/*  XTrkCad - Model Railroad CAD
 *  Copyright (C) 2005 Dave Bullis
 *						2007 Martin Fischer
 *
 *  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#ifdef WINDOWS
#if _MSC_VER >=1400
#define strdup _strdup
#endif
#endif

#define I18NHEADERFILE "i18n.h"

typedef struct helpMsg_t * helpMsg_p;
typedef struct helpMsg_t {
    char * key;
    char * title;
    char * help;
} helpMsg_t;

helpMsg_t helpMsgs[200];
int helpMsgCnt = 0;

struct transTbl {
    char *inChar;
    char *outChar[];
};

/* ATTENTION: make sure that the characters are in the same order as the equivalent escape sequences below */

/* translation table for unicode sequences understood by Halibut */
struct transTbl toUnicode = {
    "\xB0\0",
    {
        "\\u00B0",
        "\\0"
    }
};

/* translation table for escape sequences understood by C compiler */

struct transTbl toC = {
    "\n\\\"\0",
    {
        "\\n",
        "\\\\",
        "\\\"",
        "\\0"
    }
};


char *
TranslateString(char *srcString, struct transTbl *trTbl)
{
    char *destString;
    char *cp;
    size_t bufLen = strlen(srcString) + 1;
    char *idx;

    /* calculate the expected result length */
    for (cp = srcString; *cp; cp++) {
        idx = strchr(trTbl->inChar, *cp);

        if (idx) {       			/* does character need translation ? */
            bufLen += strlen((trTbl->outChar)[idx - trTbl->inChar]) -
                      1;    /* yes, extend buffer accordingly */
        }
    }

    /* allocate memory for result */
    destString = malloc(bufLen);

    if (destString) {
		char *cp2;
        /* copy and translate characters as needed */
        cp2 = destString;

        for (cp = srcString; *cp; cp++) {
            idx = strchr(trTbl->inChar, *cp);

            if (idx != NULL) {        /* does character need translation ? */
                strcpy(cp2, (trTbl->outChar)[idx -
                                                 trTbl->inChar ]);     /* yes, copy the escaped character sequence */
                cp2 += strlen((trTbl->outChar)[idx - trTbl->inChar ]);
            } else {
                *cp2++ = *cp;                       /* no, just copy the character */
            }
        }

        /* terminate string */
        *cp2 = '\0';
    } else {
        /* memory allocation failed */
        exit(1);
    }

    return (destString);
}


int cmpHelpMsg(const void * a, const void * b)
{
    helpMsg_p aa = (helpMsg_p)a;
    helpMsg_p bb = (helpMsg_p)b;
    return strcmp(aa->title, bb->title);
}

void unescapeString(FILE * f, char * str)
{
    while (*str) {
        if (*str != '\\') {
            fputc(*str, f);
        }

        str++;
    }
}

/**
 * Generate the file in help source format ( ie. the BUT file )
 */

void dumpHelp(FILE *hlpsrcF)
{
    int inx;

    fputs("\\#\n * DO NOT EDIT! This file has been automatically created by genmessages.\n * Changes to this file will be overwritten.\n",
          hlpsrcF);
    fprintf(hlpsrcF, "\n\n\\H{messageList} Message Explanations\n\n");
    /* sort in alphabetical order */
    qsort(helpMsgs, helpMsgCnt, sizeof helpMsgs[0], cmpHelpMsg);

    /* now save all the help messages */
    for (inx=0; inx<helpMsgCnt; inx++) {
		char *transStr;

        transStr = TranslateString(helpMsgs[inx].title, &toUnicode);
        fprintf(hlpsrcF, "\\S{%s} %s\n\n", helpMsgs[inx].key, transStr);
        free(transStr);
        transStr = TranslateString(helpMsgs[inx].help, &toUnicode);
        fprintf(hlpsrcF, "%s\n\n", transStr);
        free(transStr);
        fprintf(hlpsrcF, "\n\n\\rule\n\n");
    }
}


int main(int argc, char * argv[])
{
    FILE * hdrF;
    FILE *inF;
    FILE *outF;
    char buff[ 4096 ];
    char * cp;
    int inFileIdx = 1;
    enum {m_init, m_title, m_alt, m_help } mode = m_init;
    char msgName[256];
    char msgAlt[256];
    char msgTitle[1024];
    char msgHelp[4096];
    char *tName, *tAlt, *tTitle;

    int i18n = 0;

    /* check argument count */
    if (argc < 3 || argc > 4) {
        fprintf(stderr, "Usage: %s [-i18n] INFILE OUTFILE\n\n", argv[0]);
        fprintf(stderr,
                "       -i18n is used to generate a include file with gettext support.\n\n");
        exit(1);
    }

    /* check options */
    if (argc == 4) {
        if (!strcmp(argv[ 1 ], "-i18n")) {
            i18n = 1;
            inFileIdx = 2;	/* second argument is input file */
        }

        /* inFileIdx = 2;  skip over option argument */
    } else {
        inFileIdx = 1;	/* first argument is input file */
    }

