/* File: lab2.c
   Author:  Xiuwen Liu
   Purpose: a tool to sort email messages based on keywords
   Command to complie:
         see makefile
*/


#include <sys/types.h>
#include <strings.h>
#include <sys/wait.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include <thread.h>
#include <stdlib.h>
#include <ctype.h>
#include <synch.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "type-def.h"
#include "util.h"
#include "mythreads.h"

int verbose;

int main(int argc, char *argv[])
{
  int i, sum;
  
  extern char *optarg;
  extern int optind;
  thread_t *tid;      /* array of thread IDs */
  CONSUMER_INFO consumer_info;
  PRODUCER_INFO producer_info;
  char c;
  int fd;
  struct stat stat_buf;
  int seed;
  char comm[2048];
  
  /* Initialization here */
  nextc = 0;
  nextp = 0;
  done = 0;
  verbose = 0; 
  mutex_lock_flag = 0;
  seed = 0;
  producer_info.mailbox[0] = '\0';
  strcpy(consumer_info.filterwordsFile,"filterwords.dat");
  strcpy(consumer_info.categoryFile,"categorylist.dat");
  NUM_THREADS = 2;
  while ((c = getopt(argc, argv, "ms:v:f:c:t:")) != EOF) {
    switch(c) {
    case 'm':
      mutex_lock_flag = 1;
      break;
    case 'f':
      strcpy(consumer_info.filterwordsFile,optarg);
      break;
    case 'c':
      strcpy(consumer_info.categoryFile,optarg);
      break;
    case 'v':
      verbose = atoi(optarg);
      break;
    case 't':
      NUM_THREADS= atoi(optarg);
      break;
    case 's':
      seed = atoi(optarg);
      break;
    default:
      printf("%c is not valid option.\n", c);
    }
  }
  
  if (optind == (argc-1)) {
    strcpy(producer_info.mailbox,argv[optind]);
  }
  else {
    fprintf(stderr,"Usage: %s [-m] [-f filterwordfile] [-c categoryfile] ",
	    argv[0]);
    fprintf(stderr,"[-v verbose-level] [-t numberthreads] mailbox\n");
    return -1;
  }
  srandom(seed);
  if (verbose >= 1) {
    printf("Number of consumer threads is %d\n", NUM_THREADS);
    printf("The mailbox to be searched is \"%s\"\n",producer_info.mailbox);
    printf("The words to be checked are given in \"%s\".\n",
	   consumer_info.filterwordsFile);
    printf("The folders for each category are given in \"%s\".\n",
	   consumer_info.categoryFile);
    printf("The synchronizatoin is ");
    if (mutex_lock_flag ==0) {
      printf("DISABLED.\n");
    }
    else {
      printf("ENABLED.\n");
    }
  } 
  /* Read the words from the filterwordsFile
   */
  consumer_info.nwords = Count_Item_InFile(consumer_info.filterwordsFile);
  if (consumer_info.nwords <= 0) {
    fprintf(stderr,"There is no filter word read from \"%s\".\n",
	    consumer_info.filterwordsFile);
    return -1;
  }
  consumer_info.words =
    (WORD_INFO *)malloc(sizeof(WORD_INFO) *
			consumer_info.nwords);
  Read_Items_FromFile(consumer_info.filterwordsFile,
		      consumer_info.words,
		      consumer_info.nwords);
  // We initilize the total occurrence
  for (i=0; i < consumer_info.nwords; i++) {
    consumer_info.words[i].saved_messages = 0;
  }
  /* Read the categories from the categoryFile
   */
  consumer_info.ncategories =
    Count_Item_InFile(consumer_info.categoryFile);
  if (consumer_info.ncategories <= 0) {
    fprintf(stderr,"There is no category read from \"%s\".\n",
	    consumer_info.categoryFile);
    return -1;
  }
  consumer_info.categories =
    (WORD_INFO *)malloc(sizeof(WORD_INFO) *
			consumer_info.ncategories);
  Read_Items_FromFile(consumer_info.categoryFile,
		      consumer_info.categories,
		      consumer_info.ncategories);
  if (verbose >= 1) {
    printf("There are %d filtering words to be used and they are\n",
	   consumer_info.nwords);
    for (i=0; i < consumer_info.nwords; i++) {
      printf("\t%s (%d)\n",consumer_info.words[i].word,
	     consumer_info.words[i].category);
    }
    printf("There are %d categories to be used and they are\n",
	   consumer_info.ncategories);
    for (i=0; i < consumer_info.ncategories; i++) {
      printf("\t%s (%d)\n",consumer_info.categories[i].word,
	     consumer_info.categories[i].category);
    }
  }
  for (i=0; i < consumer_info.ncategories; i++) {
    consumer_info.categories[i].saved_messages = 0;
    // We also need to truncate the file every time
    // Note in real life we may not need to do this as
    // normally only check new messages
    fd = open(consumer_info.categories[i].word,O_WRONLY|O_CREAT|O_TRUNC,
	      S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
    if (fd > 0) {
      fchmod(fd, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
      close(fd);
    }
    else {
      fprintf(stderr,"Cannot open file \"%s\" for writing the first time.\n",
	      consumer_info.categories[i].word);
      if (chmod(consumer_info.categories[i].word,
		S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) < 0) {
	printf("Cannot change the permission of file \"%s\".\n",
	       consumer_info.categories[i].word);
	exit(0-1);
      }
      fd = open(consumer_info.categories[i].word,O_WRONLY|O_CREAT|O_TRUNC,
		S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
      if (fd > 0) {
	fchmod(fd, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
	close(fd);
	fprintf(stderr,"The problem was fixed for file \"%s\".\n",
	       consumer_info.categories[i].word);
      }
      else {
	fprintf(stderr,"Cannot open file \"%s\" for writing second time.\n",
	      consumer_info.categories[i].word);
	exit(-1);
      }
    }
  }
  fd = open(producer_info.mailbox,O_RDONLY);
  if (fd < 0) {
    fprintf(stderr,"Cannot open the mailbox \"%s\" to be searched.\n",
	    producer_info.mailbox);
    return -1;
  }
  fstat(fd, &stat_buf);
  mailbox = (char *)malloc(sizeof(char)*(stat_buf.st_size+1));
  mailbox_len = (int)read(fd, (void *)mailbox, stat_buf.st_size);
  if (mailbox_len != (int)stat_buf.st_size) {
    fprintf(stderr,"Something is wrong with mailbox \"%s\".\n",
	    producer_info.mailbox);
    fprintf(stderr,"We should read %d bytes but %d were read.\n",
	    stat_buf.st_size, mailbox_len);
    close(fd);
    return -1;
  }
  close(fd);
  
