/* This is dvipdfmx, an eXtended version of dvipdfm by Mark A. Wicks.

   Copyright (C) 2002-2019 by Jin-Hwan Cho and Shunsaku Hirata,
   the dvipdfmx project team.

   Copyright (C) 1998, 1999 by Mark A. Wicks <mwicks@kettering.edu>

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/

#include "dpx-spc_dvips.h"

#include <assert.h>
#include <ctype.h>
#include <math.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "tectonic_bridge_core.h"
#include "dpx-dpxfile.h"
#include "dpx-dvi.h"
#include "dpx-dvicodes.h"
#include "dpx-epdf.h"
#include "dpx-error.h"
#include "dpx-mem.h"
#include "dpx-mpost.h"
#include "dpx-pdfdev.h"
#include "dpx-pdfdraw.h"
#include "dpx-pdfobj.h"
#include "dpx-pdfparse.h"
#include "dpx-pdfximage.h"
#include "dpx-spc_util.h"
#include "dpx-spc_xtx.h"
#include "dpx-specials.h"

static int    block_pending = 0;
static double pending_x     = 0.0;
static double pending_y     = 0.0;
static int    position_set  = 0;

static char** ps_headers = 0;
static int num_ps_headers = 0;


static int
spc_handler_ps_header (struct spc_env *spe, struct spc_arg *args)
{
    char *pro;
    rust_input_handle_t ps_header;

    skip_white(&args->curptr, args->endptr);
    if (args->curptr + 1 >= args->endptr || args->curptr[0] != '=') {
        spc_warn(spe, "No filename specified for PSfile special.");
        return -1;
    }

    args->curptr++;

    pro = xmalloc(args->endptr - args->curptr + 1);
    strncpy(pro, args->curptr, args->endptr - args->curptr);
    pro[args->endptr - args->curptr] = 0;

    ps_header = ttstub_input_open(pro, TTBC_FILE_FORMAT_TEX_PS_HEADER, 0);
    if (!ps_header) {
        spc_warn(spe, "PS header %s not found.", pro);
        free(pro);
        return -1;
    }

    ttstub_input_close(ps_header);

    if (!(num_ps_headers & 0x0f))
        ps_headers = xrealloc(ps_headers, sizeof(char*) * (num_ps_headers + 16));

    ps_headers[num_ps_headers++] = pro;
    args->curptr = args->endptr;
    return 0;
}


static char *
parse_filename (const char **pp, const char *endptr)
{
    char *r;
    const char *q = NULL, *p = *pp;
    char qchar;
    int n;

    if (!p || p >= endptr)
        return NULL;
    else if (*p == '\"' || *p == '\'')
        qchar = *p++;
    else
        qchar = ' ';

    for (n = 0, q = p; p < endptr && *p != qchar; n++, p++) {
        /* nothing */
    }

    if (qchar != ' ') {
        if (*p != qchar)
            return NULL;
        p++;
    }

    if (!q || n == 0)
        return NULL;

    r = NEW(n + 1, char);
    memcpy(r, q, n);
    r[n] = '\0';
    *pp = p;
    return r;
}


/* =filename ... */
static int
spc_handler_ps_file (struct spc_env *spe, struct spc_arg *args)
{
    int            form_id;
    char          *filename;
    transform_info ti;
    load_options   options = {1, 0, NULL};

    assert(spe && args);

    skip_white(&args->curptr, args->endptr);
    if (args->curptr + 1 >= args->endptr || args->curptr[0] != '=') {
        spc_warn(spe, "No filename specified for PSfile special.");
        return -1;
    }

    args->curptr++;

    filename = parse_filename(&args->curptr, args->endptr);
    if (!filename) {
        spc_warn(spe, "No filename specified for PSfile special.");
        return -1;
    }

    transform_info_clear(&ti);
    if (spc_util_read_dimtrns(spe, &ti, args, 1) < 0) {
        free(filename);
        return -1;
    }

    form_id = pdf_ximage_load_image(NULL, filename, options);
    if (form_id < 0) {
        spc_warn(spe, "Failed to read image file: %s", filename);
        free(filename);
        return -1;
    }

    free(filename);
    spc_put_image(spe, form_id, &ti, spe->x_user, spe->y_user);
    return 0;
}


