Week 9 Code Examples

// Week 8 Tuesday Lecture
// Modified Week 9 Monday Lecture and Week 9 Tuesday Lecture
// Delete the first node in the linked list
// Delete all nodes in a linked list
// Search and delete in a linked list

#include <stdio.h>
#include <stdlib.h>

struct node {
    int data;
    struct node *next;
};

struct node *create_node(int data, struct node *next);
void print_list(struct node *head);
struct node *insert_at_tail(struct node *head, int data);  

//Deletion related functions
struct node *delete_first(struct node *head); 
void delete_all(struct node *head);
struct node *search_and_delete(struct node *head, int value);
struct node *search_and_delete_all(struct node *head, int value);


int main(void) {
    //create a node with data value i using function
    //add node to tail/end of list  
    struct node *head = NULL;
    print_list(head);

    printf("Search and delete from empty list\n");
    head = search_and_delete_all(head, 99);
    print_list(head);

    for (int i = 0; i < 10; i++) {
        head = insert_at_tail(head, 0);
    }

    for (int i = 10; i > 0; i--) {
        head = insert_at_tail(head, 0);
    }
    
    print_list(head); 

    // Between nodes
    printf("Search and delete 4\n");
    head = search_and_delete_all(head, 4);
    print_list(head);

    //Not in list
    printf("Search and delete 99\n");
    head = search_and_delete_all(head,99);
    print_list(head);

    //Last element in the list
    printf("Search and delete 9\n");
    head = search_and_delete_all(head,9);
    print_list(head);

    //First element in list
    printf("Search and delete 0\n");
    head = search_and_delete_all(head, 0);
    print_list(head);



    // printf("Delete first element\n");
    // for(int i = 0; i <= 10; i++) {
    //     head = delete_first(head);
    //     print_list(head);
    // }
    delete_all(head);
    // check for memory leaks
    return 0;
}

struct node *create_node(int data, struct node *next) {
    struct node *new_node = malloc(sizeof(struct node));
    if (new_node == NULL) {
        return NULL;
    }
    new_node->data = data;
    new_node->next = next;
    return new_node;
}

void print_list(struct node *head) {
    printf("list:\n");
    struct node *curr = head;
    while (curr != NULL) {
        printf("%d ", curr->data);
        curr = curr->next;
    }
    printf("\n");
}

struct node *insert_at_tail(struct node *head, int data) {
    struct node *new_node = create_node(data, NULL);
    struct node *current = head;

    // Case for when the list is empty
    if (head == NULL) {
        head = new_node;
    } else {
        // Find the last node in the list
        while (current->next != NULL) {
            current = current->next;
        }
        current->next = new_node;
    }
    return head;
}

// Deletes and frees the memory of the first node in the list
// returns the head of the list
struct node *delete_first(struct node *head) {
    if (head != NULL) {
        struct node *tmp = head;
        head = head->next;
        free(tmp);
    }
    return head;
}

// frees memory of all nodes in the given list
void delete_all(struct node *head) {
     struct node *current = head;
     while (current != NULL) {
        head = head->next;
        free(current);
        current = head;
     }
}

// searches for a value in the list, deletes it and frees
// the memory.
// returns the head of the list
// Only deletes the first occurrence of a value in the list
struct node *search_and_delete_original(struct node *head, int value) {
    struct node *prev = NULL;
    struct node *curr = head;

    // Find node to delete
    while (curr != NULL && curr->data != value) {
        prev = curr;
        curr = curr->next;
    }

    // Make sure curr is not NULL (ie make sure we found a node to delete)
    if (curr != NULL) {
        if (prev == NULL) {
            head = head->next;
        } else {
            prev->next = curr->next;
        }
        free(curr);
    }

    return head;
}

// searches for a value in the list, deletes it and frees
// the memory.
// returns the head of the list
// Only deletes the first occurrence of a value in the list
struct node *search_and_delete(struct node *head, int value) {
    if (head != NULL) {
        if (head->data == value) {
            struct node *tmp = head;
            head = head->next;
            free(tmp);
        } else {
            struct node *curr = head;
            
            // Find node to delete
            // check the next node exists and
            // look at the data in the next node
            while (curr->next != NULL && curr->next->data != value) {
                curr = curr->next;
            }

            //TODO COMPLETE AND DEBUG
            struct node *tmp = curr->next;
            if (tmp != NULL) {
                curr->next = tmp->next;
                free(tmp);
            }
        }
    }

    return head;
}

// Modify to delete all occurrences of value, not just the first one.
struct node *search_and_delete_all(struct node *head, int value) {
    struct node *prev = NULL;
    struct node *curr = head;

