using Neo.IO;
using Neo.Ledger;
using Neo.SmartContract.Manifest;
using Neo.VM.Types;
using System;
using System.Linq;
using System.Numerics;
using Array = Neo.VM.Types.Array;

namespace Neo.SmartContract
{
    partial class ApplicationEngine
    {
        public static readonly InteropDescriptor NEP5_EmitTransfer = Register("NEP5.EmitTransfer", nameof(NEP5EmitTransfer), 0, CallFlags.AllowModifyStates, false);

        protected internal void NEP5EmitTransfer(UInt160 from, UInt160 to, BigInteger amount)
        {
            // Send notification

            SendNotification(CurrentScriptHash, "Transfer",
                new Array { from == null ? StackItem.Null : from.ToArray(), to == null ? StackItem.Null : to.ToArray(), amount });

            if (to == null)
            {
                return;
            }

            // Call onPayment method if exists

            ContractState contract = Snapshot.Contracts.TryGet(to);
            if (contract is null)
            {
                return;
            }
            ContractMethodDescriptor md = contract.Manifest.Abi.GetMethod("onPayment");
            if (md is null)
            {
                return;
            }

            ContractManifest currentManifest = Snapshot.Contracts.TryGet(CurrentScriptHash)?.Manifest;
            if (currentManifest != null && !currentManifest.CanCall(contract.Manifest, md.Name))
                throw new InvalidOperationException($"Cannot Call Method {md.Name} Of Contract {contract.ScriptHash} From Contract {CurrentScriptHash}");

            CallContractInternal(contract, md, new Array(ReferenceCounter) { amount }, CallFlags.All, CheckReturnType.EnsureIsEmpty);
        }
    }
}