#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <stdlib.h>
#include <syslog.h>
#include "misc.h"
#include "mailhead.h"

PUBLIC MAILADR::MAILADR()
{
	adr[0] = '\0';
	name[0] = '\0';
}

PUBLIC MAILHEADER::MAILHEADER()
{
	nbreceived = 0;
	reply[0] = '\0';
	subject[0] = '\0';
	msgid[0] = '\0';
	replyid[0] = '\0';
	date[0] = '\0';
	priority[0] = '\0';
}


void mail2fax_stripcopy (
	char dst[MAXHLINE+1],
	char *src)
{
	strip_end (src);
	src = str_skip (src);
	if (src[0] == '"'){
		src = str_skip (src+1);
		int last = strlen(src) -1;
		if (last >= 0 && src[last] == '"') src[last] = '\0';
		strip_end (src);
	}
	strncpy (dst,src,MAXHLINE);
	dst[MAXHLINE] = '\0';
}


static void mail2fax_copy2adr(
	char *accum,
	char *split,
	char endsplit,
	char first[MAXHLINE+1],
	char second[MAXHLINE+1])
{
	*split++ = '\0';
	mail2fax_stripcopy (first,accum);
	accum = split;
	split = strchr(accum,endsplit);
	if (split != NULL) *split = '\0';
	mail2fax_stripcopy (second,accum);
}

/*
	Parse a user address + name
*/
static void mail2fax_parsename (
	MAILADR &adr,
	char *accum)
{
	/*
		We have either "user name <email>"
		or "email (user name)
		or simply email
	*/
	char *split = strchr(accum,'<');
	if (split != NULL){
		mail2fax_copy2adr (accum,split,'>',adr.name,adr.adr);
	}else{
		split = strchr (accum,'(');
		if (split != NULL){
			mail2fax_copy2adr (accum,split,')',adr.adr,adr.name);
		}else{
			mail2fax_stripcopy (adr.adr,accum);
			adr.name[0] = '\0';
		}
	}
}

/*
	Parse one line of the header
*/
static void mail2fax_parsehead (
	char *accum,	// One line
	MAILHEADER &head,
	int *ret)		// Put any error in that
{
	// syslog (LOG_ERR,"Parse %d %s",*ret,accum);
	if (strncasecmp(accum,"From: ",6)==0){
		mail2fax_parsename (head.from,accum+6);
		*ret = 0;
	}else if (strncasecmp(accum,"To: ",4)==0){
		mail2fax_parsename (head.to,accum+4);
	}else if (strncmp(accum,"Received: ",10)==0){
		head.nbreceived++;
	}else if (strncasecmp(accum,"Reply-to: ",10)==0){
		MAILADR tmp;
		mail2fax_parsename (tmp,accum+10);
		strncpy (head.reply,tmp.adr,MAXHLINE);
		head.reply[MAXHLINE] = '\0';
	}else if (strncasecmp(accum,"Message-ID: ",12)==0){
		strncpy (head.msgid,accum+12,MAXHLINE);
		head.msgid[MAXHLINE] = '\0';
	}else if (strncasecmp(accum,"In-Reply-to: ",13)==0){
		MAILADR tmp;
		mail2fax_parsename (tmp,accum+13);
		strncpy (head.replyid,tmp.adr,MAXHLINE);
		head.replyid[MAXHLINE] = '\0';
	}else if (strncasecmp(accum,"Date: ",6)==0){
		strncpy (head.date,accum+6,MAXHLINE);
		head.date[MAXHLINE] = '\0';
	}else if (strncasecmp(accum,"Precedence: ",12)==0){
		strncpy (head.priority,accum+12,MAXHLINE);
		head.priority[MAXHLINE] = '\0';
	}else if (strncasecmp(accum,"Subject: ",9)==0){
		strncpy (head.subject,accum+9,MAXHLINE);
		head.subject[MAXHLINE] = '\0';
	}
}

unsigned long mailhead_getdate (MAILHEADER &head)
{
	unsigned long ret = 0;
	char tmp[6][MAXHLINE];
	if (sscanf (head.date,"%s %s %s %s %s %s"
		,tmp[0],tmp[1],tmp[2],tmp[3],tmp[4],tmp[5])==6){
		static const char *tbmonth[]={
			"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep",
			"Oct","Nov","Dec"
		};
		int i;
		struct tm t;
		t.tm_mday = atoi(tmp[1]);
		t.tm_year = atoi(tmp[3])-1900;
		t.tm_hour = atoi(tmp[4]);
		t.tm_min = atoi(tmp[4]+3);
		t.tm_sec = atoi(tmp[4]+6);
		t.tm_isdst = -1;
		for (i=0; i<12; i++){
			if (strcmp(tmp[2],tbmonth[i])==0){
				t.tm_mon = i;
				ret = mktime (&t);
				break;
			}
		}
	}
	return ret;
}

/*
	Read the beginning of the mail and extract various useful
	field from the header.
	Stop at the first empty line (end of the header)
*/
int mail2fax_getheader (
	FILE *fin,
	MAILHEADER &head,
	char *collect,		// Will contain the header if not NULL
	int size)			// size of the collect buffer
{
	int ret = -1;
	char buf[500];
	char accum[2000];
	accum[0] = '\0';
	head.nbreceived = 0;
	head.from.adr[0] = head.from.name[0] = '\0';
	head.to.adr[0] = head.to.name[0] = '\0';
	head.reply[0] = head.subject[0] = '\0';
	head.date[0] = head.replyid[0] = head.msgid[0] = '\0';
	char *ptcol = collect;
	size -= sizeof(buf);	// Avoid overflow without thinking much
	int lenaccum = 0;
	while (fgets(buf,sizeof(buf)-1,fin)!=NULL){
		if (ptcol != NULL && (ptcol - collect) < size){
//			ptcol = stpcpy (ptcol,buf);
			ptcol = strcpy (ptcol,buf) + strlen(buf);
		}
		strip_end (buf);
		if (buf[0] == '\0'){
			break;
		}else if (isspace(buf[0])){
			int len = strlen(buf);
			if (len + lenaccum < (int)sizeof(accum)-1){
				strcat (accum,buf);
				lenaccum += len;
			}
			// We ignore header line larger than accum
		}else{
			if (accum[0] != '\0'){
				mail2fax_parsehead (accum,head,&ret);
			}
			strcpy (accum,buf);
			lenaccum = strlen(accum);
		}
	}
	if (accum[0] != '\0'){
		mail2fax_parsehead (accum,head,&ret);
	}
	return ret;
}

int mail2fax_getheader (FILE *fin, MAILHEADER &head)
{
	return mail2fax_getheader (fin,head,NULL,0);
}


int mail2fax_getheader (MAILHEADER &head)
{
	return mail2fax_getheader (stdin,head);
}