/*
 * File:
 *   tdli.c
 * Author:
 *   Lindsey Kuper
 * Summary:
 *   A simple interactive interface for a to-do list.
 */

#include "tdli.h"

list myList;

int main (void) {
  char input[128];
  char option;
  myList = (list)newList();
  /* Print a friendly menu. */
  printf ("Welcome to your to-do list interface!\n");
  while (1) {
    printf ("\nMenu Options\n");
    printf ("    P - Print entire to-do list\n");
    printf ("    H - Print highest-priority task\n");
    printf ("    S - Save to-do list to a file\n");
    printf ("    R - Read to-do list from a file\n");
    printf ("    N - Show next task on list\n");
    printf ("    A - Add a task to the list\n");
    printf ("    D - Remove all tasks from the list\n");
    printf ("    Q - Quit\n");
    printf ("Enter desired option: ");
    scanf (" %c", &option);
    switch (option) { 
        case 'p':
        case 'P': 
          if (printAll(myList)) printf("Printing completed\n\n");
          else printf("Error printing list\n\n");
          break;
        case 'h':
        case 'H':  
          if (printHighestPriority(myList)) printf("Printing completed\n\n");
          else printf("Error printing highest-priority task\n\n");
          break;
        case 's':
        case 'S':
          if (saveToFile(myList)) printf("List saved\n\n");
          else printf("Error saving list\n\n");
          break;
        case 'r':
        case 'R': 
          if (readFromFile(myList)) 
            printf("Finished reading from file\n\n");
          else printf("Error reading from file\n\n");
          break;
        case 'n':
        case 'N': 
          if (printNext(myList)) printf("Printing completed\n\n");
          else printf("Error printing list item");
          break;
        case 'a':
        case 'A':
          if (addTask()) printf("Task added to list\n\n");
          else printf("Error adding task to list");
          break;
        case 'd':
        case 'D':
          if (removeAll(myList)) printf("All tasks removed\n\n");
          else printf("Error removing all tasks");
          break;
        case 'q':
        case 'Q':
          printf ("Program terminated successfully\n");
          exit(EXIT_SUCCESS);
          break;
        default: printf("Invalid option\n\n");
      }
  }
  return EXIT_SUCCESS;
}

int printAll(list ls) {
  /* Check that the list exists and is not empty. */
  if ((!ls) || (!(ls->current)) || (!(ls->current->contents)))
    return 0;
  /* Move cursor to the beginning. */
  moveCursorToHead(ls);
  /* Print first task. */
  printTask(getCurrentContents(ls));
  /* Advance the cursor. */
  advance(ls);
  /* Continue through rest of list. */
  while (ls->current != ls->head) {
    printTask(getCurrentContents(ls));
    advance(ls);
  }
  return 1;
}

/* No time to implement this one.  Oops. */
int printHighestPriority(list ls) {}

int saveToFile(list ls) {
  char outfilename[128];
  FILE *outputFile;
  
  /* Ask the user what file to write to. */
  printf("Enter output file name: ");
  scanf("%s", &outfilename);
  /* Check that the file is open for writing; create it if necessary. */
  if (!(outputFile = fopen(outfilename, "w+")))
    return 0;
  /* Check that the list exists and is not empty. */
  if ((!ls) || (!ls->current))
    return 0;
  /* Cursor to beginning. */
  moveCursorToHead(ls);
  /* Print first task to file. */
  fprintf(outputFile, "Name: %s\nDeadline: %sPriority: %d\n", 
          ((task *)ls->current->contents)->taskname, 
          ctime(&((task *)ls->current->contents)->deadline), 
          ((task *)ls->current->contents)->priority);
  /* Advance the cursor. */
  advance(ls);
  /* Continue through rest of list. */
  while(ls->current != ls->head) {
    fprintf(outputFile, "Name: %s\nDeadline: %sPriority: %d\n", 
            ((task *)ls->current->contents)->taskname, 
            ctime(&((task *)ls->current->contents)->deadline), 
            ((task *)ls->current->contents)->priority);
    advance(ls);
  }
  return 1;
} 

int readFromFile(list ls) {
  char infilename[128];
  FILE *inputFile;
  int ch;

  char taskname[128];
  task *new;
  int tmpmonth;
  int tmpday;
  int tmpyear;
  struct tm dlstruct;
  time_t deadline;
  int priority;
  
  /* Find out which file to read from. */
  printf("Enter input file name: ");
  scanf("%s", &infilename); 
  /* Check that the file is open for reading. */
  if (!(inputFile = fopen(infilename, "r")))
    return 0;
  /* While fscanf works... */
  while ((fscanf(inputFile, "%s\t%d\t%d\t%d\t%d", 
                  taskname, &priority, &tmpmonth, &tmpday, &tmpyear))
          == 5) {
    /* Initialize the time structure (Daren's idea) */
    memset(&dlstruct, '\0', sizeof(struct tm));
    /* tm_mon stores month of the year (from 0) */
    dlstruct.tm_mon = (tmpmonth - 1);
    /* tm_mday stores day of the month (from 1) */
    dlstruct.tm_mday = tmpday;
    /* tm_year stores years since 1900 */
    dlstruct.tm_year = (tmpyear - 1900); 
    /* mktime returns the completed time_t */
    deadline = mktime(&dlstruct);
    /* Create a new task. */
    new = makeNewTask(taskname, deadline, priority);
    /* Add it to the list. */
    if (!(addAfterCurrent(myList, new)))
      return 0;
  }
  /* Close the file on our way out. */
  return (fclose(inputFile) == EOF);
}

int printNext(list ls) {
  /* Does this really need inline comments? */
  printTask(getCurrentContents(ls));
  advance(ls);
}

int addTask() {
  char taskname[128];
  task *new;
  int tmpmonth;
  int tmpday;
  int tmpyear;
  struct tm dlstruct;
  time_t deadline;
  int priority;
  /* Get task info from the user. */
  printf("Enter task name: ");
  scanf("%s", &taskname);
  printf("Enter task priority: ");
  scanf("%d", &priority);
  printf("Enter deadline (MM.DD.YYYY): ");
  scanf("%d.%d.%d", &tmpmonth, &tmpday, &tmpyear);
  /* tm_mon stores month of the year (from 0) */
  dlstruct.tm_mon = (tmpmonth - 1);
  /* tm_mday stores day of the month (from 1) */
  dlstruct.tm_mday = tmpday;
  /* tm_year stores years since 1900 */
  dlstruct.tm_year = (tmpyear - 1900);
  /* Our time_t object is ready to go. */
  deadline = mktime(&dlstruct);
  /* Create the new task. */
  new = makeNewTask(taskname, deadline, priority);
  /* Add it to the list on our way out. */
  return (addAfterCurrent(myList, new));
}

int removeAll(list ls) {
  /* Check that the list exists and is not empty. */
  if ((!ls) || (!ls->current))
    return 0;
  /* While there are still elements in the list... */
  while (advance(ls)) {
    /* Delete them. */
    if (!(deleteCurrent(ls))) return 0;
  }
  return 1;
}