/*
 * Copyright (C) 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.android.launcher3.celllayout;

import android.graphics.Point;
import android.graphics.Rect;

import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.Set;


public class CellLayoutBoard {

    static final int INFINITE = 99999;

    char[][] mBoard = new char[30][30];

    List<TestBoardWidget> mWidgetsRects = new ArrayList<>();
    Map<Character, TestBoardWidget> mWidgetsMap = new HashMap<>();

    List<TestBoardAppIcon> mIconPoints = new ArrayList<>();
    Map<Character, TestBoardAppIcon> mIconsMap = new HashMap<>();

    Point mMain = new Point();

    CellLayoutBoard() {
        for (int x = 0; x < mBoard.length; x++) {
            for (int y = 0; y < mBoard[0].length; y++) {
                mBoard[x][y] = '-';
            }
        }
    }

    public List<TestBoardWidget> getWidgets() {
        return mWidgetsRects;
    }

    public Point getMain() {
        return mMain;
    }

    public TestBoardWidget getWidgetRect(char c) {
        return mWidgetsMap.get(c);
    }

    public static TestBoardWidget getWidgetRect(int x, int y, Set<Point> used, char[][] board) {
        char type = board[x][y];
        Queue<Point> search = new ArrayDeque<Point>();
        Point current = new Point(x, y);
        search.add(current);
        used.add(current);
        List<Point> neighbors = new ArrayList<>(List.of(
                new Point(-1, 0),
                new Point(0, -1),
                new Point(1, 0),
                new Point(0, 1))
        );
        Rect widgetRect = new Rect(INFINITE, -INFINITE, -INFINITE, INFINITE);
        while (!search.isEmpty()) {
            current = search.poll();
            widgetRect.top = Math.max(widgetRect.top, current.y);
            widgetRect.right = Math.max(widgetRect.right, current.x);
            widgetRect.bottom = Math.min(widgetRect.bottom, current.y);
            widgetRect.left = Math.min(widgetRect.left, current.x);
            for (Point p : neighbors) {
                Point next = new Point(current.x + p.x, current.y + p.y);
                if (next.x < 0 || next.x >= board.length) continue;
                if (next.y < 0 || next.y >= board[0].length) continue;
                if (board[next.x][next.y] == type && !used.contains(next)) {
                    used.add(next);
                    search.add(next);
                }
            }
        }
        return new TestBoardWidget(type, widgetRect);
    }

    public static boolean isWidget(char type) {
        return type != 'i' && type != '-';
    }

    public static boolean isIcon(char type) {
        return type == 'i';
    }

    private static List<TestBoardWidget> getRects(char[][] board) {
        Set<Point> used = new HashSet<>();
        List<TestBoardWidget> widgetsRects = new ArrayList<>();
        for (int x = 0; x < board.length; x++) {
            for (int y = 0; y < board[0].length; y++) {
                if (!used.contains(new Point(x, y)) && isWidget(board[x][y])) {
                    widgetsRects.add(getWidgetRect(x, y, used, board));
                }
            }
        }
        return widgetsRects;
    }

    private static List<TestBoardAppIcon> getIconPoints(char[][] board) {
        List<TestBoardAppIcon> iconPoints = new ArrayList<>();
        for (int x = 0; x < board.length; x++) {
            for (int y = 0; y < board[0].length; y++) {
                if (isIcon(board[x][y])) {
                    iconPoints.add(new TestBoardAppIcon(new Point(x, y), board[x][y]));
                }
            }
        }
        return iconPoints;
    }

    public static CellLayoutBoard boardFromString(String boardStr) {
        String[] lines = boardStr.split("\n");
        CellLayoutBoard board = new CellLayoutBoard();

        for (int y = 0; y < lines.length; y++) {
            String line = lines[y];
            for (int x = 0; x < line.length(); x++) {
                char c = line.charAt(x);
                if (c == 'm') {
                    board.mMain = new Point(x, y);
                }
                if (c != '-') {
                    board.mBoard[x][y] = line.charAt(x);
                }
            }
        }
        board.mWidgetsRects = getRects(board.mBoard);
        board.mWidgetsRects.forEach(
                widgetRect -> board.mWidgetsMap.put(widgetRect.mType, widgetRect));
        board.mIconPoints = getIconPoints(board.mBoard);
        return board;
    }
}