#define FOOLOS_MODULE_NAME "syscalls"

#include "lib/logger/log.h"
#include "lib/string/string.h"
#include "fs/fs.h"
#include "fs/ext2.h"
#include "kernel.h"
#include "fifo.h"
#include "fd.h"
#include "terminal/terminal.h"
#include "driver/screen.h"
#include <sys/stat.h>
#include <sys/time.h>
#include <stdbool.h>
#include <stddef.h>

// TODO: use includes!!!
uint64_t timer_get_ms();

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

static fifo fifos[MAX_FIFOS];
static uint32_t next_fifo=0;

// screen / terminal
term_out screen;
terminal_tty tty1;

int syscall_unhandled(int nr)
{
    char msg[256];
    tfp_sprintf(msg, "unhandled syscall : %d",nr);
    panic(FOOLOS_MODULE_NAME,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) 
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"lseek (file=%d, ptr=%d, dir=%d)", file,ptr,dir);
    #endif

    panic(FOOLOS_MODULE_NAME,"unhandled syscall: lseek");

    return 0;
}

// TODO: /dev/console or /dev/tty1 - /dev/ttyN
int syscall_write(int file, char *buf, int len)
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"[%d] write(file=%d, buf=0x%08X, len=%d)", task_get_current_pid(),file,buf,len);
    #endif

    for(int i=0;i<len;i++)
    {
	fd_write(&fds[file],buf[i]);
    }

    return len;
}

int syscall_read(int file, char *buf, int len)
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"read(file=%d, buf=0x%08X, len=%d)", file,buf,len);
    #endif
    //file 0 = stdin ,  file 1 = stdout , file 2 = stderr

    char c;
    int l=0;

    while(1)
    {
	while(!fd_has(&fds[file]));
	c=fd_read(&fds[file]);

	*buf=c;
	buf++;
	l++;

	if(l==len)return l;
	if(c=='\n')return l;
    }
}

//TODO: replace with dirent!
int syscall_readdir(const char *name,fs_dirent *dirs,int max)
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"readdir(name=0x%08X, dirs=0x%08X,  %d)", name,dirs,max);
    #endif

    return fs_readdir(name,dirs,max);
}

// for non blocking io?
int syscall_poll(int file)
{
    file=2; //workaround
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"has data waiting?");
    #endif

    return fd_has(&fds[file]);
}

// TODO: DELETE THIS SHIT!
int syscall_tune(int v1,int v2, int v3)
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"tuning request");
    #endif

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

    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"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;
}

int syscall_execve(char *name, char **argv, char **env)
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"execve (name=0x%08X(%s), argvs=0x%08X,  env=0x%08X)", name,name,argv,env);
    #endif

    int arg_count=0;
    while(argv[arg_count]!=NULL)arg_count++;

    char **argv1=kballoc(1);
    if(argv!=NULL)
    {
        copy_args(argv,argv1);
    }
    else{
	argv1=NULL;
    }

    char **env1=kballoc(1);
    if(env!=NULL)
    {
	copy_args(env,env1);
    }
    else{
	env1=NULL;
    }

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

    task_set_brk(alloc);

    if(!entry_global)
    {
	#ifdef LOG_SYSCALLS
	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"execve: bailing out!");
	#endif
	return -1; // errror loading
    }

    /* try to move this to asm */
    //    asm volatile("jmp ."); // loop forever
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"returning to jump addy (0x%08X)", entry_global);

    asm volatile("mov $0x8fff000,%esp"); // set stack at high end of process image

    asm volatile ("push %0" :: "r" (argv1));
    asm volatile ("push %0" :: "r" (arg_count));
    //asm volatile ("push %0" :: "r" (kballoc(1)));
    asm volatile ("push %0" :: "r" (env1));

    // push addr and return to it
    asm volatile ("pushl %0"::"r"(entry_global));

    asm volatile ("sti");
    asm volatile ("ret");

    // this is never reached!
}

// 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)
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"open (name=0x%08X(\"%s\"), flags=%d,  mode=%d)",name, name,flags,mode);
    #endif
    
    if( next_fifo>=MAX_FIFOS || next_fd>=MAX_FD)panic(FOOLOS_MODULE_NAME,"we ran out of fd's or fifo's");
    
    if(0!=strcmp(name,"term"))
    {
	fifos[next_fifo]=fifo_create_buffered(1);
	fds[next_fd]=fd_from_fifo(&fifos[next_fifo]);
    }
    else
    {
	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]);
    }

    next_fifo++;
    next_fd++;

    return next_fd-1;
}

//newcomers
//
int syscall_close(int file,int none1,int none2)  
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"close (file=%d)", file);
    #endif

    //if(file!=0&&file!=1&&file!=2)
    //    panic(FOOLOS_MODULE_NAME,"unhandled syscall: close");
    
    return -1;
}

// TODO: check if file is termminal!
int syscall_isatty(int file,int none1,int none2)  
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"isatty (file=%d)", file);
    #endif

    return 1;
}
uint32_t fuckalloc=0x8500000;

// TODO: per process basis!
uint32_t syscall_sbrk(int incr, int none1, int none2) 
{
    uint32_t alloc=task_get_brk();

    uint32_t oldalloc=fuckalloc;
    fuckalloc+=incr;

    task_set_brk(alloc);

    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"sbrk (incr=%d) = 0x%08X", incr,oldalloc);
    #endif

    return oldalloc;
}

// stat, fstat, lstat
int syscall_stat(const char *path, struct stat *st,int none)
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"stat (path=0x%08X,stat=0x%08X)", path,st);
    #endif

    st->st_mode = S_IFCHR;
    return 0;
}