#include "lib/string/string.h"
#include "lib/printf/printf.h"
#include "fs/ext2.h"
#include "kernel.h"
#include "driver/vesa.h"
#include "fifo.h"
#include "fd.h"
#include "fs/elf.h"
#include "driver/terminal.h"
#include "driver/screen.h"
#include <sys/stat.h>
#include <sys/time.h>
#include <stdbool.h>
#include <stddef.h>
#include "syscalls.h"
#include "scheduler.h"
#include "log.h"
#include "timer.h"
#include "mount.h"
#include "mem.h"
#include "reent.h"
#include "errno.h"

void set_errno(int no)
{
    struct _reent *impure_ptr=VMEM_USER_NEWLIB;
    impure_ptr->_errno=no;
}

static fd fds[MAX_FD];
static uint32_t next_fd=0;

// fifos for backing up some file descrpitors
static fifo fifos[MAX_FIFOS];
static uint32_t next_fifo=0;

// screen / terminal
term_out screen;
terminal_tty tty1;

char* syscall_get_name(uint32_t num)
{
    switch(num)
    {
	case 60:
	    return "SYSCALL_EXIT"; 
	case 66:
	    return "SYSCALL_CLOSE"; 
	case 64:
	    return "SYSCALL_EXECVE"; 
	case 72:
	    return "SYSCALL_FORK"; 
	case 78:
	    return "SYSCALL_GETPID"; 
	case 68:
	    return "SYSCALL_ISATTY"; 
	case 82:
	    return "SYSCALL_LINK"; 
	case 69:
	    return "SYSCALL_LSEEK"; 
	case 65:
	    return "SYSCALL_OPEN"; 
	case 62:
	    return "SYSCALL_READ"; 
	case 70:
	    return "SYSCALL_SBRK"; 
	case 74:
	    return "SYSCALL_STAT"; 
	case 67:
	    return "SYSCALL_FSTAT"; 
	case 79:
	    return "SYSCALL_LSTAT"; 
	case 75:
	    return "SYSCALL_TIMES"; 
	case 76:
	    return "SYSCALL_UNLINK"; 
	case 77:
	    return "SYSCALL_WAIT"; 
	case 61:
	    return "SYSCALL_WRITE"; 
	case 71:
	    return "SYSCALL_GETTIMEOFDAY"; 
	case 63:
	    return "SYSCALL_READDIR"; 
	case 73:
	    return "SYSCALL_KILL"; 
	case 80:
	    return "SYSCALL_POLL"; 
	case 83:
	    return "SYSCALL_CLONE"; 
    }
    return "UNKNOWN SYSCALL NUM";
}

int syscall_unhandled(int nr)
{
    char msg[256];
    tfp_sprintf(msg, "unhandled syscall : %d",nr);
    kpanic("%s",msg);
}

int syscall_gettimeofday(struct timeval *tv, struct timezone *tz)
{
    if(tv!=NULL)
    {
	uint64_t t=timer_get_ms();
	tv->tv_sec=t/1000+2*3600; // add gmt+2
	tv->tv_usec=0;//t-tv->tv_sec*1000;
    }

    // tz struct is obsolote
    if(tz!=NULL)
    {
	tz->tz_minuteswest=0;// -21*60; // warsaw
	tz->tz_dsttime=DST_NONE;
    }
    return 0;
}

int syscall_lseek(int file,int ptr,int dir) 
{

#ifndef SEEK_SET
#define	SEEK_SET	0	/* set file offset to offset */
#endif
#ifndef SEEK_CUR
#define	SEEK_CUR	1	/* set file offset to current plus offset */
#endif
#ifndef SEEK_END
#define	SEEK_END	2	/* set file offset to EOF plus offset */
#endif

    if(dir==SEEK_CUR)
    {
	uint32_t *dat=fds[file].data;
	dat[1]+=ptr;
	return dat[1];
    }

    kpanic("not fully handled lseek! dir=%d",dir);
    return 0;
}

// TODO: /dev/console or /dev/tty1 - /dev/ttyN
int syscall_write(int file, char *buf, int len)
{
    for(int i=0;i<len;i++)
    {
	fd_write(&fds[file],buf[i]);
    }
    return len;
}

