import { inject, injectable } from 'inversify';

import '../common/extensions';

import { IProcessServiceFactory } from '../common/process/types';

import { IInterpreterVersionService } from './contracts';

export const PIP_VERSION_REGEX = '\\d+\\.\\d+(\\.\\d+)?';

@injectable()

export class InterpreterVersionService implements IInterpreterVersionService {

constructor(@inject(IProcessServiceFactory) private readonly processServiceFactory: IProcessServiceFactory) { }

public async getVersion(pythonPath: string, defaultValue: string): Promise<string> {

const processService = await this.processServiceFactory.create();

return processService.exec(pythonPath, ['--version'], { mergeStdOutErr: true })

.then(output => output.stdout.splitLines()[0])

.then(version => version.length === 0 ? defaultValue : version)

.catch(() => defaultValue);

}

public async getPipVersion(pythonPath: string): Promise<string> {

const processService = await this.processServiceFactory.create();

const output = await processService.exec(pythonPath, ['-m', 'pip', '--version'], { mergeStdOutErr: true });

if (output.stdout.length > 0) {

// Here's a sample output:

// pip 9.0.1 from /Users/donjayamanne/anaconda3/lib/python3.6/site-packages (python 3.6).

const re = new RegExp(PIP_VERSION_REGEX, 'g');

const matches = re.exec(output.stdout);

if (matches && matches.length > 0) {

return matches[0].trim();

}

}

throw new Error(`Unable to determine pip version from output '${output.stdout}'`);

}

}