    // Find node to delete
    while (curr != NULL) {
        if (curr->data == value) {
            if (prev == NULL) {
                head = head->next;
                free(curr);
                curr = head;
            } else {
                prev->next = curr->next;
                free(curr);
                curr = prev->next;
            }
            
        } else {
            prev = curr;
            curr = curr->next;
        }
    }    
    
    return head;
}
// email_management_system.c
// Tammy Zhong
// Implementation file for email management system functions
// Modified by Angela Finlayson
// (TODO)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "email_management_system.h"

// Function prototypes 
// ADD YOUR OWN FUNCTION PROTOTYPES HERE 


// Function definitions

// Creates a new empty email folder 
//(TODO)
struct folder *create_folder(char name[]) {
    // TODO: implement this function
    printf("create_folder not yet implemented.\n");
    exit(1);  
}

// Add a new email to the folder at the head 
// Similar to previous lecture code insert_head
// (TODO)
void insert_email_at_head(struct folder *email_folder, char sender[], 
    char subject[], double size, enum email_type type, int priority) {
     // TODO: implement this function
    printf("insert_email_at_head not yet implemented.\n");
    exit(1); 
}

// Given a string, look for email where the subject is this string 
// (TODO)
struct email *search_email(struct folder *email_folder, char subject[]) {
    // TODO: implement this function
    printf("search_email not yet implemented.\n");
    exit(1); 
}

// Removes all emails from a folder
// clears and delete associated memory of folder and emails in it
void clear_folder(struct folder *email_folder) {
     // TODO: implement this function
    printf("clear_folder not yet implemented.\n");
    exit(1);
}

// Remove email(s) with certain priority (e.g. filter out low priority emails)
void delete_email_of_priority(struct folder *email_folder, int priority) {
    // TODO: implement this function
    printf("delete_email_of_priority not yet implemented.\n");
    exit(1);
}

// Append emails from folder_2 after folder_1 and returns them in the one folder
// Assumption made here assumes not same subject email in folder_1 and folder_2
struct folder *merge_folders(char merged_folder_name[], 
    struct folder *folder_1, struct folder *folder_2) {
    // TODO: implement this function
    printf("merge_folders not yet implemented.\n");
    exit(1);
}

// Split emails in a given folder into 3 folders based on email type 
// keeping original ordering
// assumption: inbox, sent and draft are folders already malloc-ed and initialised
void split_folder(struct folder *given_folder, 
    struct folder *inbox, struct folder *sent, struct folder *draft) {
    // TODO: implement this function
    printf("split_folder not yet implemented.\n");
    exit(1);
}

// returns number of emails in a given folder 
// (EXTENSION TODO: Improve this)
int count_emails(struct folder *email_folder) {
    int counter = 0;
    struct email *current = email_folder->emails;
    while (current != NULL) {
        counter++;
        current = current->next;
    }
    return counter;
}


// Your functions here (include function comments):


////////////////////////////////////////////////////////////////////////////////
//                              Provided Code                              //
////////////////////////////////////////////////////////////////////////////////

// Print/display all emails in folder 
// Similar to previous lecture code print_list
void print_emails(struct folder *email_folder) {
    printf("Folder Name: %s\n", email_folder->name);
    struct email *current = email_folder->emails;

    if (current == NULL) {
        printf("There are no emails in this folder.\n");
    }

    while (current != NULL) {
        printf("---\n");
        print_single_email(current);
        current = current->next;
    }
}

// Prints out details of a single email 
void print_single_email(struct email *email) {
    if (email == NULL) {
        printf("Email is NULL.\n");
        return;
    }

    printf("Sender: %s\n", email->sender);
    printf("Subject: %s\n", email->subject);
    printf("Size: %lfmb\n", email->size);
    printf("Type: ");
    if (email->type == RECEIVED) {
        printf("RECEIVED\n");
    } else if (email->type == SENT) {
        printf("SENT\n");
    } else if (email->type == DRAFT) {
        printf("DRAFT\n");
    } else {
        printf("UNKNOWN\n");
    }
    printf("Priority: ");
    if (email->priority == HIGH_PRIORITY) {
        printf("HIGH_PRIORITY\n");
    } else if (email->priority == NORMAL_PRIORITY) {
        printf("NORMAL_PRIORITY\n");
    } else if (email->priority == LOW_PRIORITY) {
        printf("LOW_PRIORITY\n");
    } else {
        printf("UNKNOWN\n");
    }
}
// email_management_system.h
// Tammy Zhong
// Header file for email management system functions
// Modified by Angela Finlayson
// (Provided)

