/* Time planner program 	                                         */

#include "cd103.h"
char dummy ; /* Used to store the value of getc(stdin) to prevent        */
	     /* the 'Code has no effect' compiler warning.               */

void main ()
{
/* Description ......
SECTION 1 MAKE COPY OF FILE AND UPDATE REPEATING RECORDS
   calculate current date as an integer
   Open input and output files
   Read first record
   initialise record counter
   WHILE not end of file
      calculate record date as an integer
      IF record current (i.e. not expired)
	 set record's number equal to counter
	 Write record to output file
	 Add 1 to counter
      ELSE record has expired
         IF a Repeating record
            DO
               case Daily repeat   : add 1 to days field (check month & year)
               case Weekly repeat  : add 7 to days field (check month & year)
	       case Monthly repeat : add 1 to month field (check year)
	    WHILE record still expired
         set record's number equal to counter
         Write updated record to output file
         Add 1 to counter
      Read next record
   Write terminating record to output file
   Close the files
   Replace input file with output file

SECTION 2 DISPLAY TODAY'S APPOINTMENTS
   Open input file
   DO
      Clear the screen
      Initialise counter to 1
      Display headings for Today's Reminders
      Read first record from file
      WHILE not end of file and screen not full
         Calculate record's date as integer
         IF record's date = today
            Display record on screen
	    Add 1 to counter
	 Read next record
      IF not end of file
	 Display Hit a key to see next screenful
	 Accept key stroke
   WHILE not end of file
   Close input file
   Display Hit any key to continue
   Accept key stroke

SECTION 3 DISPLAY MENU AND PROCESS RECORDS
   DO
      Display the main menu
      Accept user's choice
      case choice = 1 : Add a record to file
      case choice = 2 : Delete a record
      case choice = 3 : Amend a record
      case choice = 4 : Display today's appointments
      case choice = 5 : Display file contents
      case choice = 6 : Exit program
      otherwise       : Display error message
   WHILE user not choose exit
*/

/* Identifiers as needed                                                 */
int user_choice ;
int counter ;

/* Prototypes for the functions                                          */

int DaysInMonth (int, int) ;
void  DisplayFile (void) ;
void  DisplayMenu (void) ;
void  AddRecord (void) ;
void  DeleteRecord (void) ;
void  AmendRecord (void) ;
void  DisplayToday (void) ;

/* End of Declarations section                                           */

/* SECTION 1                                                             */
system_date = GetDate () ;

input_file = fopen (in_filename, "r") ;
output_file = fopen (out_filename, "w");
ReadRecord () ;
counter = 1 ;
while (day != 99) /* while not at end of the data file                */
{
	long_year = year ;
	long_month = month ;
	record_date = long_year * 10000 + long_month * 100 + day ;
	if (record_date >= system_date) /* record not expired              */
	{
		number = counter ;
		WriteRecord () ;
		++ counter ;
	}
	else /* record expired, check to see if it needs to be repeated    */
	{
		if (type == 'R') /* repeating record                            */
	    	{
	    		do
			{
				switch (frequency)
				{
					case 'D' : AddDays (frequency) ;
						day  = day  + 1;
						break ;

					case 'W' : AddDays (frequency) ;
			     			day = day + 7 ;
			     			break ;
		  			case 'M' : /* month ;*/
			     			IncrementMonth ();
			     			month = month + 1 ;
			     			break ;
		      		}
	       			long_year = year ;
	       			long_month = month ;
	       			record_date = long_year * 10000 + long_month * 100 + day ;
	       		}
	    		while ( record_date < system_date ) ;
	    		number = counter ;
	    		WriteRecord () ;
	    		++ counter ;
	    	}
	}
      	ReadRecord () ;
} /* END while loop                                                */

WriteTerminator () ;
fcloseall () ;
remove (in_filename) ;
rename (out_filename, in_filename) ;

