// Copyright 2017 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import * as shimmer from 'shimmer';

const SUPPORTED_VERSIONS = '^1.0.0';

function createCreateQueryWrap(api) {
  return function createQueryWrap(createQuery) {
    // eslint-disable-next-line @typescript-eslint/no-unused-vars
    return function createQuery_trace(sql, values, cb, config) {
      const span = api.createChildSpan({
        name: 'mysql-query',
      });
      // eslint-disable-next-line prefer-rest-params
      const query = createQuery.apply(this, arguments);
      if (!api.isRealSpan(span)) {
        return query;
      }
      if (api.enhancedDatabaseReportingEnabled()) {
        span.addLabel('sql', query.sql);
        if (query.values) {
          span.addLabel('values', query.values);
        }
      }
      api.wrapEmitter(query);
      if (query.onResult) {
        query.onResult = wrapCallback(api, span, query.onResult);
      } else {
        query.on('end', () => {
          span.endSpan();
        });
      }
      return query;
    };
  };
}

function wrapCallback(api, span, done) {
  const fn = function (err, res) {
    if (api.enhancedDatabaseReportingEnabled()) {
      if (err) {
        span.addLabel('error', err);
      }
      if (res) {
        span.addLabel('result', res);
      }
    }
    span.endSpan();
    if (done) {
      done(err, res);
    }
  };
  return api.wrap(fn);
}

function createWrapGetConnection(api) {
  return function wrapGetConnection(getConnection) {
    return function getConnection_trace(cb) {
      return getConnection.call(this, api.wrap(cb));
    };
  };
}

module.exports = [
  {
    file: 'lib/connection.js',
    versions: SUPPORTED_VERSIONS,
    patch: function (Connection, api) {
      shimmer.wrap(Connection, 'createQuery', createCreateQueryWrap(api));
    },
    unpatch: function (Connection) {
      shimmer.unwrap(Connection, 'createQuery');
    },
  },
  {
    file: 'index.js',
    versions: SUPPORTED_VERSIONS,
    patch: function (mysql2, api) {
      shimmer.wrap(
        mysql2.Pool.prototype,
        'getConnection',
        createWrapGetConnection(api)
      );
    },
    unpatch: function (mysql2) {
      shimmer.unwrap(mysql2.Pool.prototype, 'getConnection');
    },
  },
];

export default {};