// #defines
#define MAX_LEN 100

// enum definition
enum email_type {
    DRAFT,
    RECEIVED,
    SENT,
};

enum priority_type {
    LOW_PRIORITY,
    NORMAL_PRIORITY,
    HIGH_PRIORITY
};

// struct definitions
struct folder {
    char name[MAX_LEN];
    //int num_emails; // to use later :)
    struct email *emails;
};

struct email {
    char sender[MAX_LEN];
    char subject[MAX_LEN];
    double size;
    enum email_type type;
    enum priority_type priority; 
    struct email *next;
};

// Creates a new empty email folder 
// (TODO)
struct folder *create_folder(char name[]);

// Add a new email to the folder at the head 
// (TODO)
void insert_email_at_head(struct folder *email_folder, char sender[], 
    char subject[], double size, enum email_type type, int priority);

// Given a string, look for email where the subject is this string 
// (TODO)
struct email *search_email(struct folder *email_folder, char subject[]);

// Remove email(s) with certain priority (e.g. filter out low priority emails)
// (TODO)
void delete_email_of_priority(struct folder *email_folder, int priority);

// Append emails from folder_2 after folder_1 and returns them in the one folder
// (TODO)
struct folder *merge_folders(char merged_folder_name[], 
    struct folder *folder_1, struct folder *folder_2);

// Split emails in a given folder into 3 folders based on email type 
// keeping original ordering
// (TODO)
void split_folder(struct folder *given_folder, 
    struct folder *inbox, struct folder *sent, struct folder *draft);

// Removes all emails from a folder
// (TODO)
void clear_folder(struct folder *email_folder); // leak-check demo

// Returns number of emails in a given folder 
// (PROVIDED - TODO CAN BE IMPROVED)
int count_emails(struct folder *email_folder);

// CHALLENGE at home for fun: Sort emails in folder based on size
// (slightly out of scope of COMP1511 - touches on sorting algorithms)
// (TODO)
void sort_emails(struct folder *email_folder);

// Prints out details of a single email 
// (PROVIDED)
void print_single_email(struct email *email);

// Print/display all emails in folder 
// (PROVIDED)
void print_emails(struct folder *email_folder);
// main.c
// Angela Finlayson 
// Uses the email management system to allow a user to create a folder
// and and emails (with not content) to it.
// Only works for 1 folder... 
// (Provided)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "email_management_system.h"

void print_instructions(void);
void handle_search(struct folder *current_folder);
void handle_add_email(struct folder *current_folder);
void trim_newline(char str[]);

int main(void) {
    struct folder *current_folder = create_folder("inbox");
    char command;

    print_instructions();
    printf("\nEnter command: ");
    while (scanf(" %c", &command) == 1 && command != 'q') {
        if (command == 'a') {
            handle_add_email(current_folder);
        } else if (command == 'p') {
            print_emails(current_folder);
        } else if (command == 'n') { 
            printf("Number of emails: %d\n", count_emails(current_folder));
        } else if (command == 's') {
            handle_search(current_folder);
        } else {
            printf("Unknown command. Try again.\n");
        }
        printf("\nEnter command: ");
    }
    printf("Exiting\n");
    clear_folder(current_folder);
    return 0;
}

// Prints instructions to users
void print_instructions(void) {
    printf("Email Manager - Command Interface\n");
    printf("Commands:\n");
    printf("a - Add a new email to the folder\n");
    printf("p - Print all emails in the folder\n");
    printf("n - Count emails in the folder\n");
    printf("s - Search for an email by subject\n");
    printf("q - Quit\n");
}

// Handles adding a new email to the folder
// Assumes no error checking needed
void handle_add_email(struct folder *current_folder) {
    char sender[MAX_LEN] = "";
    char subject[MAX_LEN]= "";
    double size;
    int priority, type;

    // Remove whitespace from buffer
    int whitespace_ch;
    while ((whitespace_ch = getchar()) != '\n' && whitespace_ch != EOF) {}

    printf("Enter sender: ");
    fgets(sender, MAX_LEN, stdin);
    trim_newline(sender);
    printf("Enter subject: ");
    fgets(subject, MAX_LEN, stdin);
    trim_newline(subject);
    printf("Enter size (in MB): ");
    scanf("%lf", &size);
    printf("Enter email type (0 for DRAFT, 1 for RECEIVED, 2 for SENT): ");
    scanf("%d", &type);
    printf("Enter priority (0 for LOW, 1 for NORMAL, 3 for HIGH): ");
    scanf("%d", &priority);
    insert_email_at_head(current_folder, sender, subject, size, type, priority);
    printf("Email added to folder '%s'.\n", current_folder->name);
}

