import {
	URL,
} from 'url';

import {
	Request,
	sign,
} from 'aws4';

import {
	OptionsWithUri,
} from 'request';

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

import {
	ICredentialDataDecryptedObject,
	IDataObject,
	NodeApiError,
	NodeOperationError,
} from 'n8n-workflow';

import {
	get,
} from 'lodash';

function getEndpointForService(service: string, credentials: ICredentialDataDecryptedObject): string {
	let endpoint;
	if (service === 'lambda' && credentials.lambdaEndpoint) {
		endpoint = credentials.lambdaEndpoint;
	} else if (service === 'sns' && credentials.snsEndpoint) {
		endpoint = credentials.snsEndpoint;
	} else {
		endpoint = `https://${service}.${credentials.region}.amazonaws.com`;
	}
	return (endpoint as string).replace('{region}', credentials.region as string);
}

export async function awsApiRequest(this: IHookFunctions | IExecuteFunctions | ILoadOptionsFunctions | IWebhookFunctions, service: string, method: string, path: string, body?: string, headers?: object): Promise<any> { // tslint:disable-line:no-any
	const credentials = await this.getCredentials('aws');
	if (credentials === undefined) {
		throw new NodeOperationError(this.getNode(), 'No credentials got returned!');
	}

	// Concatenate path and instantiate URL object so it parses correctly query strings
	const endpoint = new URL(getEndpointForService(service, credentials) + path);

	// Sign AWS API request with the user credentials
	const signOpts = { headers: headers || {}, host: endpoint.host, method, path, body } as Request;
	sign(signOpts, { accessKeyId: `${credentials.accessKeyId}`.trim(), secretAccessKey: `${credentials.secretAccessKey}`.trim() });


	const options: OptionsWithUri = {
		headers: signOpts.headers,
		method,
		uri: endpoint.href,
		body: signOpts.body,
	};

	try {
		return await this.helpers.request!(options);
	} catch (error) {
		throw new NodeApiError(this.getNode(), error); // no XML parsing needed
	}
}

export async function awsApiRequestREST(this: IHookFunctions | IExecuteFunctions | ILoadOptionsFunctions, service: string, method: string, path: string, body?: string, headers?: object): Promise<any> { // tslint:disable-line:no-any
	const response = await awsApiRequest.call(this, service, method, path, body, headers);
	try {
		return JSON.parse(response);
	} catch (error) {
		return response;
	}
}

export async function awsApiRequestRESTAllItems(this: IHookFunctions | IExecuteFunctions | ILoadOptionsFunctions, propertyName: string, service: string, method: string, path: string, body?: string, query: IDataObject = {}, headers: IDataObject = {}, option: IDataObject = {}, region?: string): Promise<any> { // tslint:disable-line:no-any

	const returnData: IDataObject[] = [];

	let responseData;

	const propertyNameArray = propertyName.split('.');

	do {
		responseData = await awsApiRequestREST.call(this, service, method, path, body, query);

		if (get(responseData, `${propertyNameArray[0]}.${propertyNameArray[1]}.NextToken`)) {
			query['NextToken'] = get(responseData, `${propertyNameArray[0]}.${propertyNameArray[1]}.NextToken`);
		}
		if (get(responseData, propertyName)) {
			if (Array.isArray(get(responseData, propertyName))) {
				returnData.push.apply(returnData, get(responseData, propertyName));
			} else {
				returnData.push(get(responseData, propertyName));
			}
		}
	} while (
		get(responseData, `${propertyNameArray[0]}.${propertyNameArray[1]}.NextToken`) !== undefined
	);

	return returnData;
}