/* Copyright (C) 2001-2021 Artifex Software, Inc.
   All Rights Reserved.

   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied,
   modified or distributed except as expressly authorized under the terms
   of the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact
   Artifex Software, Inc.,  1305 Grant Avenue - Suite 200, Novato,
   CA 94945, U.S.A., +1(415)492-9861, for further information.
*/


/* pxstream.c */
/* PCL XL user-defined stream operators */

#include "memory_.h"
#include "gsmemory.h"
#include "scommon.h"
#include "pxoper.h"
#include "pxstate.h"
#include "pxparse.h"
#include "pxptable.h"

/* ---------------- Internal procedures ---------------- */

/* Tag a stream name with its character width. */
static int
tag_stream_name(const px_value_t * psnv, gs_string * pstr,
                gs_memory_t * mem, client_name_t cname)
{
    uint size = array_value_size(psnv);
    byte *str = gs_alloc_string(mem, size + 1, cname);

    if (str == 0)
        return_error(errorInsufficientMemory);
    str[0] = value_size(psnv);
    memcpy(str + 1, psnv->value.array.data, size);
    pstr->data = str;
    pstr->size = size + 1;
    return 0;
}

/* ---------------- Operators ---------------- */

const byte apxBeginStream[] = {
    pxaStreamName, 0, 0
};
int
pxBeginStream(px_args_t * par, px_state_t * pxs)
{
    int code = tag_stream_name(par->pv[0], &pxs->stream_name, pxs->memory,
                               "pxBeginStream(name)");

    if (code < 0)
        return code;
    pxs->stream_def.size = 0;
    pl_dict_undef(&pxs->stream_dict, pxs->stream_name.data,
                  pxs->stream_name.size);
    return 0;
}

const byte apxReadStream[] = {
    pxaStreamDataLength, 0, 0
};
int
pxReadStream(px_args_t * par, px_state_t * pxs)
{
    ulong len = par->pv[0]->value.i;
    ulong copy = min(len - par->source.position, par->source.available);
    uint old_size = pxs->stream_def.size;
    byte *str;

    if (copy == 0)
        return pxNeedData;
    if (old_size == 0)
        str = gs_alloc_bytes(pxs->memory, copy, "pxReadStream");
    else
        str = gs_resize_object(pxs->memory, pxs->stream_def.data,
                               old_size + copy, "pxReadStream");
    if (str == 0)
        return_error(errorInsufficientMemory);
    memcpy(str + old_size, par->source.data, copy);
    pxs->stream_def.data = str;
    pxs->stream_def.size = old_size + copy;
    par->source.data += copy;
    par->source.available -= copy;
    return ((par->source.position += copy) == len ? 0 : pxNeedData);
}

const byte apxEndStream[] = { 0, 0 };
int
pxEndStream(px_args_t * par, px_state_t * pxs)
{
    int code = pl_dict_put(&pxs->stream_dict, pxs->stream_name.data,
                           pxs->stream_name.size, pxs->stream_def.data);

    gs_free_string(pxs->memory, pxs->stream_name.data,
                   pxs->stream_name.size, "pxEndStream(name)");
    return (code < 0 ? gs_note_error(errorInsufficientMemory) : 0);
}

const byte apxRemoveStream[] = {
    pxaStreamName, 0, 0
};

int
pxRemoveStream(px_args_t * par, px_state_t * pxs)
{
    gs_string str;
    void *def;

    int code = tag_stream_name(par->pv[0], &str, pxs->memory,
                               "pxExecStream(name)");

    if (code < 0)
        return code;
    {
        bool found = pl_dict_find(&pxs->stream_dict, str.data, str.size,
                                  &def);

        if (!found)
            return_error(errorStreamUndefined);
        pl_dict_undef(&pxs->stream_dict, str.data, str.size);
        gs_free_string(pxs->memory, str.data, str.size,
                       "pxRemoveStream(name)");
    }
    return 0;
}

const byte apxExecStream[] = {
    pxaStreamName, 0, 0
};
int
pxExecStream(px_args_t * par, px_state_t * pxs)
{
    gs_string str;
    void *def;
    const byte *def_data;
    uint def_size;
    bool big_endian;
    const byte *start;
    px_parser_state_t *pst = par->parser;
    px_parser_state_t st;
    stream_cursor_read r;

    int code = tag_stream_name(par->pv[0], &str, pxs->memory,
                               "pxExecStream(name)");

    if (code < 0)
        return code;

    if (pxs->stream_level > 32)
        return_error(errorStreamNestingFull);

    {
        bool found = pl_dict_find(&pxs->stream_dict, str.data, str.size,
                                  &def);

        gs_free_string(pxs->memory, str.data, str.size, "pxExecStream(name)");
        if (!found)
            return_error(errorStreamUndefined);
    }
    def_data = def;
    def_size = gs_object_size(pxs->memory, def);
    /* We do all the syntax checking for streams here, rather than */
    /* in ReadStream or EndStream, for simplicity. */
    switch (def_data[0]) {
        case '(':
            big_endian = true;
            break;
        case ')':
            big_endian = false;
            break;
        default:
            return_error(errorUnsupportedBinding);
    }
    if (def_size < 16 || strncmp((const char *)def_data + 1, " HP-PCL XL", 10)
        )
        return_error(errorUnsupportedClassName);
    /* support protocol level 1, 2 and 3 */
    if (strncmp((const char *)def_data + 11, ";1;", 3) &&
        strncmp((const char *)def_data + 11, ";2;", 3) &&
        strncmp((const char *)def_data + 11, ";3;", 3))
        return_error(errorUnsupportedProtocol);
    start = memchr(def_data + 14, '\n', def_size - 14);
    if (!start)
        return_error(errorIllegalStreamHeader);
    st.memory = pxs->memory;
    px_process_init(&st, big_endian);
    st.macro_state = pst->macro_state | ptsExecStream;
    st.last_operator = pst->last_operator;
    r.ptr = start;
    r.limit = def_data + def_size - 1;
    pxs->stream_level++;
    code = px_process(&st, pxs, &r);
    pxs->stream_level--;
    pst->macro_state = st.macro_state & ~ptsExecStream;
    if (code < 0) {             /* Set the operator counts for error reporting. */
        pst->parent_operator_count = pst->operator_count;
        pst->operator_count = st.operator_count;
        pst->last_operator = st.last_operator;
    }
    return code;
}