/* SECTION 2                                                             */
input_file = fopen (in_filename, "r") ;
do
{
	clrscr () ;
	counter = 0 ;
	printf ("\n\n\n\n\n") ;
	printf ("%12c** Today's reminders **\n\n", ' ') ;
	printf ("%12cDate   Start End   Message\n", ' ') ;
	printf ("%12c============================================\n", ' ') ;
	ReadRecord () ;
	while ((day != 99) && (counter < 10))
	{
		long_year = year ;
		long_month = month ;
		record_date = long_year * 10000 + long_month * 100 + day ;
		if (record_date == system_date) /* display appointment for today */
		{
			printf ("%12c%d-%s %02d:%02d %02d:%02d %s\n", ' ', day,
			LookupMonth (month), start_hours, start_minutes,
				end_hours,end_minutes, message) ;
			++ counter ;
		}
		ReadRecord () ;
	}
	if (day != 99)
	{
		printf ("\n%12cHit a key to see next screenful", ' ') ;
		getch () ;
	}
}
while (day != 99) ;
fclose (input_file) ;
printf ("\n%12cHit any key to continue", ' ') ;
getch () ;

/* SECTION 3  */
do
{ 
	DisplayMenu ();

	
	user_response=getch () ;
	switch (user_response)
	{
		case '1' : AddRecord ();
			break ;
		case '2' : DeleteRecord () ;
			break ;
		case '3' : AmendRecord () ;
			break ;
       		case '4' : DisplayToday () ;
			break ;
		case '5' : DisplayFile () ;
			break ;
		case '6' : WriteTerminator () ;
			exit() ;
		default : DisplayError (6);
       	}
}
while ( user_response != 6 ) ;

}

   /* END main  */


/*Function definitions  */

/* function DisplayFile                                                  */
/* This function displays the contents of the data file on the screen    */
/* ten records at a time.                                                */

void DisplayFile (void)
{
/* Description ......
   Open input file
   DO
      Clear the screen
      Display headings
      Read first record from file
      Initialise counter to 0
      WHILE screen not full (counter < 10) and not end of file
	 Calculate record duration
	 Display record on screen
	 Read next record
	 Add 1 to counter
      if not end of file
	 Display Hit a key to see next screenful
	 Accept key stroke
   WHILE not end of file
   Close input file
   Prompt user to continue
*/

int counter ;
input_file = fopen ("in_filename", "r") ;

do
   {
   clrscr () ;
   printf ("\n\n\n\n\n%12c** File Contents **\n\n", ' ') ;
   printf
   ("  Date      Start End    Duration Type Freq. Message                   Number\n") ;
   printf
   ("=============================================================================\n") ;

   ReadRecord () ;
   counter = 0 ;
   while ((counter < 10) && (day !=99))
      {
      start_time = start_hours * 60 + start_minutes ;
      end_time = end_hours * 60 + end_minutes ;
      duration = (end_time - start_time) ;
      printf ("%02d-%s-%d %02d:%02d %02d:%02d  %02d:%02d     %c    %c    %s  %5d\n", day,
	     LookupMonth (month), year, start_hours, start_minutes,
	     end_hours, end_minutes, duration / 60, duration % 60,
	     type, frequency, message, number) ;
      ++ counter ;
      ReadRecord () ;
      }
   if (day !=99)
      {
      printf ("\n%12cHit a key to see next screenful", ' ') ;
      getch () ;
      }
   }
while (day !=99) ;
fclose (input_file) ;
printf ("\n%12cHit a key to continue", ' ') ;
getch () ;
}