// Handles searching for an email by subject in the folder
void handle_search(struct folder *current_folder) {
    char subject[MAX_LEN];
    
    // Remove whitespace from buffer
    int whitespace_ch;
    while ((whitespace_ch = getchar()) != '\n' && whitespace_ch != EOF) {}

    printf("Enter subject to search: ");
    fgets(subject, MAX_LEN, stdin);
    trim_newline(subject);
    
    struct email *found_email = search_email(current_folder, subject);
    if (found_email != NULL) {
        printf("Email found:\n");
        print_single_email(found_email);
    } else {
        printf("No email with subject '%s' found.\n", subject);
    }
}

// removes trailing newline character
void trim_newline(char str[]) {
    int len = strlen(str);
    if (len > 0 && str[len - 1] == '\n') {
        str[len - 1] = '\0';  
    }
}
// main.c
// Tammy Zhong
// Program to test email management system functions
// Modified by Angela Finlayson 9/11/2025
// (Provided)


#include <stdio.h>
#include <stdlib.h>

#include "email_management_system.h"

int main(void) {
    // STAGE 1
    printf("*****1. Creating Folder 1...*****\n");
    struct folder *folder_1 = create_folder("Folder 1");

    printf("\n*****2. Number of emails in Empty Folder 1:*****\n");
    printf("%d\n", count_emails(folder_1));

    printf("\n*****3. Printing Empty Folder 1...*****\n");
    print_emails(folder_1);

    printf("\n*****4. Inserting emails in Empty Folder 1 *****\n");
 
    insert_email_at_head(folder_1, "Jon", "AAA", 10.2, RECEIVED, HIGH_PRIORITY);
    insert_email_at_head(folder_1, "Tim", "BBB", 20.44, DRAFT, NORMAL_PRIORITY);
    insert_email_at_head(folder_1, "Brianna", "CCC", 150.0, SENT, LOW_PRIORITY);
    insert_email_at_head(folder_1, "Tammy", "DDD", 90.2, SENT, NORMAL_PRIORITY);
    insert_email_at_head(folder_1, "Tammy", "EEE", 90.0, DRAFT, LOW_PRIORITY);

    printf("\n*****5. Printing Folder 1...*****\n");
    print_emails(folder_1); 

    printf("\n*****6. Number of emails in Folder 1: *****\n");
    printf("%d\n", count_emails(folder_1));
   
    
    printf("\n*****7. Look for email with subject 'AAA'...*****\n");
    struct email *email_found = search_email(folder_1, "AAA");
    
    printf("\n*****8. Printing email found in Folder 1 ...*****\n");
    print_single_email(email_found);

    printf("\n*****9. Look for email with subject 'DDD'...*****\n");
    email_found = search_email(folder_1, "DDD");
    
    printf("\n*****10. Printing email found in Folder 1 ...*****\n");
    print_single_email(email_found);

    printf("\n*****11. Look for email with subject 'EEE'...*****\n");
    email_found = search_email(folder_1, "EEE");
    
    printf("\n*****12. Printing email found in Folder 1 ...*****\n");
    print_single_email(email_found);

    printf("\n*****13. Look for email with subject 'Holiday'...*****\n");
    email_found = search_email(folder_1, "Holiday");
    
    printf("\n*****14. Printing email found in Folder 1 ...*****\n");
    print_single_email(email_found);
    

    printf("\n*****15. Creating Folder 2... and inserting emails...*****\n");
    struct folder *folder_2 = create_folder("Folder 2");
    insert_email_at_head(folder_2, "Tammy", "E", 50.5, SENT, LOW_PRIORITY);
    insert_email_at_head(folder_2, "Sofia", "F", 5.97, RECEIVED, HIGH_PRIORITY);
    insert_email_at_head(folder_2, "Grace", "G", 30.28, SENT, NORMAL_PRIORITY);
    insert_email_at_head(folder_2, "Andrew", "H", 5.5, RECEIVED, LOW_PRIORITY);
    insert_email_at_head(folder_2, "Holly", "I", 25.25, RECEIVED, LOW_PRIORITY);
    insert_email_at_head(folder_2, "Ibby", "J", 15.25, RECEIVED, NORMAL_PRIORITY);
    
    printf("\n*****16. Printing Folder 2...*****\n");
    print_emails(folder_2);
    