/** 
 * __read()__ attemts to read up to _len_ bytes from file descriptor _file_ 
 * into the buffer starting at _buf_. 
 */
int syscall_read(int file, char *buf, int len)
{
	if(fd_eof(&fds[file]))return 0;
        *buf=fd_read(&fds[file]);
	return 1;
}

//TODO: replace with dirent!
int syscall_readdir(const char *name,fs_dirent *dirs,int *pos)
{
    int ret=mount_read_dir(name, dirs, pos);
    if(ret==-1)
    {
	set_errno(ENOENT);
    }
    return ret;
}

// for non blocking io?
int syscall_poll(int file)
{
    file=2; //workaround

    return fd_has(&fds[file]);
}

// TODO: DELETE THIS SHIT!
int syscall_tune(int v1,int v2, int v3)
{

    // osbolete
    /*
    if(v1==0) // regular tty mode
    {
	get_fool()->tty->set_buff=true;
	get_fool()->tty->set_echo=true;
    }
    if(v1==1) // gaming tty mode
    {
	get_fool()->tty->set_buff=false;
	get_fool()->tty->set_echo=false;
    }
    */

    return 0;
}

int copy_args(char **in, char **out)
{
    //klog("copy_args(0x%08x, 0x%08X)",in,out);
    int count=0;
    while(in[count]!=NULL)
    {
//	klog("args(0x%08x: %s)",in[count],out);
	count++;
    };

  //  klog("copy_args : count: %d",count);
    
    char **pos=out;
    pos+=sizeof(char **)*(count+1); 

    int i=0;
    do{
	int l=strlen(in[i]);
	char *var=pos;
	memcpy(var,in[i],l+1);
	pos+=sizeof(char *)*(l+1); 
	out[i]=var;
	i++;
    }while(in[i]!=NULL);
    out[i]=NULL;

    return count;
}

/** does not return on success otherwise -1 and errrno set */
int syscall_execve(const char *name, char *const argv[], char *const env[], int pid)
{

    fixme("not overwrite yourself?");
    int arg_count=0;
    while(argv[arg_count]!=NULL)arg_count++;

    char **argv1=VMEM_USER_ENV;
    if(argv!=NULL)copy_args(argv,argv1);
    else argv1=NULL;

    char **env1=VMEM_USER_ENV+1024*2;
    if(env!=NULL)copy_args(env,env1);
    else env1=NULL;

    uint32_t alloc;
    uint32_t entry_global=load_elf(name,&alloc);

    if(!entry_global){
	set_errno(ENOENT);
	return -1;
    }

    uint32_t *stack=VMEM_USER_STACK_TOP-4*32;
    *--stack=argv1;
    *--stack=arg_count;
    *--stack=env1;
    task_reset(pid,entry_global,stack,alloc);
    return 0;
}

// minihack
int get_max_fd()
{
    return next_fd-1;
}

// TODO: support other files too (not only fifo pipes)
// TODO: allow opening existing files/named pipes
int syscall_open(char *name, int flags, int mode)
{
    if( next_fifo>=MAX_FIFOS || next_fd>=MAX_FD)kpanic("we ran out of fd's or fifo's");

    bool create_fifo=true;
    if(name[0]!='~')create_fifo=false;

    if(create_fifo)
    {

	if(!strcmp(name,"~term")) 
	{
		screen.put_char=console_put_char;
		screen.update_cursor=update_cursor;

		tty1=terminal_init(&screen,NULL);

		fifos[next_fifo].data=&tty1;
		fifos[next_fifo].put=terminal_put;

		fds[next_fd]=fd_from_fifo(&fifos[next_fifo]);
	}
	else if(!strcmp(name,"~xterm")) 
	{
		screen.put_char=vesa_console_put_char;
		screen.update_cursor=vesa_update_cursor;

		tty1=terminal_init(&screen,NULL);

		fifos[next_fifo].data=&tty1;
		fifos[next_fifo].put=terminal_put;

		fds[next_fd]=fd_from_fifo(&fifos[next_fifo]);
	}
	else
	{
	    fifos[next_fifo]=fifo_create_buffered(1);
	    fds[next_fd]=fd_from_fifo(&fifos[next_fifo]);
	}
	
	next_fifo++;
    }
    else
    {
	fds[next_fd]=mount_file_open(name);
	if(*(uint32_t *)fds[next_fd].data==0)return -1;
    }

    next_fd++;
    return next_fd-1;
}
uint32_t syscall_fork(int pid)
{
    return task_fork(pid);