/* This isn't correct implementation but dvipdfm supports... */
static int
spc_handler_ps_plotfile (struct spc_env *spe, struct spc_arg *args)
{
    int            error = 0;
    int            form_id;
    char          *filename;
    transform_info p;
    load_options   options = {1, 0, NULL};

    assert(spe && args);

    spc_warn(spe, "\"ps: plotfile\" found (not properly implemented)");

    skip_white(&args->curptr, args->endptr);
    filename = parse_filename(&args->curptr, args->endptr);
    if (!filename) {
        spc_warn(spe, "Expecting filename but not found...");
        return -1;
    }

    form_id = pdf_ximage_load_image(NULL, filename, options);
    if (form_id < 0) {
        spc_warn(spe, "Could not open PS file: %s", filename);
        error = -1;
    } else {
        transform_info_clear(&p);
        p.matrix.d = -1.0; /* xscale = 1.0, yscale = -1.0 */
        spc_put_image(spe, form_id, &p, 0, 0);
    }

    free(filename);
    return error;
}


static int
spc_handler_ps_literal (struct spc_env *spe, struct spc_arg *args)
{
    int     error = 0;
    int     st_depth, gs_depth;
    double  x_user, y_user;
    pdf_coord cp;

    spc_get_current_point(spe, &cp);

    if (args->curptr + strlen(":[begin]") <= args->endptr && strstartswith(args->curptr, ":[begin]")) {
        block_pending++;
        position_set = 1;
        x_user = pending_x = cp.x;
        y_user = pending_y = cp.y;
        args->curptr += strlen(":[begin]");
    } else if (args->curptr + strlen(":[end]") <= args->endptr && strstartswith(args->curptr, ":[end]")) {
        if (block_pending <= 0) {
            spc_warn(spe, "No corresponding ::[begin] found.");
            return -1;
        }

        block_pending--;
        position_set = 0;
        x_user = pending_x;
        y_user = pending_y;
        args->curptr += strlen(":[end]");
    } else if (args->curptr < args->endptr && args->curptr[0] == ':') {
        x_user = position_set ? pending_x : cp.x;
        y_user = position_set ? pending_y : cp.y;
        args->curptr++;
    } else {
        position_set = 1;
        x_user = pending_x = cp.x;
        y_user = pending_y = cp.y;
    }

    skip_white(&args->curptr, args->endptr);

    if (args->curptr < args->endptr) {
        st_depth = mps_stack_depth();
        gs_depth = pdf_dev_current_depth();

        error = mps_exec_inline(&args->curptr, args->endptr, x_user, y_user);
        if (error) {
            spc_warn(spe, "Interpreting PS code failed!!! Output might be broken!!!");
            pdf_dev_grestore_to(gs_depth);
        } else if (st_depth != mps_stack_depth()) {
            spc_warn(spe, "Stack not empty after execution of inline PostScript code.");
            spc_warn(spe, ">> Your macro package makes some assumption on internal behaviour of DVI drivers.");
            spc_warn(spe, ">> It may not compatible with dvipdfmx.");
        }
    }

    return error;
}


static int
spc_handler_ps_trickscmd (struct spc_env *spe, struct spc_arg *args)
{
    dpx_warning("PSTricks commands are disallowed in Tectonic");
    args->curptr = args->endptr;
    return -1;
}

static int
spc_handler_ps_tricksobj (struct spc_env *spe, struct spc_arg *args)
{
    dpx_warning("PSTricks commands are disallowed in Tectonic");
    args->curptr = args->endptr;
    return -1;
}


static int
spc_handler_ps_default (struct spc_env *spe, struct spc_arg *args)
{
    int error;
    int st_depth, gs_depth;

    assert(spe && args);

    pdf_dev_gsave();

    st_depth = mps_stack_depth();
    gs_depth = pdf_dev_current_depth();