    //STAGE 2

    //printf("\n*****17. Deleting LOW_PRIORITY emails from Folder 2...*****\n");
    //delete_email_of_priority(folder_2, LOW_PRIORITY);
    
    //printf("\n*****18. Printing Folder 2...*****\n");
    //print_emails(folder_2);
  
    /*
    printf("\n*****19. Merging Folder 1 and Folder 2...*****\n");
    struct folder *merged_folder = merge_folders("Merged Folder", folder_1, 
                                                                  folder_2);
    
    printf("\n*****20. Printing merged folder...*****\n");
    print_emails(merged_folder);
   
    printf("\n*****21. Split merged folder into inbox, sent, draft...*****\n");
    struct folder *inbox = create_folder("inbox");
    struct folder *sent = create_folder("sent");
    struct folder *draft = create_folder("draft");
    split_folder(merged_folder, inbox, sent, draft);
    
    printf("\n*****22. Printing inbox...*****\n");
    print_emails(inbox);

    printf("\n*****23. Printing sent...*****\n");
    print_emails(sent);

    printf("\n*****24. Printing draft...*****\n");
    print_emails(draft);
    */
    
    // STAGE 1: comment this section out once you implement merge
    printf("\n*****Clearing stage 1 folders folder_1 and folder_2...*****\n");

    clear_folder(folder_1);
    clear_folder(folder_2);

    // STAGE 2 merge:  comment this section out once you implement split
    //printf("\n*****Clearing stage 2 merged_folder...*****\n");
    //clear_folder(merged_folder);

    // STAGE 2 
    //printf("\n*****Clearing inbox, sent, draft (freeing all memory)...*****\n");
    //clear_folder(inbox);
    //clear_folder(sent);
    //clear_folder(draft);
   
    
    return 0;
}
// email_management_system.c
// Tammy Zhong
// Implementation file for email management system functions
// Modified by Angela Finlayson
// (TODO)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "email_management_system.h"

// Function prototypes 
// ADD YOUR OWN FUNCTION PROTOTYPES HERE 
struct email *create_email(char sender[],  char subject[], double size, 
    enum email_type type, int priority, struct email *next);

// Function definitions

// Creates a new empty email folder 
//(TODO)
struct folder *create_folder(char name[]) {
    struct folder *new_folder = malloc(sizeof(struct folder));
    strcpy(new_folder->name, name);
    new_folder->emails = NULL;
    return new_folder;
}

// Add a new email to the folder at the head 
// Similar to previous lecture code insert_head
// (TODO)
void insert_email_at_head(struct folder *email_folder, char sender[], 
    char subject[], double size, enum email_type type, int priority) {
    
    struct email *new_email = create_email(sender, subject, size, type, 
        priority, email_folder->emails);

    email_folder->emails = new_email; 

}

// Given a string, look for email where the subject is this string 
// (TODO)
struct email *search_email(struct folder *email_folder, char subject[]) {
    struct email *curr = email_folder->emails;
    while (curr != NULL && strcmp(curr->subject, subject) != 0) {
        curr = curr->next;
    }
    return curr;
}

// Removes all emails from a folder
// clears and delete associated memory of folder and emails in it
void clear_folder(struct folder *email_folder) {
    
    struct email *current = email_folder->emails;
    while (current != NULL) {
        email_folder->emails = email_folder->emails->next;
        free(current);
        current = email_folder->emails;
    }
    free(email_folder);

}

// Remove email(s) with certain priority (e.g. filter out low priority emails)
void delete_email_of_priority(struct folder *email_folder, int priority) {
    struct email *prev = NULL;
    struct email *curr = email_folder->emails;

    // Find node to delete
    while (curr != NULL) {
        if (curr->priority == priority) {
            if (prev == NULL) {
                email_folder->emails = email_folder->emails->next;
                free(curr);
                curr = email_folder->emails;
            } else {
                prev->next = curr->next;
                free(curr);
                curr = prev->next;
            }
            
        } else {
            prev = curr;
            curr = curr->next;
        }
    }    
}

// Append emails from folder_2 after folder_1 and returns them in the one folder
// Assumption made here assumes not same subject email in folder_1 and folder_2
struct folder *merge_folders(char merged_folder_name[], 
    struct folder *folder_1, struct folder *folder_2) {
    
    struct folder *merged_folder = create_folder(merged_folder_name);
    merged_folder->emails = folder_1->emails;
    
    if (folder_1->emails == NULL) {
        merged_folder->emails = folder_2->emails;
    } else {
        //Find the last node in folder_1 emails
        struct email *curr = folder_1->emails;
        while (curr->next != NULL) {
            curr = curr->next;
        }
        curr->next = folder_2->emails;
    }
    free(folder_1);
    free(folder_2);
    return merged_folder;

