/**

  * The MIT License (MIT)

  *

  * Copyright (C) 2013 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * Permission is hereby granted, free of charge, to any person obtaining a copy

  * of this software and associated documentation files (the "Software"), to deal

  * in the Software without restriction, including without limitation the rights

  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

  * copies of the Software, and to permit persons to whom the Software is

  * furnished to do so, subject to the following conditions:

  *

  * The above copyright notice and this permission notice shall be included in

  * all copies or substantial portions of the Software.

  *

  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

  * THE SOFTWARE.

  */

 package org.apidesign.demo.minesweeper;

 import java.util.ArrayList;

 import java.util.List;

 import java.util.Random;

 import net.java.html.json.ComputedProperty;

 import net.java.html.json.Function;

 import net.java.html.json.Model;

 import net.java.html.json.ModelOperation;

 import net.java.html.json.Property;

 import net.java.html.sound.AudioClip;

 /** Model of the mine field.

  */

 @Model(className = "Mines", properties = {

     @Property(name = "state", type = MinesModel.GameState.class),

     @Property(name = "rows", type = Row.class, array = true),

 })

 public final class MinesModel {

     enum GameState {

         IN_PROGRESS, WON, LOST;

     }

     @Model(className = "Row", properties = {

         @Property(name = "columns", type = Square.class, array = true)

     })

     static class RowModel {

     }

     @Model(className = "Square", properties = {

         @Property(name = "state", type = SquareType.class),

         @Property(name = "mine", type = boolean.class)

     })

     static class SquareModel {

         @ComputedProperty static String html(SquareType state) {

             if (state == null) return " ";

             switch (state) {

                 case EXPLOSION: return "✗";

                 case UNKNOWN: return " ";

                 case DISCOVERED: return "✔";  

                 case N_0: return " ";

             }

             return "&#x278" + (state.ordinal() - 1);

         }

         @ComputedProperty static String style(SquareType state) {

             return state == null ? null : state.toString();

         }

     }

     enum SquareType {

         N_0, N_1, N_2, N_3, N_4, N_5, N_6, N_7, N_8,

         UNKNOWN, EXPLOSION, DISCOVERED;

         final boolean isVisible() {

             return name().startsWith("N_");

         }

         final SquareType moreBombsAround() {

             switch (this) {

                 case EXPLOSION:

                 case UNKNOWN:

                 case DISCOVERED:

                 case N_8:

                     return this;

             }

             return values()[ordinal() + 1];

         }

     }

     @ComputedProperty static boolean fieldShowing(GameState state) {

         return state != null;

     }

     @Function static void showHelp(Mines model) {

         model.setState(null);

     }

     @Function static void smallGame(Mines model) {

         model.init(5, 5, 5);

     }

     @Function static void normalGame(Mines model) {

         model.init(10, 10, 10);

     }

     @Function static void giveUp(Mines model) {

         showAllBombs(model, SquareType.EXPLOSION);

         model.setState(GameState.LOST);

     }

     @ModelOperation static void init(Mines model, int width, int height, int mines) {

         List<Row> rows = model.getRows();

         if (rows.size() != height || rows.get(0).getColumns().size() != width) {

             rows = new ArrayList<Row>(height);

             for (int y = 0; y < height; y++) {

                 Square[] columns = new Square[width];

                 for (int x = 0; x < width; x++) {

                     columns[x] = new Square(SquareType.UNKNOWN, false);

                 }

                 rows.add(new Row(columns));

             }

         } else {

             for (Row row : rows) {

                 for (Square sq : row.getColumns()) {

                     sq.setState(SquareType.UNKNOWN);

                     sq.setMine(false);

                 }

             }

         }

         Random r = new Random();

         while (mines > 0) {

             int x = r.nextInt(width);

             int y = r.nextInt(height);

             final Square s = rows.get(y).getColumns().get(x);

             if (s.isMine()) {

                 continue;

             }

             s.setMine(true);

             mines--;

         }

         model.setState(GameState.IN_PROGRESS);

         if (rows != model.getRows()) {

             model.getRows().clear();

             model.getRows().addAll(rows);

         }

     }

     @ModelOperation static void computeMines(Mines model) {

         List<Integer> xBombs = new ArrayList<Integer>();

         List<Integer> yBombs = new ArrayList<Integer>();

         final List<Row> rows = model.getRows();

         boolean emptyHidden = false;

