import java.util.Scanner;
import java.io.*;
 
public class linkedList {
 
	// MAIN METHOD -----------------------------------//
	public static void main(String[] args) {
 
		linkedList myLinkedList = new linkedList();
 
		myLinkedList.displayList();
		myLinkedList.insert("vinny");
		myLinkedList.insert("darrell");
		myLinkedList.insert("mcdowell");
		myLinkedList.insert("zzz");
		myLinkedList.displayList();
 
		myLinkedList.printSection("abchijqsx");
		System.out.println("The first link is " + myLinkedList.head.next.value + ". The tail link is " + myLinkedList.tail.value + ".");
 
		myLinkedList.delete("darrell");
		myLinkedList.delete("vinny");
		myLinkedList.delete("zzz");
 
	}//-----------------------------------------------//
 
 
	DataInputStream in; 
	String fname, line, alphabet = "abcdefghijklmnopqrstuvwxyz";;
	boolean looping, searching;  	
	int linkCount = 0;
	link head = new link();
	link tail = new link();
	link temp = new link();
	link current = new link();
// 	link[] index = new link[26];
 
 
	public linkedList() {
		System.out.println("...starting linkedList() method...");
    	getFileName();
    	readFileContents();
	}
 
	public class link {
		public String value; // value of element
		public link next; // referene to next
 
		// constructor
		public link() {
		}
		public link(String val) {
			value = val;
		}
		public link(String val, link n) {
				value = val;
				next = n;
		}
	}
 
 
	/////////////////////////// PROMPT USER FOR .TXT FILE NAME ///////////////////
	public void getFileName() {
	   	Scanner in = new Scanner(System.in);
	   	System.out.println("What file do you want to turn into a linked list?");
			fname = in.nextLine();
	    	System.out.println("you entered: "+fname);
   }
	//////////////////////////////////////////////////////////////////////////////
 
 
	////// TRANSFER .TXT FILE'S CONTENTS INTO AN ALPHABETICALLY LINKED LIST //////
	public void readFileContents() {
	   	System.out.println("...starting readFileContents() method...");
	   	try {
				in = new DataInputStream(new FileInputStream(fname));
	    		looping = true;
				while(looping) {
	         	if (null == (line = in.readLine())) {
						looping = false;
	            	in.close();
	            }
					else {
 
						insert(line); // call insert method
 
					}// end else	
				}// end while
			}// end try
			catch(IOException e) {
				System.out.println("Error " + e);
			}// end catch
	}// end readFileContents()
	//////////////////////////////////////////////////////////////////////////////
 
	//////////////////////////////////// ALPHABETICALLY INSERT A LINK INTO THE LIST ///
	public void insert(String line) {
			link newLink = new link(line, null);
					temp = head;
					current = head.next;
					if (linkCount == 0) { // create first link
							head.next = newLink;
							current = newLink;
							temp = head;
							tail = newLink;
							searching = false;
					}
					else if (linkCount > 0) { // create additional link & insert
						searching = true;
						while (searching) {
							int compare = line.compareTo(current.value);
								if (current.next == null) {
									if (compare > 0) {
										current.next = newLink;
										temp = current;
										current = newLink;
										tail = newLink;
										searching = false;
									}
									if (compare < 0) {
										temp.next = newLink;
										temp = newLink;
										newLink.next = current;
										tail = current;
										searching = false;
									}
								}
								else if (current.next != null) {
									if (compare > 0) {
										temp = current;
										current = current.next;
									}
									if (compare < 0) {
										temp.next = newLink;
										newLink.next = current;
										temp = newLink;
										searching = false;
									}
								}
						}
					}
					linkCount++; // increment linkCount	
					System.out.println("'" + newLink.value + "' link was created and added to the list!");
					System.out.println("    linkCount is now: " + linkCount);
	}////////////////////////////////////////////////////////////////////////
 
 
	///////////////////////////////// DELETE A PARTICULAR LINK //////////////
	public void delete(String val) {
			current = head.next;
			temp = head;
			boolean looking = true;
			while (looking) {
 
				if (current.value == val) {
					temp.next = current.next;
					current = current.next;
					looking = false;
				}
 
				else if (current.value != val) {
					temp = current;
					current = current.next;
				}
			}
 
 
			linkCount--; // decrement linkCount
			System.out.println("'" + val + "' link was DELETED from the list!");
			System.out.println("    linkCount is now: " + linkCount);
	}/////////////////////////////////////////////////////////////////////////
 
 
	////////////////////////////// DISPLAY THE WHOLE LINKED LIST /////////////////////////////
	public void displayList() {
			String listString = new String("\ndisplayList() of all " + linkCount + " links : ");
			current = head.next;
				while (current.next != null) { //concatenate link values into listString
				listString = listString + current.value + ", ";
				current = current.next;
				}
			listString = listString + current.value + "\n";
			System.out.println(listString); //print listString	}
	}/////////////////////////////////////////////////////////////////////////////////////////
 
 
	/////////////////////////////////////////// PRINT SPECIFIC SECTIONS OF THE LINKED LIST ///
	public void printSection(String section) {
			int sectionCount = 0;
			String sectionString = new String();
				for (int i = 0; i < section.length(); i++) {	
					current = head.next;
					boolean printing = true;	
						while (printing) {
							if (current.value.charAt(0) != section.charAt(i) && current.next == null) {
								System.out.println("WARNING!!! NO STRING LINKS BEGINNING WITH '" + section.charAt(i) + "'!");
								printing = false;
							}
 
							else if (current.value.charAt(0) == section.charAt(i)) {	
								while (current.value.charAt(0) == section.charAt(i)) { //concatenate section values into sectionString
									sectionString = sectionString + current.value + ", ";
									sectionCount++; // increment sectionCount
									current = current.next;
								}
								printing = false;
							}
							else if (current.value.charAt(0) != section.charAt(i)) {
								current = current.next;
							}
 
						}
					if (current.next == null && current.value.charAt(0) == section.charAt(i)) {
							sectionString = sectionString + current.value;
					}
				}
			String output = new String("printSection(" + section + ") contains " + sectionCount + ": " + sectionString);
			System.out.println(output); // print sectionString
	}/////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
 
 
}

public void delete(String val) {
        current = head.next;
        temp = head;
        boolean looking = true;
        while (looking) {
            if (current.value.equals(val)) {
                System.out.println("compare using '.equals(...)' method: " + (current.value.equals(val)));
                System.out.println("compare using '.compareTo(...)' method: " + (current.value.compareTo(val)));
                System.out.println("compare using '==' operator: " + (current.value == val));
                temp.next = current.next;
                current = current.next;
                looking = false;
            } else {
                temp = current;
                current = current.next;
            }
        }
        linkCount--; // decrement linkCount
        System.out.println("'" + val + "' link was DELETED from the list!");
        System.out.println("    linkCount is now: " + linkCount);
    }