}

// Split emails in a given folder into 3 folders based on email type 
// keeping original ordering
// assumption: inbox, sent and draft are folders already malloc-ed and initialised
void split_folder(struct folder *given_folder, 
    struct folder *inbox, struct folder *sent, struct folder *draft) {
    // TODO: implement this function
    printf("split_folder not yet implemented.\n");
    exit(1);
}

// returns number of emails in a given folder 
// (EXTENSION TODO: Improve this)
int count_emails(struct folder *email_folder) {
    int counter = 0;
    struct email *current = email_folder->emails;
    while (current != NULL) {
        counter++;
        current = current->next;
    }
    return counter;
}


// Your functions here (include function comments):
struct email *create_email(char sender[],  char subject[], double size, 
    enum email_type type, int priority, struct email *next) {

    struct email *new_email = malloc(sizeof(struct email));
    strcpy(new_email->sender, sender);
    strcpy(new_email->subject, subject);
    new_email->size = size;
    new_email->type = type;
    new_email->priority = priority;
    new_email->next = next;

    return new_email;
}

////////////////////////////////////////////////////////////////////////////////
//                              Provided Code                              //
////////////////////////////////////////////////////////////////////////////////

// Print/display all emails in folder 
// Similar to previous lecture code print_list
void print_emails(struct folder *email_folder) {
    printf("Folder Name: %s\n", email_folder->name);
    struct email *current = email_folder->emails;

    if (current == NULL) {
        printf("There are no emails in this folder.\n");
    }

    while (current != NULL) {
        printf("---\n");
        print_single_email(current);
        current = current->next;
    }
}

// Prints out details of a single email 
void print_single_email(struct email *email) {
    if (email == NULL) {
        printf("Email is NULL.\n");
        return;
    }

    printf("Sender: %s\n", email->sender);
    printf("Subject: %s\n", email->subject);
    printf("Size: %lfmb\n", email->size);
    printf("Type: ");
    if (email->type == RECEIVED) {
        printf("RECEIVED\n");
    } else if (email->type == SENT) {
        printf("SENT\n");
    } else if (email->type == DRAFT) {
        printf("DRAFT\n");
    } else {
        printf("UNKNOWN\n");
    }
    printf("Priority: ");
    if (email->priority == HIGH_PRIORITY) {
        printf("HIGH_PRIORITY\n");
    } else if (email->priority == NORMAL_PRIORITY) {
        printf("NORMAL_PRIORITY\n");
    } else if (email->priority == LOW_PRIORITY) {
        printf("LOW_PRIORITY\n");
    } else {
        printf("UNKNOWN\n");
    }
}
// email_management_system.h
// Tammy Zhong
// Header file for email management system functions
// Modified by Angela Finlayson
// (Provided)

// #defines
#define MAX_LEN 100

// enum definition
enum email_type {
    DRAFT,
    RECEIVED,
    SENT,
};

enum priority_type {
    LOW_PRIORITY,
    NORMAL_PRIORITY,
    HIGH_PRIORITY
};

// struct definitions
struct folder {
    char name[MAX_LEN];
    //int num_emails; // to use later :)
    struct email *emails;
};

struct email {
    char sender[MAX_LEN];
    char subject[MAX_LEN];
    double size;
    enum email_type type;
    enum priority_type priority; 
    struct email *next;
};

// Creates a new empty email folder 
// (TODO)
struct folder *create_folder(char name[]);

// Add a new email to the folder at the head 
// (TODO)
void insert_email_at_head(struct folder *email_folder, char sender[], 
    char subject[], double size, enum email_type type, int priority);

// Given a string, look for email where the subject is this string 
// (TODO)
struct email *search_email(struct folder *email_folder, char subject[]);

// Remove email(s) with certain priority (e.g. filter out low priority emails)
// (TODO)
void delete_email_of_priority(struct folder *email_folder, int priority);

// Append emails from folder_2 after folder_1 and returns them in the one folder
// (TODO)
struct folder *merge_folders(char merged_folder_name[], 
    struct folder *folder_1, struct folder *folder_2);

// Split emails in a given folder into 3 folders based on email type 
// keeping original ordering
// (TODO)
void split_folder(struct folder *given_folder, 
    struct folder *inbox, struct folder *sent, struct folder *draft);

// Removes all emails from a folder
// (TODO)
void clear_folder(struct folder *email_folder); // leak-check demo