/* function DisplayMenu                                                  */
/* Function to display menu and prompt for user's choice                 */
void DisplayMenu (void)
{
/* Description ......
   Clear the screen
   Display menu
   Display prompt for user's choice
*/
   clrscr () ;
   printf ("\n\n\n\n\n%12c** Daily Appointments Reminder **\n\n", ' ') ;
   printf ("%12c1: ADD Item\n\n", ' ') ;
   printf ("%12c2: DELETE Item\n\n", ' ') ;
   printf ("%12c3: AMEND Item\n\n", ' ') ;
   printf ("%12c4: DISPLAY Today's Appointments\n\n", ' ') ;
   printf ("%12c5: DISPLAY File Contents\n\n", ' ') ;
   printf ("%12c6: EXIT\n\n", ' ') ;
   printf ("%12cPlease choose option (1-6) : ", ' ') ;

}

/* function AddRecord                                                    */
/* function to add a record to the file                                  */
void AddRecord (void)
{
/* Description ......
   Open input and output files
   Read first record from input file
   WHILE not end of file
      Copy record to output file
      Store record's number
      Read next record
   Close input file
   DO
      Clear the screen
      Display headings
      Prompt for and accept Day
      Prompt for and accept Month
      Prompt for and accept Year
      Prompt for and accept Time
      Prompt for and accept Type
      Convert type to upper case
      IF Repeating record
	 Prompt for and accept frequency
	 WHILE invalid frequency
	    Display error message
	    Prompt for and accept frequency
      ELSE non-repeating message
	 Assign blank to frequency
      Prompt for and accept record message
      Prompt for saving record to file
      IF user wants to save record
	 Assign stored record number to record number
	 Write record to output file
	 Add 1 to stored record number
      Prompt for and accept Add another record
   WHILE user wants to keep adding records
   Close files
   Replace input file with output file
*/
int last_record_number ;
char filler,
     response ;

input_file = fopen (in_filename, "r") ;
output_file = fopen (out_filename, "w") ;

ReadRecord () ;
while (day !=99)
   {
   WriteRecord () ;
   last_record_number = number ;
   ReadRecord () ;
   }
fclose (input_file) ;
do
   {
   clrscr () ;
   printf ("\n\n\n\n\n            ** Add an appointment **\n\n", ' ') ;
   printf ("            Enter day (DD) ", ' ') ;
   scanf ("%d", &day) ;
   printf ("            Enter month (MM) ", ' ') ;
   scanf ("%d", &month) ;
   printf ("%12cEnter year (YYYY) ", ' ') ;
   scanf ("%d", &year) ;
   printf ("            Enter start time (HH MM) ", ' ') ;
   scanf ("%d%d", &start_hours, &start_minutes) ;
   printf ("            Enter end time (HH MM) ") ;
   scanf ("%d%d", &end_hours, &end_minutes) ;
   printf ("%12cEnter record type (R/S) ", ' ') ;
   scanf ("\n%c", &type) ;
   type = toupper (type) ; /* toupper converts a character to its        */
			   /* upper-case equivalent                      */
   if (type == 'R')
      {
      printf ("%12cEnter repeat frequency (D/W/M) ",' ') ;
      scanf ("\n%c", &frequency) ;
      frequency = toupper (frequency) ;
      while ((frequency != 'D') && (frequency != 'W') && (frequency != 'M'))
	   {
	   clrscr() ;
	   printf ("\n\n\n\n\n%12cFrequency must be one of D/W/M\n", ' ') ;
	   printf ("%12cEnter the repeat frequency (D/W/M) ", ' ' ) ;
	   scanf ("\n%c", &frequency) ;
	   frequency = toupper (frequency);
	   }
      }
   else
      {
      frequency = ' ';
      }
   printf ("%12cEnter message (max 25 characters) ", ' ') ;
   dummy = getc (stdin) ;
   gets (message) ;
   for (counter = strlen (message); counter < 25; counter ++)
      strcat (message, " ") ;

   printf ("%12cDo you want to save this message to the file? (Y/N) ", ' ') ;
   scanf ("\n%c", &response) ;
   if ((response == 'Y') || (response == 'y'))
      {
      number = last_record_number + 1 ;
      WriteRecord () ;
      ++ last_record_number ;
      }
   printf ("\n%12cDo you want to add another record? (Y/N) ", ' ');
   scanf ("\n%c", &response) ;
   }
while ((response == 'Y') || (response == 'y')) ;

