using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;
using MySql.Data.MySqlClient;

namespace Framework.Server {
    public static class MySql {

        private static MySqlConnection _connection;

        public static void Initialize(string connectionString) {
            _connection = new MySqlConnection(connectionString);
        }

        public static async Task Execute(string query) {
            await _connection.OpenAsync();
            var cmd = new MySqlCommand(query, _connection);
            await cmd.ExecuteNonQueryAsync();
            await _connection.CloseAsync();
        }

        public static async Task<List<T>> FetchAll<T>(string query) where T : new() {
            await _connection.OpenAsync();
            var cmd = new MySqlCommand(query, _connection);
            var result = await cmd.ExecuteReaderAsync();
            
            var data = new List<T>();
            var columns = new Dictionary<string, int>();
            var props = typeof(T).GetProperties();
            
            for (int i = 0; i < result.FieldCount; i++)
                columns.Add(result.GetName(i), i);

            while (await result.ReadAsync()) {
                var obj = new T();

                for (int i = 0; i < result.FieldCount; i++) {
                    foreach (var property in props) {
                        if (columns.ContainsKey(property.Name)) {
                            property.SetValue(obj, ApplyValueConversion(result[columns[property.Name]], property));
                        }
                    }
                }
                
                data.Add(obj);
            }

            await _connection.CloseAsync();

            return data;
        }

        public static async Task<T> FetchOne<T>(string query) where T : new() {
            var result = await FetchAll<T>(query);
            return result[0];
        }

        public static async void CreateTables(params string[] querys) {
            var query = string.Join(";", querys);
            await Execute(query);
        }

        private static object ApplyValueConversion(object value, PropertyInfo property) {
            if (property.PropertyType == typeof(float[])) {
                var raw = (value as string ?? "[0, 0, 0]")
                    .Replace("[", "")
                    .Replace("]", "")
                    .Replace(" ", "");

                var values = raw
                    .Split(',')
                    .Select(Convert.ToSingle)
                    .ToArray();

                return values;
            }

            if (property.PropertyType == typeof(uint)) {
                return Convert.ToUInt32(value);
            }

            return value;
        }

    }
}