// Returns number of emails in a given folder 
// (PROVIDED - TODO CAN BE IMPROVED)
int count_emails(struct folder *email_folder);

// CHALLENGE at home for fun: Sort emails in folder based on size
// (slightly out of scope of COMP1511 - touches on sorting algorithms)
// (TODO)
void sort_emails(struct folder *email_folder);

// Prints out details of a single email 
// (PROVIDED)
void print_single_email(struct email *email);

// Print/display all emails in folder 
// (PROVIDED)
void print_emails(struct folder *email_folder);
// main.c
// Angela Finlayson 
// Uses the email management system to allow a user to create a folder
// and and emails (with not content) to it.
// Only works for 1 folder... 
// (Provided)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "email_management_system.h"

void print_instructions(void);
void handle_search(struct folder *current_folder);
void handle_add_email(struct folder *current_folder);
void trim_newline(char str[]);

int main(void) {
    struct folder *current_folder = create_folder("inbox");
    char command;

    print_instructions();
    printf("\nEnter command: ");
    while (scanf(" %c", &command) == 1 && command != 'q') {
        if (command == 'a') {
            handle_add_email(current_folder);
        } else if (command == 'p') {
            print_emails(current_folder);
        } else if (command == 'n') { 
            printf("Number of emails: %d\n", count_emails(current_folder));
        } else if (command == 's') {
            handle_search(current_folder);
        } else {
            printf("Unknown command. Try again.\n");
        }
        printf("\nEnter command: ");
    }
    printf("Exiting\n");
    clear_folder(current_folder);
    return 0;
}

// Prints instructions to users
void print_instructions(void) {
    printf("Email Manager - Command Interface\n");
    printf("Commands:\n");
    printf("a - Add a new email to the folder\n");
    printf("p - Print all emails in the folder\n");
    printf("n - Count emails in the folder\n");
    printf("s - Search for an email by subject\n");
    printf("q - Quit\n");
}

// Handles adding a new email to the folder
// Assumes no error checking needed
void handle_add_email(struct folder *current_folder) {
    char sender[MAX_LEN] = "";
    char subject[MAX_LEN]= "";
    double size;
    int priority, type;

    // Remove whitespace from buffer
    int whitespace_ch;
    while ((whitespace_ch = getchar()) != '\n' && whitespace_ch != EOF) {}

    printf("Enter sender: ");
    fgets(sender, MAX_LEN, stdin);
    trim_newline(sender);
    printf("Enter subject: ");
    fgets(subject, MAX_LEN, stdin);
    trim_newline(subject);
    printf("Enter size (in MB): ");
    scanf("%lf", &size);
    printf("Enter email type (0 for DRAFT, 1 for RECEIVED, 2 for SENT): ");
    scanf("%d", &type);
    printf("Enter priority (0 for LOW, 1 for NORMAL, 3 for HIGH): ");
    scanf("%d", &priority);
    insert_email_at_head(current_folder, sender, subject, size, type, priority);
    printf("Email added to folder '%s'.\n", current_folder->name);
}

// Handles searching for an email by subject in the folder
void handle_search(struct folder *current_folder) {
    char subject[MAX_LEN];
    
    // Remove whitespace from buffer
    int whitespace_ch;
    while ((whitespace_ch = getchar()) != '\n' && whitespace_ch != EOF) {}

    printf("Enter subject to search: ");
    fgets(subject, MAX_LEN, stdin);
    trim_newline(subject);
    
    struct email *found_email = search_email(current_folder, subject);
    if (found_email != NULL) {
        printf("Email found:\n");
        print_single_email(found_email);
    } else {
        printf("No email with subject '%s' found.\n", subject);
    }
}

// removes trailing newline character
void trim_newline(char str[]) {
    int len = strlen(str);
    if (len > 0 && str[len - 1] == '\n') {
        str[len - 1] = '\0';  
    }
}
// main.c
// Tammy Zhong
// Program to test email management system functions
// Modified by Angela Finlayson 9/11/2025
// (Provided)