WriteTerminator ();
fclose (output_file) ;
remove (in_filename) ;
rename (out_filename, in_filename) ;
}

/* function DeleteRecord                                                 */
/* function to remove a record from the file                             */
void DeleteRecord (void)
{
/* Description ......
   DO
      Display file contents
      Prompt for and accept record number to delete
      Open files
      Read first record from file
      Initialise counter to 1
      WHILE not end of file
	 IF this record not to be deleted
	    Assign counter to record number
	    Write record to output file
	    Add 1 to counter
	 Read next record
      Close input file
      Write terminating record to output file]
      Close output file
      Replace input file with output file
      Prompt for user to delete another record
   WHILE user wants to delete records
*/
int counter,
    delete_number ;
char response ;

do
   {
   DisplayFile () ;
   printf ("%12cPlease enter number of record to be deleted ", ' ') ;
   scanf ("%d", &delete_number) ;
   input_file = fopen (in_filename, "r" ) ;
   output_file = fopen (out_filename, "w") ;
   ReadRecord () ;
   counter = 1 ;
   while (day != 99)
      {
      if (number != delete_number)
	 {
	  counter = number;
	  WriteRecord () ;
	  ++ counter ;
	  ReadRecord ();
	  }
	fclose (input_file) ;
   WriteTerminator ();
   fclose (output_file) ;
   remove (in_filename) ;
   rename (out_filename, in_filename) ;
   printf ("\n%12cDo you want to delete another record ? (Y/N) ", ' ') ;
   scanf ("\n%c", &response) ;


   }
}
while ((response == 'Y') || (response == 'y')) ;
}

/* function AmendRecord                                                  */
/* function to alter the contents of a record                            */
void AmendRecord ()
{
/* Description
   DO
      Display file contents
      Prompt for and accept record number to be amended
      Open files
      Read first record
      WHILE not end of file
	 IF record number equals chosen number
	    DO
	       Clear the screen
	       Display headings
	       Display record on screen
	       Display menu of fields to amend
	       Prompt for and accept field choice
	       case choice Date (1) : Clear screen
				      Display record's date
				      Prompt for and accept new date
	       case Choice Time (2) : Clear screen
				      Display record's time
				      Prompt for and accept new time
	       case choice Type (3) : Clear screen
				      Prompt for and accept type
				      IF repeating record
					 Prompt for and accept frequency
					 WHILE invalid frequency
					    Display error message
					    Prompt for and accept frequency
				      ELSE
					 Assign blank to frequency
	       case choice Frequency (4) : IF a repeating record
					     Clear screen
					     Display current frequency
					     Prompt for and accept frequency
					     IF invalid frequency entered
						Display error,
						      frequency unchanged
					     ELSE
						Assign new frequency to frequency
					  ELSE not a repeating record
					     Display error message
	       case choice Message (5)  : Clear screen
					  Prompt for and accept new message
	       case choice Exit (6)     : Exit
	       default                  : Display error message, get new choice
	    WHILE user wants to continue
	 Write record to output file
	 Read next record
      Close files
      Replace inputfile with output file
      Prompt for amending another
   WHILE user wants to amend records
*/
int amend_number,
    user_choice ;
char new_frequency,
     response,
     filler;
do
   {
   DisplayFile () ;
   printf ("\n\n%12cPlease enter number of record to be amended ", ' ') ;
   scanf ("%d", &amend_number) ;
   input_file = fopen (in_filename, "r" ) ;
   output_file = fopen (out_filename, "w") ;

