/*
  This software is distributed under GNU General Public License, ver. 2
  or higher (at your option), released by Free Software Foundation. 
  You should receive text of the GNU GPL along with this software. If not,
  you can find it at:
     http://sageshome.net/GPL.php
   or
     http://www.gnu.org/
     http://www.opensource.org/
  
  Copyright(C) Sergey A. Galin, 2002-2004. 
 
  Change Log:
  
  * Thu Nov 11 2004 Sergey Galin <sergey@sageshome.net> 
  - v. 1.3 - Changed signature to allow processing of Eudora's mailboxes.  
  - v. 1.2 - Added patch by Florian Feucht (fixed a bug of skipping first 2 chars 
    from "From:" in the first message).
  
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <fcntl.h>
#include <unistd.h>

#define VERSION "1.3"

// Signature which separates messages:
const char *const Separator="\nFrom ";
// Number of symbols to skip in signature to start of the message:
const int Rewind_Count=1; 

int Silent=0;

#define MAXPATH 65535

#define NSPRINTF if(!Silent) printf

int OutFile(const char *mdir){
  char buf[MAXPATH];
  sprintf(buf, "%s/mbox2mdirXXXXXX", mdir);
  return mkstemp(buf);
}

long strpos(const char *haystack, const char *needle){
  size_t nl=strlen(needle);
  for(size_t i=0; haystack[i]!='\0'; i++)
    if(memcmp((haystack+i), needle, nl)==0) return i;
  return -1;
}

size_t strdistance(const char *haystack, const char *needle){
  size_t nl=strlen(needle);
  for(size_t i=0; haystack[i]!='\0'; i++)
    if(memcmp((haystack+i), needle, nl)==0) return i;
  return strlen(haystack);
}

int FlushMail(const char *data, size_t sz, const char *dir){
  int f;
  if((f=OutFile(dir))<0){ perror("Unable to create output file"); return 1; }
  write(f, data, sz);
  fchmod(f, 0666);
  close(f);
  return 0;
}

int Process(const char *ifile, const char *odir, int truncate){
  int inf;
  size_t sz;
  struct stat buf;  
  char *data, *seek;
  int count=0;
  
  inf=open(ifile, O_RDWR);
  NSPRINTF("Processing %s to %s...\n", ifile, odir);
  if(inf<0){ perror("Unable to open input file"); return 1; }
  
  if(flock(inf, LOCK_EX)==-1){ perror("Unable to lock input file"); return 1; }
  
  fstat(inf, &buf);
  sz=buf.st_size;
  if(sz>0){
    data=(char *)malloc(sz+1);
    if(data==NULL){ perror("Cannot allocate buffer"); return 1; }  
    read(inf, data, sz);
    
    data[sz]=0;
    
    seek=data;
    
//size_t total=0;    
    do{

      size_t mailsz=strdistance(seek+1, Separator)+1;
//      printf("MAIL %d\n", mailsz);    
      // Added patch by Florian Feucht (fixed a bug of skipping first 2 chars 
      // from "From:" in the first message
      if (count==0) {
        // for the first time, no \n\n before mail starts.
        if(FlushMail(seek, mailsz, odir)){ 
          perror("Error processing mail, terminating"); 
	  close(inf);
	  return 1; 
        };
      }else{
        if(FlushMail(seek+Rewind_Count, mailsz, odir)){ 
          perror("Error processing mail, terminating"); 
	  close(inf);
	  return 1; 
        };
      }
      
	
      count++;
      
//total+=mailsz;      
      
      seek++;
    }while((seek=strstr(seek, Separator))!=NULL);
//printf("Total: %d\n", total);    
  
    free(data);
  }
  if(truncate)
    if(ftruncate(inf, 0)<0) 
      perror("Unable to truncate input file"); 
    else
      NSPRINTF("Input Mailbox truncated.");
  close(inf);
  NSPRINTF("Processing %s to %s successful, %d messages (%d bytes) processed.\n", ifile, odir, count, sz);  
  return 0;
}

int FindParam(const char *par, int argc, char *argv[]){
  for(int i=0; i<argc; i++)
    if(!strcmp(argv[i], par)) return i;
  return -1;    
}

int main(int argc, char *argv[]){
  //const char *ifile="Mailbox", *odir="/home/sergey/Maildir/cur";
  const char *ifile, *odir;
  if(argc<3){
    printf("Mailbox to Maildir Converter, Version "VERSION" built: "__DATE__" Copyright(C) Sergey A. Galin.\n"
           "USAGE:   mbox2mdir <input mailbox file> <output maildir> [options]\n"
           "OPTIONS: -t - Truncate input Maildir file after successful conversion.\n"
	   "         -s - Silent mode (error reporting only).\n"
	   "EXAMPLE: $ mbox2mdir /var/qmail/alias/Mailbox /home/sergey/Maildir/cur -t\n");
  }else{
    int truncate=0;
    if(FindParam("-t", argc-3, argv+3)>=0) truncate=1;
    if(FindParam("-s", argc-3, argv+3)>=0) Silent=1;
    ifile=argv[1];
    odir=argv[2];
    return Process(ifile, odir, truncate);    
  }
}