using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Windows.Data;
using DataGridDemo1.Providers;
using DataGridDemo1.Models;

namespace DataGridDemo1.ViewModels
{
    public class MainViewModel : INotifyPropertyChanged
    {
        private string searchKey;
        private PagedCollectionView employees;

        /// <summary>
        /// Gets or sets the employees.
        /// </summary>
        /// <value>The employees.</value>
        public PagedCollectionView Employees
        {
            get { return employees; }
            set
            {
                employees = value;
                OnPropertyChanged("Employees");
            }
        }

        public MainViewModel()
        {
            // Fetch the Employee Details from provider and set to Employees collection
            Employees = new PagedCollectionView(EmployeeProviders.GetEmployeeDetails());
        }

        /// <summary>
        /// Groups the name of the data by column.
        /// </summary>
        /// <param name="groupName">Name of the group.</param>
        public void GroupDataByColumnName(string groupName)
        {
            //Employees.GroupDescriptions.Clear();
            Employees.GroupDescriptions.Add(new PropertyGroupDescription(groupName));
        }

        /// <summary>
        /// Filters the data by search key.
        /// </summary>
        /// <param name="searchKey">The search key.</param>
        public void FilterDataBySearchKey(string searchKey)
        {
            this.searchKey = searchKey;
            Employees.Filter = null;
            Employees.Filter=new Predicate<object>(FilterRecords);
        }

        /// <summary>
        /// Filters the records.
        /// </summary>
        /// <param name="obj">The obj.</param>
        /// <returns></returns>
        private bool FilterRecords(object obj)
        {
            var employee = obj as Employee;

            return employee != null &&
                   (employee.Firstname.ToLower().IndexOf(searchKey) >= 0 ||
                    employee.Lastname.ToLower().IndexOf(searchKey) >= 0 ||
                    employee.City.ToLower().IndexOf(searchKey) >= 0 ||
                    employee.State.ToLower().IndexOf(searchKey) >= 0);
        }

        public event PropertyChangedEventHandler PropertyChanged;
        public void OnPropertyChanged(string propertyName)
        {
            var handler = PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }
}