   ReadRecord () ;
   while (day !=99)
      {
      if (number == amend_number)
	 {
	 do
	    {
	    clrscr () ;
   printf
   ("  Date      Start End    Duration Type Freq. Message                   Number\n") ;
   printf
   ("=============================================================================\n") ;
	    start_time = start_hours * 60 + start_minutes ;
	    end_time = end_hours * 60 + end_minutes ;
	    duration = (end_time - start_time) ;
	    printf ("%02d-%s-%02d %02d:%02d %02d:%02d  %02d:%02d     %c    %c    %s %5d\n", day,
		   LookupMonth (month), year, start_hours, start_minutes,
		   end_hours, end_minutes, duration / 60, duration % 60,
		   type,frequency, message, number) ;
	    printf ("\n\n%12cUPDATE ITEM\n", ' ') ;
	    printf ("%12c1. Date \n", ' ') ;
	    printf ("%12c2. Time\n", ' ') ;
	    printf ("%12c3. Record type\n", ' ') ;
	    printf ("%12c4. Repeat frequency\n", ' ') ;
	    printf ("%12c5. Message\n", ' ') ;
	    printf ("%12c6. Exit\n", ' ') ;
	    printf ("\n%12cPlease select a field to update : ", ' ') ;
	    scanf ("%d%c", &user_choice, &filler) ;
	    switch (user_choice)
	       {
	       case 1: clrscr () ;
		       printf ("\n\n\n\n\n") ;
		       printf ("%12cCurrent date is %02d:%02d:%d\n", ' ', day,
			       month, year) ;
		       printf ("%12cEnter new date (dd mm yyyy) ", ' ') ;
		       scanf ("%d %d %d", &day, &month, &year) ;
		       break ;
	       case 2: clrscr () ;
		       printf ("\n\n\n\n\n%12cCurrent start time is %02d:%02d\n", ' ',
			      start_hours, start_minutes) ;
		       printf ("%12cEnter new start time (hh mm) ", ' ') ;
		       scanf ("%d%d", &start_hours, &start_minutes) ;
		       printf ("\n\n            Current end time is %02d:%02d\n",
			      end_hours, end_minutes) ;
		       printf ("            Enter new end time (hh mm) ") ;
		       scanf ("%d%d", &end_hours, &end_minutes) ;
		       break ;
	       case 3: clrscr () ;
		       printf ("\n\n\n\n\n%12cCurrent type is %c\n", ' ',
			       type) ;
		       printf ("%12cEnter new record type (R/S) ", ' ') ;
		       scanf ("\n%c", &type) ;
		       type = toupper (type) ;
		       if (type == 'R')
			  {
			  printf (
			  "\n%12cNow enter the repeat frequency (D/W/M) ",' ' );
			  scanf ("\n%c", &frequency) ;
			  frequency = toupper (frequency) ;
			  while ((frequency != 'D') && (frequency != 'W') &&
				(frequency != 'M'))
			     {
			     clrscr() ;
			     printf ("\n\n\n\n\n") ;
			     printf ("%12cFrequency must be one of D/W/M\n",
				     ' ');
			     printf ("%12cEnter the repeat frequency (D/W/M) ",
				     ' ' ) ;
			     scanf ("\n%c", &frequency) ;
			     frequency = toupper (frequency);
			     }
			  }
		       else
			  {
			  frequency = ' ' ;
			  }
		       break ;
	       case 4: clrscr () ;
		       if (type == 'R')
			  {
			  clrscr () ;
			  printf ("\n\n\n\n\n") ;
			  printf ("%12cCurrent repeat frequency is %c\n",
				  ' ',frequency) ;
			  printf ("%12cEnter new frequency (D/W/M) ", ' ') ;
			  scanf ("\n%c", &new_frequency) ;
			  new_frequency = toupper (new_frequency) ;
			  if ((new_frequency != 'D') && (new_frequency != 'W') &&
			     (new_frequency != 'M'))
			     {
			     printf ("%12cFrequency must be one of D/W/M.", ' ') ;
			     printf (" Frequency is unchanged") ;
			     printf ("\n%12cHit any key to continue",' ');
			     getch () ;
			     }
			  else
			     frequency = new_frequency ;
			  }
		       else
			  {
			  clrscr () ;
			  printf ("\n\n\n\n\n") ;
			  printf ("%12cRecord is not a repeating record,", ' ');
			  printf (" cannot change frequency");
			  printf ("\n%12cHit any key to continue", ' ');
			  getch () ;
			  }
		       break ;
	       case 5: clrscr () ;
		       printf ("\n\n\n\n\n") ;
		       printf ("%12cCurrent message is :%s\n", ' ', message) ;
		       printf ("%12cEnter new message : ", ' ') ;
		       gets (message) ;
		       for (counter = strlen (message); counter < 25;
							counter ++)
			   strcat (message, " ") ;

