#include "rc.h"
#include "parse.h"

#define CAP0 512

Io*
openfd(int fd)
{
    Io *io = emalloc(sizeof(*io) + CAP0);

    io->fd  = fd;
    io->cap = CAP0;
    io->b   = io->e = io->buf;
    io->s   = nil;

    return io;
}

Io*
openstr(void)
{
    char *s;
    Io *io = emalloc(sizeof(*io) + CAP0);

    io->fd  = -1;
    io->cap = CAP0;
    io->b   = io->s = emalloc(101);
    io->e   = io->b+100;

    for(s = io->b; s<=io->e; s++)
        *s=0;

    return io;
}

#if 0
/*
 * open a corebuffer to read. EOF occurs after reading len characters from buf
 */

Io*
opencore(char *s, int len)
{
    Io *io = emalloc(sizeof(*io));
    char *buf = emalloc(len);
    io->fd = -1 /*open("/dev/null", 0)*/;
    io->b  = io->s = buf;
    io->e  = buf+len;
    memcpy(buf, s, len);

    return io;
}
#endif

void
iorewind(Io *io)
{
    if(io->fd==-1)
        io->b = io->s;
    else{
        io->b = io->e = io->buf;
        lseek(io->fd, 0L, 0);
    }
}

void
terminate(Io *io)
{
    if(io->fd>=0)
        close(io->fd);
    if(io->s)
        efree(io->s);

    efree((char *)io);
}

static
int
refill(Io *io)
{
    int n;

    if(io->fd==-1 || (n = read(io->fd, io->buf, io->cap))<=0)
        return EOF;

    io->b = io->buf;
    io->e = io->buf+n;

    return *io->b++&0xff;
}


void
flush(Io *io)
{
    int n;
    char *s;

    if(io->s){
        n = io->e-io->s;
        io->s = realloc(io->s, n+101);
        if(io->s==0)
            panicf("Can't realloc %d bytes in flush!", n+101);
        io->b = io->s+n;
        io->e = io->b+100;
        for(s = io->b;s<=io->e;s++) *s='\0';
    }else{
        n = io->b-io->buf;
        if(n && write(io->fd, io->buf, n) < 0)
            write(3, "write error\n", 12);
        io->b = io->buf;
        io->e = io->buf + io->cap;
    }
}


static
void
printchar(Io *io, int c)
{
    if(io->b==io->e)
        flush(io);

    *io->b++=c;
}

void
printquote(Io *io, char *s)
{
    printchar(io, '\'');
    for(;*s;s++)
        if(*s=='\'')
            print(io, "''");
        else printchar(io, *s);
    printchar(io, '\'');
}

void
printstr(Io *io, char *s)
{
    if(s==0)
        s="(null)";
    while(*s) printchar(io, *s++);
}

void
printword(Io *io, char *s)
{
    char *t;

    for(t = s;*t;t++)
        if(!iswordchar(*t))
            break;

    if(t==s || *t)
        printquote(io, s);
    else
        printstr(io, s);
}

void
printptr(Io *io, void *v)
{
    int n;
    uintptr p;

    p = (uintptr)v;
    if(sizeof(uintptr) == sizeof(uvlong) && p>>32)
        for(n = 60;n>=32;n-=4) printchar(io, "0123456789ABCDEF"[(p>>n)&0xF]);

    for(n = 28;n>=0;n-=4) printchar(io, "0123456789ABCDEF"[(p>>n)&0xF]);
}

static
void
printint(Io *io, int n)
{
    if(n<0){
        if(n!=INT_MIN){
            printchar(io, '-');
            printint(io, -n);
            return;
        }
        /* n is two's complement minimum integer */
        n = -(INT_MIN+1);
        printchar(io, '-');
        printint(io, n/10);
        printchar(io, n%10+'1');
        return;
    }
    if(n>9)
        printint(io, n/10);
    printchar(io, n%10+'0');
}

static
void
printoct(Io *io, unsigned n)
{
    if(n>7)
        printoct(io, n>>3);
    printchar(io, (n&7)+'0');
}

static
void
printval(Io *io, Word *a)
{
    if(a){
        while(a->link && a->link->str){
            printword(io, a->str);
            printchar(io, ' ');
            a = a->link;
        }
        printword(io, a->str);
    }
}

