/******************************************************************************
 *  Journal Wizard
 *
 *  Program using a text editor--defined by macro EDITOR--to generate dated 
 *  journal entries organized into directories by year and month. Places this 
 *  inside journal_wizard directory created in Documents directory of user's 
 *  home directory. 
 *
 *
 *  program: journal_wizard
 *  date   : 20 Oct 2022
 *  by     : yetimach
 *
 * note: set the editor to whatever you like: "vim", "neovim", "nano", 
 * "libreoffice --writer". Just be sure you have it installed.
 * Just here below 
 *****************************************************************************/
#define EDITOR "vim" 


#include <dirent.h>
#include <errno.h>
#include <sys/stat.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_YEAR 12 
#define MAX_MONTH 12
#define MAX_MONTH_NAME 4
#define MAX_DAY 3
#define MAX_DATE 11 
#define MAX_PATH 100
#define MAX_COMMAND 125

int main(void){
    char current_year[MAX_YEAR];
    char current_month[MAX_MONTH];
    char current_day[MAX_MONTH];
    char date_string[MAX_DATE];

    /* generate localtime struct and handle possible errors */

   time_t rawtime;
   struct tm *info;
   time(&rawtime);
   if (rawtime == ((time_t)-1)){
      fprintf(stderr, "Not able to access current time.\n");
      exit(EXIT_FAILURE);
   }
   info = localtime(&rawtime);
   if (info == NULL){
      fprintf(stderr, "Not able to generate localtime struct.\n");
      exit(EXIT_FAILURE);
   }
   sprintf(current_year, "%d", (info->tm_year + 1900));
   sprintf(current_month, "%d", info->tm_mon + 1);
   sprintf(current_day, "%d", info->tm_mday);

   /* make date string */
    strcpy(date_string, current_month);
    strcat(date_string, "_");
    strcat(date_string, current_day);
    strcat(date_string, "_");
    strcat(date_string, current_year);

    /* begin checking for necessary dirs and making them if they don't exist */
    char path_to_Documents[MAX_PATH];
    strcpy(path_to_Documents, getenv("HOME"));
    strcat(path_to_Documents, "/Documents");

    DIR* dir = opendir(path_to_Documents);
    if (dir) {
    /* Directory exists. */
        closedir(dir);
    }else if (ENOENT == errno) {
    /* Directory does not exist so make it. */
       mkdir(path_to_Documents, 0751);
    }else{
        fprintf(stderr, "problem detecting or creating '%s'.\n", 
                path_to_Documents);
        exit(EXIT_FAILURE);
    }
    char path_to_journal_wizard[MAX_PATH];
    strcpy(path_to_journal_wizard, path_to_Documents);
    strcat(path_to_journal_wizard, "/journal_wizard");

    dir = opendir(path_to_journal_wizard);
    if (dir) {
    /* Directory exists. */
        closedir(dir);
    }else if (ENOENT == errno) {
    /* Directory does not exist so make it. */
       mkdir(path_to_journal_wizard, 0751);
    }else{
        fprintf(stderr, "problem detecting or creating '%s'.\n", 
                path_to_journal_wizard);
        exit(EXIT_FAILURE);
    }

    char path_to_year_dir[MAX_PATH];
    strcpy(path_to_year_dir, path_to_journal_wizard);
    strcat(path_to_year_dir, "/");
    strcat(path_to_year_dir, current_year);

    dir = opendir(path_to_year_dir);
    if (dir) {
    /* Directory exists. */
        closedir(dir);
    }else if (ENOENT == errno) {
    /* Directory does not exist so make it. */
       mkdir(path_to_year_dir, 0751);
    }else{
        fprintf(stderr, "problem detecting or creating '%s'.\n", 
                path_to_year_dir);
        exit(EXIT_FAILURE);
    }
    char month_name[MAX_MONTH_NAME]; 
    char date_and_time_str[30];  
    strcpy(date_and_time_str, asctime(info));
    int p = 0;
    for (int i = 4; i <= 6; i++)
        month_name[p++] = date_and_time_str[i];
    month_name[p] = '\0';

    char path_to_month_dir[MAX_PATH];
    strcpy(path_to_month_dir, path_to_year_dir);
    strcat(path_to_month_dir, "/");
    strcat(path_to_month_dir, month_name);

    dir = opendir(path_to_month_dir);
    if (dir) {
    /* Directory exists. */
        closedir(dir);
    }else if (ENOENT == errno) {
    /* Directory does not exist so make it. */
       mkdir(path_to_month_dir, 0751);
    }else{
        fprintf(stderr, "problem detecting or creating '%s'.\n", 
                path_to_month_dir);
        exit(EXIT_FAILURE);
    }
    /* check if entry for day alredy exists if not make it */
    char path_to_current_entry[MAX_PATH];
    strcpy(path_to_current_entry, path_to_month_dir);
    strcat(path_to_current_entry, "/");
    strcat(path_to_current_entry, date_string);
    strcat(path_to_current_entry, ".txt");

    FILE *current_entry;
    if((current_entry = fopen(path_to_current_entry, "a"))){
        /* add date and time stamp to journal entry */
        fprintf(current_entry, "\n%s\n", date_and_time_str);
        fclose(current_entry);
    }else{
        fprintf(stderr, "Unable to create file '%s'.\n", 
                path_to_current_entry);
        exit(EXIT_FAILURE);
    }
    char editor_command[MAX_COMMAND];
    strcpy(editor_command, EDITOR);
    strcat(editor_command, " ");
    strcat(editor_command, path_to_current_entry);
    system(editor_command);
    exit(EXIT_SUCCESS);
}