// email_management_system.h
// Tammy Zhong
// Header file for email management system functions
// (Provided)

// #defines
#define MAX_LEN 100

#define HIGH_PRIORITY 1
#define NORMAL_PRIORITY 2
#define LOW_PRIORITY 3

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

// 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]; // assume unique
    double size;
    enum email_type type;
    int priority; // e.g. high priority = 1, normal = 2, low = 3

    struct email *next;
};

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

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

// 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);

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

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

// 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[MAX_LEN], 
    struct folder *folder_1, struct folder *folder_2);

// 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);

// 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