import {
	BINARY_ENCODING,
	IExecuteFunctions
} from 'n8n-core';
import {
	IDataObject,
	INodeExecutionData,
	INodeType,
	INodeTypeDescription,
	NodeOperationError,
} from 'n8n-workflow';

import { createTransport } from 'nodemailer';
import SMTPTransport = require('nodemailer/lib/smtp-transport');

export class EmailSend implements INodeType {
	description: INodeTypeDescription = {
		displayName: 'Send Email',
		name: 'emailSend',
		icon: 'fa:envelope',
		group: ['output'],
		version: 1,
		description: 'Sends an Email',
		defaults: {
			name: 'Send Email',
			color: '#00bb88',
		},
		inputs: ['main'],
		outputs: ['main'],
		credentials: [
			{
				name: 'smtp',
				required: true,
			},
		],
		properties: [
			// TODO: Add choice for text as text or html  (maybe also from name)
			{
				displayName: 'From Email',
				name: 'fromEmail',
				type: 'string',
				default: '',
				required: true,
				placeholder: 'admin@example.com',
				description: 'Email address of the sender optional with name.',
			},
			{
				displayName: 'To Email',
				name: 'toEmail',
				type: 'string',
				default: '',
				required: true,
				placeholder: 'info@example.com',
				description: 'Email address of the recipient.',
			},
			{
				displayName: 'CC Email',
				name: 'ccEmail',
				type: 'string',
				default: '',
				placeholder: 'cc@example.com',
				description: 'Email address of CC recipient.',
			},
			{
				displayName: 'BCC Email',
				name: 'bccEmail',
				type: 'string',
				default: '',
				placeholder: 'bcc@example.com',
				description: 'Email address of BCC recipient.',
			},
			{
				displayName: 'Subject',
				name: 'subject',
				type: 'string',
				default: '',
				placeholder: 'My subject line',
				description: 'Subject line of the email.',
			},
			{
				displayName: 'Text',
				name: 'text',
				type: 'string',
				typeOptions: {
					alwaysOpenEditWindow: true,
					rows: 5,
				},
				default: '',
				description: 'Plain text message of email.',
			},
			{
				displayName: 'HTML',
				name: 'html',
				type: 'string',
				typeOptions: {
					rows: 5,
				},
				default: '',
				description: 'HTML text message of email.',
			},
			{
				displayName: 'Attachments',
				name: 'attachments',
				type: 'string',
				default: '',
				description: 'Name of the binary properties which contain<br />data which should be added to email as attachment.<br />Multiple ones can be comma separated.',
			},
			{
				displayName: 'Options',
				name: 'options',
				type: 'collection',
				placeholder: 'Add Option',
				default: {},
				options: [
					{
						displayName: 'Ignore SSL Issues',
						name: 'allowUnauthorizedCerts',
						type: 'boolean',
						default: false,
						description: 'Do connect even if SSL certificate validation is not possible.',
					},
				],
			},
		],
	};


	async execute(this: IExecuteFunctions): Promise<INodeExecutionData[][]> {
		const items = this.getInputData();

		const returnData: INodeExecutionData[] = [];
		const length = items.length as unknown as number;
		let item: INodeExecutionData;

		for (let itemIndex = 0; itemIndex < length; itemIndex++) {

			item = items[itemIndex];

			const fromEmail = this.getNodeParameter('fromEmail', itemIndex) as string;
			const toEmail = this.getNodeParameter('toEmail', itemIndex) as string;
			const ccEmail = this.getNodeParameter('ccEmail', itemIndex) as string;
			const bccEmail = this.getNodeParameter('bccEmail', itemIndex) as string;
			const subject = this.getNodeParameter('subject', itemIndex) as string;
			const text = this.getNodeParameter('text', itemIndex) as string;
			const html = this.getNodeParameter('html', itemIndex) as string;
			const attachmentPropertyString = this.getNodeParameter('attachments', itemIndex) as string;
			const options = this.getNodeParameter('options', itemIndex, {}) as IDataObject;

			const credentials = this.getCredentials('smtp');

			if (credentials === undefined) {
				throw new NodeOperationError(this.getNode(), 'No credentials got returned!');
			}

			const connectionOptions: SMTPTransport.Options = {
				host: credentials.host as string,
				port: credentials.port as number,
				secure: credentials.secure as boolean,
			};

			if (credentials.user || credentials.password) {
				// @ts-ignore
				connectionOptions.auth = {
					user: credentials.user as string,
					pass: credentials.password as string,
				};
			}

			if (options.allowUnauthorizedCerts === true) {
				connectionOptions.tls = {
					rejectUnauthorized: false,
				};
			}

			const transporter = createTransport(connectionOptions);

			// setup email data with unicode symbols
			const mailOptions = {
				from: fromEmail,
				to: toEmail,
				cc: ccEmail,
				bcc: bccEmail,
				subject,
				text,
				html,
			};

			if (attachmentPropertyString && item.binary) {
				const attachments = [];
				const attachmentProperties: string[] = attachmentPropertyString.split(',').map((propertyName) => {
					return propertyName.trim();
				});

				for (const propertyName of attachmentProperties) {
					if (!item.binary.hasOwnProperty(propertyName)) {
						continue;
					}
					attachments.push({
						filename: item.binary[propertyName].fileName || 'unknown',
						content: Buffer.from(item.binary[propertyName].data, BINARY_ENCODING),
					});
				}

				if (attachments.length) {
					// @ts-ignore
					mailOptions.attachments = attachments;
				}
			}

			// Send the email
			const info = await transporter.sendMail(mailOptions);

			returnData.push({ json: info });
		}

		return this.prepareOutputData(returnData);
	}

}