using DiskAccessLibrary;
using DiskAccessLibrary.Mod;
using ISCSIConsole.Mods;
using System;
using System.Windows.Forms;

namespace ISCSIConsole
{
    public partial class CreateRAMDiskForm : BaseForm
    {
        public CreateRAMDiskForm()
        {
            InitializeComponent();
        }

        private void btnCancel_Click(object sender, EventArgs e)
        {
            DialogResult = DialogResult.Cancel;
            Close();
        }

        private void BaseOnCheckBox_CheckedChanged(object sender, EventArgs e)
        {
            ImageFileTextBox.Enabled = BaseOnCheckBox.Checked;
        }

        private void ImageFileButton_Click(object sender, EventArgs e)
        {
            if (false == BaseOnCheckBox.Checked) BaseOnCheckBox.Checked = true;

            var result = openDiskImageDialog.ShowDialog();
            if (result == DialogResult.OK)
            {
                ImageFileTextBox.Text = openDiskImageDialog.FileName;
                DiskInfiValueLabel.Text = DiskImage.GetDiskImageInfo(ImageFileTextBox.Text);
            }
        }

        private void btnOK_Click(object sender, EventArgs e)
        {
            BlockDifferencingDiskImage bdd = null;
            if (BaseOnCheckBox.Checked) // check size
            {
                if (string.IsNullOrWhiteSpace(ImageFileTextBox.Text))
                {
                    MessageBox.Show("Please choose file location.", "Error");
                    return;
                }

                bdd = new BlockDifferencingDiskImage(ImageFileTextBox.Text, true);

                if (false == bdd.IsNoBaseImage)
                {
                    MessageBox.Show("Only ** No Base Image Mode ** supported");
                    return;
                }

                long diskSize;
                if (MbRadioButton.Checked)
                {
                    diskSize = (int)numericDiskSize.Value * Consts.MegaByte;
                }
                else if (GbRadioButton.Checked)
                {
                    diskSize = (long)numericDiskSize.Value * Consts.Gigabyte;
                }
                else
                {
                    MessageBox.Show("What chosen?");
                    return;
                }

                if (diskSize < bdd.Size)
                {
                    MessageBox.Show("Ram disk size too small to load file");
                    return;
                }
            }

            ILoadableRamDisk loadableRamDisk;

            if (MbRadioButton.Checked)
            {
                var size = (int)numericDiskSize.Value * Consts.MegaByte;
                RAMDisk disk;
                try
                {
                    disk = new RAMDisk(size);
                }
                catch (OutOfMemoryException)
                {
                    MessageBox.Show("Not enough memory available", "Error");
                    return;
                }
                RAMDisk = disk;
                loadableRamDisk = disk;
            }
            else if (GbRadioButton.Checked)
            {
                var size = (int)numericDiskSize.Value;
                var disk = new UnmanagedGigabyteBlockSeparatedRamDisk(size); ;
                try
                {
                    disk.Allocate();
                }
                catch (OutOfMemoryException)
                {
                    disk.Free();
                    MessageBox.Show("Not enough memory available", "Error");
                    return;
                }
                RAMDisk = disk;
                loadableRamDisk = disk;
            }
            else
            {
                MessageBox.Show("What chosen?");
                return;
            }

            if (null != bdd) //Load in to ram disk
            {
                bdd.OpenForRead();
                var buffer = new byte[bdd.BlockSize];
                for (var i = 0; i < bdd.NumberOfBlocks; i++)
                {
                    if (false == bdd.IsBlockAllocated[i]) continue;

                    bdd.ReadBlock(buffer, 0, buffer.Length, i, 0);

                    loadableRamDisk.WriteData((long)i * bdd.BlockSize, buffer);
                }

                bdd.CloseForRead();
            }

            DialogResult = DialogResult.OK;
            Close();
        }

        public Disk RAMDisk { get; private set; }
    }
}