  // Add '\0' at the end to avoid segmentation problems
  mailbox[mailbox_len] = '\0';
  if (verbose >= 1) {
    printf("%d bytes were read from mailbox \"%s\".\n",
	   mailbox_len,
	   producer_info.mailbox);
  } 
  
  tid = (thread_t *)malloc(sizeof(thread_t)*(NUM_THREADS+1));

  message_buf_size = NUM_THREADS * 2;
  if (NUM_THREADS == 1) {
    // We make this one as a special case so that we can test our program
    // without synchronization
    // In this case, we have a buffer with an unlimited capacibity
    // Here the capacity is estimated based on the length of the mailbox
    // and that each message will have at least 100 bytes
    message_buf_size = (int)(mailbox_len/100);
  }
  shared_buf = (MESSAGE_INFO *)malloc(sizeof(MESSAGE_INFO) *
				      message_buf_size);
  for (i=0; i < message_buf_size; i++) {
    shared_buf[i].message_id = -1;
  }
  /* Create the producer thread here */
  if (thr_create(NULL, (int)0, Producer, (void *)(&producer_info),
		 THR_SUSPENDED, &(tid[0])) <0) {
    perror("create thread: ");
    return -1;
  }
  
  /* Create the consumer thread here */
  for (i=0; i < NUM_THREADS; i++) {
    if (thr_create(NULL, (int)0, Consumer, (void *)(&consumer_info),
		   THR_SUSPENDED, &(tid[i+1])) <0) {
      perror("create thread: ");
      return -1;
    }
  }
  
  
  for (i=0; i < (NUM_THREADS+1); i++)
  thr_continue(tid[i]);
  
  while (thr_join(NULL, NULL, NULL) == 0);
  // Free all the allocated memory spaces
  // Print the total saved messages in each category
  printf("Total messages saved in each folder\n");
  for (i=0; i < consumer_info.ncategories; i++) {
    printf("\t%s (%d):  %d\n",
	   consumer_info.categories[i].word,
	   consumer_info.categories[i].category,
	   consumer_info.categories[i].saved_messages);
  }
  printf("Total occurrences of the filtered words in mailbox \"%s.\n",
	 producer_info.mailbox);
  for (i=0; i < consumer_info.nwords; i++) {
    printf("\t%s (%d):\t\t%d\n", consumer_info.words[i].word, 
	   consumer_info.words[i].category, 
	   consumer_info.words[i].saved_messages);
  }
  for (i=0; i < consumer_info.nwords; i++) {
    free(consumer_info.words[i].word);
  }
  free(consumer_info.words);
  for (i=0; i < consumer_info.ncategories; i++) {
    free(consumer_info.categories[i].word);
  }
  free(consumer_info.categories);
  free(tid);
  free(mailbox);
  free(shared_buf);
  // Destroy_Mutex();
  return 0;
}