import * as core from '@actions/core';
import * as finder from './find-python';
import * as finderPyPy from './find-pypy';
import * as path from 'path';
import * as os from 'os';
import fs from 'fs';
import {getCacheDistributor} from './cache-distributions/cache-factory';
import {
  isCacheFeatureAvailable,
  logWarning,
  IS_MAC
} from './utils';

function isPyPyVersion(versionSpec: string) {
  return versionSpec.startsWith('pypy');
}

async function cacheDependencies(cache: string, pythonVersion: string) {
  const cacheDependencyPath =
    core.getInput('cache-dependency-path') || undefined;
  const cacheDistributor = getCacheDistributor(
    cache,
    pythonVersion,
    cacheDependencyPath
  );
  await cacheDistributor.restoreCache();
}

function resolveVersionInput(): string {
  let version = core.getInput('python-version');
  let versionFile = core.getInput('python-version-file');

  if (version && versionFile) {
    core.warning(
      'Both python-version and python-version-file inputs are specified, only python-version will be used.'
    );
  }

  if (version) {
    return version;
  }

  if (versionFile) {
    if (!fs.existsSync(versionFile)) {
      throw new Error(
        `The specified python version file at: ${versionFile} doesn't exist.`
      );
    }
    version = fs.readFileSync(versionFile, 'utf8');
    core.info(`Resolved ${versionFile} as ${version}`);
    return version;
  }

  logWarning(
    "Neither 'python-version' nor 'python-version-file' inputs were supplied. Attempting to find '.python-version' file."
  );
  versionFile = '.python-version';
  if (fs.existsSync(versionFile)) {
    version = fs.readFileSync(versionFile, 'utf8');
    core.info(`Resolved ${versionFile} as ${version}`);
    return version;
  }

  logWarning(`${versionFile} doesn't exist.`);

  return version;
}

async function run() {
  // When setting AGENT_TOOLSDIRECTORY, the actions/tool-cache function find
  // is not able to find the files cached by actions/python-version.
  if (process.env.AGENT_TOOLSDIRECTORY?.trim()) {
    process.env['RUNNER_TOOL_CACHE'] = process.env['AGENT_TOOLSDIRECTORY'];
  }
  core.debug(
    `Python is expected to be installed into RUNNER_TOOL_CACHE=${process.env['RUNNER_TOOL_CACHE']}`
  );
  try {
    const version = resolveVersionInput();
    const checkLatest = core.getBooleanInput('check-latest');

    if (version) {
      let pythonVersion: string;
      const arch: string = core.getInput('architecture') || os.arch();
      const updateEnvironment = core.getBooleanInput('update-environment');
      if (isPyPyVersion(version)) {
        const installed = await finderPyPy.findPyPyVersion(
          version,
          arch,
          updateEnvironment,
          checkLatest
        );
        pythonVersion = `${installed.resolvedPyPyVersion}-${installed.resolvedPythonVersion}`;
        core.info(
          `Successfully set up PyPy ${installed.resolvedPyPyVersion} with Python (${installed.resolvedPythonVersion})`
        );
      } else {
        const installed = await finder.useCpythonVersion(
          version,
          arch,
          updateEnvironment,
          checkLatest
        );
        pythonVersion = installed.version;
        core.info(`Successfully set up ${installed.impl} (${pythonVersion})`);
      }

      const cache = core.getInput('cache');
      if (cache && isCacheFeatureAvailable()) {
        await cacheDependencies(cache, pythonVersion);
      }
    } else {
      core.warning(
        'The `python-version` input is not set.  The version of Python currently in `PATH` will be used.'
      );
    }
    const matchersPath = path.join(__dirname, '../..', '.github');
    core.info(`##[add-matcher]${path.join(matchersPath, 'python.json')}`);
  } catch (err) {
    core.setFailed((err as Error).message);
  }
}

run();