karaoke-song-requests.js

module['exports'] = function karaokeSongRequests (hook) {
  var jwt = require('jsonwebtoken'),
      clientId = hook.env.ksr_client,
      secret = require('base64url').toBuffer(hook.env.ksr_secret),
      token = hook.req.headers.authorization && hook.req.headers.authorization.replace(/^Bearer\s+/, ''),
      store = hook.datastore,
      action = hook.params.action || 'get',
      user = {},
      errorRes = function (res, msg, code) {
        res.statusCode = code || 500;
        res.end(msg);
      },
      jsonRes = function (res, data) {
        res.setHeader('Content-Type', 'application/json');
        res.end(JSON.stringify(data || {success: true}));
      },
      needArrayPayload = function (payload) {
        return !payload || !Array.isArray(payload);
      },
      needRequestPayload = function (payload) {
        return !payload || !payload.email || !payload.key || !payload.title || !payload.artist;
      },
      mapFromPayload = function (delegate) {
        return function (input, payload) {
          var rMap = new Map(input);
          payload.forEach(function (pl) { delegate.call(null, rMap, pl); });
          var result = [];
          rMap.forEach(function (v, k) {
            result.push([k, v]);
          });
          return result;
        };
      },
      adminAction = function (thunk, arg1, arg2) {
        return function (res, payload, store, user) {
          if (!user.authenticated) { return errorRes(res, 'Action requires authentication', 401); }
          if (!user.admin) { return errorRes(res, 'Action requires admin access.', 403); }
          return thunk(arg1, arg2, res, payload, store);
        };
      },
      getSetAction = function (transform, isPayloadInvalid, res, payload, store, boomerang) {
        if (isPayloadInvalid && isPayloadInvalid(payload)) { return errorRes('Invalid payload provided.', 400); }
        store.get(store.KEY, function (err, result) {
          if (err) { return errorRes(res, err.message); }
          result = result || [];
          result = transform(result, payload);
          store.set(store.KEY, result, function (err) {
            if (err) { return errorRes(res, err.message); }
            return jsonRes(res, boomerang ? payload : void 0);
          });
        });
      },
      actions = {
        archive: adminAction(getSetAction, function (input) {
          return input.filter(function (r) {
            return !r[1].completed;
          });
        }),
        remove: adminAction(getSetAction, mapFromPayload(function (rMap, payloadItem) {
          rMap.delete(payloadItem);
        }), needArrayPayload),
        fulfill: adminAction(getSetAction, mapFromPayload(function (rMap, payloadItem) {
          rMap.get(payloadItem).completed = (new Date).toJSON();
        }), needArrayPayload),
        purge: adminAction(function (x, y, res, p, store) {
          store.del(store.KEY, function (err) {
            if (err) { return errorRes(res, err.message); }
            jsonRes(res);
          });
        }),
        add: function (res, payload, store) {
          return getSetAction(function (input) {
            input.push([payload.key, payload]);
            return input;
          }, needRequestPayload, res, payload, store, true);
        },
        get: function (res, payload, store, user) {
          store.get(store.KEY, function(err, result) {
            if (err) { return errorRes(res, err.message); }
            result = result || [];
            var pending = [], complete = [];
            
            result.forEach(function (v) {
              if (!user.admin) {
                delete v[1].name;
                delete v[1].email;
              }
              if (!v[1].completed) {
                pending.push(v);
              } else if (user.admin) {
                complete.push(v);
              }
            });
            
            return jsonRes(res, {list: pending, fulfilled: complete});
          });
        }
      };
  // Check token
  if (token) {
    try {
      user = jwt.verify(token, secret, {audience: clientId});
      user.authenticated = true;
    } catch (e) {
      errorRes(hook.res, 'Invalid user token', 401);
      return;
    }
  }
  // Perform action
  store.KEY = 'karaoke-requests';
  if (action in actions) {
    return actions[action](hook.res, hook.params.payload, store, user);
  }
  return errorRes(hook.res, 'Unknown action: ' + action, 400);
};