#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
#include <limine.h>
#include "arch/x86_64/boot/gdt.h"
#include "arch/x86_64/boot/idt.h"
#include "arch/x86_64/boot/isr.h"
#include "mm/memory.h"
#include "mm/pmm.h"
#include "mm/vmm.h"
#include "arch/x86_64/bus/ata.h"
#include "string.h"
#include "arch/x86_64/cpu/io.h"
#include "arch/x86_64/sys/pit.h"
#include "arch/x86_64/bus/pci.h"
#include "arch/x86_64/sys/apic.h"
#include "mp/mp.h"
#include "drivers/fb/fb.h"
#include "libk/debug.h"
#include "fs/elf.h"
#include "sched/sched_types.h"
#include "arch/x86_64/sys/halt.h"
#include <cpuid.h>
#include "libk/random.h"
#include "libk/kargs.h"
#include "sched/sched_types.h"
#include "sched/sched.h"
#include "arch/x86_64/serial/serial.h"
#include "arch/x86_64/sys/tsc.h"
#include "arch/x86_64/fw/acpi.h"

extern bool print_now;


static volatile struct limine_framebuffer_request framebuffer_request = {
    .id = LIMINE_FRAMEBUFFER_REQUEST,
    .revision = 6
};


static volatile struct limine_kernel_file_request limine_kernel_file_request = {
	.id = LIMINE_KERNEL_FILE_REQUEST, .revision = 0};


static volatile struct limine_memmap_request memmap_request = {
    .id = LIMINE_MEMMAP_REQUEST,
    .revision = 6
};


static volatile struct limine_rsdp_request rsdp_request = {
    .id = LIMINE_RSDP_REQUEST,
    .revision = 6
};


volatile struct limine_stack_size_request stack_size_request = {
	.id = LIMINE_STACK_SIZE_REQUEST,
	.revision = 0,
	.stack_size = CPU_STACK_SIZE,
};


volatile struct limine_smp_request mp_request = {
    .id = LIMINE_SMP_REQUEST,
    .revision = 0
};


static volatile struct limine_module_request module_request = {
	.id = LIMINE_MODULE_REQUEST, .revision = 0};

extern bool is_halting;
extern uint8_t is_pausing;

void nmi_vector(registers_t *reg) {
	if (is_halting) {
		for (;;) {
			cli();
			halt();
		}
	} else if (is_pausing) {
		while (is_pausing & PAUSING) {
			pause();
		}
		apic_eoi();
	} else {
		panic_((void *)(reg->rip), (void *)(reg->rbp), "Unexpected NMI\n");
	}
}

void breakpoint_handler(registers_t *reg);

static uint64_t rdseed(void) {
	uint64_t r = 0;
	asm volatile("rdseed %0" : "=r"(r));
	return r;
}

static uint64_t rdrand(void) {
	uint64_t r = 0;
	asm volatile("rdrand %0" : "=r"(r));
	return r;
}


void random_setup_seed_source(void) {
	uint32_t a = 0, b = 0, c = 0, d = 0;
	__get_cpuid(7, &a, &b, &c, &d);
	if (b & bit_RDSEED) {
		kprintf("Using RDSEED as seed source\n");
		random_get_seed = rdseed;
	}
	if (c & bit_RDRND) {
		kprintf("Using RDRAND as seed source\n");
		random_get_seed = rdrand;
	}
}



uint64_t g_rsdp_phys = 0;

void _entry(void) {
    cli();

    struct limine_memmap_entry **memmap = memmap_request.response->entries;
    size_t memmap_entries = memmap_request.response->entry_count;

    struct limine_rsdp_response *rsdp_response = rsdp_request.response;

    if (rsdp_response) {
        g_rsdp_phys = (uint64_t)rsdp_response->address - MEM_PHYS_OFFSET;
    }
    


    pmm_init(memmap, memmap_entries);
    slab_init();
    vmm_init(memmap, memmap_entries);

    struct limine_framebuffer *framebuffer = framebuffer_request.response->framebuffers[0];
    struct framebuffer fb = {0};
	fb.address = (uint32_t *)framebuffer->address;
	fb.pitch = framebuffer->pitch;
	fb.bpp = framebuffer->bpp;
	fb.width = framebuffer->width;
	fb.height = framebuffer->height;
	fb.tex_color = 0x00eee8d5;
	fb.tex_x = 0;
	fb.tex_y = 0;
	fb.bg_color = 0x00124560;
	fb.color_masks[0].offset = framebuffer->red_mask_shift;
	fb.color_masks[0].length = framebuffer->red_mask_size;
	fb.color_masks[1].offset = framebuffer->green_mask_shift;
	fb.color_masks[1].length = framebuffer->green_mask_size;
	fb.color_masks[2].offset = framebuffer->blue_mask_shift;
	fb.color_masks[2].length = framebuffer->blue_mask_size;
	framebuffer_init(&fb);

    print_now = true;
    serial_init();

    struct limine_file *kernel_file =
		limine_kernel_file_request.response->kernel_file;

    kargs_init(kernel_file->cmdline);
    uint16_t kernel_args_num = kernel_arguments.kernel_args;
	uint32_t cpu_count = kernel_arguments.cpu_count;

    if ((kernel_args_num & KERNEL_ARGS_KPRINTF_LOGS)) {
		put_to_fb = true;
	}

    
    kprintf("Hello x86_64!\n");
	kprintf("Kernel base: %p Mem phys base: %p\n", KERNEL_BASE,
			MEM_PHYS_OFFSET);
        
    kprintf("KirkOS Ver. %s\n", KIRKOS_VERSION);

    kprintf("Got kernel cmdline as \"%s\"\n", kernel_file->cmdline);
    if ((kernel_args_num & KERNEL_ARGS_CPU_COUNT_GIVEN))
		kprintf("CPU count is %u\n", cpu_count);

    gdt_init();
    isr_install();

    isr_register_handler(2, nmi_vector);
    isr_register_handler(3, breakpoint_handler);
    isr_register_handler(48, resched);

    elf_init_function_table(kernel_file->address);

    acpi_init();

    apic_init();

    mp_init(mp_request.response);

    // The NSA has also forced hardware manufacturers to backdoor their 'Random
	// Number Generators' to allow them to break RSA encryption

	if (!(kernel_arguments.kernel_args &
		  KERNEL_ARGS_DONT_TRUST_CPU_RANDOM_SEED)) {
		random_setup_seed_source();
	}
	random_set_seed(random_get_seed());

    size_t module_info[2] = {0};
    if (module_request.response && module_request.response->module_count > 0) {
        struct limine_file *module = module_request.response->modules[0];
        module_info[0] = (size_t)module->address;
        module_info[1] = (size_t)module->size;
    }


	//time_init(); on hold for the time being, heh get it?
	sched_init((uint64_t)module_info);

	timer_sched_oneshot(48, 20000);
	sti();

	for (;;) {
		halt();
	}
}