using Disco.Data.Repository;
using Disco.Models.Repository;
using Disco.Models.Services.Devices.Importing;
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;

namespace Disco.Services.Devices.Importing.Fields
{
    internal class DeviceLocationImportField : DeviceImportFieldBase
    {
        private string parsedValue;
        private string previousValue;

        public override DeviceImportFieldTypes FieldType { get { return DeviceImportFieldTypes.DeviceLocation; } }

        public override object RawParsedValue { get { return parsedValue; } }
        public override string FriendlyValue { get { return parsedValue; } }
        public override string FriendlyPreviousValue { get { return previousValue; } }

        public override bool Parse(DiscoDataContext Database, IDeviceImportCache Cache, IDeviceImportContext Context, string DeviceSerialNumber, Device ExistingDevice, List<IDeviceImportRecord> PreviousRecords, IDeviceImportDataReader DataReader, int ColumnIndex)
        {
            var value = DataReader.GetString(ColumnIndex);

            if (string.IsNullOrWhiteSpace(value))
                parsedValue = null;
            else
            {
                parsedValue = value.Trim();
                if (parsedValue.Length > 250)
                    return Error("Cannot be more than 250 characters");
            }

            if (ExistingDevice == null && parsedValue != null)
                return Success(EntityState.Added);
            else if (ExistingDevice != null && ExistingDevice.Location != parsedValue)
            {
                previousValue = ExistingDevice.Location;
                return Success(EntityState.Modified);
            }
            else
                return Success(EntityState.Unchanged);
        }

        public override bool Apply(DiscoDataContext Database, Device Device)
        {
            if (FieldAction == EntityState.Added ||
                FieldAction == EntityState.Modified)
            {
                Device.Location = parsedValue;
                return true;
            }
            else
            {
                return false;
            }
        }

        public override int? GuessColumn(DiscoDataContext Database, IDeviceImportContext Context, IDeviceImportDataReader DataReader)
        {
            // column name
            var possibleColumns = Context.Columns
                .Where(h => h.Type == DeviceImportFieldTypes.IgnoreColumn &&
                    h.Name.IndexOf("location", StringComparison.OrdinalIgnoreCase) >= 0);

            return possibleColumns.Select(h => (int?)h.Index).FirstOrDefault();
        }
    }
}