    {
        pdf_tmatrix M;
        M.a = M.d = 1.0; M.b = M.c = 0.0; M.e = spe->x_user; M.f = spe->y_user;
        pdf_dev_concat(&M);
        error = mps_exec_inline(&args->curptr, args->endptr, spe->x_user, spe->y_user);
        M.e = -spe->x_user; M.f = -spe->y_user;
        pdf_dev_concat(&M);
    }

    if (error) {
        spc_warn(spe, "Interpreting PS code failed!!! Output might be broken!!!");
    } else if (st_depth != mps_stack_depth()) {
        spc_warn(spe, "Stack not empty after execution of inline PostScript code.");
        spc_warn(spe, ">> Your macro package makes some assumption on internal behaviour of DVI drivers.");
        spc_warn(spe, ">> It may not compatible with dvipdfmx.");
    }

    pdf_dev_grestore_to(gs_depth);
    pdf_dev_grestore();

    return error;
}

static struct spc_handler dvips_handlers[] = {
    {"header",        spc_handler_ps_header},
    {"PSfile",        spc_handler_ps_file},
    {"psfile",        spc_handler_ps_file},
    {"ps: plotfile ", spc_handler_ps_plotfile},
    {"PS: plotfile ", spc_handler_ps_plotfile},
    {"PS:",           spc_handler_ps_literal},
    {"ps:",           spc_handler_ps_literal},
    {"PST:",          spc_handler_ps_trickscmd},
    {"pst:",          spc_handler_ps_tricksobj},
    {"\" ",           spc_handler_ps_default}
};


int
spc_dvips_at_begin_document (void)
{
    /* This function used to start the global_defs temp file. */
    return 0;
}


int
spc_dvips_at_end_document (void)
{
    if (ps_headers) {
        while (num_ps_headers > 0)
            free(ps_headers[--num_ps_headers]);
        ps_headers = mfree(ps_headers);
    }

    return 0;
}


int
spc_dvips_at_begin_page (void)
{
    /* This function used do some things related to now-removed PSTricks functionality. */
    return 0;
}


int
spc_dvips_at_end_page (void)
{
    mps_eop_cleanup();
    return 0;
}


bool
spc_dvips_check_special (const char *buf, int len)
{
    const char *p, *endptr;
    size_t i;

    p = buf;
    endptr = p + len;

    skip_white(&p, endptr);
    if (p >= endptr)
        return false;

    len = (int) (endptr - p);

    for (i = 0; i < sizeof(dvips_handlers) / sizeof(struct spc_handler); i++)
        if (len >= strlen(dvips_handlers[i].key) && !memcmp(p, dvips_handlers[i].key, strlen(dvips_handlers[i].key)))
            return true;

    return false;
}


int
spc_dvips_setup_handler (struct spc_handler *handle, struct spc_env *spe, struct spc_arg *args)
{
    const char *key;
    int keylen;
    size_t i;

    assert(handle && spe && args);

    skip_white(&args->curptr, args->endptr);

    key = args->curptr;
    while (args->curptr < args->endptr && isalpha((unsigned char) args->curptr[0]))
        args->curptr++;

    /* Test for "ps:". The "ps::" special is subsumed under this case.  */
    if (args->curptr < args->endptr && args->curptr[0] == ':') {
        args->curptr++;

        if (args->curptr + strlen(" plotfile ") <= args->endptr && strstartswith(args->curptr, " plotfile "))
            args->curptr += strlen(" plotfile ");
    } else if (args->curptr+1 < args->endptr && args->curptr[0] == '"' && args->curptr[1] == ' ') {
        args->curptr += 2;
    }

    keylen = (int) (args->curptr - key);
    if (keylen < 1) {
        spc_warn(spe, "Not ps: special???");
        return -1;
    }

    for (i = 0; i < sizeof(dvips_handlers) / sizeof(struct spc_handler); i++) {
        if (keylen == strlen(dvips_handlers[i].key) && !strncmp(key, dvips_handlers[i].key, keylen)) {
            skip_white(&args->curptr, args->endptr);
            args->command = dvips_handlers[i].key;
            handle->key  = "ps:";
            handle->exec = dvips_handlers[i].exec;
            return 0;
        }
    }

    return -1;
}