/* CubeCactusOS Kernel - Main Entry Point
 * Based on MINIX3 Microkernel Architecture
 */

#include "kernel.h"

/* Kernel library functions */
extern int printf(const char* format, ...);
extern void outb(uint16_t port, uint8_t value);
extern uint8_t inb(uint16_t port);

/* Kernel version information */
#define OS_NAME "CubeCactusOS"
#define OS_VERSION "0.1.0"
#define KERNEL_VERSION "1.0"

/* External functions */
extern void init_hardware();
extern void init_memory();
extern void init_processes();
extern void init_ipc();
extern void init_clock();
extern void scheduler();

/* Kernel panic handler */
void kernel_panic(const char* message) {
    printf("\n*** KERNEL PANIC ***\n");
    printf("Message: %s\n", message);
    printf("System halted.\n");
    
    /* Halt the system */
    for(;;) {
        __asm__ __volatile__("hlt");
    }
}

/* Kernel initialization */
void kernel_init() {
    printf("Initializing %s v%s\n", OS_NAME, OS_VERSION);
    printf("Kernel version: %s\n", KERNEL_VERSION);
    
    /* Initialize hardware */
    printf("Initializing hardware...\n");
    init_hardware();
    
    /* Initialize memory management */
    printf("Initializing memory management...\n");
    init_memory();
    
    /* Initialize process management */
    printf("Initializing process management...\n");
    init_processes();
    
    /* Initialize IPC (Inter-Process Communication) */
    printf("Initializing IPC subsystem...\n");
    init_ipc();
    
    /* Initialize clock/timer */
    printf("Initializing system clock...\n");
    init_clock();
    
    printf("Kernel initialization complete.\n");
}

/* Main kernel entry point */
int main() {
    /* Initialize kernel subsystems */
    kernel_init();
    
    printf("\n%s is now running!\n", OS_NAME);
    printf("Entering scheduler...\n\n");
    
    /* Start the scheduler - this should never return */
    scheduler();
    
    /* If we get here, something went wrong */
    kernel_panic("Scheduler returned unexpectedly");
    
    return 0;
}

/* Stub implementations - to be replaced with actual code */

void init_hardware() {
    /* TODO: Initialize CPU, interrupts, devices */
    printf("  - Hardware initialized (stub)\n");
}

void init_memory() {
    /* TODO: Set up page tables, memory allocator */
    printf("  - Memory management initialized (stub)\n");
}

void init_processes() {
    /* TODO: Create process table, init process */
    printf("  - Process management initialized (stub)\n");
}

void init_ipc() {
    /* TODO: Set up message passing mechanism */
    printf("  - IPC subsystem initialized (stub)\n");
}

void init_clock() {
    /* TODO: Set up timer interrupts */
    printf("  - System clock initialized (stub)\n");
}

void scheduler() {
    /* TODO: Implement MINIX3-style scheduler */
    printf("  - Scheduler initialized\n\n");
    
    /* Start the shell */
    extern void shell_main();
    shell_main();
    
    /* If shell returns, halt */
    for(;;) {
        __asm__ __volatile__("hlt");
    }
}