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

import { OptionsWithUri } from 'request';
import { RequestPromiseOptions } from 'request-promise-native';

export class GraphQL implements INodeType {
	description: INodeTypeDescription = {
		displayName: 'GraphQL',
		name: 'graphql',
		icon: 'file:graphql.png',
		group: ['input'],
		version: 1,
		description: 'Makes a GraphQL request and returns the received data',
		defaults: {
			name: 'GraphQL',
			color: '#E10098',
		},
		inputs: ['main'],
		outputs: ['main'],
		properties: [
			{
				displayName: 'HTTP Request Method',
				name: 'requestMethod',
				type: 'options',
				options: [
					{
						name: 'GET',
						value: 'GET',
					},
					{
						name: 'POST',
						value: 'POST',
					},
				],
				default: 'POST',
				description: 'The underlying HTTP request method to use.',
			},
			{
				displayName: 'Endpoint',
				name: 'endpoint',
				type: 'string',
				default: '',
				placeholder: 'http://example.com/graphql',
				description: 'The GraphQL endpoint.',
				required: true,
			},
			{
				displayName: 'Ignore SSL Issues',
				name: 'allowUnauthorizedCerts',
				type: 'boolean',
				default: false,
				description: 'Still fetch the response even if SSL certificate validation is not possible.',
			},
			{
				displayName: 'Request Format',
				name: 'requestFormat',
				type: 'options',
				required: true,
				options: [
					{
						name: 'GraphQL (raw)',
						value: 'graphql',
					},
					{
						name: 'JSON',
						value: 'json',
					},
				],
				displayOptions: {
					show: {
						requestMethod: [
							'POST',
						],
					},
				},
				default: 'graphql',
				description: 'The format for the query payload',
			},
			{
				displayName: 'Query',
				name: 'query',
				type: 'json',
				default: '',
				description: 'GraphQL query',
				required: true,
			},
			{
				displayName: 'Variables',
				name: 'variables',
				type: 'json',
				default: '',
				description: 'Query variables',
				displayOptions: {
					show: {
						requestFormat: [
							'json',
						],
						requestMethod: [
							'POST',
						],
					},
				},
			},
			{
				displayName: 'Operation Name',
				name: 'operationName',
				type: 'string',
				default: '',
				description: 'Name of operation to execute',
				displayOptions: {
					show: {
						requestFormat: [
							'json',
						],
						requestMethod: [
							'POST',
						],
					},
				},
			},
			{
				displayName: 'Response Format',
				name: 'responseFormat',
				type: 'options',
				options: [
					{
						name: 'JSON',
						value: 'json',
					},
					{
						name: 'String',
						value: 'string',
					},
				],
				default: 'json',
				description: 'The format in which the data gets returned from the URL.',
			},
			{
				displayName: 'Response Data Property Name',
				name: 'dataPropertyName',
				type: 'string',
				default: 'data',
				required: true,
				displayOptions: {
					show: {
						responseFormat: [
							'string',
						],
					},
				},
				description: 'Name of the property to which to write the response data.',
			},

			// Header Parameters
			{
				displayName: 'Headers',
				name: 'headerParametersUi',
				placeholder: 'Add Header',
				type: 'fixedCollection',
				typeOptions: {
					multipleValues: true,
				},
				description: 'The headers to send.',
				default: {},
				options: [
					{
						name: 'parameter',
						displayName: 'Header',
						values: [
							{
								displayName: 'Name',
								name: 'name',
								type: 'string',
								default: '',
								description: 'Name of the header.',
							},
							{
								displayName: 'Value',
								name: 'value',
								type: 'string',
								default: '',
								description: 'Value to set for the header.',
							},
						],
					},
				],
			},
		],
	};


	async execute(this: IExecuteFunctions): Promise<INodeExecutionData[][]> {

		const items = this.getInputData();

		let requestOptions: OptionsWithUri & RequestPromiseOptions;

		const returnItems: INodeExecutionData[] = [];
		for (let itemIndex = 0; itemIndex < items.length; itemIndex++) {
			const requestMethod = this.getNodeParameter('requestMethod', itemIndex, 'POST') as string;
			const endpoint = this.getNodeParameter('endpoint', itemIndex, '') as string;
			const requestFormat = this.getNodeParameter('requestFormat', itemIndex, 'graphql') as string;
			const responseFormat = this.getNodeParameter('responseFormat', 0) as string;

			const { parameter }: { parameter?: Array<{ name: string, value: string }> } = this
				.getNodeParameter('headerParametersUi', itemIndex, {}) as IDataObject;
			const headerParameters = (parameter || []).reduce((result, item) => ({
				...result,
				[item.name]: item.value,
			}), {});

			requestOptions = {
				headers: {
					'content-type': `application/${requestFormat}`,
					...headerParameters,
				},
				method: requestMethod,
				uri: endpoint,
				simple: false,
				rejectUnauthorized: !this.getNodeParameter('allowUnauthorizedCerts', itemIndex, false) as boolean,
			};

			const gqlQuery = this.getNodeParameter('query', itemIndex, '') as string;
			if (requestMethod === 'GET') {
				requestOptions.qs = {
					query: gqlQuery,
				};
			} else {
				if (requestFormat === 'json') {
					requestOptions.body = {
						query: gqlQuery,
						variables: this.getNodeParameter('variables', itemIndex, {}) as object,
						operationName: this.getNodeParameter('operationName', itemIndex, null) as string,
					};
					if (typeof requestOptions.body.variables === 'string') {
						try {
							requestOptions.body.variables = JSON.parse(requestOptions.body.variables || '{}');
						} catch (e) {
							throw new Error('Using variables failed:\n' + requestOptions.body.variables + '\n\nWith error message:\n' + e);
						}
					}
					if (requestOptions.body.operationName === '') {
						requestOptions.body.operationName = null;
					}
					requestOptions.json = true;
				} else {
					requestOptions.body = gqlQuery;
				}
			}

			const response = await this.helpers.request(requestOptions);
			if (responseFormat === 'string') {
				const dataPropertyName = this.getNodeParameter('dataPropertyName', 0) as string;

				returnItems.push({
					json: {
						[dataPropertyName]: response,
					},
				});
			} else {
				if (typeof response === 'string') {
					try {
						returnItems.push({ json: JSON.parse(response) });
					} catch (e) {
						throw new Error('Response body is not valid JSON. Change "Response Format" to "String"');
					}
				} else {
					returnItems.push({ json: response });
				}
			}
		}

		return this.prepareOutputData(returnItems);
	}
}