/* Copyright (C) 2001-2012 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.,  7 Mt. Lassen Drive - Suite A-134, San Rafael,
   CA  94903, U.S.A., +1(415)492-9861, for further information.
*/


/* Level 2 device operators */
#include "math_.h"
#include "memory_.h"
#include "ghost.h"
#include "oper.h"
#include "dstack.h"		/* for dict_find_name */
#include "estack.h"
#include "idict.h"
#include "idparam.h"
#include "igstate.h"
#include "iname.h"
#include "iutil.h"
#include "store.h"
#include "gxdevice.h"
#include "gsstate.h"

/* Exported for zfunc4.c */
int z2copy(i_ctx_t *);

/* Forward references */
static int z2copy_gstate(i_ctx_t *);
static int push_callout(i_ctx_t *, const char *);

/* Extend the `copy' operator to deal with gstates. */
/* This is done with a hack -- we know that gstates are the only */
/* t_astruct subtype that implements copy. */
/* We export this for recognition in FunctionType 4 functions. */
int
z2copy(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    int code = zcopy(i_ctx_p);

    if (code >= 0)
        return code;
    if (!r_has_type(op, t_astruct))
        return code;
    return z2copy_gstate(i_ctx_p);
}

/* - .currentshowpagecount <count> true */
/* - .currentshowpagecount false */
static int
zcurrentshowpagecount(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gx_device *dev = gs_currentdevice(igs);

    if ((*dev_proc(dev, get_page_device))(dev) == 0) {
        push(1);
        make_false(op);
    } else {
        push(2);
        make_int(op - 1, dev->ShowpageCount);
        make_true(op);
    }
    return 0;
}

/* - .currentpagedevice <dict> <bool> */
static int
zcurrentpagedevice(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gx_device *dev = gs_currentdevice(igs);

    push(2);
    if ((*dev_proc(dev, get_page_device))(dev) != 0) {
        op[-1] = istate->pagedevice;
        make_true(op);
    } else {
        make_null(op - 1);
        make_false(op);
    }
    return 0;
}

/* <local_dict|null> .setpagedevice - */
static int
zsetpagedevice(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    int code;

/******
    if ( igs->in_cachedevice )
        return_error(e_undefined);
 ******/
    if (r_has_type(op, t_dictionary)) {
        check_dict_read(*op);
#if 0	/****************/
        /*
         * In order to avoid invalidaccess errors on setpagedevice,
         * the dictionary must be allocated in local VM.
         */
        if (!(r_is_local(op)))
            return_error(e_invalidaccess);
#endif	/****************/
        /* Make the dictionary read-only. */
        code = zreadonly(i_ctx_p);
        if (code < 0)
            return code;
    } else {
        check_type(*op, t_null);
    }
    istate->pagedevice = *op;
    pop(1);
    return 0;
}

/* Default Install/BeginPage/EndPage procedures */
/* that just call the procedure in the device. */

/* - .callinstall - */
static int
zcallinstall(i_ctx_t *i_ctx_p)
{
    gx_device *dev = gs_currentdevice(igs);

    if ((dev = (*dev_proc(dev, get_page_device))(dev)) != 0) {
        int code = (*dev->page_procs.install) (dev, igs);

        if (code < 0)
            return code;
    }
    return 0;
}

/* <showpage_count> .callbeginpage - */
static int
zcallbeginpage(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gx_device *dev = gs_currentdevice(igs);

    check_type(*op, t_integer);
    if ((dev = (*dev_proc(dev, get_page_device))(dev)) != 0) {
        int code = (*dev->page_procs.begin_page)(dev, igs);

        if (code < 0)
            return code;
    }
    pop(1);
    return 0;
}

/* <showpage_count> <reason_int> .callendpage <flush_bool> */
static int
zcallendpage(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gx_device *dev = gs_currentdevice(igs);
    int code;

    check_type(op[-1], t_integer);
    check_type(*op, t_integer);
    if ((dev = (*dev_proc(dev, get_page_device))(dev)) != 0) {
        code = (*dev->page_procs.end_page)(dev, (int)op->value.intval, igs);
        if (code < 0)
            return code;
        if (code > 1)
            return_error(e_rangecheck);
    } else {
        code = (op->value.intval == 2 ? 0 : 1);
    }
    make_bool(op - 1, code);
    pop(1);
    return 0;
}

/* ------ Wrappers for operators that save the graphics state. ------ */

/* When saving the state with the current device a page device, */
/* we need to make sure that the page device dictionary exists */
/* so that grestore can use it to reset the device parameters. */
/* This may have significant performance consequences, but we don't see */
/* any way around it. */

/* Check whether we need to call out to create the page device dictionary. */
static bool
save_page_device(gs_state *pgs)
{
    return
        (r_has_type(&gs_int_gstate(pgs)->pagedevice, t_null) &&
         (*dev_proc(gs_currentdevice(pgs), get_page_device))(gs_currentdevice(pgs)) != 0);
}

/* - gsave - */
static int
z2gsave(i_ctx_t *i_ctx_p)
{
    if (!save_page_device(igs))
        return gs_gsave(igs);
    return push_callout(i_ctx_p, "%gsavepagedevice");
}

/* - save - */
static int
z2save(i_ctx_t *i_ctx_p)
{
    if (!save_page_device(igs))
        return zsave(i_ctx_p);
    return push_callout(i_ctx_p, "%savepagedevice");
}

