import * as fs from 'fs';
import * as path from 'path';
import * as tmp from 'tmp';

import * as subProcess from './sub-process';
import { legacyCommon } from '@snyk/cli-interface';

export function getMetaData(
  command: string,
  baseargs: string[],
  root: string,
  targetFile: string
) {
  return subProcess
    .execute(command, [...baseargs, '--version'], { cwd: root })
    .then((output) => {
      return {
        name: 'snyk-python-plugin',
        runtime: output.replace('\n', ''),
        // specify targetFile only in case of Pipfile or setup.py
        targetFile: path.basename(targetFile).match(/^(Pipfile|setup\.py)$/)
          ? targetFile
          : undefined,
      };
    });
}

// path.join calls have to be exactly in this format, needed by "pkg" to build a standalone Snyk CLI binary:
// https://www.npmjs.com/package/pkg#detecting-assets-in-source-code
function createAssets() {
  return [
    path.join(__dirname, '../../pysrc/pip_resolve.py'),
    path.join(__dirname, '../../pysrc/distPackage.py'),
    path.join(__dirname, '../../pysrc/package.py'),
    path.join(__dirname, '../../pysrc/pipfile.py'),
    path.join(__dirname, '../../pysrc/reqPackage.py'),
    path.join(__dirname, '../../pysrc/setup_file.py'),
    path.join(__dirname, '../../pysrc/utils.py'),

    path.join(__dirname, '../../pysrc/requirements/fragment.py'),
    path.join(__dirname, '../../pysrc/requirements/parser.py'),
    path.join(__dirname, '../../pysrc/requirements/requirement.py'),
    path.join(__dirname, '../../pysrc/requirements/vcs.py'),
    path.join(__dirname, '../../pysrc/requirements/__init__.py'),

    path.join(__dirname, '../../pysrc/pytoml/__init__.py'),
    path.join(__dirname, '../../pysrc/pytoml/core.py'),
    path.join(__dirname, '../../pysrc/pytoml/parser.py'),
    path.join(__dirname, '../../pysrc/pytoml/writer.py'),
  ];
}

function writeFile(writeFilePath: string, contents: string) {
  const dirPath = path.dirname(writeFilePath);
  if (!fs.existsSync(dirPath)) {
    fs.mkdirSync(dirPath);
  }
  fs.writeFileSync(writeFilePath, contents);
}

function getFilePathRelativeToDumpDir(filePath: string) {
  let pathParts = filePath.split('\\pysrc\\');

  // Windows
  if (pathParts.length > 1) {
    return pathParts[1];
  }

  // Unix
  pathParts = filePath.split('/pysrc/');
  return pathParts[1];
}

function dumpAllFilesInTempDir(tempDirName: string) {
  createAssets().forEach((currentReadFilePath) => {
    if (!fs.existsSync(currentReadFilePath)) {
      throw new Error('The file `' + currentReadFilePath + '` is missing');
    }

    const relFilePathToDumpDir = getFilePathRelativeToDumpDir(
      currentReadFilePath
    );

    const writeFilePath = path.join(tempDirName, relFilePathToDumpDir);

    const contents = fs.readFileSync(currentReadFilePath, 'utf8');
    writeFile(writeFilePath, contents);
  });
}

export async function inspectInstalledDeps(
  command: string,
  baseargs: string[],
  root: string,
  targetFile: string,
  allowMissing: boolean,
  includeDevDeps: boolean,
  args?: string[]
): Promise<legacyCommon.DepTree> {
  const tempDirObj = tmp.dirSync({
    unsafeCleanup: true,
  });

  dumpAllFilesInTempDir(tempDirObj.name);
  try {
    // See ../../pysrc/README.md
    const output = await subProcess.execute(
      command,
      [
        ...baseargs,
        ...buildArgs(
          targetFile,
          allowMissing,
          tempDirObj.name,
          includeDevDeps,
          args
        ),
      ],
      { cwd: root }
    );
    return JSON.parse(output) as legacyCommon.DepTree;
  } catch (error) {
    if (typeof error === 'string') {
      if (error.indexOf('Required packages missing') !== -1) {
        let errMsg = error;
        if (path.basename(targetFile) === 'Pipfile') {
          errMsg += '\nPlease run `pipenv update`.';
        } else if (path.basename(targetFile) === 'setup.py') {
          errMsg += '\nPlease run `pip install -e .`.';
        } else {
          errMsg += '\nPlease run `pip install -r ' + targetFile + '`.';
        }
        errMsg += ' If the issue persists try again with --skip-unresolved.';
        throw new Error(errMsg);
      }
    }
    throw error;
  } finally {
    tempDirObj.removeCallback();
  }
}

// Exported for tests only
export function buildArgs(
  targetFile: string,
  allowMissing: boolean,
  tempDirPath: string,
  includeDevDeps: boolean,
  extraArgs?: string[]
) {
  const pathToRun = path.join(tempDirPath, 'pip_resolve.py');
  let args = [pathToRun];
  if (targetFile) {
    args.push(targetFile);
  }
  if (allowMissing) {
    args.push('--allow-missing');
  }
  if (includeDevDeps) {
    args.push('--dev-deps');
  }
  if (extraArgs) {
    args = args.concat(extraArgs);
  }
  return args;
}