#include <stddef.h>
#include <stdint.h>
#include "intr.h"
#include "io.h"
#include "gdt.h"
#include "hal/hal.h"
#include "kprintf.h"
#include "compiler/attr.h"
#include "pic.h"
#include "apic.h"
#include "pit.h"

void hal_intr_disable(void) {
  asm volatile("cli");
}

void hal_intr_enable(void) {
  asm volatile("sti");
}

typedef struct {
  uint16_t intrlow;
  uint16_t kernelcs;
  uint8_t ist;
  uint8_t attrs;
  uint16_t intrmid;
  uint32_t intrhigh;
  uint32_t resv;
} PACKED IdtGate;

typedef struct {
  uint16_t limit;
  uint64_t base;
} PACKED Idt;

#define ENTRIES 256
ALIGNED(0x10) static IdtGate idtgates[ENTRIES] = {0};
static Idt idt = {0};

void idt_setentry(int i, uint64_t handler, uint8_t ist, uint8_t flags) {
  idtgates[i].intrlow = handler & 0xffff;
  idtgates[i].kernelcs = KCODE;
  idtgates[i].ist = ist;
  idtgates[i].attrs = flags;
  idtgates[i].intrmid = (handler >> 16) & 0xFFFF;
  idtgates[i].intrhigh = (handler >> 32) & 0xFFFFFFFF;
  idtgates[i].resv = 0;
}

void idt_init(void) {
  idt.base = (uint64_t)&idtgates;
  idt.limit = ENTRIES * sizeof(IdtGate) - 1;
  asm volatile("lidt %0" :: "m"(idt) : "memory");

  LOG("hal", "idt init\n");
}

typedef struct {
  uint64_t r15;
  uint64_t r14;
  uint64_t r13;
  uint64_t r12;
  uint64_t r11;
  uint64_t r10;
  uint64_t r9;
  uint64_t r8;
  uint64_t rsi;
  uint64_t rdi;
  uint64_t rbp;
  uint64_t rdx;
  uint64_t rcx;
  uint64_t rbx;
  uint64_t rax;
} PACKED CpuRegs;

typedef struct {
  uint64_t cr8;
  uint64_t cr4;
  uint64_t cr3;
  uint64_t cr2;
  uint64_t cr0;
} PACKED CpuCtrlRegs;

typedef struct {
  CpuCtrlRegs ctrl;
  CpuRegs regs;
  uint64_t trapnum;
  uint64_t errnum;

  uint64_t rip;
  uint64_t cs;
  uint64_t rflags;
  uint64_t rsp;
  uint64_t ss;
} PACKED IntrStackFrame;

extern void *ISR_REDIRTABLE[];

static const char *exceptions[] = {
  "#DE", "#DB", "NMI",
  "#BP", "#OF", "#BR",
  "#UD", "#NM", "#DF",
  "CSO", "#TS", "#NP",
  "#SS", "#GP", "#PF",
  "RES", "#MF", "#AC",
  "#MC", "#XM", "#VE",
  "#CP",
};

void intr_init(void) {
  #define MKINTR(N, IST) \
    extern void intr_vec##N(void); \
    idt_setentry(N, (uint64_t)&intr_vec##N, IST, 0x8E);

  MKINTR(0, 0);
  MKINTR(1, 0);
  MKINTR(2, 2);
  MKINTR(4, 0);
  MKINTR(5, 0);
  MKINTR(6, 0);
  MKINTR(7, 0);
  MKINTR(8, 1);
  MKINTR(9, 0);
  MKINTR(10, 0);
  MKINTR(11, 0);
  MKINTR(12, 0);
  MKINTR(13, 0);
  MKINTR(14, 0);
  MKINTR(15, 0);
  MKINTR(16, 0);
  MKINTR(17, 0);
  MKINTR(18, 0);
  MKINTR(19, 0);
  MKINTR(20, 0);
  MKINTR(21, 0);
  MKINTR(22, 0);
  MKINTR(23, 0);
  MKINTR(24, 0);
  MKINTR(25, 0);
  MKINTR(26, 0);
  MKINTR(27, 0);
  MKINTR(28, 0);
  MKINTR(29, 0);
  MKINTR(30, 0);
  MKINTR(31, 0);
  MKINTR(32, 0);
  MKINTR(33, 0);
  MKINTR(34, 0);
  MKINTR(35, 0);
  MKINTR(36, 0);
  MKINTR(37, 0);
  MKINTR(38, 0);
  MKINTR(39, 0);
  MKINTR(40, 3);
  MKINTR(41, 0);
  MKINTR(42, 0);
  MKINTR(43, 0);
  MKINTR(44, 0);
  MKINTR(45, 0);
  MKINTR(46, 0);
  MKINTR(47, 0);

  idt_init();
}

void intr_dumpframe(IntrStackFrame *frame) {
  kprintf("r15=%016lx r14=%016lx r13=%016lx r12=%016lx\n"
          "r11=%016lx r10=%016lx r9 =%016lx r8 =%016lx\n"
          "rsi=%016lx rdi=%016lx rbp=%016lx rdx=%016lx\n"
          "rcx=%016lx rbx=%016lx rax=%016lx\n"
          "cr8=%016lx cr4=%016lx cr3=%016lx cr2=%016lx\n"
          "cr0=%016lx rip=%016lx cs =%016lx rfl=%016lx\n"
          "rsp=%016lx ss =%016lx trp=%016lx err=%016lx\n",
          frame->regs.r15, frame->regs.r14, frame->regs.r13, frame->regs.r12,
          frame->regs.r11, frame->regs.r10, frame->regs.r9, frame->regs.r8,
          frame->regs.rsi, frame->regs.rdi, frame->regs.rbp, frame->regs.rdx,
          frame->regs.rcx, frame->regs.rbx, frame->regs.rax,
          frame->ctrl.cr8, frame->ctrl.cr4, frame->ctrl.cr3,
          frame->ctrl.cr2, frame->ctrl.cr0, frame->rip, frame->cs, frame->rflags,
          frame->rsp, frame->ss, frame->trapnum, frame->errnum
    );
}

void intr_handleintr(IntrStackFrame *frame) {
  if (frame->trapnum >= 0 && frame->trapnum <= 31) {
    // EXCEPTION
    ERR("ERROR", "%s, 0x%lX\n", exceptions[frame->trapnum], frame->errnum);
    intr_dumpframe(frame);
    hal_hang();  
  } else if (frame->trapnum >= 32 && frame->trapnum <= 47) {
    if (frame->trapnum == INTR_TIMER) {
      kprintf("ACK %d\n", PIT_TICKS);
      PIT_TICKS++;
      io_out8(PIC2_CMD, 0x20);
    }

    io_out8(PIC1_CMD, 0x20);
    lapic_write(LAPIC_EOI, 0x00);
  }
}