         SquareType[][] arr = new SquareType[rows.size()][];

         for (int y = 0; y < rows.size(); y++) {

             final List<Square> columns = rows.get(y).getColumns();

             arr[y] = new SquareType[columns.size()];

             for (int x = 0; x < columns.size(); x++) {

                 Square sq = columns.get(x);

                 if (sq.isMine()) {

                     xBombs.add(x);

                     yBombs.add(y);

                 }

                 if (sq.getState().isVisible()) {

                     arr[y][x] = SquareType.N_0;

                 } else {

                     if (!sq.isMine()) {

                         emptyHidden = true;

                     }

                 }

             }

         }

         for (int i = 0; i < xBombs.size(); i++) {

             int x = xBombs.get(i);

             int y = yBombs.get(i);

             incrementAround(arr, x, y);

         }

         for (int y = 0; y < rows.size(); y++) {

             final List<Square> columns = rows.get(y).getColumns();

             for (int x = 0; x < columns.size(); x++) {

                 Square sq = columns.get(x);

                 final SquareType newState = arr[y][x];

                 if (newState != null && newState != sq.getState()) {

                     sq.setState(newState);

                 }

             }

         }

         if (!emptyHidden) {

             model.setState(GameState.WON);

             showAllBombs(model, SquareType.DISCOVERED);

             AudioClip applause = AudioClip.create("applause.wav");

             applause.play();

         }

     }

     private static void incrementAround(SquareType[][] arr, int x, int y) {

         incrementAt(arr, x - 1, y - 1);

         incrementAt(arr, x - 1, y);

         incrementAt(arr, x - 1, y + 1);

         incrementAt(arr, x + 1, y - 1);

         incrementAt(arr, x + 1, y);

         incrementAt(arr, x + 1, y + 1);

         incrementAt(arr, x, y - 1);

         incrementAt(arr, x, y + 1);

     }

     private static void incrementAt(SquareType[][] arr, int x, int y) {

         if (y >= 0 && y < arr.length) {

             SquareType[] r = arr[y];

             if (x >= 0 && x < r.length) {

                 SquareType sq = r[x];

                 if (sq != null) {

                     r[x] = sq.moreBombsAround();

                 }

             }

         }

     }

     static void showAllBombs(Mines model, SquareType state) {

         for (Row row : model.getRows()) {

             for (Square square : row.getColumns()) {

                 if (square.isMine()) {

                     square.setState(state);

                 }

             }

         }

     }

     @Function static void click(Mines model, Square data) {

         if (model.getState() != GameState.IN_PROGRESS) {

             return;

         }

         if (data.getState() != SquareType.UNKNOWN) {

             return;

         }

         if (data.isMine()) {

             Square fair = atLeastOnePlaceWhereBombCantBe(model);

             if (fair == null) {

                 if (placeBombElseWhere(model, data)) {

                     cleanedUp(model, data);

                     return;

                 }

             }

             explosion(model);

         } else {

             Square takeFrom = tryStealBomb(model, data);

             if (takeFrom != null) {

                 final Square fair = atLeastOnePlaceWhereBombCantBe(model);

                 if (fair != null) {

                     takeFrom.setMine(false);

                     data.setMine(true);

                     explosion(model);

                     return;

                 }

             }

             cleanedUp(model, data);

         }

     }

     private static void cleanedUp(Mines model, Square data) {

         AudioClip touch = AudioClip.create("move.mp3");

         touch.play();

         expandKnown(model, data);

         model.computeMines();

     }

     private static void explosion(Mines model) {

         showAllBombs(model, SquareType.EXPLOSION);

         model.setState(GameState.LOST);

         AudioClip oops = AudioClip.create("oops.wav");

         oops.play();

     }

     private static Square tryStealBomb(Mines model, Square data) {

         data.setMine(true);

         final List<Row> rows = model.getRows();

         for (int y = 0; y < rows.size(); y++) {

             final List<Square> columns = rows.get(y).getColumns();

             for (int x = 0; x < columns.size(); x++) {

                 Square sq = columns.get(x);

                 if (sq == data) {

                     continue;

                 }

                 if (sq.isMine()) {

                     sq.setMine(false);

                     final boolean ok = isConsistent(model);

                     sq.setMine(true);

                     if (ok) {

                         data.setMine(false);

                         return sq;

                     }

                 }

             }

         }

         data.setMine(false);        

         return null;

