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 * with or without modification, are permitted provided 
 * that the following conditions are met: 
 * 
 * *   Redistributions of source code must retain the above 
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 *     following disclaimer. 
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 *     copyright notice, this list of conditions and the 
 *     following disclaimer in the documentation and/or other 
 *     materials provided with the distribution. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
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 */

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using XenAPI;


namespace XenAdmin.Actions
{
    public class GetDiskSpaceRequirementsAction : PureAsyncAction
    {
        private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

        private readonly string updateName;
        private readonly long updateSize;
        private readonly Pool_patch currentPatch;

        public DiskSpaceRequirements DiskSpaceRequirements { get; private set; }

        /// <summary>
        /// This constructor is used to calculate the disk space requirements for installing or uploading a single patch
        /// </summary>
        public GetDiskSpaceRequirementsAction(Host host, Pool_patch patch, bool suppressHistory)
            : this(host, patch.Name, patch.size, suppressHistory)
        {
            currentPatch = patch;
        }

        /// <summary>
        /// This constructor is used to calculate the disk space requirements for uploading a single update file
        /// </summary>
        public GetDiskSpaceRequirementsAction(Host host, string path, bool suppressHistory)
            : this(host, FileName(path), FileSize(path), suppressHistory)
        { }

        /// <summary>
        /// This constructor is used to check disk space for installing or uploading an update of given size
        /// </summary>
        public GetDiskSpaceRequirementsAction(Host host, string updateName, long size, bool suppressHistory)
            : base(host.Connection, Messages.ACTION_GET_DISK_SPACE_REQUIREMENTS_TITLE, suppressHistory)
        {
            if (host == null)
                throw new ArgumentNullException("host");
            Host = host;
            this.updateName = updateName;
            updateSize = size; 
        }

        private static long FileSize(string path)
        {
            FileInfo fileInfo = new FileInfo(path);
            return fileInfo.Length;
        }

        private static string FileName(string path)
        {
            FileInfo fileInfo = new FileInfo(path);
            return fileInfo.Name;
        }

        protected override void Run()
        {
            Description = String.Format(Messages.ACTION_GET_DISK_SPACE_REQUIREMENTS_DESCRIPTION, Host.Name);

            string result;

            // get required disk space
            long requiredDiskSpace = updateSize;
            try
            {
                var args = new Dictionary<string, string>();
                args.Add("size", updateSize.ToString());

                result = Host.call_plugin(Session, Host.opaque_ref, "disk-space", "get_required_space", args);
                requiredDiskSpace = Convert.ToInt64(result);
            }
            catch (Failure failure)
            {
                log.WarnFormat("Plugin call disk-space.get_required_space on {0} failed with {1}", Host.Name, failure.Message);
                requiredDiskSpace = 0;
            }

            // get available disk space
            long availableDiskSpace = 0;
            try
            {
                result = Host.call_plugin(Session, Host.opaque_ref, "disk-space", "get_avail_host_disk_space", new Dictionary<string, string>());
                availableDiskSpace = Convert.ToInt64(result);
            }
            catch (Failure failure)
            {
                log.WarnFormat("Plugin call disk-space.get_avail_host_disk_space on {0} failed with {1}", Host.Name, failure.Message);
            }

            // get reclaimable disk space (excluding current patch)
            long reclaimableDiskSpace = 0;
            try
            {
                var args = new Dictionary<string, string>();
                if (currentPatch != null)
                    args.Add("exclude", currentPatch.uuid);
                 result = Host.call_plugin(Session, Host.opaque_ref, "disk-space", "get_reclaimable_disk_space", args);
                 reclaimableDiskSpace = Convert.ToInt64(result);
            }
            catch (Failure failure)
            {
                log.WarnFormat("Plugin call disk-space.get_reclaimable_disk_space on {0} failed with {1}", Host.Name, failure.Message);
            }

            var operation = Actions.DiskSpaceRequirements.OperationTypes.upload;

            DiskSpaceRequirements = new DiskSpaceRequirements(operation, Host, updateName, requiredDiskSpace, availableDiskSpace, reclaimableDiskSpace);

            log.WarnFormat("Cleanup message: \r\n{0}", DiskSpaceRequirements.GetSpaceRequirementsMessage());
        }
    }


    public class DiskSpaceRequirements
    {
        public readonly OperationTypes Operation;
        public readonly Host Host;
        public readonly string UpdateName;
        public readonly long RequiredDiskSpace;
        public readonly long AvailableDiskSpace;
        public readonly long ReclaimableDiskSpace;

        public enum OperationTypes { install, upload }
      
        public DiskSpaceRequirements(OperationTypes operation, Host host, string updateName, long requiredDiskSpace, long availableDiskSpace, long reclaimableDiskSpace)
        {
            Operation = operation;
            Host = host;
            UpdateName = updateName;
            RequiredDiskSpace = requiredDiskSpace;
            AvailableDiskSpace = availableDiskSpace;
            ReclaimableDiskSpace = reclaimableDiskSpace;
        }

        public bool CanCleanup
        {
            get { return ReclaimableDiskSpace + AvailableDiskSpace > RequiredDiskSpace && RequiredDiskSpace > 0 && ReclaimableDiskSpace > 0; }
        }

        public string GetSpaceRequirementsMessage()
        {
            StringBuilder sbMessage = new StringBuilder();

            switch (Operation)
            {
                case OperationTypes.install :
                    sbMessage.AppendFormat(Messages.NOT_ENOUGH_SPACE_MESSAGE_INSTALL, Host.Name, UpdateName);
                    break;
                case OperationTypes.upload :
                    sbMessage.AppendFormat(Messages.NOT_ENOUGH_SPACE_MESSAGE_UPLOAD, Host.Name, UpdateName);
                    break;
            }

            sbMessage.AppendLine();
            sbMessage.AppendLine();
            if (RequiredDiskSpace > 0)
            {
                sbMessage.AppendFormat(Messages.NOT_ENOUGH_SPACE_MESSAGE_REQUIRED_SPACE, Util.DiskSizeString(RequiredDiskSpace));
                sbMessage.AppendLine();
            }
            sbMessage.AppendFormat(Messages.NOT_ENOUGH_SPACE_MESSAGE_AVAILABLE_SPACE, Util.DiskSizeString(AvailableDiskSpace));
            sbMessage.AppendLine();
            sbMessage.AppendLine();
            if (CanCleanup)
                sbMessage.AppendFormat(Messages.NOT_ENOUGH_SPACE_MESSAGE_CLEANUP, Util.DiskSizeString(ReclaimableDiskSpace));
            else
                sbMessage.AppendLine(Messages.NOT_ENOUGH_SPACE_MESSAGE_NOCLEANUP);
            return sbMessage.ToString();
        }

        public string GetMessageForActionLink()
        {
            return CanCleanup ? Messages.PATCHINGWIZARD_CLEANUP : Messages.PATCHINGWIZARD_MORE_INFO;
        }
    }
}