#include "isr.h"
#include "pic.h"
#include "process.h"
#include "syscall.h"
#include "keyboard.h"
#include "floppy.h"
#include "ne2000.h"
#include "e3c509.h"
#include <stdint.h>

/* Forward declaration for kernel panic or similar */
void offset_print(const char *str);
void print_hex(uint32_t val);

/* Exception messages */
char *exception_messages[] = {
    "Division By Zero",
    "Debug",
    "Non Maskable Interrupt",
    "Breakpoint",
    "Into Detected Overflow",
    "Out of Bounds",
    "Invalid Opcode",
    "No Coprocessor",
    "Double Fault",
    "Coprocessor Segment Overrun",
    "Bad TSS",
    "Segment Not Present",
    "Stack Fault",
    "General Protection Fault",
    "Page Fault",
    "Unknown Interrupt",
    "Coprocessor Fault",
    "Alignment Check",
    "Machine Check",
    "Reserved",
    "Reserved",
    "Reserved",
    "Reserved",
    "Reserved",
    "Reserved",
    "Reserved",
    "Reserved",
    "Reserved",
    "Reserved",
    "Reserved",
    "Reserved",
    "Reserved"
};

void isr_handler(registers_t *regs)
{
    /* System call (INT 0x80) */
    if (regs->int_no == 0x80) {
        syscall_handler(regs);
        return;
    }

    /* Hardware interrupts (IRQs 0-15, mapped to vectors 32-47) */
    if (regs->int_no >= 32 && regs->int_no < 48) {
        /* Send EOI to PIC (IRQ number 0-15) */
        pic_send_eoi(regs->int_no - 32);
    
        if (regs->int_no == 32) {
            /* Timer tick - invoke scheduler */
            schedule_tick(regs);
        } else if (regs->int_no == 33) {
            /* Keyboard IRQ */
            keyboard_irq(regs);
        } else if (regs->int_no == 38) {
            /* Floppy IRQ */
            floppy_irq();
        } else if (regs->int_no == 41) {
            /* NE2000 Ethernet IRQ (IRQ 9, vector 41) */
            ne2k_irq();
        } else if (regs->int_no == 42) {
            /* 3C509B Ethernet IRQ (IRQ 10, vector 42) */
            e3c509_irq();
        }
        return;
    }

    /* CPU exceptions (vectors 0-31) */
    offset_print("received interrupt: ");
    print_hex(regs->int_no);
    offset_print("\n");

    if (regs->int_no < 32)
    {
        offset_print(exception_messages[regs->int_no]);
        offset_print(" Exception. System Halted!\n");
        offset_print("  EIP: ");
        print_hex(regs->eip);
        offset_print("  CS:  ");
        print_hex(regs->cs);
        offset_print("  ERR: ");
        print_hex(regs->err_code);
        for (;;) ;
    }
}