/* File: mythread.c
   Author: Xiuwen Liu
   Created on: Sept. 25, 2003
   Description: It includes a set of functions used by threads.
   Compile:
      See makefile
*/

#define MYTHREADS_SOURCE_C_C
#include "mythreads.h"

void * Producer(void *arg)
{
  FILE *fp;
  int ch, ch1;
  char aword[MAX_WORD_LEN];
  int len;
  int matching_tag;
  int k;
  char *pattern = "From ";
  int nmeg;
  int prev;
  MESSAGE_INFO amessage;
  int priority;
  
  // We let the producer run first
  priority = (1+NUM_THREADS) * 5;
  if (priority > 127)
    priority = 127;
  thr_setprio(thr_self(), priority);
  nmeg = 0;
  
  for(k=0; k < (mailbox_len-strlen(pattern)); k++) {
    if (((mailbox[k] == '\n') && (mailbox[k+1] == '\n')) || (k==0)) {
      if ((strncmp(&(mailbox[k+2]), pattern, strlen(pattern)) ==0) ||
	  ((k==0) && strncmp(&(mailbox[k]), pattern, strlen(pattern)) ==0)) {
	if (nmeg > 0) {
	  mailbox[k+1] = '\0';
	  amessage.beginning = prev;
	  amessage.end = k;
	  amessage.message_id = nmeg;
	  Produce_A_Message(&amessage);
	}
	nmeg++;
	
	if (k > 0) {
	  prev = k+2;
	}
	else {
	  prev = k;
	}
      }
    }
  }
  k = mailbox_len-1;
  amessage.beginning = prev;
  amessage.end = k;
  amessage.message_id = nmeg;
  Produce_A_Message(&amessage);
  printf("Producer (thread %d) produced %d messages\n",
	 thr_self(), nmeg);

  return (void *)NULL;
}

void *Consumer(void *arg)
{
  CONSUMER_INFO *info; 
  int  *wordsCount;
  int  k, pos, tmp;
  MESSAGE_INFO amessage;
  char *temp_buf;
  FILE *fp;
  int max, class;
  int priority;
  int processed;
  int flags;
  sleep(2);
  processed = 0;
  // We let the producer run first
  priority = (5+NUM_THREADS) * 5/2;
  if (priority > 127)
    priority = 127;
  thr_setprio(thr_self(), priority);
  thr_yield();
  info = (CONSUMER_INFO *)arg;
  printf("Consumer (thread %d) started.\n", thr_self());
  wordsCount = (int *)malloc(sizeof(int) * info->nwords); 
  temp_buf = (char *)NULL;
  /* Add your program for consumer here */
  while(Consume_A_Message(&amessage)>=0) {
    processed ++;
    for (k=0; k < info->nwords; k++) {
      wordsCount[k] = 0;
    }
    if (temp_buf != NULL) {
      free(temp_buf);
    }
    temp_buf =
      (char *)malloc(sizeof(char) * (amessage.end-amessage.beginning+1));
    pos = amessage.beginning;
    
    // Here we skip the headers
    // Note that the headers will be ended by two consective '\n' 's 
    while(pos < amessage.end) {
      if ((mailbox[pos] == '\n') && (mailbox[pos+1] == '\n') ) {
	pos += 2;
	break;
      }
      pos++;
    }
    flags =1;
    // We find the next one that is not a while space
    while(pos <= amessage.end) {
      while (pos <= amessage.end) {
	if (isspace(mailbox[pos])) pos++;
	else break;
      }
      if (pos > amessage.end) break;
      // We read the next word. This is not the optimal to do the matching
      if (sscanf(&(mailbox[pos]), "%s", temp_buf) ==1) {
	
	for (k=0; k < info->nwords; k++) {
	  if (strcasecmp(info->words[k].word, temp_buf) ==0) { 
	    wordsCount[k]++;
	  }
        }
	pos += strlen(temp_buf);
      }
      else {
	break;
      }
      //printf("Consumer: %s\n", aword);
    }
    printf("Filtered words' occurrence report in message %d (%d -> %d).\n",
	   amessage.message_id,amessage.beginning,amessage.end);
    max = wordsCount[0];
    class = info->words[0].category;
    for (k=0; k < info->nwords; k++) {
      printf("\t%s (%d):\t\t%d\n", info->words[k].word, 
	     info->words[k].category, wordsCount[k]);
      // We add this to the total
      tmp = info->words[k].saved_messages;
      thr_yield();
      tmp += wordsCount[k];
      thr_yield();
      info->words[k].saved_messages = tmp;
      thr_yield();
      if (max < wordsCount[k]) {
        max = wordsCount[k];
        class = info->words[k].category;
      }
    }
    if (max <= 0) {
      class = 0;
    }
    for (k=0; k < info->ncategories; k++) {
      if (info->categories[k].category == class) break;
    }
    if (k >= info->ncategories) {
      fprintf(stderr, "%d cateogry was not found ", class); 
      fprintf(stderr, "and default is used instead.\n");
      class = 0;
    }
    else {
      class = k;
    }
    /* Now save the message to the corresponding folder */
    printf("Thead %d Save message %d (%d -> %d) to folder %s (%d).\n",
	   thr_self(),
	   amessage.message_id,amessage.beginning,amessage.end,
	   info->categories[class].word, info->categories[class].category);
    fp = fopen(info->categories[class].word,"ab");
    if (fp == NULL) {
      fprintf(stderr,"Could not open file \"%s\" for appending.\n",
	      info->categories[class].word);
      fprintf(stderr,"Please change the permission of the file.\n");
    }
    else {
      for (k=amessage.beginning; k <= amessage.end; k++) {
	if (isascii((int)mailbox[k])) {
	  fputc((int)mailbox[k], fp);
	  thr_yield();
	}
	
      }
      
      fputc((int)'\n', fp);
      fclose(fp);
    }
    k = info->categories[class].saved_messages;
    thr_yield();
    k = k + 1;
    thr_yield();
    info->categories[class].saved_messages = k;
    if ((random()%2) ==0)
      sleep(1);
   
  } 
  free(wordsCount);
  if (temp_buf != NULL) {
    free(temp_buf);
  }
  printf("Consumer thread %d is done with %d messaged processed.\n",
	 thr_self(), processed);
  return (void *)NULL;
}


int Produce_A_Message(MESSAGE_INFO *amessage)
{
  int i;
  
  /* Add to the shared buffer here */
  /* Remember that you need to add concurrency control at here */
  
  shared_buf[nextp] = *amessage;
  nextp = (nextp+1) % message_buf_size;
 
  return i;
}

int Consume_A_Message(MESSAGE_INFO *amessage)
{
  //sleep(1);
  /* Add to the shared buffer here */
  /* Remember that you need to add concurrency control at here */
  int tmp;
  int saved_priority;
  int new_priority;
  if (done) return -1;
  *amessage = shared_buf[nextc];
  thr_getprio(thr_self(), &saved_priority);
 
  new_priority = thr_self() * 5;
  if (new_priority > 127)
    new_priority = 127;
  thr_setprio(thr_self(), new_priority);
  thr_yield();
  
  tmp = nextc;
  tmp = (nextc+1)%message_buf_size;
  thr_yield();
  if ((random()%10) ==0) {
    sleep(1);
  }
  nextc = tmp;
  if (amessage->end >= (mailbox_len-2)) {
    done = 1;
  }
  thr_setprio(thr_self(), saved_priority);
  return 0;
}