/* Copyright (c) Cloud Software Group, Inc. 
 * 
 * Redistribution and use in source and binary forms, 
 * with or without modification, are permitted provided 
 * that the following conditions are met: 
 * 
 * *   Redistributions of source code must retain the above 
 *     copyright notice, this list of conditions and the 
 *     following disclaimer. 
 * *   Redistributions in binary form must reproduce the above 
 *     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 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE.
 */

using System.Collections.Generic;
using System.Linq;
using XenAdmin.Controls;
using XenAdmin.Mappings;
using XenAdmin.Wizards.GenericPages;
using XenAPI;

namespace XenAdmin.Wizards.CrossPoolMigrateWizard
{
    class CrossPoolMigrateStoragePage : SelectVMStorageWithMultipleVirtualDisksPage
    {
        private readonly bool templatesOnly = false;
        private readonly WizardMode wizardMode;

        public CrossPoolMigrateStoragePage(WizardMode wizardMode)
        {
            DisplayDiskCapacity = false;
            this.wizardMode = wizardMode;

            InitializeText();
        }

        protected override bool ImplementsIsDirty()
        {
            return true;
        }

        protected override bool SrsAreSuitable(SR sourceSr, SR targetSr)
        {
            if (sourceSr == null || targetSr == null || sourceSr.HBALunPerVDI() || targetSr.HBALunPerVDI())
                return false;

            // intra-pool move of halted VMs does not require the SRs to support migration because we use VMMoveAction (vdi copy & destroy)
            if (wizardMode == WizardMode.Move && sourceSr.Connection == targetSr.Connection)
                return true;

            return sourceSr.SupportsStorageMigration() && targetSr.SupportsStorageMigration();
        }

	    protected override bool IsExtraSpaceNeeded(SR sourceSr, SR targetSr)
	    {
	        // No extra space is needed for Migrate or Move operation on same SR.
			if (sourceSr != null && targetSr != null && targetSr.opaque_ref.Equals(sourceSr.opaque_ref) && 
			    (wizardMode == WizardMode.Migrate || wizardMode == WizardMode.Move))
				return false;
	        return true;
	    }


        public override string PageTitle => Messages.CPM_WIZARD_SELECT_STORAGE_PAGE_TITLE;
        public override string Text => Messages.CPM_WIZARD_SELECT_STORAGE_PAGE_TEXT;
        public override string HelpID => wizardMode == WizardMode.Copy ? "StorageCopyMode" : "Storage";

        protected override string IntroductionText => Messages.CPM_WIZARD_STORAGE_INSTRUCTIONS;
        protected override string AllOnSameSRRadioButtonText => Messages.CPM_WIZARD_ALL_ON_SAME_SR_RADIO;
        protected override string OnSpecificSRRadioButtonText => Messages.CPM_WIZARD_SPECIFIC_SR_RADIO;
        protected override string VmDiskColumnHeaderText => templatesOnly
            ? Messages.CPS_WIZARD_STORAGE_PAGE_DISK_COLUMN_HEADER_FOR_TEMPLATE
            : Messages.CPS_WIZARD_STORAGE_PAGE_DISK_COLUMN_HEADER_FOR_VM;


        public override StorageResourceContainer ResourceData(string sysId)
        {
            VM vm = Connection.Resolve(new XenRef<VM>(sysId));

            if (vm == null)
                return null;

            List<VDI> vdis = Connection.ResolveAll(vm.VBDs).Select(v => vm.Connection.Resolve(v.VDI)).ToList();
            vdis.RemoveAll(vdi => vdi == null || Connection.Resolve(vdi.SR).GetSRType(true) == SR.SRTypes.iso);
            return new CrossPoolMigrationStorageResourceContainer(vdis);
        }

        protected override void PageLeaveCore(PageLoadedDirection direction, ref bool cancel)
        {
            if (!CrossPoolMigrateWizard.AllVMsAvailable(VmMappings, Connection))
            {
                cancel = true;
                SetButtonNextEnabled(false);
                SetButtonPreviousEnabled(false);
            }
        }

        /// <summary>
        /// Add storage mappings for snapshots and CD-ROMs
        /// </summary>
        protected override void AddAdditionalMappings(Dictionary<string, VmMapping> vmMappings)
        {
            foreach (var kvp in vmMappings)
            {
                var vm = Connection.Resolve(new XenRef<VM>(kvp.Key));
                if (vm == null)
                    continue;

                var vmMapping = kvp.Value;
                var suitableSr = vmMapping.Storage.Values.FirstOrDefault(); //an SR already selected for VM's disks

                foreach (var snapshot in Connection.ResolveAll(vm.snapshots))
                {
                    foreach (IStorageResource resourceData in ResourceData(snapshot.opaque_ref))
                    {
                        var snapshotVdi = Connection.Resolve(new XenRef<VDI>(resourceData.Tag.ToString()));
                        if (snapshotVdi == null)
                            continue;

                        // try to use the mapping of the original vdi; if this doesn't exist, then use another suitable SR
                        if (snapshotVdi.snapshot_of != null && vmMapping.Storage.ContainsKey(snapshotVdi.snapshot_of.opaque_ref))
                            vmMapping.Storage[snapshotVdi.opaque_ref] = vmMapping.Storage[snapshotVdi.snapshot_of.opaque_ref];
                        else if (suitableSr != null)
                            vmMapping.Storage[snapshotVdi.opaque_ref] = suitableSr;
                    }
                }

                if (suitableSr == null || suitableSr.Connection != vm.Connection)
                    continue;

                //CA-339584: for intra-pool migrations ensure any CDs (except guest tools)
                //will remain in their drives

                foreach (var vbdRef in vm.VBDs)
                {
                    var vbd = vm.Connection.Resolve(vbdRef);
                    if (vbd == null || !vbd.IsCDROM())
                        continue;

                    var vdi = vm.Connection.Resolve(vbd.VDI);
                    if (vdi == null || vdi.IsToolsIso())
                        continue;

                    var sr = vm.Connection.Resolve(vdi.SR);
                    vmMapping.Storage[vdi.opaque_ref] = sr;
                }
            }
        }
    }
}