/***********************************************************************/
/*                                                                     */
/* mail_archive.c saves mails and removes unnecessary headers          */
/*                                                                     */
/* by Boris Lutz (lutz@.n-r-g.com) 01.04.1999                          */
/*                                                                     */
/***********************************************************************/

/* This application is still in development. The parameters are hard   */
/* coded. However I will add suport for an external configuration file */
/* soon. */


/* Don't change the buffer size! */
#define  BUFFER_SIZE 3072
#define  NUMOFHDRS 3
/* Change this when you add or remove mail files and adresses */
#define  NUMOFACCNTS 2

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <assert.h>
#include <string.h>


void get_alowedheaders(char *input_buf, long in_len, char *output_buf, long *out_len, char *mail_file);


int main()
{	
	FILE		*MailFile;
	char		*mail_buff,
			*temp_buff,
			file_name[256];
	long		bytes_read,
			temp_len,
			return_status = 0;


	mail_buff = (char*)  malloc(sizeof(char) * BUFFER_SIZE);
	temp_buff = (char*)  malloc(sizeof(char) * BUFFER_SIZE);

	bytes_read = fread(mail_buff, sizeof(char), BUFFER_SIZE, stdin);
	if(bytes_read == 0) {
		perror("error reading stdin\n");
		exit(-39);
	}
	get_alowedheaders(mail_buff, bytes_read, temp_buff, &temp_len, file_name);
	printf("Filename: %s\n", file_name);
	MailFile = fopen(file_name, "r+");
	if(MailFile == (FILE*) NULL) {
		perror("can not open mailfile\n");
		exit(-37);
	}
	return_status = fseek(MailFile, 0L, SEEK_END);
		if(return_status != 0) {
				perror("can not set r/w pos of mailfile\n");
				exit(-35);
		}
	fprintf(MailFile, "\n");
	return_status =  fwrite(temp_buff, sizeof(char), temp_len, MailFile);
		if(return_status != temp_len) {
				perror("can not write mailfile\n");
				exit(-33); 
		} 
	printf("wrote header\n");

	while(!feof(stdin)) {
		bytes_read = fread(mail_buff, sizeof(char), BUFFER_SIZE, stdin);
		if(bytes_read == 0) {
			perror("error reading stdin\n");
			exit(-39);
		}
		return_status = fwrite(mail_buff, sizeof(char), bytes_read, MailFile);
		if(return_status != bytes_read) {
			perror("can not write mailfile\n");
			exit(-31); 
		} 
		printf("wrote body\n");
	}

	fprintf(MailFile, "\n------------------------------------------------------------------------------\n");
	fclose(MailFile);
	free(mail_buff);
	free(temp_buff);

	return 0;
}


void get_alowedheaders(char *input_buf, long in_len, char *output_buf, long *out_len, char *mail_file)
{
	long		i,
			j,
			k,
			offset,
			offind;
	char		Alowed_Hdrs[NUMOFHDRS][256] = {"From: ", "Date: ", "Subject: "},
			Addr_found = 0,
			/* put your mailaddresses and mail files here */
			Known_Froms[NUMOFACCNTS][256] = {"mailaddress1", "mailaddress2"};
			Mail_Dest[NUMOFACCNTS][256] = {"Mail_file1", "Mail_file2"};


	*out_len = 0;
	/* Set your path for saving the mail files here */
	strcpy(mail_file, "/home/username/Mail/");

	for(i = 0 ; i < in_len; i++) {
		if(i > 0 && input_buf[i-1] == '\n' && input_buf[i] == '\n') {
			printf("End of header\n");
			memcpy(output_buf + *out_len, input_buf + i, in_len - i);
			(*out_len) += in_len - i;
			assert( (*out_len) <= in_len);
			if(Addr_found == 0) {
				printf("Unknown sender, using default Mail-File\n");
				strcat(mail_file, "Div_Mails");
			}
			return;
		}
		for(j = 0; j < NUMOFHDRS; j++) {
			if( (i + strlen(Alowed_Hdrs[j]) ) < in_len && ( i == 0 ||
			 input_buf[i-1] == '\n') && memcmp(Alowed_Hdrs[j], input_buf + i,
			 strlen(Alowed_Hdrs[j]) ) == 0) {
				printf("Match found\n");
				offset = i;
				while(offset < in_len && input_buf[offset] != '\n') {
					output_buf[(*out_len)++] = input_buf[offset++];
				}
				output_buf[(*out_len)++] = '\n'; 
				if(j == 0) {
					for(offind = i; offind < offset && Addr_found == 0; offind++) {
						for(k = 0; k < NUMOFACCNTS; k++) {
							if(offind >= (offset - strlen(Known_Froms[k])) )
								continue;
							if(memcmp(Known_Froms[k], input_buf + offind,
							 strlen(Known_Froms[k]) ) == 0) {
								strcat(mail_file, Mail_Dest[k]);
								Addr_found = 1;
								break;
							}
						}
					}
				}
				i = offset;
			}
		}
	}
	printf("SHOULD NOT GET HERE!!! BUFFER_SIZE must be large enough to read header in one peace otherwise it won't work as expected!\n\n");
	assert( (*out_len) <= in_len);
	if(Addr_found == 0) {
		printf("Unknown sender, using default Mail-File\n");
		strcat(mail_file, "Div_Mails");
	}
	return;
}