		       break ;
	       case 6: break ;
	       default : DisplayError (6) ; break ;
	       }
	    }
	 while (user_choice !=6) ;
	 }
      WriteRecord () ;
      ReadRecord () ;
      }
   fclose (input_file) ;
   WriteTerminator ();
   fclose (output_file) ;
   remove (in_filename) ;
   rename (out_filename, in_filename) ;

   printf ("\n%12cDo you want to amend another record ? (Y/N) ", ' ') ;
   scanf ("\n%c", &response) ;
   }
while ((response == 'Y') || (response == 'y')) ;
}

/* function DisplayToday                                                 */
/* function to display today's appointments                              */
void DisplayToday ()
{
/* Description ......
   Open input file
   DO
      Clear screen
      Display headings
      Initialise counter to 0
      Read first record from file
      WHILE screen not full and not end of file
	 Calculate record date as integer
	 IF record date = today
	    Display record
	    Add 1 to counter
	 Read next record
      if not end of file
	 Display Hit a key to see next screenful
	 Accept key stroke
   WHILE not end of file
   Close file
   Display Hit a key to continue
   Accept key stroke
*/
int counter ;

input_file = fopen (in_filename, "r") ;
do
   {
   clrscr () ;
   printf ("\n\n\n\n\n%12c** Today's Appointments **\n\n", ' ') ;
   printf ("%12cStart End   Message\n", ' ') ;
   printf ("%12c============================================\n", ' ') ;
   counter = 0 ;
   ReadRecord () ;
   while (( counter < 10) && (day !=99))
      {
      long int GetDate () ;

      if (record_date == system_date )
       {
	    printf ("%12c%d-%s %02d:%02d %02d:%02d %s\n", ' ', day,
		   LookupMonth (month), start_hours, start_minutes,
		   end_hours,end_minutes, message) ;
	    ++ counter ;
	    }
	ReadRecord () ;
	}
	if (day != 99)
	{
	printf ("\n%12cHit a key to see next screenful", ' ') ;
	getch () ;
	}
}
while (day != 99) ;
fclose (input_file) ;
printf ("\n\n%12cHit a key to continue", ' ') ;
getch () ;
}
/* function DaysInMonth                                                       */
/* function to return the number of days in a given month                     */
int DaysInMonth (int mm, int yy)
{
/* Description ......
   case month = 4,6,9,11 (Apr, Jun, Sep, Nov)
		: number of days = 30
   case month = 2 (Feb)
		: IF a leap year (century or normal)
		     number of days = 29
		  ELSE
		     number of days = 28
   default      : number of days = 31
*/
/* Remember, a leap year is one in which the year is divisible by 4      */
/* except for century years (1900, 2000 etc) in which case the year must */
/* be divisible by 400. Thus 1900 was not a leap year (even though it's  */
/* divisible by 4) whilst 2000 is a leap year (divisible by 400).        */

int no_days,
    month,
    year;



	    switch(mm)
	    {
	 case 4  :
	 case 6  :
	 case 9  :
	 case 11 : no_days = 30 ;
		    break ;
	 case 2  : if (yy % 4 == 0)
		       no_days = 29 ;
		    else
		       no_days = 28 ;
		    break ;
	 default : no_days = 31 ;

	 }
return no_days;

}