// Mines is free software: you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the Free Software
// Foundation, either version 3 of the License, or (at your option) any later
// version.

// Mines is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
// A PARTICULAR PURPOSE. See the GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along with
// Mines. If not, see <https://www.gnu.org/licenses/>.

package space.jakob.mines

import android.support.v7.app.AppCompatActivity
import android.support.v4.view.GestureDetectorCompat
import android.os.Bundle
import android.view.GestureDetector
import android.view.ScaleGestureDetector
import android.view.MotionEvent
import android.util.Log

class GameActivity : AppCompatActivity() {
    lateinit var gameView: GameView
    lateinit var gestureDetector: GestureDetectorCompat
    lateinit var scaleGestureDetector: ScaleGestureDetector

    // Implements the callbacks for gestureDetector.
    val gestureListener = object : GestureDetector.SimpleOnGestureListener() {
        override fun onDown(e: MotionEvent): Boolean {
            with (gameView) {
                grid?.let {
                    val (x, y) = toGridCoordinates(e.x.toInt(), e.y.toInt())
                    it.reveal(x, y)
                    invalidate()
                }
            }
            return false
        }

        override fun onScroll(e1: MotionEvent, e2: MotionEvent, dx: Float, dy: Float): Boolean {
            with (gameView) {
                cameraX = (cameraX + dx / 100.0).coerceIn(0.0, gameView.maxCameraX)
                cameraY = (cameraY + dy / 100.0).coerceIn(0.0, gameView.maxCameraY)
                invalidate()
            }
            return false
        }
    }

    // Implements the callbacks for scaleGestureDetector.
    val scaleListener = object : ScaleGestureDetector.SimpleOnScaleGestureListener() {
        override fun onScale(scaleGestureDetector: ScaleGestureDetector) : Boolean {
            with (gameView) {
                grid?.let {
                    val factor = scaleGestureDetector.getScaleFactor()

                    var currentDistance = sightX - cameraX
                    var desiredDistance = currentDistance / factor
                    var deltaDistance = Math.abs(desiredDistance - currentDistance) / 2

                    if (factor < 1.0) {
                        cameraX = (cameraX - deltaDistance).coerceAtLeast(0.0)
                        sightX = (sightX + deltaDistance).coerceAtMost(it.width.toDouble() - cameraX)
                    } else {
                        cameraX = cameraX + deltaDistance
                        sightX = sightX - deltaDistance
                    }

                    currentDistance = sightY - cameraY
                    desiredDistance = currentDistance / factor
                    deltaDistance = Math.abs(desiredDistance - currentDistance) / 2

                    if (factor < 1.0) {
                        cameraY = (cameraY - deltaDistance).coerceAtLeast(0.0)
                        sightY = (sightY + deltaDistance).coerceAtMost(it.height.toDouble() - cameraY)
                    } else {
                        cameraY = cameraY + deltaDistance
                        sightY = sightY - deltaDistance
                    }
                }
            }
            return false
        }
    }

    override fun onTouchEvent(event: MotionEvent): Boolean {
        return gestureDetector.onTouchEvent(event)
            || scaleGestureDetector.onTouchEvent(event)
            || super.onTouchEvent(event)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_game)

        var width = 8
        var height = 8
        var mines = 10

        getIntent()?.let {
            width = it.getIntExtra("WIDTH", width)
            height = it.getIntExtra("HEIGHT", height)
            mines = it.getIntExtra("MINES", mines)
        }

        gameView = findViewById(R.id.view) as GameView
        gameView.grid = Grid(width, height, mines)

        gestureDetector = GestureDetectorCompat(this, gestureListener)
        scaleGestureDetector = ScaleGestureDetector(this, scaleListener)
    }
}