'use strict';

let Path = require('path');

function try_load(path) {
  try {
    return require(path);
  } catch(err) {
    if (err.code === 'MODULE_NOT_FOUND') {
      return null;
    }
    throw err;
  }
}

function load_plugins(config, plugin_configs, params, sanity_check) {
  let plugins = Object.keys(plugin_configs || {}).map(function(p) {
    let plugin;

    // try local plugins first
    plugin = try_load(Path.resolve(__dirname + '/plugins', p));

    // npm package
    if (plugin === null && p.match(/^[^\.\/]/)) {
      plugin = try_load(`verdaccio-${p}`);
      // compatibility for old sinopia plugins
      if (!plugin) {
        plugin = try_load(`sinopia-${p}`);
      }
    }

    if (plugin === null) {
      plugin = try_load(p);
    }

    // relative to config path
    if (plugin === null && p.match(/^\.\.?($|\/)/)) {
      plugin = try_load(Path.resolve(Path.dirname(config.self_path), p));
    }

    if (plugin === null) {
      throw Error('"' + p + '" plugin not found\ntry "npm install verdaccio-' + p + '"');
    }

    if (typeof(plugin) !== 'function')
      throw Error('"' + p + '" doesn\'t look like a valid plugin');

    plugin = plugin(plugin_configs[p], params);

    if (plugin === null || !sanity_check(plugin))
      throw Error('"' + p + '" doesn\'t look like a valid plugin');

    return plugin;
  });

  return plugins;
}

exports.load_plugins = load_plugins;