package ru.dbotthepony.kstarbound

import com.google.gson.JsonElement
import com.google.gson.JsonObject
import com.google.gson.JsonParser
import ru.dbotthepony.kstarbound.api.IVFS
import ru.dbotthepony.kstarbound.api.PhysicalFS
import ru.dbotthepony.kstarbound.defs.TileDefinition
import ru.dbotthepony.kstarbound.defs.TileDefinitionBuilder
import ru.dbotthepony.kstarbound.io.StarboundPak
import ru.dbotthepony.kstarbound.world.World
import java.io.*
import java.nio.ByteBuffer
import java.util.*
import kotlin.collections.ArrayList
import kotlin.collections.HashMap

const val METRES_IN_STARBOUND_UNIT = 0.25
const val METRES_IN_STARBOUND_UNITf = 0.25f

const val PIXELS_IN_STARBOUND_UNIT = 8.0
const val PIXELS_IN_STARBOUND_UNITf = 8.0f

class TileDefLoadingException(message: String, cause: Throwable? = null) : IllegalStateException(message, cause)

object Starbound : IVFS {
	private val tiles = HashMap<String, TileDefinition>()
	val tilesAccess = object : Map<String, TileDefinition> by tiles {}

	var initializing = false
		private set
	var initialized = false
		private set
	var terminateLoading = false

	private val archivePaths = ArrayList<File>()
	private val fileSystems = ArrayList<IVFS>()

	fun addFilePath(path: File) {
		fileSystems.add(PhysicalFS(path))
	}

	/**
	 * Добавляет уже прочитанный pak
	 */
	fun addPak(pak: StarboundPak) {
		fileSystems.add(pak)
	}

	/**
	 * Добавляет pak к чтению при initializeGame
	 */
	fun addPakPath(pak: File) {
		archivePaths.add(pak)
	}

	fun loadJson(path: String): JsonElement {
		return JsonParser.parseReader(getReader(path))
	}

	fun getTileDefinition(name: String) = tiles[name]
	private val initCallbacks = ArrayList<() -> Unit>()

	fun initializeGame(callback: (finished: Boolean, replaceStatus: Boolean, status: String) -> Unit) {
		if (initializing) {
			throw IllegalStateException("Already initializing!")
		}

		if (initialized) {
			throw IllegalStateException("Already initialized!")
		}

		initializing = true

		Thread({
			val time = System.currentTimeMillis()

			if (archivePaths.isNotEmpty()) {
				callback(false, false, "Reading pak archives...")

				for (path in archivePaths) {
					callback(false, false, "Reading ${path.name}...")

					addPak(StarboundPak(path) { _, status ->
						callback(false, true, "${path.name}: $status")
					})
				}
			}

			callback(false, false, "Loading materials...")

			loadTileMaterials {
				if (terminateLoading) {
					throw InterruptedException("Game is terminating")
				}

				callback(false, true, it)
			}

			callback(false, true, "Loaded materials")

			initializing = false
			initialized = true
			callback(true, false, "Finished loading in ${System.currentTimeMillis() - time}ms")
		}, "Asset Loader").start()
	}

	override fun pathExists(path: String): Boolean {
		for (fs in fileSystems) {
			if (fs.pathExists(path)) {
				return true
			}
		}

		return false
	}

	override fun readOrNull(path: String): ByteBuffer? {
		for (fs in fileSystems) {
			if (fs.pathExists(path)) {
				return fs.read(path)
			}
		}

		return null
	}

	override fun listFiles(path: String): List<String> {
		val listing = mutableListOf<String>()

		for (fs in fileSystems) {
			listing.addAll(fs.listFiles(path))
		}

		return listing
	}

	fun onInitialize(callback: () -> Unit) {
		if (initialized) {
			callback()
		} else {
			initCallbacks.add(callback)
		}
	}

	fun pollCallbacks() {
		if (initialized && initCallbacks.isNotEmpty()) {
			for (callback in initCallbacks) {
				callback()
			}

			initCallbacks.clear()
		}
	}

	private fun loadTileMaterials(callback: (String) -> Unit) {
		for (fs in fileSystems) {
			for (listedFile in fs.listFiles("tiles/materials")) {
				if (listedFile.endsWith(".material")) {
					try {
						callback("Loading $listedFile")

						val tileDef = TileDefinitionBuilder.fromJson(JsonParser.parseReader(getReader(listedFile)) as JsonObject).build("/tiles/materials")

						check(tiles[tileDef.materialName] == null) { "Already has material with ID ${tileDef.materialName} loaded!" }
						tiles[tileDef.materialName] = tileDef
					} catch (err: Throwable) {
						throw TileDefLoadingException("Loading tile file $listedFile", err)
					}
				}
			}
		}
	}
}