/* - gstate <gstate> */
static int
z2gstate(i_ctx_t *i_ctx_p)
{
    if (!save_page_device(igs))
        return zgstate(i_ctx_p);
    return push_callout(i_ctx_p, "%gstatepagedevice");
}

/* <gstate1> <gstate2> copy <gstate2> */
static int
z2copy_gstate(i_ctx_t *i_ctx_p)
{
    if (!save_page_device(igs))
        return zcopy_gstate(i_ctx_p);
    return push_callout(i_ctx_p, "%copygstatepagedevice");
}

/* <gstate> currentgstate <gstate> */
static int
z2currentgstate(i_ctx_t *i_ctx_p)
{
    if (!save_page_device(igs))
        return zcurrentgstate(i_ctx_p);
    return push_callout(i_ctx_p, "%currentgstatepagedevice");
}

/* ------ Wrappers for operators that reset the graphics state. ------ */

/* Check whether we need to call out to restore the page device. */
static bool
restore_page_device(const gs_state * pgs_old, const gs_state * pgs_new)
{
    gx_device *dev_old = gs_currentdevice(pgs_old);
    gx_device *dev_new;
    gx_device *dev_t1;
    gx_device *dev_t2;
    bool samepagedevice = obj_eq(dev_old->memory, &gs_int_gstate(pgs_old)->pagedevice,
        &gs_int_gstate(pgs_new)->pagedevice);

    if ((dev_t1 = (*dev_proc(dev_old, get_page_device)) (dev_old)) == 0)
        return false;
    /* If we are going to putdeviceparams in a callout, we need to */
    /* unlock temporarily.  The device will be re-locked as needed */
    /* by putdeviceparams from the pgs_old->pagedevice dict state. */
    if (!samepagedevice)
        dev_old->LockSafetyParams = false;
    dev_new = gs_currentdevice(pgs_new);
    if (dev_old != dev_new) {
        if ((dev_t2 = (*dev_proc(dev_new, get_page_device)) (dev_new)) == 0)
            return false;
        if (dev_t1 != dev_t2)
            return true;
    }
    /*
     * The current implementation of setpagedevice just sets new
     * parameters in the same device object, so we have to check
     * whether the page device dictionaries are the same.
     */
    return !samepagedevice;
}

/* - grestore - */
static int
z2grestore(i_ctx_t *i_ctx_p)
{
    if (!restore_page_device(igs, gs_state_saved(igs)))
        return gs_grestore(igs);
    return push_callout(i_ctx_p, "%grestorepagedevice");
}

/* - grestoreall - */
static int
z2grestoreall(i_ctx_t *i_ctx_p)
{
    for (;;) {
        if (!restore_page_device(igs, gs_state_saved(igs))) {
            bool done = !gs_state_saved(gs_state_saved(igs));

            gs_grestore(igs);
            if (done)
                break;
        } else
            return push_callout(i_ctx_p, "%grestoreallpagedevice");
    }
    return 0;
}

/* <save> restore - */
static int
z2restore(i_ctx_t *i_ctx_p)
{
    while (gs_state_saved(gs_state_saved(igs))) {
        if (restore_page_device(igs, gs_state_saved(igs)))
            return push_callout(i_ctx_p, "%restore1pagedevice");
        gs_grestore(igs);
    }
    if (restore_page_device(igs, gs_state_saved(igs)))
        return push_callout(i_ctx_p, "%restorepagedevice");
    return zrestore(i_ctx_p);
}

/* <gstate> setgstate - */
static int
z2setgstate(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;

    check_stype(*op, st_igstate_obj);
    if (!restore_page_device(igs, igstate_ptr(op)))
        return zsetgstate(i_ctx_p);
    return push_callout(i_ctx_p, "%setgstatepagedevice");
}

/* ------ Initialization procedure ------ */

const op_def zdevice2_l2_op_defs[] =
{
    op_def_begin_level2(),
    {"0.currentshowpagecount", zcurrentshowpagecount},
    {"0.currentpagedevice", zcurrentpagedevice},
    {"1.setpagedevice", zsetpagedevice},
                /* Note that the following replace prior definitions */
                /* in the indicated files: */
    {"1copy", z2copy},		/* zdps1.c */
    {"0gsave", z2gsave},	/* zgstate.c */
    {"0save", z2save},		/* zvmem.c */
    {"0gstate", z2gstate},	/* zdps1.c */
    {"1currentgstate", z2currentgstate},	/* zdps1.c */
    {"0grestore", z2grestore},	/* zgstate.c */
    {"0grestoreall", z2grestoreall},	/* zgstate.c */
    {"1restore", z2restore},	/* zvmem.c */
    {"1setgstate", z2setgstate},	/* zdps1.c */
                /* Default Install/BeginPage/EndPage procedures */
                /* that just call the procedure in the device. */
    {"0.callinstall", zcallinstall},
    {"1.callbeginpage", zcallbeginpage},
    {"2.callendpage", zcallendpage},
    op_def_end(0)
};

/* ------ Internal routines ------ */

/* Call out to a PostScript procedure. */
static int
push_callout(i_ctx_t *i_ctx_p, const char *callout_name)
{
    int code;

    check_estack(1);
    code = name_enter_string(imemory, callout_name, esp + 1);
    if (code < 0)
        return code;
    ++esp;
    r_set_attrs(esp, a_executable);
    return o_push_estack;
}
