/* Copyright (C) 2001-2023 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.,  39 Mesa Street, Suite 108A, San Francisco,
   CA 94129, USA, for further information.
*/

/* SFF format writer for CAPI fax devices */
#include "gdevprn.h"
#include "strimpl.h"
#include "scfx.h"
#include "gdevfax.h"

/* The device descriptor */
static dev_proc_print_page(cfax_print_page);
static dev_proc_close_device(cfax_prn_close);

/* Define procedures for cfax. For sff multipage documents  */
/* a special close procedure is required because sff needs  */
/* an additional "end of document" signature after the last */
/* "end page" signature */
/* Since the print_page doesn't alter the device, this device can print in the background */
static void
cfax_initialize_device_procs(gx_device *dev)
{
    gdev_prn_initialize_device_procs_mono_bg(dev);

    set_dev_proc(dev, close_device, cfax_prn_close);
    set_dev_proc(dev, get_params, gdev_fax_get_params);
    set_dev_proc(dev, put_params, gdev_fax_put_params);
}

const gx_device_fax gs_cfax_device = {
    FAX_DEVICE_BODY(gx_device_fax, cfax_initialize_device_procs,
                    "cfax", cfax_print_page)
};

/* ---------------- SFF output ----------------- */

static void
cfax_byte(uint c, gp_file * file)
{
    gp_fputc(c & 0xff, file);
}

static void
cfax_word(ushort c, gp_file * file)
{
    cfax_byte(c & 0xff, file);
    cfax_byte(c >> 8, file);
}

static void
cfax_dword(ulong c, gp_file * file)
{
    cfax_byte(c & 0xff, file);
    cfax_byte(c >> 8, file);
    cfax_byte(c >> 16, file);
    cfax_byte(c >> 24, file);
}

static void
cfax_doc_hdr(gp_file * file)
{
    cfax_byte('S', file);
    cfax_byte('f', file);
    cfax_byte('f', file);
    cfax_byte('f', file);
    cfax_byte(1, file);
    cfax_byte(0, file);
    cfax_word(0, file);
    cfax_word(0, file);
    cfax_word(20, file);
    cfax_dword(0, file);
    cfax_dword(0, file);
}

static void
cfax_page_hdr(gx_device_printer * pdev, gp_file * file)
{
    cfax_byte(254, file);
    cfax_byte(16, file);
    cfax_byte((pdev->y_pixels_per_inch < 100 ? 0 : 1), file);
    cfax_byte(0, file);
    cfax_byte(0, file);
    cfax_byte(0, file);
    cfax_word(pdev->width, file);
    cfax_word(pdev->height, file);
    cfax_dword(0, file);
    cfax_dword(0, file);
}

static void
cfax_doc_end(gp_file * file)
{
    cfax_byte(254, file);
    cfax_byte(0, file);
}

/* Send the page to the printer. */
static int
cfax_stream_print_page_width(gx_device_printer * pdev, gp_file * prn_stream,
                             const stream_template * temp, stream_state * ss,
                             int width)
{
    gs_memory_t *mem = pdev->memory;
    int code = 0;
    stream_cursor_read r;
    stream_cursor_write w;
    int in_size = gdev_prn_raster((gx_device *) pdev);
    /*
     * Because of the width adjustment for fax systems, width may
     * be different from (either greater than or less than) pdev->width.
     * Allocate a large enough buffer to account for this.
     */
    int col_size = (width * pdev->color_info.depth + 7) >> 3;
    int max_size = max(in_size, col_size);
    int lnum, nbytes, i;
    byte *in;
    byte *out;
    /* If the file is 'nul', don't even do the writes. */
    bool nul = !strcmp(pdev->fname, "nul");

    /* Initialize the common part of the encoder state. */
    ss->templat = temp;
    ss->memory = mem;

    /* Allocate the buffers. */
    in = gs_alloc_bytes(mem, temp->min_in_size + max_size + 1,
        "cfax_stream_print_page(in)");

#define OUT_SIZE 1000
    out = gs_alloc_bytes(mem, OUT_SIZE, "cfax_stream_print_page(out)");
    if (in == 0 || out == 0) {
        code = gs_note_error(gs_error_VMerror);
        goto done;
    }

    /* Process the image */
    for (lnum = 0; lnum < pdev->height; lnum++) {
        /* Initialize read and write pointer each time, because they're getting modified */
        r.ptr = in - 1;
        r.limit = in + col_size;
        w.ptr = out - 1;
        w.limit = w.ptr + OUT_SIZE;
        /* Decoder must encode line for line, so init it for each line */
        code = (*temp->init) (ss);
        if (code < 0)
            return_error(gs_error_limitcheck);
        /* Now, get the bits and encode them */
        code = gdev_prn_copy_scan_lines(pdev, lnum, in, in_size);
        if (code < 0)
            goto done;
        if (col_size > in_size) {
            memset(in + in_size , 0, col_size - in_size);
        }
        code = (*temp->process) (ss, &r, &w, 1 /* always last line */);
        nbytes = w.ptr - out + 1;
        if (!nul) {
            if (nbytes > 0) {
                if (nbytes < 217) {
                    cfax_byte(nbytes, prn_stream);
                    for (i = 0; i < nbytes; i++)
                          cfax_byte(out[i], prn_stream);
                } else {
                    cfax_byte(0, prn_stream);
                    cfax_word(nbytes, prn_stream);
                    for (i = 0; i < nbytes; i++)
                          cfax_byte(out[i], prn_stream);
                }
            } else {
                cfax_byte(218, prn_stream);
            }
        }
        if (temp->release != 0)
            (*temp->release) (ss);
    }
#undef OUT_SIZE

  done:
    gs_free_object(mem, out, "cfax_stream_print_page(out)");
    gs_free_object(mem, in, "cfax_stream_print_page(in)");
    return code;
}

/* Begin a capi fax page. */
static int
cfax_begin_page(gx_device_printer * pdev, gp_file * fp, int width)
{
    /* Patch the width to reflect fax page width adjustment. */
    int save_width = pdev->width;

    pdev->width = width;
    if (gdev_prn_file_is_new(pdev)) {
        cfax_doc_hdr(fp);
    }
    cfax_page_hdr(pdev, fp);

    pdev->width = save_width;
    return 0;
}

/* Print an capi fax (sff-encoded) page. */
static int
cfax_print_page(gx_device_printer * pdev, gp_file * prn_stream)
{
    stream_CFE_state state;
    int code;

    gdev_fax_init_fax_state(&state, (gx_device_fax *)pdev);
    state.EndOfLine = false;
    state.EndOfBlock = false;
    state.EncodedByteAlign = true;
    state.FirstBitLowOrder = true;
    state.K = 0;

    cfax_begin_page(pdev, prn_stream, state.Columns);
    code = cfax_stream_print_page_width(pdev, prn_stream,
      &s_CFE_template, (stream_state *) &state, state.Columns);
    return code;
}

/* Close an capi fax (sff-encoded) document. */
static int
cfax_prn_close(gx_device * pdev)
{
    gx_device_printer * const ppdev = (gx_device_printer *)pdev;

    if (ppdev->file != NULL) {
      cfax_doc_end(ppdev->file);
    }
    return gdev_prn_close(pdev);
}