package basicgraph;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import util.GraphLoader;

/**
 * @author UCSD MOOC Development Team
 * Grader for Module 1, Part 2
 */
public class GraphGrader {
 private String feedback;

 private int correct;

 private static final int TESTS = 16;

 /** Turn a list into a readable and printable string */
 public static String printList(List<Integer> lst) {
 String res = "";
 for (int i : lst) {
 res += i + "-";
 }
 // Last character will be a '-'
 return res.substring(0, res.length() - 1);
 }

 /** Format readable feedback */
 public static String printOutput(double score, String feedback) {
 return "Score: " + score + "\nFeedback: " + feedback;
 }

 /** Format test number and description */
 public static String appendFeedback(int num, String test) {
 return "\n** Test #" + num + ": " + test + "...";
 }

 public static void main(String[] args) {
 GraphGrader grader = new GraphGrader();
 grader.run();
 }

 /** Run a test case on an adjacency list and adjacency matrix.
 * @param i The graph number
 * @param desc A description of the graph
 * @param start The node to start from
 * @param corr A list containing the correct answer
 */
 public void runTest(int i, String desc, int start, List<Integer> corr) {
 GraphAdjList lst = new GraphAdjList();
 GraphAdjMatrix mat = new GraphAdjMatrix();
 
 feedback += "\n\nGRAPH: " + desc;
 feedback += appendFeedback(i * 2 - 1, "Testing adjacency list"); 

 // Load the graph, get the user's answer, and compare with right answer
 GraphLoader.loadGraph("data/graders/mod1/graph" + i + ".txt", lst);
 List<Integer> result = lst.getDistance2(start);
 judge(result, corr);
 
 feedback += appendFeedback(i * 2, "Testing adjacency matrix");
 GraphLoader.loadGraph("data/graders/mod1/graph" + i + ".txt", mat);
 result = mat.getDistance2(start);
 judge(result, corr);
 }

 /** Run a road map/airplane route test case.
 * @param i The graph number
 * @param file The file to read the correct answer from
 * @param desc A description of the graph
 * @param start The node to start from
 * @param corr A list containing the correct answer
 * @param type The type of graph to use
 */
 public void runSpecialTest(int i, String file, String desc, int start, List<Integer> corr, String type) {
 GraphAdjList lst = new GraphAdjList();
 GraphAdjMatrix mat = new GraphAdjMatrix();

 String prefix = "data/graders/mod1/";

 feedback += "\n\n" + desc;
 feedback += appendFeedback(i * 2 - 1, "Testing adjacency list");

 // Different method calls for different graph types
 if (type.equals("road")) {
 GraphLoader.loadRoadMap(prefix + file, lst);
 GraphLoader.loadRoadMap(prefix + file, mat);
 } else if (type.equals("air")) {
 GraphLoader.loadRoutes(prefix + file, lst);
 GraphLoader.loadRoutes(prefix + file, mat);
 }

 List<Integer> result = lst.getDistance2(start);
 judge(result, corr);

 feedback += appendFeedback(i * 2, "Testing adjacency matrix");
 result = mat.getDistance2(start);
 judge(result, corr);
 }

 /** Compare the user's result with the right answer.
 * @param result The list with the user's result
 * @param corr The list with the correct answer
 */
 public void judge(List<Integer> result, List<Integer> corr) {
 // Correct answer if both lists contain the same elements
 	if (result == null) {
 		feedback += "FAILED. Result returned was NULL. ";
 	}
 	else if (result.size() != corr.size() || !result.containsAll(corr)) {
 feedback += "FAILED. Expected " + printList(corr) + ", got " + printList(result) + ". ";
 if (result.size() > corr.size()) {
 feedback += "Make sure you aren't including vertices of distance 1. ";
 }
 if (result.size() < corr.size()) { 
 feedback += "Make sure you're exploring all possible paths. ";
 }
 } else {
 feedback += "PASSED.";
 correct++;
 }
 }

 /** Read a correct answer from a file.
 * @param file The file to read from
 * @return A list containing the correct answer
 */
 public ArrayList<Integer> readCorrect(String file) {
 ArrayList<Integer> ret = new ArrayList<Integer>();
 try {
 BufferedReader br = new BufferedReader(new FileReader("data/graders/mod1/" + file));
 String next;
 while ((next = br.readLine()) != null) {
 ret.add(Integer.parseInt(next));
 }
 } catch (Exception e) {
 // shouldn't happen
 feedback += "\nCould not open answer file! Please submit a bug report.";
 }
 return ret;
 }

 /** Run the grader */
 public void run() {
 feedback = "";
 correct = 0;
 ArrayList<Integer> correctAns;

 try {
 correctAns = new ArrayList<Integer>();
 correctAns.add(7);
 runTest(1, "Straight line (0->1->2->3->...)", 5, correctAns);

 correctAns = new ArrayList<Integer>();
 correctAns.add(4);
 correctAns.add(6);
 correctAns.add(6);
 correctAns.add(8);
 runTest(2, "Undirected straight line (0<->1<->2<->3<->...)", 6, correctAns);

 correctAns = new ArrayList<Integer>();
 for (int i = 0; i < 9; i++) {
 correctAns.add(0);
 }
 runTest(3, "Star graph - 0 is connected in both directions to all nodes except itself (starting at 0)", 0, correctAns);

 correctAns = new ArrayList<Integer>();
 for (int i = 1; i < 10; i++)
 correctAns.add(i);
 runTest(4, "Star graph (starting at 5)", 5, correctAns);
 
 correctAns = new ArrayList<Integer>();
 for (int i = 6; i < 11; i++)
 correctAns.add(i);
 runTest(5, "Star graph - Each 'arm' consists of two undirected edges leading away from 0 (starting at 0)", 0, correctAns);

 correctAns = new ArrayList<Integer>();
 runTest(6, "Same graph as before (starting at 5)", 5, correctAns);

 correctAns = readCorrect("ucsd.map.twoaway");
 runSpecialTest(7, "ucsd.map", "UCSD MAP: Intersections around UCSD", 3, correctAns, "road");

 correctAns = readCorrect("routesUA.dat.twoaway");
 runSpecialTest(8, "routesUA.dat", "AIRLINE MAP: Airplane routes around the world", 6, correctAns, "air");

 if (correct == TESTS)
 feedback = "All tests passed. Great job!" + feedback;
 else
 feedback = "Some tests failed. Check your code for errors, then try again:" + feedback;

 } catch (Exception e) {
 feedback += "\nError during runtime: " + e;
 e.printStackTrace();
 }
 
 System.out.println(printOutput((double)correct / TESTS, feedback));
 }
}