import { Entry, ContensisClient } from '../models';
import { EntryOperations } from './entry-operations';

import {
	AssetUpload,
	IHttpClient, isNodejs, SysAssetFile, UrlBuilder
} from 'contensis-core-api';

import * as FormData from 'form-data';
import * as fs from 'graceful-fs';

export class EntryOperationsForServer extends EntryOperations {
	constructor(protected httpClient: IHttpClient, protected contensisClient: ContensisClient) {
		super(httpClient, contensisClient);
	}

	createAsset(asset: Entry, assetFilePath: string, parentNodePath: string): Promise<Entry> {
		this.ensureIsNode('createAsset');
		if (!asset) {
			throw new Error('A valid asset needs to be specified.');
		}

		if (!assetFilePath) {
			throw new Error('A valid asset file path needs to be specified.');
		}

		if (!parentNodePath) {
			throw new Error('A valid parent node path needs to be specified.');
		}

		if (!asset.sys || !asset.sys.dataFormat) {
			asset.sys = asset.sys || {};
			asset.sys.dataFormat = 'asset';
		}

		let form = new FormData();
		form.append('file', fs.createReadStream(assetFilePath));

		let url = UrlBuilder.create('/api/management/projects/:projectId/assets',
			{})
			.setParams(this.contensisClient.getParams())
			.toUrl();

		return this.contensisClient.ensureBearerToken().then(() => {
			return this.httpClient.request<AssetUpload[]>(url, {
				headers: form.getHeaders(this.contensisClient.getHeaders(null)),
				method: 'POST',
				body: form as any
			})
				.then((assetUploads: AssetUpload[]) => {
					if (!assetUploads || assetUploads.length === 0) {
						throw new Error('The asset file could not be uploaded.');
					}

					let sysAssetFile: SysAssetFile = {
						fileId: assetUploads[0].fileId,
						parentNodePath: parentNodePath
					};
					asset.sysAssetFile = sysAssetFile;

					return this.create(asset);
				});
		});
	}

	updateAsset(asset: Entry, assetFilePath: string): Promise<Entry> {
		this.ensureIsNode('updateAsset');
		if (!asset) {
			throw new Error('A valid asset needs to be specified.');
		}

		if (!assetFilePath) {
			return this.update(asset);
		}

		let form = new FormData();
		form.append('file', fs.createReadStream(assetFilePath));

		let url = UrlBuilder.create('/api/management/projects/:projectId/assets',
			{})
			.setParams(this.contensisClient.getParams())
			.toUrl();

		return this.contensisClient.ensureBearerToken().then(() => {
			return this.httpClient.request<AssetUpload[]>(url, {
				headers: form.getHeaders(this.contensisClient.getHeaders(null)),
				method: 'POST',
				body: form as any
			})
				.then((assetUploads: AssetUpload[]) => {
					if (!assetUploads || assetUploads.length === 0) {
						throw new Error('The asset file could not be uploaded.');
					}

					let sysAssetFile: SysAssetFile = {
						fileId: assetUploads[0].fileId
					};
					asset.sysAssetFile = sysAssetFile;

					return this.update(asset);
				});
		});
	}

	private ensureIsNode(functionName: string): void {
		if (!isNodejs()) {
			throw new Error(`The function IEntryOperations.${functionName} can only be called in a Node.js process.`);
		}
	}
}