/*  RemoveT - removes _T macro from C source files

    This program removes the _T macro from all files listed on the
    command line. Each occurence of _T("somestring") will be changed
    into "somestring", whereby 'somestring' stands for an arbitrary
    C string. The program does take into account escape sequences.

    This program is mentioned at: http://www.iwriteiam.nl/D1502.html#25
    
    Copyright (C) 2015 Frans Faase    http://www.iwriteiam.nl/

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

GNU General Public License:
    http://www.iwriteiam.nl/GNU.txt
*/
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>
#include <string.h>


int main(int argc, char *argv[])
{
    // Process all files on the input:
    for (int i = 1; i < argc; i++)
    {   char *arg = argv[i];

        FILE *fin = fopen(arg, "rb");
        if (fin == 0)
        {
            fprintf(stderr, "File '%s' could not be opened\n", arg);
        }
        else
        {
            // Read file into buffer:
            char* buffer;
            {
                int fh = fileno(fin);
                long file_len = lseek(fh, 0L, SEEK_END);
                lseek(fh, 0L, SEEK_SET);
                buffer = new char[file_len+2];
                file_len = read(fh, buffer, file_len);
                buffer[file_len] = '\0';
            }
            fclose(fin);
            
            // Check if it does contain a _T macro:
            bool found = false;
            char *s = buffer;
            for (;;)
            {
                // Find the following occurence of the _T macro:
                char *sf = strstr(s, "_T(");
                if (sf == 0 )
                    break;
                if (!isalnum(sf[-1]) && sf[-1] != '_')
                {
                    found = true;
                    break;
                }
                s = sf + 3;
            }
            
            if (found)
            {
                FILE *fout = fopen(arg, "wb");
                if (fout == 0)
                {
                    fprintf(stderr, "File '%s' could not be opened for writing\n", arg);
                }
                else
                {
                    int nr_removed = 0;
                    char *s = buffer;
                    for (;;)
                    {
                        // Find the following occurence of the _T macro:
                        char *sf = strstr(s, "_T(");
                        if (sf == 0 )
                        {
                            // Process remainder of the file
                            for(; *s != '\0'; s++)
                                fprintf(fout, "%c", *s);
                            break;
                        }                    
                        if (isalnum(sf[-1]) || sf[-1] == '_')
                        {
                            // Some identifier character found for _T; skip and copy:
                            sf += 3;
                            for ( ; s < sf; s++)
                                fprintf(fout, "%c", *s);
                        }
                        else
                        {
                            nr_removed++;
                            // Copy till start of macro:
                            for (; s < sf; s++)
                                fprintf(fout, "%c", *s);
                            s += 3;
                            // Copy spaces before the string
                            for (; isspace(*s); s++)
                                fprintf(fout, "%c", *s);
                            // Copy string or character (if found)
                            while (*s == '"' || *s == '\'')
                            {
                                char quote = *s;
                                s++;
                                fprintf(fout, "%c", quote);
                                for (; *s != '\0' && *s != quote; s++)
                                {
                                    fprintf(fout, "%c", *s);
                                    if (*s == '\\')
                                    {
                                        s++;
                                        fprintf(fout, "%c", *s);
                                    }
                                }
                                if (*s == quote)
                                {
                                    fprintf(fout, "%c", quote);
                                    // Copy spaces following the string
                                    for (s++; isspace(*s); s++)
                                        fprintf(fout, "%c", *s);
                                }
                            }
                            // Skip closing bracket
                            if (*s == ')')
                                s++;
                        }
                    }
                    fprintf(stderr, "File '%s': removed %d _T macros\n", arg, nr_removed);
                    fclose(fout);
                }
            }
            delete buffer;
        }
    }
    
    return 0;
}