// Kernel HAL binding and generic platform-operation wrappers.

#include <stdbool.h>
#include <kernel/ke_hal.h>

static const HAL_API* gHal;

// Binds the bootstrap HAL table before kernel code begins using interrupt-state primitives.
KSTATUS KeBindBootstrapHal(void) {
    const HAL_API* hal = HalGetApi();
    if (!hal || hal->Size != sizeof(HAL_API) || hal->Version != HAL_API_VERSION ||
        !hal->Processor.DisableInterrupts || !hal->Processor.RestoreInterrupts ||
        !hal->Processor.EnableInterrupts || !hal->Processor.WaitForInterrupt ||
        !hal->Processor.Halt || !hal->Processor.Stop) {
        return NTLSTATUS_INVALID_PARAMETER;
    }
    gHal = hal;
    return NTLSTATUS_SUCCESS;
}

// Returns whether the initialized table contains every mandatory kernel platform service.
static bool KiHalRuntimeTableValid(const HAL_API* hal) {
    return hal && hal->Size == sizeof(HAL_API) && hal->Version == HAL_API_VERSION &&
           hal->Processor.DisableInterrupts && hal->Processor.RestoreInterrupts &&
           hal->Processor.EnableInterrupts && hal->Processor.WaitForInterrupt &&
           hal->Processor.Halt && hal->Processor.Stop && hal->Processor.QueryTopology &&
           hal->Processor.Start &&
           hal->Screen.GetFramebuffer &&
           hal->Output.RegisterEndpoint && hal->Output.Write && hal->Output.QueryStats &&
           hal->Timer.QueryTicks && hal->Timer.QueryTickFrequency && hal->Timer.Stall &&
           hal->Timer.HandleInterrupt && hal->Timer.ConfigureCurrentProcessor &&
           hal->Rtc.QueryTime && hal->Pci.Read32 && hal->Pci.Write32 &&
           hal->InterruptController.RouteGsi && hal->InterruptController.MaskGsi &&
           hal->InterruptController.ResolveIsa && hal->InterruptController.SendEoi &&
           hal->InterruptController.SetTaskPriority && hal->InterruptController.QueryTaskPriority &&
           hal->InterruptController.VectorPending &&
           hal->InterruptController.InitializeCurrentProcessor &&
           hal->InterruptController.SendProcessorInterrupt &&
           hal->InterruptController.SendProcessorNmi && hal->InterruptController.BroadcastNmi &&
           hal->InterruptController.ComposeMsi && hal->Power.Shutdown;
}

// Initializes the HAL and validates every mandatory runtime service consumed by the kernel.
KSTATUS KeInitializeHal(const HAL_INIT_PARAMS* params) {
    if (!gHal || !params)
        return NTLSTATUS_INVALID_PARAMETER;

    KSTATUS status = HalInitialize(params);
    if (!KSUCCESS(status))
        return status;

    const HAL_API* hal = HalGetApi();
    if (hal != gHal || !KiHalRuntimeTableValid(hal))
        return NTLSTATUS_INVALID_PARAMETER;
    return NTLSTATUS_SUCCESS;
}

// Returns the bound HAL table.
const HAL_API* KeGetHal(void) {
    return gHal;
}

// Masks interrupts and returns the previous processor flags.
__declspec(dllexport) uintptr_t KeDisableInterrupts(void) {
    return gHal->Processor.DisableInterrupts();
}

// Restores a previously saved processor interrupt state.
__declspec(dllexport) void KeRestoreInterrupts(uintptr_t flags) {
    gHal->Processor.RestoreInterrupts(flags);
}

// Enables maskable interrupts on the current processor.
void KeEnableInterrupts(void) {
    gHal->Processor.EnableInterrupts();
}

// Enables interrupts and waits for the next interrupt on the current processor.
void KeWaitForInterrupt(void) {
    gHal->Processor.WaitForInterrupt();
}

// Halts the current processor once without changing interrupt state.
void KeHaltProcessor(void) {
    gHal->Processor.Halt();
}

// Permanently stops the current processor.
_Noreturn void KeStopProcessor(void) {
    gHal->Processor.Stop();
    for (;;) {
    }
}

// Queries platform processor topology without exposing interrupt-controller details.
KSTATUS KeQueryProcessorTopology(HAL_PROCESSOR_TOPOLOGY* topologyOut) {
    return gHal->Processor.QueryTopology(topologyOut);
}

// Starts one processor at a physical bootstrap entry address.
KSTATUS KeStartProcessor(uint32_t hardwareId, uintptr_t startPhysical) {
    return gHal->Processor.Start(hardwareId, startPhysical);
}

// Initializes the current processor's local interrupt-controller state.
void KeInitializeCurrentProcessorInterruptController(void) {
    gHal->InterruptController.InitializeCurrentProcessor();
}

// Sends one fixed-vector interrupt to a processor hardware ID.
void KeSendProcessorInterrupt(uint32_t hardwareId, uint8_t vector) {
    gHal->InterruptController.SendProcessorInterrupt(hardwareId, vector);
}

// Sends one non-maskable interrupt to a processor hardware ID.
void KeSendProcessorNmi(uint32_t hardwareId) {
    gHal->InterruptController.SendProcessorNmi(hardwareId);
}

// Sends a non-maskable interrupt to every other processor.
void KeBroadcastProcessorNmi(void) {
    gHal->InterruptController.BroadcastNmi();
}

// Arms the calibrated periodic timer on the current processor.
void KeConfigureCurrentProcessorTimer(void) {
    gHal->Timer.ConfigureCurrentProcessor();
}