#ifndef __FENNIX_KERNEL_APIC_H__
#define __FENNIX_KERNEL_APIC_H__

#include <types.h>

#include <interrupts.hpp>
#include <cpu.hpp>

namespace APIC
{
    enum APICRegisters
    {
        // source from: https://github.com/pdoane/osdev/blob/master/intr/local_apic.c
        APIC_ID = 0x20,       // Local APIC ID
        APIC_VER = 0x30,      // Local APIC Version
        APIC_TPR = 0x80,      // Task Priority
        APIC_APR = 0x90,      // Arbitration Priority
        APIC_PPR = 0xA0,      // Processor Priority
        APIC_EOI = 0xB0,      // EOI
        APIC_RRD = 0xC0,      // Remote Read
        APIC_LDR = 0xD0,      // Logical Destination
        APIC_DFR = 0xE0,      // Destination Format
        APIC_SVR = 0xF0,      // Spurious Interrupt Vector
        APIC_ISR = 0x100,     // In-Service (8 registers)
        APIC_TMR = 0x180,     // Trigger Mode (8 registers)
        APIC_IRR = 0x200,     // Interrupt Request (8 registers)
        APIC_ESR = 0x280,     // Error Status
        APIC_ICRLO = 0x300,   // Interrupt Command
        APIC_ICRHI = 0x310,   // Interrupt Command [63:32]
        APIC_TIMER = 0x320,   // LVT Timer
        APIC_THERMAL = 0x330, // LVT Thermal Sensor
        APIC_PERF = 0x340,    // LVT Performance Counter
        APIC_LINT0 = 0x350,   // LVT LINT0
        APIC_LINT1 = 0x360,   // LVT LINT1
        APIC_ERROR = 0x370,   // LVT Error
        APIC_TICR = 0x380,    // Initial Count (for Timer)
        APIC_TCCR = 0x390,    // Current Count (for Timer)
        APIC_TDCR = 0x3E0,    // Divide Configuration (for Timer)
    };

    typedef union
    {
        struct
        {
            /** @brief Interrupt Vector */
            uint64_t Vector : 8;
            /** @brief Reserved */
            uint64_t Reserved0 : 4;
            /**
             * @brief Delivery Status
             *
             * 0: Idle
             * 1: Send Pending
             */
            uint64_t DeliveryStatus : 1;
            /** @brief Reserved */
            uint64_t Reserved1 : 3;
            /**
             * @brief Mask
             *
             * 0: Not masked
             * 1: Masked
             */
            uint64_t Mask : 1;
            /** @brief Timer Mode
             *
             * 0: One-shot
             * 1: Periodic
             * 2: TSC-Deadline
             */
            uint64_t TimerMode : 1;
            /** @brief Reserved */
            uint64_t Reserved2 : 14;
        };
        uint64_t raw;
    } __attribute__((packed)) LVTTimer;

    class APIC
    {
    private:
        bool x2APICSupported = false;

    public:
        uint32_t Read(uint32_t Register);
        void Write(uint32_t Register, uint32_t Value);
        void IOWrite(uint64_t Base, uint32_t Register, uint32_t Value);
        uint32_t IORead(uint64_t Base, uint32_t Register);
        void EOI();
        void RedirectIRQs(int CPU = 0);
        void IPI(uint8_t CPU, uint32_t InterruptNumber);
        uint32_t IOGetMaxRedirect(uint32_t APICID);
        void RawRedirectIRQ(uint8_t Vector, uint32_t GSI, uint16_t Flags, int CPU, int Status);
        void RedirectIRQ(int CPU, uint8_t IRQ, int Status);
        APIC(int Core);
        ~APIC();
    };

    class Timer : public Interrupts::Handler
    {
    private:
        APIC *lapic;
        uint64_t TicksIn10ms = 0;
        void OnInterruptReceived(CPU::x64::TrapFrame *Frame);

    public:
        uint64_t GetTicksIn10ms() { return TicksIn10ms; }
        void OneShot(uint32_t Vector, uint64_t Miliseconds);
        Timer(APIC *apic);
        ~Timer();
    };
}

#endif // !__FENNIX_KERNEL_APIC_H__