/* NATUSER Shell — FULL real commands. N=7 */
#include "../kernel.h"
#define COM1 0x3F8
#define MAX_LINE 256
#define MAX_ARGS 32
static char line[MAX_LINE];
static char* argv[MAX_ARGS];
static inline int seq(const char* a, const char* b) { while(*a&&*a==*b){a++;b++;} return *a==*b; }
static inline void serial_init(void) { 
    outb(COM1+1,0);outb(COM1+3,0x80);outb(COM1+0,1);outb(COM1+1,0);
    outb(COM1+3,3);outb(COM1+2,0xC7);outb(COM1+4,0x0B);
    inb(COM1); /* flush any pending byte */
}
static inline int serial_rx(void) { return inb(COM1+5)&1; }
static inline char serial_getc(void) { while(!serial_rx()); return inb(COM1); }
static inline void serial_putc(char c) { while(!(inb(COM1+5)&0x20)); outb(COM1, c); }
static void serial_puts(const char* s) { for(;*s;s++) serial_putc(*s); }
static void serial_putn(u32 n) { char b[16]; int i=15; b[15]=0; do{b[--i]='0'+n%10;n/=10;}while(n); serial_puts(b+i); }
static u32 read_line(void) {
    u32 pos=0;
    for(;;){char c=serial_getc();if(c=='\r'||c=='\n'){line[pos]=0;serial_putc('\n');break;}
    if(c=='\b'||c==0x7F){if(pos>0){pos--;serial_putc('\b');serial_putc(' ');serial_putc('\b');}continue;}
    if(pos<MAX_LINE-1){line[pos++]=c;serial_putc(c);}}
    return pos;
}
static int parse_cmd(void) {
    u32 argc=0;char*p=line;while(*p==' ')p++;if(!*p)return 0;argv[argc++]=p;
    while(*p){if(*p==' '){*p=0;p++;while(*p==' ')p++;if(*p&&argc<MAX_ARGS)argv[argc++]=p;continue;}p++;}
    argv[argc]=NULL;return argc;
}
static void cmd_ls(void){char b[512];u32 r=vfs_list(0,b,512);if(!r){serial_puts("(empty)\n");return;}for(u32 i=0;i<r;i++)serial_putc(b[i]);}
static void cmd_ps(void){serial_puts("PID  STATE\n");for(u32 i=0;i<256;i++){Process* p=sched_procs(i);if(!p||p->pid==0)continue;serial_putn(p->pid);switch(p->state){case PROC_READY:serial_puts(" READY\n");break;case PROC_RUNNING:serial_puts(" RUNNING\n");break;case PROC_BLOCKED:serial_puts(" BLOCKED\n");break;default:serial_puts(" ?\n");}}serial_puts("Total: ");serial_putn(sched_count());serial_putc('\n');}
static void cmd_cat(const char* n){u32 f=vfs_open(n,0);if(!f){serial_puts("No file\n");return;}char b[256];u32 r;while((r=vfs_read(f,b,255))>0){b[r]=0;serial_puts(b);}vfs_close(f);}
static void cmd_write(const char* n,const char* c){u32 f=vfs_open(n,4);if(!f){serial_puts("Cannot create\n");return;}u32 l=0;while(c[l])l++;u32 w=vfs_write(f,c,l);vfs_close(f);serial_puts("OK ");serial_putn(w);serial_puts(" bytes\n");}
static void cmd_hash(const char* d){u32 l=0;while(d[l])l++;u8 h[32];sha256((u8*)d,l,h);for(int i=0;i<32;i++){serial_putc("0123456789abcdef"[h[i]>>4]);serial_putc("0123456789abcdef"[h[i]&0xF]);}serial_putc('\n');}
static void cmd_mem(void){serial_puts("Free: ");serial_putn(get_free()*4096/1024);serial_puts(" KB  Used: ");serial_putn(get_allocated());serial_puts(" pages\n");}
static void worker_a(void){for(volatile u64 i=0;i<20000000;i++)asm volatile("nop");}
static void cmd_spawn(void){u32 p=sched_spawn(worker_a);if(p){serial_puts("PID=");serial_putn(p);serial_putc('\n');}else{serial_puts("No slots\n");}}
void shell_run(void) {
    serial_init();
    for(volatile u32 d=0;d<100000;d++) asm volatile("nop");
    serial_puts("\n===== NATKERNEL v3.0 =====\n");
    serial_puts("ls ps cat write hash mem spawn ver exit\n\n");
    for(;;){
        serial_puts("> ");
        if(!read_line()||!line[0]) continue;
        int argc=parse_cmd();if(!argc)continue;
        if(seq(argv[0],"exit")){serial_puts("Bye\n");break;}
        else if(seq(argv[0],"ver"))serial_puts("N=7\n");
        else if(seq(argv[0],"ls"))cmd_ls();
        else if(seq(argv[0],"ps"))cmd_ps();
        else if(seq(argv[0],"cat")){if(argc>1)cmd_cat(argv[1]);}
        else if(seq(argv[0],"write")){if(argc>2)cmd_write(argv[1],argv[2]);}
        else if(seq(argv[0],"hash")){if(argc>1)cmd_hash(argv[1]);}
        else if(seq(argv[0],"mem"))cmd_mem();
        else if(seq(argv[0],"spawn"))cmd_spawn();
        else if(seq(argv[0],"echo")){for(int i=1;i<argc;i++){serial_puts(argv[i]);if(i<argc-1)serial_putc(' ');}serial_putc('\n');}
        else{serial_puts("?\n");}
    }
}