}
uint32_t syscall_clone(int pid)
{
    return task_clone(pid);
}

uint32_t syscall_wait(int pid)
{
    return 0;
}

uint32_t syscall_exit(int pid)
{
    fixme("free allll mem");
    task_exit(pid);
    return 0;
}

//newcomers
//
int syscall_close(int file,int none1,int none2)  
{
    if(file<3)return 0;
    fd_close(&fds[file]);
    return 0;
}

// TODO: check if file is termminal!
int syscall_isatty(int file,int none1,int none2)  
{
    return 1;
}

// TODO: per process basis!
uint32_t syscall_sbrk(uint32_t incr, int none1, int none2, uint32_t pid) 
{
    uint32_t alloc=task_get_brk(pid);
    uint32_t oldalloc=alloc;
    alloc+=incr;
    task_set_brk(pid,alloc);
    fixme("fake syscall_sbrk(0x%08X) return %08X",incr,oldalloc);
    return oldalloc;
}

// stat, fstat, lstat
int syscall_stat(const char *path, struct stat *st,int none)
{
    st->st_mode = S_IFCHR;
    return 0;
}

/// there also is task_fork, task_wait, task_exit.. which is in scheduler.c
////////////////////////////////////////
uint32_t syscall_generic_test(uint32_t nr,uint32_t p1, uint32_t p2, uint32_t p3, uint32_t pid)
{
    switch(nr){
	case SYSCALL_WAIT :
	    return !task_runs(p1);
	case SYSCALL_READ :
	    return fd_has(&fds[p1]);
	case SYSCALL_EXIT :
	    return 1;
    }
    return 1;
}

uint32_t syscall_generic(uint32_t nr,uint32_t p1, uint32_t p2, uint32_t p3, uint32_t pid)
{
    switch(nr){
	case SYSCALL_EXIT :
	    return syscall_exit(pid);
	case  SYSCALL_CLOSE       :
	    return syscall_close(p1,p2,p3);
	case  SYSCALL_EXECVE      :
	    return syscall_execve(p1,p2,p3,pid);
	case  SYSCALL_FORK        :
	    return syscall_fork(pid);
	case  SYSCALL_CLONE        :
	    return syscall_clone(pid);
	case  SYSCALL_GETPID      :
    //	return syscall_getpid(p1,p2,p3);
	    return -1;
	case  SYSCALL_ISATTY      :
	    return syscall_isatty(p1,p2,p3);
	case  SYSCALL_LINK        :
    //	return syscall_link(p1,p2,p3);
	    return -1;
	case  SYSCALL_LSEEK       :
	    return syscall_lseek(p1,p2,p3);
	case  SYSCALL_OPEN        :
	    return syscall_open(p1,p2,p3);
	case  SYSCALL_READ        :
	    return syscall_read(p1,p2,p3);
	case  SYSCALL_SBRK        :
	    return syscall_sbrk(p1,p2,p3,pid);
	case  SYSCALL_STAT        :
	    return syscall_stat(p1,p2,p3);
	case  SYSCALL_FSTAT       :
	    return syscall_stat(p1,p2,p3);
	case  SYSCALL_LSTAT       :
	    return syscall_stat(p1,p2,p3);
	case  SYSCALL_TIMES       :
    //	return syscall_times(p1,p2,p3);
	    return -1;
	case  SYSCALL_UNLINK      :
    //	return syscall_unlink(p1,p2,p3);
	    return -1;
	case  SYSCALL_WAIT        :
	    return syscall_wait(pid);
	case  SYSCALL_WRITE       :
	    return syscall_write(p1,p2,p3);
	case  SYSCALL_GETTIMEOFDAY:
	    return syscall_gettimeofday(p1,p2);
	case  SYSCALL_READDIR     :
	    return syscall_readdir(p1,p2,p3);
	case  SYSCALL_KILL        :
    //	return task_kill(p1,p2,p3);
	    return -1;
	case  SYSCALL_POLL        :
	    return syscall_poll(p1);
    }
    return -1;
}