    /* open the file for reading */
    inF = fopen(argv[ inFileIdx ], "r");

    if (!inF) {
        fprintf(stderr, "Could not open %s for reading!\n", argv[ inFileIdx ]);
        exit(1);
    }

    /* open the include file to generate */
    hdrF = fopen("messages.h", "w");

    if (!hdrF) {
        fprintf(stderr, "Could not open messages.h for writing!\n");
        exit(1);
    }

    fputs("/*\n * DO NOT EDIT! This file has been automatically created by genmessages.\n * Changes to this file will be overwritten.\n */\n",
          hdrF);
    fputs("#ifndef HAVE_MESSAGES_H\n#define HAVE_MESSAGES_H\n", hdrF);
    /* open the help file to generate */
    outF = fopen(argv[ inFileIdx + 1 ], "w");

    if (!inF) {
        fprintf(stderr, "Could not open %s for writing!\n", argv[ inFileIdx ]);
        exit(1);
    }

    /* Include i18n header, if needed */
    if (i18n) {
        fprintf(hdrF, "#include \"" I18NHEADERFILE "\"\n\n");
    }

    while (fgets(buff, sizeof buff, inF)) {
        /* skip comment lines */
        if (buff[0] == '#') {
            continue;
        }

        /* remove trailing whitespaces */
        cp = buff+strlen(buff)-1;

        while (cp >= buff && isspace(*cp)) {
            *cp = '\0';
            cp--;
        }

        if (strncmp(buff, "MESSAGE ", 8) == 0) {
            /* skip any spaces */
            cp = strchr(buff+8, ' ');

            if (cp)
                while (*cp == ' ') {
                    *cp++ = 0;
                }

            /* save the name of the message */
            strcpy(msgName, buff + 8);
            msgAlt[0] = 0;
            msgTitle[0] = 0;
            msgHelp[0] = 0;
            mode = m_title;
        } else if (strncmp(buff, "ALT", 3) == 0) {
            mode = m_alt;
            msgAlt[0] = 0;
        } else if (strncmp(buff, "HELP", 4) == 0) {
            mode = m_help;
        } else if (strncmp(buff, "END", 3) == 0) {
            /* the whole message has been read */
            /* create escape sequences */
            tName = TranslateString(msgName, &toC);
            tTitle = TranslateString(msgTitle, &toC);
            tAlt = TranslateString(msgAlt, &toC);

            if (msgHelp[0]==0) {
                /* no help text is included */
                if (i18n) {
                    fprintf(hdrF, "#define %s N_(\"%s\")\n", tName, tTitle);
                } else {
                    fprintf(hdrF, "#define %s \"%s\"\n", tName, tTitle);
                }
            } else if (msgAlt[0]) {
                /* a help text and an alternate description are included */
                if (i18n) {
                    fprintf(hdrF, "#define %s N_(\"%s\\t%s\\t%s\")\n", tName, tName, tAlt, tTitle);
                } else {
                    fprintf(hdrF, "#define %s \"%s\\t%s\\t%s\"\n", tName, tName, tAlt, tTitle);
                }
            } else {
                /* a help text but no alternate description are included */
                if (i18n) {
                    fprintf(hdrF, "#define %s N_(\"%s\\t%s\")\n", tName, tName, tTitle);
                } else {
                    fprintf(hdrF, "#define %s \"%s\\t%s\"\n", tName, tName, tTitle);
                }
            }

            /*free temp stzrings */
            free(tName);
            free(tTitle);
            free(tAlt);

            /* save the help text for later use */
            if (msgHelp[0]) {
                helpMsgs[helpMsgCnt].key = strdup(msgName);

                if (msgAlt[0]) {
                    helpMsgs[helpMsgCnt].title = strdup(msgAlt);
                } else {
                    helpMsgs[helpMsgCnt].title = strdup(msgTitle);
                }

                helpMsgs[helpMsgCnt].help = strdup(msgHelp);
                helpMsgCnt++;
            }

            mode = 0;
        } else {
            /* are we currently reading the message text? */
            if (mode == m_title) {
                /* yes, is the message text split over two lines ? */
                if (msgTitle[0]) {
                    /* if yes, keep the first part as the short text */
                    if (msgAlt[0] == 0) {
                        strcpy(msgAlt, msgTitle);
                        strcat(msgAlt, "...");
                    }

                    /* add a newline to the first part */
                    strcat(msgTitle, "\n");
                }

                /* now save the buffer into the message title */
                strcat(msgTitle, buff);
            } else if (mode == m_alt) {
                /* an alternate text was explicitly specified, save */
                if (msgAlt[ 0 ]) {
                    strcat(msgAlt, " ");
                    strcat(msgAlt, buff);
                } else {
                    strcpy(msgAlt, buff);
                }
            } else if (mode == m_help) {
                /* we are reading the help text, save in buffer */
                strcat(msgHelp, buff);
                strcat(msgHelp, "\n");
            }
        }
    }

    dumpHelp(outF);
    fputs("#endif // HAVE_MESSAGES_H\n", hdrF);
    fclose(hdrF);
    fclose(inF);
    fclose(outF);
    printf("%d messages\n", helpMsgCnt);
    return 0;
}