/*
 * LuckTester.java
 *
 * Created on January 7, 2003, 2:51 PM
 *
 * Modify this file, and turn in it.  Do not change the package name, class name,
 *      or any method signatures.
 */

package project0;  //don't change

/** Does the God/Godess of Luck know you?  A class to help answer this urgent
 * question.
 *
 * @author  dickey 143-03wi
 */
public class LuckTester {
    
    /** Creates a new instance of LuckTester */
    public LuckTester() {
    }
    
    /** Check that a pair of initials is suitable for presentation to the 
     *  God/Goddess of Luck.
     *  @param initials A person's initials: must be exactly two uppercase English letters.
     *  @return true iff both initials are valid (thus avoiding the wrath of the gods).
     *  
     */
    public boolean checkInitials(String initials) {
        if (initials.length() != 2) {
            return false;
        }
        char firstI = initials.charAt(0);
        char secondI = initials.charAt(1);
        if (CharGenerator.isEnglishUpperCase(firstI) && 
                        CharGenerator.isEnglishUpperCase(secondI)) {
            return true;
        }
        return false;
        //end checkInitialsArg
    }
    
    /** Given a person's initials, how long does it take the God/Goddess of luck
     *  to recognize that person?
        Algorithm: Generate pairs of characters randomly 
            until the desired initials are observed.
     * To avoid infinite loops, at most 1,000,000 pairs are tested.
     * @param initials A string of exactly two uppercase alphabetic characters;
            invalid initials risk inciting the wrath of the gods.
     * @return the number of random pairs which were generated before the initials
     *      were generated.  The minimum possible value is 0, which would mean
     *      the the very first pair generated was the pair requested.
     */
    public int tryUntilSuccess(String initials) {
        assert initials.length() == 2;
        char char1 = initials.charAt(0);
        char char2 = initials.charAt(1);
        int tryCount = 0;
        final int maxTrials = 1000000;
        while (tryCount < maxTrials) {//remain in the loop until a break is executed
            char c1 = CharGenerator.randomUpperChar();
            char c2 = CharGenerator.randomUpperChar();
            if (c1 == initials.charAt(0) && c2 == initials.charAt(1)) {
                break; //have found the pair!
            }
            tryCount++;
        }
        return tryCount;
    //end tryUntilSuccess
    }
    
    /** Report on how lucky a result is.
     *  The cutoff points for various messages are somewhat based on estimations
     *  of how probable various result are, given that the size of the alphabet is 26.
        @param score a value representing the number of trials needed before the god or
     *      goddess recognized someone's initials; these values are on the same
     *      scale as those produced by the tryUntilSuccess method.
     *  @return an English message explaining or evaluating the result.  For example,
     *  it could be "You are truly beloved of Fortuna" or "You need to increase
     *  your offerings or disaster will befall", as appropriate.
     */
    String interpret(double score) {
        final double aSize = 26.0;
        if (score <= (aSize/4) * (aSize/4)) {
            return "Incredible Luck!  You are truly beloved of the gods.";
        }
        if (score < (aSize/2) * (aSize/2)) {
            return "The gods smile upon you.";
        }
        if (score <= aSize * (aSize/2)) {
            return "The gods of luck are just a tiny bit displeased.";
        }
        if (score <= aSize * aSize) {
            return "Caution -- luck does not favor you.";
        }
        else {
            return "EXTREME DANGER -- the gods are wrathful unto thee.";
        }
    //end interpret   
    }
    
//end class LuckTester    
}