//
// aegis - project change supervisor
// Copyright (C) 1998, 1999, 2001, 2002, 2004-2008, 2012 Peter Miller
//
// 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 3 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, see <http://www.gnu.org/licenses/>.
//

#include <common/ac/assert.h>

#include <common/mem.h>
#include <common/regula_expre.h>
#include <common/trace.h>
#include <libaegis/aer/expr.h>
#include <libaegis/aer/func/substitute.h>
#include <libaegis/aer/value/error.h>
#include <libaegis/aer/value/integer.h>
#include <libaegis/aer/value/string.h>
#include <libaegis/sub.h>


rpt_func_substitute::~rpt_func_substitute()
{
}


rpt_func_substitute::rpt_func_substitute()
{
}


rpt_func::pointer
rpt_func_substitute::create()
{
    return pointer(new rpt_func_substitute());
}


const char *
rpt_func_substitute::name()
    const
{
    return "subst";
}


bool
rpt_func_substitute::optimizable()
    const
{
    return true;
}


bool
rpt_func_substitute::verify(const rpt_expr::pointer &ep)
    const
{
    return (ep->get_nchildren() == 3 || ep->get_nchildren() == 4);
}


rpt_value::pointer
rpt_func_substitute::run(const rpt_expr::pointer &ep, size_t argc,
    rpt_value::pointer *argv) const
{
    trace(("rpt_func_substitute::run()\n"));
    //
    // Get the match pattern.
    //
    rpt_value::pointer arg = argv[0];
    assert(!arg->is_an_error());
    arg = rpt_value::stringize(arg);
    rpt_value_string *s0p = dynamic_cast<rpt_value_string *>(arg.get());
    if (!s0p)
    {
        sub_context_ty sc(__FILE__, __LINE__);
        sc.var_set_charstar("Function", "subst");
        sc.var_set_long("Number", 1);
        sc.var_set_charstar("Name", argv[0]->name());
        nstring s
        (
            sc.subst_intl
            (
                i18n("$function: argument $number: string value required "
                    "(was given $name)")
            )
        );
        return rpt_value_error::create(ep->get_pos(), s);
    }
    nstring lhs(s0p->query());

    //
    // Get the replacement pattern.
    //
    arg = argv[1];
    assert(!arg->is_an_error());
    arg = rpt_value::stringize(arg);
    rpt_value_string *s1p = dynamic_cast<rpt_value_string *>(arg.get());
    if (!s1p)
    {
        sub_context_ty sc(__FILE__, __LINE__);
        sc.var_set_charstar("Function", "subst");
        sc.var_set_long("Number", 2);
        sc.var_set_charstar("Name", argv[1]->name());
        nstring s
        (
            sc.subst_intl
            (
                i18n("$function: argument $number: string value required "
                    "(was given $name)")
            )
        );
        return rpt_value_error::create(ep->get_pos(), s);
    }
    nstring rhs(s1p->query());

    //
    // Get the string to be worked over.
    //
    arg = argv[2];
    assert(!arg->is_an_error());
    arg = rpt_value::stringize(arg);
    rpt_value_string *s2p = dynamic_cast<rpt_value_string *>(arg.get());
    if (!s2p)
    {
        sub_context_ty sc(__FILE__, __LINE__);
        sc.var_set_charstar("Function", "subst");
        sc.var_set_long("Number", 3);
        sc.var_set_charstar("Name", argv[2]->name());
        nstring s
        (
            sc.subst_intl
            (
                i18n("$function: argument $number: string value required "
                    "(was given $name)")
            )
        );
        return rpt_value_error::create(ep->get_pos(), s);
    }
    nstring query_input(s2p->query());

    //
    // Get the count of how many times to match.
    //
    long maximum_matches = 0;
    if (argc >= 4)
    {
        arg = argv[3];
        assert(!arg->is_an_error());
        arg = rpt_value::integerize(arg);
        rpt_value_integer *rip = dynamic_cast<rpt_value_integer *>(arg.get());
        if (!rip)
        {
            sub_context_ty sc(__FILE__, __LINE__);
            sc.var_set_charstar("Function", "subst");
            sc.var_set_long("Number", 2);
            sc.var_set_charstar("Name", argv[3]->name());
            nstring s
            (
                sc.subst_intl
                (
                    i18n("$function: argument $number: integer value "
                        "required (was given $name)")
                )
            );
            return rpt_value_error::create(ep->get_pos(), s);
        }
        maximum_matches = rip->query();
    }

    //
    // perform the substitution
    //
    regular_expression re(lhs);
    nstring result;
    if (!re.match_and_substitute(rhs, query_input, maximum_matches, result))
    {
        //
        // Error... probably the LHS pattern was erroneous, but it could
        // have been the RHS pattern.
        //
        // Return an error result.
        //
        sub_context_ty sc(__FILE__, __LINE__);
        sc.var_set_charstar("Function", "subst");
        sc.var_set_long("Number", 1);
        sc.var_set_charstar("MeSsaGe", re.strerror());
        nstring s(sc.subst_intl(i18n("$function: argument $number: $message")));
        return rpt_value_error::create(ep->get_pos(), s);
    }

    //
    // build the result
    //
    trace_nstring(result);
    return rpt_value_string::create(result);
}


// vim: set ts=8 sw=4 et :