

		if (headerData['x-hook-secret'] !== undefined) {
			// Is a create webhook confirmation request
			webhookData.hookSecret = headerData['x-hook-secret'];

			const res = this.getResponseObject();
			res.set('X-Hook-Secret', webhookData.hookSecret as string);
			res.status(200).end();

			return {
				noWebhookResponse: true,
			};
		}

		// Is regular webhook call
		// Check if it contains any events
		if (bodyData.events === undefined || !Array.isArray(bodyData.events) ||
			bodyData.events.length === 0) {
			// Does not contain any event data so nothing to process so no reason to
			// start the workflow
			return {};
		}

		// TODO: Had to be deactivated as it is currently not possible to get the secret
		//       in production mode as the static data overwrites each other because the
		//       two exist at the same time (create webhook [with webhookId] and receive
		//       webhook [with secret])
		// // Check if the request is valid
		// // (if the signature matches to data and hookSecret)
		// const computedSignature = createHmac('sha256', webhookData.hookSecret as string).update(JSON.stringify(req.body)).digest('hex');
		// if (headerData['x-hook-signature'] !== computedSignature) {
		// 	// Signature is not valid so ignore call
		// 	return {};
		// }

		return {
			workflowData: [
				this.helpers.returnJsonArray(req.body.events)
			],
		};
	}
}