Terrarum/src/net/torvald/terrarum/weather/WeatherMixer.kt

package net.torvald.terrarum.weather

import com.jme3.math.FastMath
import net.torvald.JsonFetcher
import net.torvald.colourutil.CIELChUtil
import net.torvald.colourutil.ColourUtil
import net.torvald.random.HQRNG
import net.torvald.terrarum.Terrarum
import net.torvald.terrarum.gameworld.WorldTime
import org.newdawn.slick.Color
import org.newdawn.slick.GameContainer
import org.newdawn.slick.Graphics
import org.newdawn.slick.Image
import org.newdawn.slick.fills.GradientFill
import org.newdawn.slick.geom.Rectangle
import java.io.File
import java.util.*

/**
 * Current, next are there for cross-fading two weathers
 *
 * Created by minjaesong on 16-07-11.
 */
object WeatherMixer {
    lateinit var weatherList: HashMap<String, ArrayList<BaseModularWeather>>

    lateinit var currentWeather: BaseModularWeather
    lateinit var nextWeather: BaseModularWeather

    lateinit var mixedWeather: BaseModularWeather

    private var skyBoxCurrent = Rectangle(0f, 0f, Terrarum.WIDTH.toFloat(), Terrarum.HEIGHT.toFloat())
    private var skyBoxNext = Rectangle(0f, 0f, Terrarum.WIDTH.toFloat(), Terrarum.HEIGHT.toFloat())
    val globalLightNow = Color(0)

    // Weather indices
    const val WEATHER_GENERIC = "generic"
    const val WEATHER_GENERIC_RAIN = "genericrain"
    // TODO add weather classification indices manually

    const val RAW_DIR = "./assets/raw/weathers"

    init {
        weatherList = HashMap<String, ArrayList<BaseModularWeather>>()

        // read weather descriptions from assets/weather (modular weather)
        val weatherRawValidList = ArrayList<File>()
        val weatherRaws = File(RAW_DIR).listFiles()
        weatherRaws.forEach {
            if (!it.isDirectory && it.name.endsWith(".json"))
                weatherRawValidList.add(it)
        }
        // --> read from directory and store file that looks like RAW
        for (raw in weatherRawValidList) {
            val weather = readFromJson(raw)

            // if List for the classification does not exist, make one
            if (!weatherList.containsKey(weather.classification))
                weatherList.put(weather.classification, ArrayList())

            weatherList[weather.classification]!!.add(weather)
        }



        // initialise
        currentWeather = weatherList[WEATHER_GENERIC]!![0]
        nextWeather = getRandomWeather(WEATHER_GENERIC)
    }

    fun update(gc: GameContainer, delta: Int) {
        currentWeather = weatherList[WEATHER_GENERIC]!![0]

    }

    fun render(g: Graphics) {

        // we will not care for nextSkybox for now
        val timeNow = Terrarum.ingame.world.time.elapsedSeconds()
        val skyboxColourMap = currentWeather.skyboxGradColourMap
        val lightColourMap = currentWeather.globalLightColourMap

        // draw skybox to provided (should be main) graphics instance
        val skyColourFill = GradientFill(
                0f, 0f,
                getGradientColour(skyboxColourMap, 0, timeNow),
                0f, Terrarum.HEIGHT.toFloat(),
                getGradientColour(skyboxColourMap, 1, timeNow)
        )
        g.fill(skyBoxCurrent, skyColourFill)

        // calculate global light
        val gradCol = getGradientColour(lightColourMap, 0, timeNow)
        globalLightNow.r = gradCol.r
        globalLightNow.g = gradCol.g
        globalLightNow.b = gradCol.b
    }

    /**
     * Get a GL of specific time
     */
    fun getGlobalLightOfTime(timeInSec: Int): Color =
            getGradientColour(currentWeather.globalLightColourMap, 0, timeInSec)

    fun getGradientColour(image: Image, row: Int, timeInSec: Int): Color {
        val dataPointDistance = WorldTime.DAY_LENGTH / image.width

        val phaseThis: Int = timeInSec / dataPointDistance // x-coord in gradmap
        val phaseNext: Int = (phaseThis + 1) % image.width

        val colourThis = image.getColor(phaseThis, row)
        val colourNext = image.getColor(phaseNext, row)

