#include <stdint.h>
#include <stddef.h>
#include "apic.h"
#include "uacpi/tables.h"
#include "uacpi/acpi.h"
#include "kprintf.h"
#include "hal/hal.h"
#include "dlmalloc/malloc.h"
#include "bootinfo/bootinfo.h"
#include "assert.h"
#include "util/util.h"
#include "cpu.h"
#include "util/mmio.h"

#define IOAPIC_IOREGSEL   0x00
#define IOAPIC_IOWIN      0x10

#define IOAPIC_IOAPICID   0x00
#define IOAPIC_IOAPICVER  0x01
#define IOAPIC_IOAPICARB  0x02
#define IOAPIC_IOREDTBL   0x10

#define LAPIC_ID      0x0020
#define LAPIC_VER     0x0030
#define LAPIC_TPR     0x0080
#define LAPIC_APR     0x0090
#define LAPIC_PPR     0x00A0
#define LAPIC_EOI     0x00B0
#define LAPIC_RRD     0x00C0
#define LAPIC_LDR     0x00D0
#define LAPIC_DFR     0x00E0
#define LAPIC_SVR     0x00F0
#define LAPIC_ISR     0x0100
#define LAPIC_TMR     0x0180
#define LAPIC_IRR     0x0200
#define LAPIC_ESR     0x0280
#define LAPIC_ICRLO   0x0300
#define LAPIC_ICRHI   0x0310
#define LAPIC_TIMER   0x0320
#define LAPIC_THERMAL 0x0330
#define LAPIC_PERF    0x0340
#define LAPIC_LINT0   0x0350
#define LAPIC_LINT1   0x0360
#define LAPIC_ERROR   0x0370
#define LAPIC_TICR    0x0380
#define LAPIC_TCCR    0x0390
#define LAPIC_TDCR    0x03E0

#define ICR_FIXED         0x00000000
#define ICR_LOWEST        0x00000100
#define ICR_SMI           0x00000200
#define ICR_NMI           0x00000400
#define ICR_INIT          0x00000500
#define ICR_STARTUP       0x00000600
#define ICR_PHYS          0x00000000
#define ICR_LOGC          0x00000800
#define ICR_IDLE          0x00000000
#define ICR_SEND_PENDING  0x00001000
#define ICR_DEASSERT      0x00000000
#define ICR_ASSERT        0x00004000
#define ICR_EDGE          0x00000000
#define ICR_LEVEL         0x00008000
#define ICR_NO_SHORTHAND  0x00000000
#define ICR_SELF          0x00040000
#define ICR_ALL_INC_SELF  0x00080000
#define ICR_ALL_EXCL_SELF 0x000C0000

#define ICR_DEST_SHIFT 24

typedef struct LApic {
  struct LApic *next;
  uint8_t id;
} LApic;

struct acpi_madt *MADT = NULL;
uint8_t *IOAPIC;
uint8_t *LAPIC;
LApic *LAPICS = NULL;

void ioapic_write(uint8_t *base, uint8_t reg, uint32_t data) {
  mmiowrite32(base + IOAPIC_IOREGSEL, reg);
  mmiowrite32(base + IOAPIC_IOWIN, data);
}

uint32_t ioapic_read(uint8_t *base, uint8_t reg) {
  mmiowrite32(base + IOAPIC_IOREGSEL, reg);
  return mmioread32(base + IOAPIC_IOWIN);
}

void ioapic_setentry(uint8_t *base, uint8_t idx, uint64_t data) {
  ioapic_write(base, IOAPIC_IOREDTBL + idx * 2, (uint32_t) data);
  ioapic_write(base, IOAPIC_IOREDTBL + idx * 2 + 1, (uint32_t) (data >> 32));
}

void ioapic_init(void) {
  uint32_t x = ioapic_read(IOAPIC, IOAPIC_IOAPICVER);
  uint32_t count = ((x >> 16) & 0xff) + 1;
  LOG("hal", "IOAPIC pins = %d\n", count);

  for (uint32_t i = 0; i < count; i++) {
    ioapic_setentry(IOAPIC, i, 1 << 16);
  }
}

uint32_t lapic_read(uint32_t reg) {
  return mmioread32(LAPIC + reg);
}

void lapic_write(uint32_t reg, uint32_t data) {
  mmiowrite32(LAPIC + reg, data);
}

void lapic_init(void) {
  lapic_write(LAPIC_TPR, 0);
  lapic_write(LAPIC_DFR, 0xffffffff);
  lapic_write(LAPIC_LDR, 0x01000000);
  lapic_write(LAPIC_SVR, 0x100 | 0xff);
}

uint32_t lapic_getid(void) {
  return lapic_read(LAPIC_ID) >> 24;
}

void lapic_sendinit(uint32_t id) {
  lapic_write(LAPIC_ICRHI, id << ICR_DEST_SHIFT);
  lapic_write(LAPIC_ICRLO, ICR_INIT | ICR_PHYS | ICR_ASSERT | ICR_EDGE | ICR_NO_SHORTHAND);
  while (lapic_read(LAPIC_ICRLO) & ICR_SEND_PENDING);
}

void lapic_sendstartup(uint32_t id, uint32_t vec) {
  lapic_write(LAPIC_ICRHI, id << ICR_DEST_SHIFT);
  lapic_write(LAPIC_ICRLO, vec | ICR_STARTUP | ICR_PHYS | ICR_ASSERT | ICR_EDGE | ICR_NO_SHORTHAND);
  while (lapic_read(LAPIC_ICRLO) & ICR_SEND_PENDING);
}

void apic_init(void) {
  uacpi_status r;

  uacpi_table madt;
  r = uacpi_table_find_by_signature("APIC", &madt);
  if (r != UACPI_STATUS_OK) {
    ERR("hal", "could not find MADT\n");
    hal_hang();
  }
  MADT = madt.ptr;

  LAPIC = (uint8_t *)(MADT->local_interrupt_controller_address + BOOT_INFO.hhdm_off);

  uint64_t cur = (uint64_t)&MADT->entries;
  uint64_t end = cur + MADT->hdr.length;

  while (cur < end) {
    struct acpi_entry_hdr *ent = (struct acpi_entry_hdr *)cur;

    if (ent->type == ACPI_MADT_ENTRY_TYPE_IOAPIC) {
      struct acpi_madt_ioapic *ioapic = (struct acpi_madt_ioapic *)ent;
      IOAPIC = (uint8_t *)(ioapic->address + BOOT_INFO.hhdm_off);
      LOG("hal", "IOAPIC p=%p v=%p id=%d gsi=%d\n", ioapic->address, IOAPIC, ioapic->id, ioapic->gsi_base);
    } else if (ent->type == ACPI_MADT_ENTRY_TYPE_LAPIC) {
      struct acpi_madt_lapic *lapic = (struct acpi_madt_lapic *)ent;

      LApic *new = dlmalloc(sizeof(*new));
      ASSERT("hal", new != NULL, "out of memory\n");
      new->id = lapic->id;
      LL_APPEND(LAPICS, new);
      LOG("hal", "LAPIC id=%d\n", lapic->id);
    } else if (ent->type == ACPI_MADT_ENTRY_TYPE_LAPIC_ADDRESS_OVERRIDE) {
      struct acpi_madt_lapic_address_override *override= (struct acpi_madt_lapic_address_override *)ent;
      uint8_t *prev = LAPIC;
      LAPIC = (uint8_t *)(override->address + BOOT_INFO.hhdm_off);
      LOG("hal", "LAPIC override %p -> %p (v)\n", prev, LAPIC);
    }

    cur += ent->length;
  }

  lapic_init();
  ioapic_init();
}