//
// Copyright (c) 2010-2024 Antmicro
//
// This file is licensed under the MIT License.
// Full license text is available in 'licenses/MIT.txt'.
//

using System.Text;
using System.Linq;
using Antmicro.Renode.Peripherals.Bus;
using Antmicro.Renode.Peripherals.CPU;
using Antmicro.Renode.Core.ACPI;
using Antmicro.Renode.Utilities.Packets;

namespace Antmicro.Renode.Core.Extensions
{
    public static class ACPIExtensions
    {
        public static void GenerateACPITable(this IBusController bus, ulong address)
        {
            var rootSystemDescriptionTableOffset =
                (uint)address + (uint)Packet.CalculateLength<RootSystemDescriptionPointer>();
            var rootSystemDescriptionPointer = new RootSystemDescriptionPointer(rootSystemDescriptionTableOffset);
            bus.WriteBytes(Packet.Encode(rootSystemDescriptionPointer), address);

            var fixedACPIDescriptionTableAddress =
                rootSystemDescriptionTableOffset + (uint)Packet.CalculateLength<RootSystemDescriptionTable>();
            var multipleAPICDescriptionTableHeaderAddress =
                fixedACPIDescriptionTableAddress + (uint)Packet.CalculateLength<FixedACPIDescriptionTable>();

            var rootSystemDescriptionTable = new RootSystemDescriptionTable(fixedACPIDescriptionTableAddress, multipleAPICDescriptionTableHeaderAddress);
            bus.WriteBytes(Packet.Encode(rootSystemDescriptionTable), rootSystemDescriptionTableOffset);

            var fixedACPIDescriptionTable = new FixedACPIDescriptionTable(multipleAPICDescriptionTableHeaderAddress - (uint)address, fixedACPIDescriptionTableAddress);
            bus.WriteBytes(Packet.Encode(fixedACPIDescriptionTable), fixedACPIDescriptionTableAddress);

            var ids = bus.GetCPUs().OfType<BaseX86>().Select(x => (ulong)x.Lapic.ID).ToList();

            var multipleAPICDescriptionTableLength = Packet.CalculateLength<MultipleAPICDescriptionTable>();
            var recordLength = (uint)Packet.CalculateLength<ProcessorLocalAPICRecord>();

            // Define table without records. They will be defined based on CPUs.
            var multipleAPICDescriptionTable = new MultipleAPICDescriptionTable((uint)(multipleAPICDescriptionTableLength + ids.Count() * recordLength));
            bus.WriteBytes(Packet.Encode(multipleAPICDescriptionTable), multipleAPICDescriptionTableHeaderAddress);

            var recordAddress =
                multipleAPICDescriptionTableHeaderAddress + (uint)Packet.CalculateLength<MultipleAPICDescriptionTable>();

            foreach(var id in ids)
            {
                var processorLocalAPICRecord = new ProcessorLocalAPICRecord
                {
                    EntryType = 0x0,    // 0x0 means local APIC entry type
                    RecordLength = 0x8,
                    APICID = (byte)id,
                    Flags = 0x01        // bit 0 = Processor Enabled
                };
                var table = Packet.Encode(processorLocalAPICRecord).ToArray();
                bus.WriteBytes(table, recordAddress);

                recordAddress += recordLength;
            }
        }
    }
}