package tools.mapletools;

import provider.wz.WZFiles;

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.time.Duration;
import java.time.Instant;
import java.util.*;

/**
 * @author RonanLana
 * <p>
 * This application parses the Quest.wz file inputted and generates a report showing
 * all cases where quest script files have not been found for quests that requires a
 * script file.
 * As an extension, it highlights missing script files for questlines that hand over
 * skills as rewards.
 * <p>
 * Running it should generate a report file under "output" folder with the search results.
 */
public class QuestlineFetcher {
    private static final Path OUTPUT_FILE = ToolConstants.getOutputFile("questline_report.txt");
    private static final String ACT_NAME = WZFiles.QUEST.getFilePath() + "/Act.img.xml";
    private static final String CHECK_NAME = WZFiles.QUEST.getFilePath() + "/Check.img.xml";
    private static final int INITIAL_STRING_LENGTH = 50;

    private static final Stack<Integer> skillObtainableQuests = new Stack<>();
    private static final Set<Integer> scriptedQuestFiles = new HashSet<>();
    private static final Set<Integer> expiredQuests = new HashSet<>();
    private static final Map<Integer, List<Integer>> questDependencies = new HashMap<>();
    private static final Set<Integer> nonScriptedQuests = new HashSet<>();
    private static final Set<Integer> skillObtainableNonScriptedQuests = new HashSet<>();

    private static PrintWriter printWriter = null;
    private static InputStreamReader fileReader = null;
    private static BufferedReader bufferedReader = null;
    private static byte status = 0;
    private static int questId = -1;
    private static int isCompleteState = 0;
    private static boolean isScriptedQuest;
    private static boolean isExpiredQuest;
    private static List<Integer> questDependencyList;
    private static int curQuestId;
    private static int curQuestState;

    private static String getName(String token) {
        int i, j;
        char[] dest;
        String d;

        i = token.lastIndexOf("name");
        i = token.indexOf("\"", i) + 1; //lower bound of the string
        j = token.indexOf("\"", i);     //upper bound

        dest = new char[INITIAL_STRING_LENGTH];
        token.getChars(i, j, dest, 0);

        d = new String(dest);
        return (d.trim());
    }

    private static String getValue(String token) {
        int i, j;
        char[] dest;
        String d;

        i = token.lastIndexOf("value");
        i = token.indexOf("\"", i) + 1; //lower bound of the string
        j = token.indexOf("\"", i);     //upper bound

        dest = new char[INITIAL_STRING_LENGTH];
        token.getChars(i, j, dest, 0);

        d = new String(dest);
        return (d.trim());
    }

    private static void forwardCursor(int st) {
        String line = null;

        try {
            while (status >= st && (line = bufferedReader.readLine()) != null) {
                simpleToken(line);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static void simpleToken(String token) {
        if (token.contains("/imgdir")) {
            status -= 1;
        } else if (token.contains("imgdir")) {
            status += 1;
        }
    }

    private static void translateTokenCheck(String token) {
        String d;

        if (token.contains("/imgdir")) {
            status -= 1;

            if (status == 1) {
                evaluateCurrentQuest();
            } else if (status == 4) {
                evaluateCurrentQuestDependency();
            }
        } else if (token.contains("imgdir")) {
            if (status == 1) {           //getting QuestId
                d = getName(token);
                questId = Integer.parseInt(d);

                isScriptedQuest = false;
                isExpiredQuest = false;
                questDependencyList = new LinkedList<>();
            } else if (status == 2) {      //start/complete
                d = getName(token);
                isCompleteState = Integer.parseInt(d);
            } else if (status == 3) {
                if (isCompleteState == 1 || !token.contains("quest")) {
                    forwardCursor(status);
                }
            }

            status += 1;
        } else {
            if (status == 3) {
                d = getName(token);

                if (d.contains("script")) {
                    isScriptedQuest = true;
                } else if (d.contains("end")) {
                    isExpiredQuest = true;
                }
            } else if (status == 5) {
                readQuestLabel(token);
            }
        }
    }

    private static void translateTokenAct(String token) {
        String d;

        if (token.contains("/imgdir")) {
            status -= 1;
        } else if (token.contains("imgdir")) {
            if (status == 1) {           //getting QuestId
                d = getName(token);
                questId = Integer.parseInt(d);
            } else if (status == 2) {      //start/complete
                d = getName(token);
                isCompleteState = Integer.parseInt(d);
            } else if (status == 3) {
                if (isCompleteState == 1 && token.contains("skill")) {
                    skillObtainableQuests.add(questId);
                }

                forwardCursor(status);
            }

            status += 1;
        }
    }

    private static void readQuestLabel(String token) {
        String name = getName(token);
        String value = getValue(token);

        switch (name) {
            case "id" -> curQuestId = Integer.parseInt(value);
            case "state" -> curQuestState = Integer.parseInt(value);
        }
    }

    private static void evaluateCurrentQuestDependency() {
        if (curQuestState == 2) {
            questDependencyList.add(curQuestId);
        }
    }

    private static void evaluateCurrentQuest() {
        if (isScriptedQuest && !scriptedQuestFiles.contains(questId)) {
            nonScriptedQuests.add(questId);
        }
        if (isExpiredQuest) {
            expiredQuests.add(questId);
        }

        questDependencies.put(questId, questDependencyList);
    }

    private static void instantiateQuestScriptFiles(String directoryName) {
        File directory = new File(directoryName);

