const {
  SUBSCRIBE_COMMENT_ACCEPTED,
  SUBSCRIBE_COMMENT_REJECTED,
  SUBSCRIBE_COMMENT_FLAGGED,
  SUBSCRIBE_ALL_COMMENT_EDITED,
  SUBSCRIBE_ALL_COMMENT_ADDED,
  SUBSCRIBE_ALL_USER_SUSPENDED,
  SUBSCRIBE_ALL_USER_BANNED,
  SUBSCRIBE_ALL_USERNAME_REJECTED,
  SUBSCRIBE_ALL_USERNAME_APPROVED,
} = require('../perms/constants');

const merge = require('lodash/merge');
const debug = require('debug')('talk:graph:setupFunctions');
const plugins = require('../services/plugins');

const setupFunctions = {
  commentAdded: (options, args, comment, context) => {

    // Only privileged users can subscribe to all assets.
    if (!args.asset_id && (!context.user || !context.user.can(SUBSCRIBE_ALL_COMMENT_ADDED))) {
      return false;
    }

    // If user subscribes for statuses other than NONE and/or ACCEPTED statuses, it needs
    // special privileges.
    if (
      (!args.statuses || args.statuses.some((status) => !['NONE', 'ACCEPTED'].includes(status))) &&
          (!context.user || !context.user.can(SUBSCRIBE_ALL_COMMENT_ADDED))
    ) {
      return false;
    }

    if (args.asset_id && comment.asset_id !== args.asset_id) {
      return false;
    }

    if (args.statuses && !args.statuses.includes(comment.status)) {
      return false;
    }

    return true;
  },
  commentEdited: (options, args, comment, context) => {
    if (!args.asset_id && (!context.user || !context.user.can(SUBSCRIBE_ALL_COMMENT_EDITED))) {
      return false;
    }
    return !args.asset_id || comment.asset_id === args.asset_id;
  },
  commentFlagged: (options, args, comment, context) => {
    if (!context.user || !context.user.can(SUBSCRIBE_COMMENT_FLAGGED)) {
      return false;
    }
    return !args.asset_id || comment.asset_id === args.asset_id;
  },
  commentAccepted: (options, args, comment, context) => {
    if (!context.user || !context.user.can(SUBSCRIBE_COMMENT_ACCEPTED)) {
      return false;
    }
    return !args.asset_id || comment.asset_id === args.asset_id;
  },
  commentRejected: (options, args) =>  (comment, context) => {
    if (!context.user || !context.user.can(SUBSCRIBE_COMMENT_REJECTED)) {
      return false;
    }
    return !args.asset_id || comment.asset_id === args.asset_id;
  },
  userSuspended: (options, args, user, context) => {
    if (
      !context.user
          || args.user_id !== user.id && !context.user.can(SUBSCRIBE_ALL_USER_SUSPENDED)
    ) {
      return false;
    }
    return !args.user_id || user.id === args.user_id;
  },
  userBanned: (options, args, user, context) => {
    if (
      !context.user
          || args.user_id !== user.id && !context.user.can(SUBSCRIBE_ALL_USER_BANNED)
    ) {
      return false;
    }
    return !args.user_id || user.id === args.user_id;
  },
  usernameRejected: (options, args, user, context) => {
    if (
      !context.user
          || args.user_id !== user.id && !context.user.can(SUBSCRIBE_ALL_USERNAME_REJECTED)
    ) {
      return false;
    }
    return !args.user_id || user.id === args.user_id;
  },
  usernameApproved: (options, args, user, context) => {
    if (
      !context.user
          || args.user_id !== user.id && !context.user.can(SUBSCRIBE_ALL_USERNAME_APPROVED)
    ) {
      return false;
    }
    return !args.user_id || user.id === args.user_id;
  },
};

/**
 * Plugin support requires that we merge in existing setupFunctions with our new
 * plugin based ones. This allows plugins to extend existing setupFunctions as
 * well as provide new ones. We'll remap our internal representation of the
 * setupFunctions into the format needed by Apollo.
 */
module.exports = plugins.get('server', 'setupFunctions').reduce((acc, {plugin, setupFunctions}) => {
  debug(`added plugin '${plugin.name}'`);

  return merge(acc, setupFunctions);
}, Object.keys(setupFunctions).map((key) => {
  const filter = setupFunctions[key];

  return {
    [key]: (options, args) => ({
      [key]: {
        filter: (user, ctx) => filter(options, args, user, ctx)
      }
    })
  };
})
  .reduce((setupFunction, setupFunctions) => {
    return merge(setupFunctions, setupFunction);
  }, {}));