        // interpolate R, G and B
        val scale = (timeInSec % dataPointDistance).toFloat() / dataPointDistance // [0.0, 1.0]

        //val newCol = ColourUtil.getGradient(scale, colourThis, colourNext)
        val newCol = CIELChUtil.getGradient(scale, colourThis, colourNext)

        /* // very nice monitor code
        // 65 -> 66 | 300 | 19623 | RGB8(255, 0, 255) -[41%]-> RGB8(193, 97, 23) | * `230`40`160`
        // ^ step   |width| time  | colour from        scale   colour to         | output
        if (dataPointDistance == 300)
            println("$phaseThis -> $phaseNext | $dataPointDistance | $timeInSec" +
                    " | ${colourThis.toStringRGB()} -[${scale.times(100).toInt()}%]-> ${colourNext.toStringRGB()}" +
                    " | * `$r`$g`$b`")*/

        return newCol
    }

    fun Color.toStringRGB() = "RGB8(${this.red}, ${this.green}, ${this.blue})"

    fun getWeatherList(classification: String) = weatherList[classification]!!
    fun getRandomWeather(classification: String) =
            getWeatherList(classification)[HQRNG().nextInt(getWeatherList(classification).size)]

    fun readFromJson(file: File): BaseModularWeather = readFromJson(file.path)

    fun readFromJson(path: String): BaseModularWeather {
        /* JSON structure:
{
  "globalLight": "colourmap/sky_colour.png", // integer for static, string (path to image) for dynamic
  "skyboxGradColourMap": "colourmap/sky_colour.png", // integer for static, string (path to image) for dynamic
  "extraImages": [
      // if any, it will be like:
      sun01.png,
      clouds01.png,
      clouds02.png,
      auroraBlueViolet.png
  ]
}
         */
        val pathToImage = "./assets/graphics/weathers"

        val JSON = JsonFetcher(path)

        val globalLightInJson = JSON.get("globalLight").asJsonPrimitive
        val skyboxInJson = JSON.get("skyboxGradColourMap").asJsonPrimitive
        val extraImagesPath = JSON.getAsJsonArray("extraImages")

        val globalLight: Image
        val skybox: Image
        val extraImages = ArrayList<Image>()
        val classification = JSON.get("classification").asJsonPrimitive.asString
        val mixFrom: String?
        try { mixFrom = JSON.get("mixFrom").asJsonPrimitive.asString }
        catch (e: NullPointerException) { mixFrom = null }
        val mixPercentage: Double?
        try { mixPercentage = JSON.get("mixPercentage").asJsonPrimitive.asDouble }
        catch (e: NullPointerException) { mixPercentage = null }

        // parse globalLight
        if (globalLightInJson.isString)
            globalLight = Image("$pathToImage/${globalLightInJson.asString}")
        else if (globalLightInJson.isNumber) {
            // make 1x1 image with specified colour
            globalLight = Image(1, 1)
            globalLight.graphics.color = Color(globalLightInJson.asNumber.toInt())
            globalLight.graphics.fillRect(0f, 0f, 1f, 1f)
        }
        else
            throw IllegalStateException("In weather descriptor $path -- globalLight seems malformed.")

        // parse skyboxGradColourMap
        if (skyboxInJson.isString)
            skybox = Image("$pathToImage/${skyboxInJson.asString}")
        else if (globalLightInJson.isNumber) {
            // make 1x2 image with specified colour
            skybox = Image(1, 2)
            skybox.graphics.color = Color(skyboxInJson.asNumber.toInt())
            skybox.graphics.fillRect(0f, 0f, 1f, 2f)
        }
        else
            throw IllegalStateException("In weather descriptor $path -- skyboxGradColourMap seems malformed.")

        // get extra images
        for (i in extraImagesPath)
            extraImages.add(Image("$pathToImage/${i.asString}"))

        // get mix from


        return BaseModularWeather(globalLight, skybox, classification, extraImages)
    }
}