#define C0 t->child[0]
#define C1 t->child[1]
#define C2 t->child[2]

static
void
printtree(Io *io, Tree *t)
{
    if(!t)
        return;

    switch(t->type){
    default: print(io, "bad(%d)[%p %p %p]", t->type, C0, C1, C2); break;
    case '$': print(io,"$%t",C0);      break;
    case '&': print(io,"%t&",C0);      break;
    case '^': print(io,"%t^%t",C0,C1); break;
    case '`': print(io,"`%t",C0);      break;

    case Tbasic:    print(io, "%t", C0);    break;
    case Tbang:     print(io, "!%t", C0);   break;
    case Tblock:    print(io, "{%t}", C0);  break;
    case Tcount:    print(io, "$#%t", C0);  break;
    case Tparen:    print(io, "(%t)", C0);  break;
    case Tjoin:     print(io,"$\"%t",C0);   break;
    case Tindex:    print(io, "%t(%t)",C0); break;
    case Tsubshell: print(io, "@ %t",C0);   break;
    //case Ttwiddle:  print(io, "~ %t %t", C0, C1);  break;

    case Toror:
    case Tandand:

    case Targs:
        if(!C0)
            print(io, "%t", C1);
        else if(!C1)
            print(io, "%t", C0);
        else
            print(io, "%t %t", C0, C1);
        break;

    case ';':
        if(C0){
            if(C1)
                print(io, "%t;%t", C0, C1);
            else
                print(io, "%t", C0);
        }else
            print(io, "%t", C1);
        break;

    case Twords:
        if(C0)
            print(io, "%t", C0);
        print(io, "%t", C1);

    case Tword:
        if(t->quoted)
            print(io, "%Q", t->str);
        print(io, "%q", t->str);
        break;

    case '=':
        print(io, "%t=%t", C0, C1);
        if(C2)
            print(io, " %t", C2);
        break;

    case Tdup:
        if(t->redir.type == Rdupfd)
            print(io, ">[%d=%d]", t->redir.fd[1], t->redir.fd[0]);
        else
            print(io, ">[%d=]", t->redir.fd[0]);
        print(io, "%t", C1);
        break;

    case Tredir:
        switch(t->redir.type){
        case Rhere:
            printchar(io, '<');
        case Rread:
            printchar(io, '<');
            goto readfd;
        case Rrdwr:
            printchar(io, '<');
            printchar(io, '>');
        readfd:
            if(t->redir.fd[0]!=0)
                print(io, "[%d]", t->redir.fd[0]);
            break;
        case Rappend:
            printchar(io, '>');
            goto writefd;
        case Rwrite:
            printchar(io, '>');
            printchar(io, '>');
        writefd:
            if(t->redir.fd[0]!=1)
                print(io, "[%d]", t->redir.fd[0]);
            break;
        }
        print(io, "%t", C0);
        if(C1)
            print(io, " %t", C1);
        break;

    case Tpipe:
        print(io, "%t|", C0);
        if(t->redir.fd[1]==0){
            if(t->redir.fd[0]!=1)
                print(io, "[%d]", t->redir.fd[0]);
        }
        else
            print(io, "[%d=%d]", t->redir.fd[0], t->redir.fd[1]);
        print(io, "%t", C1);
        break;
    }
}

#undef C0
#undef C1
#undef C2

// -----------------------------------------------------------------------
// exports

/* readers */
int
get(Io *io)
{
    if(io->b==io->e)
        return refill(io);

    return *io->b++ & 0xFF;
}

/* writers */
int
put(Io **iop, char c)
{
    int nb, ne, nc;
    Io *io  = *iop;
    char *e = io->b + io->cap;

    if(io->e == e){
        nb = io->b - io->buf;
        ne = io->e - io->buf;
        nc = 2*io->cap;

        if(!(io = erealloc(io, sizeof(*io)+nc)))
            return 0;

        io->b   = io->buf + nb;
        io->e   = io->buf + ne;
        io->cap = nc;

        *iop = io;
    }

    *io->e++ = c;
    return 1;
}

/* printers */
static int pfmtnest;

void
print(Io *io, char *fmt, ...)
{
    va_list args;
    char err[ERRMAX];

    va_start(args, fmt);
    pfmtnest++;

    for(;*fmt;fmt++)
        if(*fmt!='%')
            printchar(io, *fmt);
        else
            switch(*++fmt){
            case '\0':
                va_end(args);
                return;
            case 'c':
                printchar(io, va_arg(args, int));
                break;
            case 'd':
                printint(io, va_arg(args, int));
                break;
            case 'o':
                printoct(io, va_arg(args, unsigned));
                break;
            case 'p':
                printptr(io, va_arg(args, void*));
                break;
            case 'Q':
                printquote(io, va_arg(args, char *));
                break;
            case 'q':
                printword(io, va_arg(args, char *));
                break;
            case 's':
                printstr(io, va_arg(args, char *));
                break;
            case 't':
                printtree(io, va_arg(args, struct Tree *));
                break;
            case 'v':
                printval(io, va_arg(args, struct Word *));
                break;
            default:
                printchar(io, *fmt);
                break;
            }

    va_end(args);

    if(--pfmtnest==0)
        flush(io);
}