     }

     private static Square atLeastOnePlaceWhereBombCantBe(Mines model) {

         final List<Row> rows = model.getRows();

         Square cantBe = null;

         int discovered = 0;

         for (int y = 0; y < rows.size(); y++) {

             final List<Square> columns = rows.get(y).getColumns();

             for (int x = 0; x < columns.size(); x++) {

                 Square sq = columns.get(x);

                 if (sq.getState() == SquareType.UNKNOWN) {

                     if (!sq.isMine()) {

                         if (tryStealBomb(model, sq) == null) {

                             cantBe = sq;

                         }

                     }

                 } else {

                     discovered++;

                 }

             }

         }

         if (discovered > 5) {

             return cantBe;

         }

         return null;

     }

     private static boolean placeBombElseWhere(Mines model, Square moveBomb) {

         List<Square> ok = new ArrayList<Square>();

         moveBomb.setMine(false);

         final List<Row> rows = model.getRows();

         for (int y = 0; y < rows.size(); y++) {

             final List<Square> columns = rows.get(y).getColumns();

             for (int x = 0; x < columns.size(); x++) {

                 Square sq = columns.get(x);

                 if (sq == moveBomb || sq.isMine() || sq.getState().isVisible()) {

                     continue;

                 }

                 sq.setMine(true);

                 if (isConsistent(model)) {

                     ok.add(sq);

                 }

                 sq.setMine(false);

             }

         }

         if (ok.isEmpty()) {

             moveBomb.setMine(true);

             return false;

         } else {

             int r = new Random().nextInt(ok.size());

             ok.get(r).setMine(true);

             return true;

         }

     }

     private static void expandKnown(Mines model, Square data) {

         final List<Row> rows = model.getRows();

         for (int y = 0; y < rows.size(); y++) {

             final List<Square> columns = rows.get(y).getColumns();

             for (int x = 0; x < columns.size(); x++) {

                 Square sq = columns.get(x);

                 if (sq == data) {

                     expandKnown(model, x, y);

                     return;

                 }

             }

         }

     }

     private static void expandKnown(Mines model, int x , int y) {

         if (y < 0 || y >= model.getRows().size()) {

             return;

         }

         final List<Square> columns = model.getRows().get(y).getColumns();

         if (x < 0 || x >= columns.size()) {

             return;

         }

         final Square sq = columns.get(x);

         if (sq.getState() == SquareType.UNKNOWN) {

             int around = around(model, x, y);

             final SquareType t = SquareType.valueOf("N_" + around);

             sq.setState(t);

             if (t == SquareType.N_0) {

                 expandKnown(model, x - 1, y - 1);

                 expandKnown(model, x - 1, y);

                 expandKnown(model, x - 1, y + 1);

                 expandKnown(model, x , y - 1);

                 expandKnown(model, x, y + 1);

                 expandKnown(model, x + 1, y - 1);

                 expandKnown(model, x + 1, y);

                 expandKnown(model, x + 1, y + 1);

             }

         }

     }

     private static int around(Mines model, int x, int y) {

         return 

             minesAt(model, x - 1, y - 1) +

             minesAt(model, x - 1, y) +

             minesAt(model, x - 1, y + 1) +

             minesAt(model, x , y - 1) +

             minesAt(model, x, y + 1) +

             minesAt(model, x + 1, y - 1) +

             minesAt(model, x + 1, y) +

             minesAt(model, x + 1, y + 1);

     }

     private static int minesAt(Mines model, int x, int y) {

         if (y < 0 || y >= model.getRows().size()) {

             return 0;

         }

         final List<Square> columns = model.getRows().get(y).getColumns();

         if (x < 0 || x >= columns.size()) {

             return 0;

         }

         Square sq = columns.get(x);

         return sq.isMine() ? 1 : 0;

     }

     private static boolean isConsistent(Mines m) {

         for (int row = 0; row < m.getRows().size(); row++) {

             Row r = m.getRows().get(row);

             for (int col = 0; col < r.getColumns().size(); col++) {

                 Square sq = r.getColumns().get(col);

                 if (sq.getState().isVisible()) {

                     int around = around(m, col, row);

                     if (around != sq.getState().ordinal()) {

                         return false;

                     }

                 }

             }

         }

         return true;

     }

     /**

      * Called when page is ready

      */

     public static void main(String... args) throws Exception {

         Mines m = new Mines();

         m.applyBindings();

     }

 }