#pragma once

/**
 *
 * TASK 0: result codes
 * --------------------
 * Idiomatic named return codes instead of raw numbers.
 */
typedef enum {
  RESULT_VALID = 0,
  RESULT_INVALID_NAME = 1,
  RESULT_INVALID_INDEX = 2,
  RESULT_ARRAY_FULL = 3,
  RESULT_NULL_POINTER = 4
} Result;

/**
 *
 * TASK 1: validate_first_name
 * ---------------------------
 * Check if the first name is valid.
 * - Cannot be NULL or empty
 * - Only letters (a-z, A-Z)
 * - Minimum length: 2
 */
int validate_first_name(const char *first_name);

/**
 * TASK 2: validate_last_name
 * --------------------------
 * Check if the last name is valid.
 * - Cannot be NULL or empty
 * - Only letters (a-z, A-Z)
 * - Minimum length: 2
 */
int validate_last_name(const char *last_name);

/**
 * TASK 3: validate_full_name
 * --------------------------
 * Check if a full name "First Last" is valid.
 * Use TASK 1 and TASK 2 internally.
 */
int validate_full_name(const char *full_name);

/**
 * TASK 4: validate_index
 * ----------------------
 * Check if a student index is valid.
 * - Exactly 6 digits
 */
int validate_index(const char *index);

/**
 * TASK 5: register_student
 * ------------------------
 * Register a student given full name and index.
 * Return codes:
 * 0 -> valid
 * 1 -> invalid name
 * 2 -> invalid index
 */
int register_student(const char *full_name, const char *index);

/**
 * TASK 6: name_length
 * ------------------
 * Return length of the string (do not use strlen).
 */
int name_length(const char *name);

/**
 * TASK 7: student struct
 * ---------------------
 * Simple student structure
 */
typedef struct {
  char full_name[64];
  char index[16];
} Student;

/**
 * TASK 8: add_student
 * -------------------
 * Add a student to an array of Student. Return 0 if added.
 */
int add_student(Student *array, int max_length, const char *name,
                const char *index);

/**
 * TASK 9: get_error_message
 * ------------------------
 * Return error message string for code returned by register_student
 */
const char *get_error_message(int code);