// Q1 Programming Quiz - Solution
// Author: Chris Wilcox
// Date:   12/6/2015
// Class:  CS270
// Email:  wilcox@cs.colostate.edu

// Include files
#include "Q1.h"

// Global variables
Student *head = NULL;
Student *tail = NULL;

// Read a file
void readFile(char *filename)
{
    // Open file
    FILE *file = fopen(filename, "r");

    char name[80];
    int id = 0;
    float gpa = 0.0;

    // Read file
    while (fscanf(file, "%s %d %f\n", name, &id, &gpa) == 3) {

        // Insert student
        insertStudent(name, id, gpa);
    }

    // Close file
    fclose(file);
}

// Insert student
void insertStudent(char *name, int id, float gpa)
{
    // Allocate new Student
    Student *new = malloc(sizeof(Student));
    new->name = strdup(name);
    new->id = id;
    new->gpa = gpa;
    new->next = NULL;

    // Check head
    if (head == NULL) {

        // Create list
        head = new;
        tail = new;

    } else if (strcmp(head->name, name) > 0) {

        // Insert head
        new->next = head;
        head = new;

    } else if (strcmp(tail->name, name) < 0) {

        // Insert tail
        tail->next = new;
        tail = new;

    } else {
    
        // Insert middle
        Student *previous = head;
        Student *current = head->next;

        // Search list
        while (current) {

            // Check entry
            if (strcmp(current->name, name) > 0) {

                // Insert previous
                previous->next = new;
                new->next = current;
                break;
            }

            // Advance pointers
            previous = current;
            current = current->next;
        }
    }
}

// Remove student
void removeStudent(char *name)
{
    Student *temp;

    // Head matches?
    if (!strcmp(head->name, name)) {

        // Delete head
        temp = head;
        head = head->next;
        free(temp->name);
        free(temp);

    } else {

        Student *previous = head;
        Student *current = head->next;

        // Search list
        while (current != NULL) {

            // Check entry
            if (!strcmp(current->name, name)) {

                // Delete current
                temp = previous->next;
                previous->next = current->next;
                free(temp->name);
                free(temp);
                break;
            }

            // Advance pointers
            previous = current;
            current = current->next;
        }
    }
}

// Iterate students
void iterate(iterate_function func)
{
    Student *current = head;
    while (current != NULL) {

        // Print entry
        (*func)(current);
        current = current->next;
    }
}

// Terminate
void terminate(iterate_function func)
{
    while (head != NULL) {

        // Print entry
        Student *temp = head;
        head = head->next;
        free(temp->name);
        free(temp);
    }
    head = NULL;
}