#include <stdio.h>
#include <stdlib.h>

#include "email_management_system.h"

int main(void) {
    // STAGE 1
    printf("*****1. Creating Folder 1...*****\n");
    struct folder *folder_1 = create_folder("Folder 1");

    printf("\n*****2. Number of emails in Empty Folder 1:*****\n");
    printf("%d\n", count_emails(folder_1));

    printf("\n*****3. Printing Empty Folder 1...*****\n");
    print_emails(folder_1);

    printf("\n*****4. Inserting emails in Empty Folder 1 *****\n");
 
    insert_email_at_head(folder_1, "Jon", "AAA", 10.2, RECEIVED, HIGH_PRIORITY);
    insert_email_at_head(folder_1, "Tim", "BBB", 20.44, DRAFT, NORMAL_PRIORITY);
    insert_email_at_head(folder_1, "Brianna", "CCC", 150.0, SENT, LOW_PRIORITY);
    insert_email_at_head(folder_1, "Tammy", "DDD", 90.2, SENT, NORMAL_PRIORITY);
    insert_email_at_head(folder_1, "Tammy", "EEE", 90.0, DRAFT, LOW_PRIORITY);

    printf("\n*****5. Printing Folder 1...*****\n");
    print_emails(folder_1); 

    printf("\n*****6. Number of emails in Folder 1: *****\n");
    printf("%d\n", count_emails(folder_1));
   
    
    printf("\n*****7. Look for email with subject 'AAA'...*****\n");
    struct email *email_found = search_email(folder_1, "AAA");
    
    printf("\n*****8. Printing email found in Folder 1 ...*****\n");
    print_single_email(email_found);

    printf("\n*****9. Look for email with subject 'DDD'...*****\n");
    email_found = search_email(folder_1, "DDD");
    
    printf("\n*****10. Printing email found in Folder 1 ...*****\n");
    print_single_email(email_found);

    printf("\n*****11. Look for email with subject 'EEE'...*****\n");
    email_found = search_email(folder_1, "EEE");
    
    printf("\n*****12. Printing email found in Folder 1 ...*****\n");
    print_single_email(email_found);

    printf("\n*****13. Look for email with subject 'Holiday'...*****\n");
    email_found = search_email(folder_1, "Holiday");
    
    printf("\n*****14. Printing email found in Folder 1 ...*****\n");
    print_single_email(email_found);
    

    printf("\n*****15. Creating Folder 2... and inserting emails...*****\n");
    struct folder *folder_2 = create_folder("Folder 2");
    insert_email_at_head(folder_2, "Tammy", "E", 50.5, SENT, LOW_PRIORITY);
    insert_email_at_head(folder_2, "Sofia", "F", 5.97, RECEIVED, HIGH_PRIORITY);
    insert_email_at_head(folder_2, "Grace", "G", 30.28, SENT, NORMAL_PRIORITY);
    insert_email_at_head(folder_2, "Andrew", "H", 5.5, RECEIVED, LOW_PRIORITY);
    insert_email_at_head(folder_2, "Holly", "I", 25.25, RECEIVED, LOW_PRIORITY);
    insert_email_at_head(folder_2, "Ibby", "J", 15.25, RECEIVED, LOW_PRIORITY);
    
    printf("\n*****16. Printing Folder 2...*****\n");
    print_emails(folder_2);
    
    //STAGE 2

    printf("\n*****17. Deleting LOW_PRIORITY emails from Folder 2...*****\n");
    delete_email_of_priority(folder_2, LOW_PRIORITY);
    
    printf("\n*****18. Printing Folder 2...*****\n");
    print_emails(folder_2);
  
    
    printf("\n*****19. Merging Folder 1 and Folder 2...*****\n");
    struct folder *merged_folder = merge_folders("Merged Folder", folder_1, 
                                                                  folder_2);
    
    printf("\n*****20. Printing merged folder...*****\n");
    print_emails(merged_folder);
   /*
    printf("\n*****21. Split merged folder into inbox, sent, draft...*****\n");
    struct folder *inbox = create_folder("inbox");
    struct folder *sent = create_folder("sent");
    struct folder *draft = create_folder("draft");
    split_folder(merged_folder, inbox, sent, draft);
    
    printf("\n*****22. Printing inbox...*****\n");
    print_emails(inbox);

    printf("\n*****23. Printing sent...*****\n");
    print_emails(sent);

    printf("\n*****24. Printing draft...*****\n");
    print_emails(draft);
    */
    
    // STAGE 1: comment this section out once you implement merge
    // printf("\n*****Clearing stage 1 folders folder_1 and folder_2...*****\n");

    // clear_folder(folder_1);
    // clear_folder(folder_2);

    // STAGE 2 merge:  comment this section out once you implement split
    printf("\n*****Clearing stage 2 merged_folder...*****\n");
    clear_folder(merged_folder);

    // STAGE 2 
    //printf("\n*****Clearing inbox, sent, draft (freeing all memory)...*****\n");
    //clear_folder(inbox);
    //clear_folder(sent);
    //clear_folder(draft);
   
    
    return 0;
}