/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

namespace Apache.Ignite.Benchmarks
{
    using System;
    using System.Linq;
    using System.Reflection;
    using System.Text;
    using System.Threading;
    using Apache.Ignite.Benchmarks.Model;

    /// <summary>
    /// Utility methods for benchmarks.
    /// </summary>
    internal static class BenchmarkUtils
    {
        /** Property binding flags. */
        private static readonly BindingFlags PropFlags = BindingFlags.Instance | BindingFlags.Public;

        /** Thread-local random. */
        private static readonly ThreadLocal<Random> Rand;

        /** Cached ANSI chcracters. */
        private static readonly char[] Chars;

        /** Seed to randoms. */
        private static int _seedCtr;

        /// <summary>
        /// Static initializer.
        /// </summary>
        static BenchmarkUtils()
        {
            Rand = new ThreadLocal<Random>(() =>
            {
                var seed = Interlocked.Add(ref _seedCtr, 100);

                return new Random(seed);
            });

            Chars = new char[10 + 26 + 26];

            var pos = 0;

            for (var i = '0'; i < '0' + 10; i++)
                Chars[pos++] = i;

            for (var i = 'A'; i < 'A' + 26; i++)
                Chars[pos++] = i;

            for (var i = 'a'; i < 'a' + 26; i++)
                Chars[pos++] = i;
        }

        /// <summary>
        /// Generate random integer.
        /// </summary>
        /// <param name="max">Maximum value (exclusive).</param>
        /// <returns></returns>
        public static int GetRandomInt(int max)
        {
            return GetRandomInt(0, max);
        }

        /// <summary>
        /// Generate random integer.
        /// </summary>
        /// <param name="min">Minimum value (inclusive).</param>
        /// <param name="max">Maximum value (exclusive).</param>
        /// <returns></returns>
        public static int GetRandomInt(int min, int max)
        {
            return Rand.Value.Next(min, max);
        }

        /// <summary>
        /// Generate random string.
        /// </summary>
        /// <param name="len">Length.</param>
        /// <returns>String.</returns>
        public static string GetRandomString(int len)
        {
            var rand = Rand.Value;

            var sb = new StringBuilder();

            for (var i = 0; i < len; i++)
                sb.Append(Chars[rand.Next(Chars.Length)]);

            return sb.ToString();
        }

        /// <summary>
        /// Generate random address.
        /// </summary>
        /// <returns>Address.</returns>
        public static Address GetRandomAddress()
        {
            return new Address(
                GetRandomString(15),
                GetRandomString(20),
                GetRandomInt(1, 500),
                GetRandomInt(1, 35)
            );
        }

        /// <summary>
        /// Generate random company.
        /// </summary>
        /// <returns>Company.</returns>
        public static Company GetRandomCompany()
        {
            return new Company(
                GetRandomInt(0, 100),
                GetRandomString(20),
                GetRandomInt(100, 3000),
                GetRandomAddress(),
                GetRandomString(20)
            );
        }

        /// <summary>
        /// Generate random employee.
        /// </summary>
        /// <param name="payload">Payload size.</param>
        /// <returns>Employee.</returns>
        public static Employee GetRandomEmployee(int payload)
        {
            return new Employee(
                GetRandomInt(0, 1000),
                GetRandomString(15),
                GetRandomInt(0, 1000),
                GetRandomInt(18, 60),
                (Sex)GetRandomInt(0, 1),
                GetRandomInt(10000, 30000),
                GetRandomAddress(),
                (Department)GetRandomInt(0, 5),
                payload
            );
        }

        /// <summary>
        /// List all properties present in the given object.
        /// </summary>
        /// <param name="obj">Object.</param>
        /// <returns>Properties.</returns>
        public static PropertyInfo[] GetProperties(object obj)
        {
            return obj.GetType().GetProperties(PropFlags);
        }

        /// <summary>
        /// Find property with the given name in the object.
        /// </summary>
        /// <param name="obj">Object.</param>
        /// <param name="name">Name.</param>
        /// <returns>Property.</returns>
        public static PropertyInfo GetProperty(object obj, string name)
        {
            return GetProperties(obj)
                .FirstOrDefault(prop => prop.Name.Equals(name, StringComparison.OrdinalIgnoreCase));
        }

        /// <summary>
        /// Set property on the given object.
        /// </summary>
        /// <param name="obj">Object.</param>
        /// <param name="prop">Property.</param>
        /// <param name="val">Value.</param>
        public static void SetProperty(object obj, PropertyInfo prop, string val)
        {
            object val0;

            var propType = prop.PropertyType;

            if (propType == typeof(int))
            {
                try
                {
                    val0 = int.Parse(val);
                }
                catch (Exception e)
                {
                    throw new Exception("Failed to parse property value [property=" + prop.Name +
                        ", value=" + val + ']', e);
                }
            }
            else if (propType == typeof(long))
            {
                try
                {
                    val0 = long.Parse(val);
                }
                catch (Exception e)
                {
                    throw new Exception("Failed to parse property value [property=" + prop.Name +
                        ", value=" + val + ']', e);
                }
            }
            else if (propType == typeof(bool))
            {
                try
                {
                    val0 = bool.Parse(val);
                }
                catch (Exception e)
                {
                    throw new Exception("Failed to parse property value [property=" + prop.Name +
                        ", value=" + val + ']', e);
                }
            }
            else if (propType == typeof(string))
                val0 = val;                            
            else
                throw new Exception("Unsupported property type [property=" + prop.Name +
                    ", type=" + propType.Name + ']');

            prop.SetValue(obj, val0, null);
        }
    }
}