/*
   This file is part of Fennix Kernel.

   Fennix Kernel is free software: you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation, either version 3 of
   the License, or (at your option) any later version.

   Fennix Kernel is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/

#include "acpi.hpp"

#include <debug.h>
#include <io.h>

#include "../../kernel.h"

#pragma GCC diagnostic ignored "-Wint-to-pointer-cast"

namespace ACPI
{
    void *ACPI::FindTable(ACPI::ACPIHeader *ACPIHeader, char *Signature)
    {
        for (uint64_t t = 0; t < ((ACPIHeader->Length - sizeof(ACPI::ACPIHeader)) / (XSDTSupported ? 8 : 4)); t++)
        {
            // TODO: Should I be concerned about unaligned memory access?
            ACPI::ACPIHeader *SDTHdr = nullptr;
            if (XSDTSupported)
                SDTHdr = (ACPI::ACPIHeader *)(*(uint64_t *)((uint64_t)ACPIHeader + sizeof(ACPI::ACPIHeader) + (t * 8)));
            else
                SDTHdr = (ACPI::ACPIHeader *)(*(uint32_t *)((uint64_t)ACPIHeader + sizeof(ACPI::ACPIHeader) + (t * 4)));

            for (int i = 0; i < 4; i++)
            {
                if (SDTHdr->Signature[i] != Signature[i])
                    break;
                if (i == 3)
                {
                    trace("%s found at address %p", Signature, (uintptr_t)SDTHdr);
                    return SDTHdr;
                }
            }
        }
        // warn("%s not found!", Signature);
        return nullptr;
    }

    void ACPI::SearchTables(ACPIHeader *Header)
    {
        if (!Header)
            return;

        HPET = (HPETHeader *)FindTable(Header, (char *)"HPET");
        FADT = (FADTHeader *)FindTable(Header, (char *)"FACP");
        MCFG = (MCFGHeader *)FindTable(Header, (char *)"MCFG");
        BGRT = (BGRTHeader *)FindTable(Header, (char *)"BGRT");
        SRAT = (SRATHeader *)FindTable(Header, (char *)"SRAT");
        TPM2 = (TPM2Header *)FindTable(Header, (char *)"TPM2");
        TCPA = (TCPAHeader *)FindTable(Header, (char *)"TCPA");
        WAET = (WAETHeader *)FindTable(Header, (char *)"WAET");
        MADT = (MADTHeader *)FindTable(Header, (char *)"APIC");
        HEST = (HESTHeader *)FindTable(Header, (char *)"HEST");
        FindTable(Header, (char *)"BERT");
        FindTable(Header, (char *)"CPEP");
        FindTable(Header, (char *)"DSDT");
        FindTable(Header, (char *)"ECDT");
        FindTable(Header, (char *)"EINJ");
        FindTable(Header, (char *)"ERST");
        FindTable(Header, (char *)"FACS");
        FindTable(Header, (char *)"MSCT");
        FindTable(Header, (char *)"MPST");
        FindTable(Header, (char *)"OEMx");
        FindTable(Header, (char *)"PMTT");
        FindTable(Header, (char *)"PSDT");
        FindTable(Header, (char *)"RASF");
        FindTable(Header, (char *)"RSDT");
        FindTable(Header, (char *)"SBST");
        FindTable(Header, (char *)"SLIT");
        FindTable(Header, (char *)"SSDT");
        FindTable(Header, (char *)"XSDT");
        FindTable(Header, (char *)"DRTM");
        FindTable(Header, (char *)"FPDT");
        FindTable(Header, (char *)"GTDT");
        FindTable(Header, (char *)"PCCT");
        FindTable(Header, (char *)"S3PT");
        FindTable(Header, (char *)"MATR");
        FindTable(Header, (char *)"MSDM");
        FindTable(Header, (char *)"WPBT");
        FindTable(Header, (char *)"OSDT");
        FindTable(Header, (char *)"RSDP");
        FindTable(Header, (char *)"NFIT");
        FindTable(Header, (char *)"ASF!");
        FindTable(Header, (char *)"BOOT");
        FindTable(Header, (char *)"CSRT");
        FindTable(Header, (char *)"DBG2");
        FindTable(Header, (char *)"DBGP");
        FindTable(Header, (char *)"DMAR");
        FindTable(Header, (char *)"IBFT");
        FindTable(Header, (char *)"IORT");
        FindTable(Header, (char *)"IVRS");
        FindTable(Header, (char *)"LPIT");
        FindTable(Header, (char *)"MCHI");
        FindTable(Header, (char *)"MTMR");
        FindTable(Header, (char *)"SLIC");
        FindTable(Header, (char *)"SPCR");
        FindTable(Header, (char *)"SPMI");
        FindTable(Header, (char *)"UEFI");
        FindTable(Header, (char *)"VRTC");
        FindTable(Header, (char *)"WDAT");
        FindTable(Header, (char *)"WDDT");
        FindTable(Header, (char *)"WDRT");
        FindTable(Header, (char *)"ATKG");
        FindTable(Header, (char *)"GSCI");
        FindTable(Header, (char *)"IEIT");
        FindTable(Header, (char *)"HMAT");
        FindTable(Header, (char *)"CEDT");
        FindTable(Header, (char *)"AEST");
    }

    ACPI::ACPI()
    {
        trace("Initializing ACPI");
        if (bInfo.RSDP->Revision >= 2 && bInfo.RSDP->XSDTAddress)
        {
            debug("XSDT supported");
            XSDTSupported = true;
            XSDT = (ACPIHeader *)(bInfo.RSDP->XSDTAddress);
        }
        else
        {
            debug("RSDT supported");
            XSDT = (ACPIHeader *)(uintptr_t)bInfo.RSDP->RSDTAddress;
        }

        this->SearchTables(XSDT);

        if (FADT)
        {
            outb(s_cst(uint16_t, FADT->SMI_CommandPort), FADT->AcpiEnable);
            while (!(inw(s_cst(uint16_t, FADT->PM1aControlBlock)) & 1))
                ;
        }
    }

    ACPI::~ACPI()
    {
    }
}