StudyPlanner/src/db.c

/* Create a database and handel it
 * Created by Jan on 13.12.2024.
 * INPUT: query for previous state
 *        linked list of tasks to store
 *
 * OUTPUT:
 *        linked list of tasks from file
 *        OK
 *
 *
 */


#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "planner.h"
#include "list.h"

/*
write a complete linkedlist to a Event csv file.
 */
void write_linkedlist_to_csv(llist* head, const char* filename) {
	//Open file with write permision
	FILE* file = fopen(filename, "w");
	//if there is no file or a wrong file path you becom an error
	if (file == NULL) {
    	perror("Could not open file %s\n", filename);
  	}
  	else{
    	//write the file header
    	fprintf(file, "TaskName, Created, Deadline, Priority, Spare, EventStartTime, EventEndTime, EventSpare\n");

    	// Iterate through the linked list and write the data to the CSV
  		llist* current = head;
  		while (current != NULL) {
    		// Extract data from the current node
    		Event* event = (Event*)current->data;  // Assumed that current->data holds an Event pointer

    		// Extract the associated task from the event
    		Task* task = event->task;

    		// Write the task and event data to the CSV file
    		fprintf(file, "%s, %lu, %lu, %d, %lu, %lu, %lu, %lu\n",
            	task->name,
            	task->created,
            	task->deadline,
            	task->priority,
            	task->spare,
            	event->plannedStartTime,
            	event->plannedEndTime,
            	event->spare);

    		current = current->next;
  		}
	fclose(file); // Close the file
	}
}

/*
read an event csv file and write the data in a linked list
 */

void write_csv_to_llist(const char* filename) {
	//Open file with read permision
  FILE* file = fopen(filename, "r");
  if (file == NULL) {
    perror("Could not open file %s\n", filename);
  }
  else{
	char line[1024]; //Line Buffer
    int count = 0; //task counter
    llist *list = NULL
    fgets(line, sizeof(line), file); //read and ignore file head
    while (fgets(line, sizeof(line), file)) {
      	count++;
    	//remove newline sign
        line[strcspn(line, "\n")] = '\0';

        // column slice
        char *taskname = strtok(line, ",");
        char *tsakcreation_dateSTR = strtok(NULL, ",");
        char *tsakdeadline_dateSTR = strtok(NULL, ",");
        char *tsakprioritySTR = strtok(NULL, ",");
        char *tsakspareSTR = strtok(NULL, ",");
        char *eventStartTimeSTR = strtok(NULL, ",");
        char *eventEndTimeSTR = strtok(NULL, ",");
        char *eventSpareSTR = strtok(NULL, ",");

        // convert char in integer and date
        unsigned long int taskcreation_date = strtoul(taskcreation_dateSTR,NULL,10);
        unsigned long int taskdeadline_date = strtoul(taskdeadline_dateSTR,NULL,10);
        unsigned long int taskspare = strtoul(taskspareSTR,NULL,10);
        unsigned long int eventStartTime = strtoul(eventStartTimeSTR,NULL,10);
        unsigned long int eventEndTime = strtoul(eventEndTimeSTR,NULL,10);
        unsigned long int eventSpare = strtoul(eventSpareSTR,NULL,10);

        int priority = atoi(prioritySTR);



        //create Task
        Task *task = newTask(taskname, taskcreation_date, taskdeadline_date, taskpriority, taskspare);

        //create Event
        Event *event = newEvent(task,eventStartTime, eventEndTime, eventSpare);

        // Insert task into the linked list
        if (list == NULL) {
            // If the list is empty, initialize it with the first task
            list = llistNew(event, NULL);
        }
        else {
            // Append the task to the linked list
            llistAppend(list, event);
        }
    }

    fclose(file);
  }



}