const fs = require('fs');
const path = require('path');
const _ = require('lodash');

module.exports = async () => {
  // Check if the plugin users-permissions is installed because the documentation needs it
  if (Object.keys(strapi.plugins).indexOf('users-permissions') === -1) {
    throw new Error(
      'In order to make the documentation plugin works the users-permissions one is required'
    );
  }

  const pluginStore = strapi.store({
    environment: '',
    type: 'plugin',
    name: 'documentation',
  });
  const restrictedAccess = await pluginStore.get({ key: 'config' });

  if (!restrictedAccess) {
    pluginStore.set({ key: 'config', value: { restrictedAccess: false } });
  }

  let shouldUpdateFullDoc = false;
  const services = strapi.plugins['documentation'].services.documentation;
  // Generate plugins' documentation
  const pluginsWithDocumentationNeeded = services.getPluginsWithDocumentationNeeded();
  pluginsWithDocumentationNeeded.forEach(plugin => {
    const isDocExisting = services.checkIfPluginDocumentationFolderExists(
      plugin
    );

    if (!isDocExisting) {
      services.createDocumentationDirectory(
        services.getPluginDocumentationPath(plugin)
      );
      // create the overrides directory
      services.createDocumentationDirectory(
        services.getPluginOverrideDocumentationPath(plugin)
      );
      services.createPluginDocumentationFile(plugin);
      shouldUpdateFullDoc = true;
    } else {
      const needToUpdatePluginDoc = services.checkIfPluginDocNeedsUpdate(
        plugin
      );

      if (needToUpdatePluginDoc) {
        services.createPluginDocumentationFile(plugin);
        shouldUpdateFullDoc = true;
      }
    }
  });

  // Retrieve all the apis from the apis directory
  const apis = services.getApis();
  // Generate APIS' documentation
  apis.forEach(api => {
    const isDocExisting = services.checkIfDocumentationFolderExists(api);

    if (!isDocExisting) {
      // If the documentation directory doesn't exist create it
      services.createDocumentationDirectory(services.getDocumentationPath(api));
      // Create the overrides directory
      services.createDocumentationDirectory(
        services.getDocumentationOverridesPath(api)
      );
      // Create the documentation files per version
      services.createDocumentationFile(api); // Then create the {api}.json documentation file
      shouldUpdateFullDoc = true;
    } else {
      const needToUpdateAPIDoc = services.checkIfAPIDocNeedsUpdate(api);

      if (needToUpdateAPIDoc) {
        services.createDocumentationFile(api);
        shouldUpdateFullDoc = true;
      }
    }
  });

  const fullDoc = services.generateFullDoc();
  // Verify that the correct documentation folder exists in the documentation plugin
  const isMergedDocumentationExists = services.checkIfMergedDocumentationFolderExists();
  const documentationPath = services.getMergedDocumentationPath();

  if (isMergedDocumentationExists) {
    /**
     * Retrieve all tags from the documentation and join them
     * @param {Object} documentation
     * @returns {String}
     */
    const getDocTagsToString = documentation => {
      const defaultGeneratedTags = [
        'email',
        'upload - file',
        'users-permissions - role',
        'authentication',
        'users-permissions - user',
      ];

      return _.get(documentation, 'tags', [])
        .map(tag => {
          return tag.name.toLowerCase();
        })
        .filter(tag => defaultGeneratedTags.indexOf(tag) === -1)
        .sort((a, b) => a - b)
        .join('.');
    };
    const oldDoc = require(path.resolve(
      documentationPath,
      'full_documentation.json'
    ));
    const oldDocTags = getDocTagsToString(oldDoc);
    const currentDocTags = getDocTagsToString(fullDoc);

    // If the tags are different (an api has been deleted) we need to rebuild the documentation
    if (oldDocTags !== currentDocTags) {
      shouldUpdateFullDoc = true;
    }
  }

  if (!isMergedDocumentationExists || shouldUpdateFullDoc) {
    // Create the folder
    services.createDocumentationDirectory(documentationPath);
    // Write the file
    fs.writeFileSync(
      path.resolve(documentationPath, 'full_documentation.json'),
      JSON.stringify(fullDoc, null, 2),
      'utf8'
    );
  }
};