#define FOOLOS_MODULE_NAME "syscalls"

#include "lib/buffer/ringbuffer.h"
#include "lib/logger/log.h"
#include "fs/fs.h"
#include "fs/ext2.h"
#include "kernel/console.h"
#include "kernel/config.h"
#include <sys/stat.h>
#include  <stdbool.h>
#include  <stddef.h>

int syscall_unhandled(int nr)
{
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"syscall: %d", nr);
    panic(FOOLOS_MODULE_NAME,"unhandled syscall (generic handler)");
}

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)
{
    lock_spin(2);

    //x86_int_disable();
    #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

    if(file!=1&&file!=2) panic(FOOLOS_MODULE_NAME,"unhandled syscall: write (only stdout and stderr)");

    //stderr and stdout go to console
    for(int i=0;i<len;i++)
    {
	console_put_char_green(buf[i]);
    }
    lock_release(2);
    //x86_int_enable();
    return len;
}

// TODO: /dev/kb
int syscall_read(int file, char *buf, int len)
{
    static bool eof=false;

    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"read(file=%d, buf=0x%08X, len=%d)", file,buf,len);
    #endif


    // stdin TODO: other descroptiors!
    if(file!=0) panic(FOOLOS_MODULE_NAME,"unhandled syscall: read (only stdin)");
    {
	if(eof)
	{
	    eof=false;
	    return 0;
	}
    
	char c;
	int l=0;

	while(1)
	{
	    bool ret=ringbuffer_get(&c);
	    
	    if(ret)
	    {
		if(c==0x08)
		{
		    if(l>0)
		    {
			console_del_char();
			buf--;
			l--;
		    }
		}
		else{

		    *buf=c;
		    buf++;
		    l++;
		    if(c!=0x04)console_put_char_white(c);
		    if(c=='\n')return l;
		    if(c==0x04)
		    {
			l--;
			buf--;
			eof=true;
			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);
}

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 **argv1, char **env1)
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"execve (name=0x%08X(%s), argvs=0x%08X,  env=0x%08X)", name,name,argv1,env1);
    #endif

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

    asm volatile ("push %0" :: "r" (argv1));
    asm volatile ("push %0" :: "r" (arg_count));
    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!
}


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
    panic(FOOLOS_MODULE_NAME,"unhandled syscall: open");
}


//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;
}

int syscall_fstat(int file, struct stat *st,int none)
{
    #ifdef LOG_SYSCALLS
    log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"fstat (file=%d,stat=0x%08X)", file,st);
    #endif

    st->st_mode = S_IFCHR;
    return 0;
}


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

    st->st_mode = S_IFCHR;
    return 0;
}