//
// aegis - project change supervisor
// Copyright (C) 2002, 2004-2008, 2012, 2014 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/string.h>

#include <common/nstring/accumulator.h>
#include <libaegis/sub/plural_lex.h>
#include <libaegis/sub/plural_gram.yacc.h>


static nstring text;
static size_t pos;


void
sub_plural_lex_open(const nstring &s)
{
    text = s;
    pos = 0;
}


void
sub_plural_lex_close(void)
{
    text.clear();
    pos = 0;
}


static int
lex_getc(void)
{
    int c = 0;
    if (!text || pos >= text.size())
        c = 0;
    else
        c = (unsigned char)text[pos];
    ++pos;
    return c;
}


static void
lex_getc_undo(int)
{
    if (pos > 0)
        --pos;
}


int
sub_plural_gram_lex(void)
{
    for (;;)
    {
        int c = lex_getc();
        switch (c)
        {
        case 0:
            return 0;

        case ' ':
        case '\t':
        case '\n':
        case '\f':
            break;

        case '!':
            c = lex_getc();
            if (c == '=')
                return NE;
            lex_getc_undo(c);
            return NOT;

        case '%':
            return MOD;

        case '&':
            c = lex_getc();
            if (c == '&')
                return ANDAND;
            lex_getc_undo(c);
            return BITAND;

        case '(':
            return LP;

        case ')':
            return RP;

        case '*':
            return MUL;

        case '+':
            return PLUS;

        case '-':
            return MINUS;

        case '/':
            return DIV;

        case '0': case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
            {
                long n = 0;
                for (;;)
                {
                    n = n * 10 + c - '0';
                    c = lex_getc();
                    switch (c)
                    {
                    case '0': case '1': case '2': case '3': case '4':
                    case '5': case '6': case '7': case '8': case '9':
                        continue;

                    default:
                        break;
                    }
                    lex_getc_undo(c);
                    break;
                }
                sub_plural_gram_lval.lv_number = n;
            }
            return INTEGER;

        case ':':
            return COLON;

        case ';':
            return SEMI;

        case '<':
            c = lex_getc();
            if (c == '=')
                return LE;
            if (c == '>')
                return NE;
            lex_getc_undo(c);
            return LT;

        case '=':
            c = lex_getc();
            if (c == '=')
                return EQ;
            lex_getc_undo(c);
            return EQU;

        case '>':
            c = lex_getc();
            if (c == '=')
                return GE;
            lex_getc_undo(c);
            return GT;

        case '?':
            return QUEST;
        case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': case 'G':
        case 'H': case 'I': case 'J': case 'K': case 'L': case 'M': case 'N':
        case 'O': case 'P': case 'Q': case 'R': case 'S': case 'T': case 'U':
        case 'V': case 'W': case 'X': case 'Y': case 'Z':
        case '_':
        case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g':
        case 'h': case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
        case 'o': case 'p': case 'q': case 'r': case 's': case 't': case 'u':
        case 'v': case 'w': case 'x': case 'y': case 'z':
            {
                static nstring_accumulator sa;
                sa.clear();
                for (;;)
                {
                    sa.push_back(c);
                    c = lex_getc();
                    switch (c)
                    {
                    case 'A': case 'B': case 'C': case 'D': case 'E':
                    case 'F': case 'G': case 'H': case 'I': case 'J':
                    case 'K': case 'L': case 'M': case 'N': case 'O':
                    case 'P': case 'Q': case 'R': case 'S': case 'T':
                    case 'U': case 'V': case 'W': case 'X': case 'Y':
                    case 'Z': case '_':
                    case 'a': case 'b': case 'c': case 'd': case 'e':
                    case 'f': case 'g': case 'h': case 'i': case 'j':
                    case 'k': case 'l': case 'm': case 'n': case 'o':
                    case 'p': case 'q': case 'r': case 's': case 't':
                    case 'u': case 'v': case 'w': case 'x': case 'y':
                    case 'z':
                    case '0': case '1': case '2': case '3': case '4':
                    case '5': case '6': case '7': case '8': case '9':
                        continue;

                    case 0:
                        break;

                    default:
                        lex_getc_undo(c);
                        break;
                    }
                    break;
                }
                nstring s = sa.mkstr();
                if (0 == strcasecmp(s.c_str(), "n"))
                    return NUMBER;
                if (0 == strcasecmp(s.c_str(), "nplurals"))
                    return NPLURALS;
                if (0 == strcasecmp(s.c_str(), "plural"))
                    return PLURAL;
            }
            return JUNK;

        case '^':
            return BITXOR;

        case '|':
            c = lex_getc();
            if (c == '|')
                return OROR;
            lex_getc_undo(c);
            return BITOR;

        case '~':
            return BITNOT;

        default:
            return JUNK;
        }
    }
}


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