        // get all the files from a directory
        File[] fList = directory.listFiles();
        for (File file : fList) {
            if (file.isFile()) {
                String fname = file.getName();

                try {
                    Integer questid = Integer.parseInt(fname.substring(0, fname.indexOf('.')));
                    scriptedQuestFiles.add(questid);
                } catch (NumberFormatException nfe) {
                }
            }
        }
    }

    private static void readQuestsWithMissingScripts() throws IOException {
        String line;

        fileReader = new InputStreamReader(new FileInputStream(CHECK_NAME), StandardCharsets.UTF_8);
        bufferedReader = new BufferedReader(fileReader);

        while ((line = bufferedReader.readLine()) != null) {
            translateTokenCheck(line);
        }

        bufferedReader.close();
        fileReader.close();
    }

    private static void readQuestsWithSkillReward() throws IOException {
        String line;

        fileReader = new InputStreamReader(new FileInputStream(ACT_NAME), StandardCharsets.UTF_8);
        bufferedReader = new BufferedReader(fileReader);

        while ((line = bufferedReader.readLine()) != null) {
            translateTokenAct(line);
        }

        bufferedReader.close();
        fileReader.close();
    }

    private static void calculateSkillRelatedMissingQuestScripts() {
        Stack<Integer> frontierQuests = skillObtainableQuests;
        Set<Integer> solvedQuests = new HashSet<>();

        while (!frontierQuests.isEmpty()) {
            Integer questid = frontierQuests.pop();
            solvedQuests.add(questid);

            if (nonScriptedQuests.contains(questid)) {
                skillObtainableNonScriptedQuests.add(questid);
                nonScriptedQuests.remove(questid);
            }

            List<Integer> questDependency = questDependencies.get(questid);
            for (Integer i : questDependency) {
                if (!solvedQuests.contains(i)) {
                    frontierQuests.add(i);
                }
            }
        }
    }

    private static void printReportFileHeader() {
        printWriter.println(" # Report File autogenerated from the MapleQuestlineFetcher feature by Ronan Lana.");
        printWriter.println(" # Generated data takes into account several data info from the server-side WZ.xmls.");
        printWriter.println();
    }

    private static List<Integer> getSortedListEntries(Set<Integer> set) {
        List<Integer> list = new ArrayList<>(set);
        Collections.sort(list);

        return list;
    }

    private static void printReportFileResults() {
        if (!skillObtainableNonScriptedQuests.isEmpty()) {
            printWriter.println("SKILL-RELATED NON-SCRIPTED QUESTS");
            for (Integer nsq : getSortedListEntries(skillObtainableNonScriptedQuests)) {
                printWriter.println("  " + nsq + (expiredQuests.contains(nsq) ? " EXPIRED" : ""));
            }

            printWriter.println();
        }

        printWriter.println("\nCOMMON NON-SCRIPTED QUESTS");
        for (Integer nsq : getSortedListEntries(nonScriptedQuests)) {
            printWriter.println("  " + nsq + (expiredQuests.contains(nsq) ? " EXPIRED" : ""));
        }
    }

    private static void reportQuestlineData() {
        // This will reference one line at a time

        try (PrintWriter pw = new PrintWriter(Files.newOutputStream(OUTPUT_FILE))) {
            System.out.println("Reading quest scripts...");
            instantiateQuestScriptFiles(ToolConstants.SCRIPTS_PATH + "/quest");

            System.out.println("Reading WZs...");
            readQuestsWithSkillReward();
            readQuestsWithMissingScripts();

            System.out.println("Calculating skill related quests...");
            calculateSkillRelatedMissingQuestScripts();

            System.out.println("Reporting results...");
            printWriter = pw;

            printReportFileHeader();
            printReportFileResults();

            System.out.println("Done!");
        } catch (FileNotFoundException ex) {
            System.out.println("Unable to open quest file.");
        } catch (IOException ex) {
            System.out.println("Error reading quest file.");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /*
    private static List<Pair<Integer, List<Integer>>> getSortedMapEntries(Map<Integer, List<Integer>> map) {
        List<Pair<Integer, List<Integer>>> list = new ArrayList<>(map.size());
        for(Map.Entry<Integer, List<Integer>> e : map.entrySet()) {
            List<Integer> il = new ArrayList<>(2);
            for(Integer i : e.getValue()) {
                il.add(i);
            }

            Collections.sort(il, new Comparator<Integer>() {
                @Override
                public int compare(Integer o1, Integer o2) {
                    return o1 - o2;
                }
            });

            list.add(new Pair<>(e.getKey(), il));
        }

        Collections.sort(list, new Comparator<Pair<Integer, List<Integer>>>() {
            @Override
            public int compare(Pair<Integer, List<Integer>> o1, Pair<Integer, List<Integer>> o2) {
                return o1.getLeft() - o2.getLeft();
            }
        });

        return list;
    }

    private static void DumpQuestlineData() {
        for(Pair<Integer, List<Integer>> questDependency : getSortedMapEntries(questDependencies)) {
            if(!questDependency.right.isEmpty()) {
                System.out.println(questDependency);
            }
        }
    }
    */

    public static void main(String[] args) {
    	Instant instantStarted = Instant.now();
        reportQuestlineData();
        Instant instantStopped = Instant.now();
        Duration durationBetween = Duration.between(instantStarted, instantStopped);
        System.out.println("Get elapsed time in milliseconds: " + durationBetween.toMillis());
        System.out.println("Get elapsed time in seconds: " + durationBetween.toSeconds());

    }
}