KStarbound/src/main/kotlin/ru/dbotthepony/kstarbound/defs/tile/RenderTemplate.kt

package ru.dbotthepony.kstarbound.defs.tile

import com.google.gson.GsonBuilder
import com.google.gson.JsonSyntaxException
import com.google.gson.TypeAdapter
import com.google.gson.stream.JsonReader
import com.google.gson.stream.JsonToken
import com.google.gson.stream.JsonWriter
import it.unimi.dsi.fastutil.objects.ObjectArraySet
import org.apache.logging.log4j.LogManager
import ru.dbotthepony.kstarbound.Starbound
import ru.dbotthepony.kstarbound.io.json.builder.EnumAdapter
import ru.dbotthepony.kstarbound.io.json.builder.FactoryAdapter
import ru.dbotthepony.kstarbound.registerTypeAdapter
import ru.dbotthepony.kstarbound.util.WriteOnce
import ru.dbotthepony.kstarbound.world.ITileGetter
import ru.dbotthepony.kstarbound.world.ITileState
import ru.dbotthepony.kvector.vector.nint.Vector2i
import java.util.concurrent.ConcurrentHashMap

data class RenderPiece(
	val texture: String? = null,
	val textureSize: Vector2i,
	val texturePosition: Vector2i,
	val colorStride: Vector2i? = null,
	val variantStride: Vector2i? = null,
) {
	companion object {
		val ADAPTER = FactoryAdapter.Builder(RenderPiece::class)
			.auto(
				RenderPiece::texture,
				RenderPiece::textureSize,
				RenderPiece::texturePosition,
				RenderPiece::colorStride,
				RenderPiece::variantStride,
			)
			.build()
	}
}

fun interface EqualityRuleTester {
	fun test(thisTile: ITileState, otherTile: ITileState): Boolean
}

data class RenderRuleList(
	val entries: List<Entry>,
	val join: Combination = Combination.ALL
) {
	enum class Combination {
		ALL, ANY;
	}

	data class Entry(
		val type: String,
		val matchHue: Boolean = false,
		val inverse: Boolean = false,
	) {
		private fun doTest(getter: ITileGetter, equalityTester: EqualityRuleTester, thisPos: Vector2i, offsetPos: Vector2i): Boolean {
			return when (type) {
				"EqualsSelf" -> equalityTester.test(getter[thisPos], getter[thisPos + offsetPos])
				"Connects" -> getter[thisPos + offsetPos].material != null

				else -> {
					if (LOGGED.add(type)) {
						LOGGER.error("Unknown render rule test $type!")
					}

					false
				}
			}
		}

		fun test(getter: ITileGetter, equalityTester: EqualityRuleTester, thisPos: Vector2i, offsetPos: Vector2i): Boolean {
			if (inverse) {
				return !doTest(getter, equalityTester, thisPos, offsetPos)
			}

			return doTest(getter, equalityTester, thisPos, offsetPos)
		}

		companion object {
			private val LOGGER = LogManager.getLogger()
			private val LOGGED = ObjectArraySet<String>()

			val ADAPTER = FactoryAdapter.Builder(Entry::class)
				.auto(
					Entry::type,
					Entry::matchHue,
					Entry::inverse,
				)
				.build()
		}
	}

	fun test(getter: ITileGetter, equalityTester: EqualityRuleTester, thisPos: Vector2i, offset: Vector2i): Boolean {
		when (join) {
			Combination.ALL -> {
				for (entry in entries) {
					if (!entry.test(getter, equalityTester, thisPos, offset)) {
						return false
					}
				}

				return true
			}

			Combination.ANY -> {
				for (entry in entries) {
					if (entry.test(getter, equalityTester, thisPos, offset)) {
						return true
					}
				}

				return false
			}
		}
	}

	companion object {
		val ADAPTER = FactoryAdapter.Builder(RenderRuleList::class)
			.autoList(RenderRuleList::entries)
			.auto(RenderRuleList::join)
			.build()
	}
}

data class RenderMatch(
	val pieces: List<Piece> = listOf(),
	val matchAllPoints: List<Matcher> = listOf(),
	val matchAnyPoints: List<Matcher> = listOf(),
	val subMatches: List<RenderMatch> = listOf(),
	val haltOnMatch: Boolean = false,
	val haltOnSubMatch: Boolean = false,
) {
	data class Piece(
		val name: String,
		val offset: Vector2i
	) {
		var piece by WriteOnce<RenderPiece>()

		fun resolve(template: RenderTemplate) {
			piece = template.pieces[name] ?: throw IllegalStateException("Unable to find render piece $name")
		}
	}

	data class Matcher(
		val offset: Vector2i,
		val ruleName: String
	) {
		var rule by WriteOnce<RenderRuleList>()

		fun test(getter: ITileGetter, equalityTester: EqualityRuleTester, thisPos: Vector2i): Boolean {
			return rule.test(getter, equalityTester, thisPos, offset)
		}

		fun resolve(template: RenderTemplate) {
			rule = template.rules[ruleName] ?: throw IllegalStateException("Unable to find render rule $ruleName")
		}
	}

	fun resolve(template: RenderTemplate) {
		for (value in matchAllPoints) {
			value.resolve(template)
		}

		for (value in pieces) {
			value.resolve(template)
		}

		for (value in matchAnyPoints) {
			value.resolve(template)
		}

		for (value in subMatches) {
			value.resolve(template)
		}
	}

	/**
	 * Возвращает, сработали ли ВСЕ [matchAllPoints] или ЛЮБОЙ ИЗ [matchAnyPoints]
	 *
	 * Если хотя бы один из них вернул false, весь тест возвращает false
	 *
	 * [subMatches] стоит итерировать только если это вернуло true
	 *
	 * [equalityTester] требуется для проверки раенства между "этим" тайлом и другим
	 */
	fun test(tileAccess: ITileGetter, equalityTester: EqualityRuleTester, thisPos: Vector2i): Boolean {
		for (matcher in matchAllPoints) {
			if (!matcher.test(tileAccess, equalityTester, thisPos)) {
				return false
			}
		}

		if (matchAnyPoints.isEmpty()) {
			return true
		}

		for (matcher in matchAnyPoints) {
			if (matcher.test(tileAccess, equalityTester, thisPos)) {
				return true
			}
		}

		return false
	}

	companion object {
		val ADAPTER = FactoryAdapter.Builder(RenderMatch::class)
			.autoList(RenderMatch::pieces)
			.autoList(RenderMatch::matchAllPoints)
			.autoList(RenderMatch::matchAnyPoints)
			.autoList(RenderMatch::subMatches)
			.auto(RenderMatch::haltOnMatch)
			.auto(RenderMatch::haltOnSubMatch)
			.build()

		val PIECE_ADAPTER = FactoryAdapter.Builder(Piece::class)
			.auto(Piece::name)
			.auto(Piece::offset)
			.inputAsList()
			.build()

		val MATCHER_ADAPTER = FactoryAdapter.Builder(Matcher::class)
			.auto(Matcher::offset)
			.auto(Matcher::ruleName)
			.inputAsList()
			.build()
	}
}

data class RenderMatchList(
	val name: String,
	val list: List<RenderMatch>
) {
	fun resolve(template: RenderTemplate) {
		for (value in list) {
			value.resolve(template)
		}
	}

	companion object {
		val ADAPTER = FactoryAdapter.Builder(RenderMatchList::class)
			.auto(RenderMatchList::name)
			.autoList(RenderMatchList::list)
			.inputAsList()
			.build()
	}
}

data class RenderTemplate(
	val pieces: Map<String, RenderPiece>,
	val representativePiece: String,
	val matches: List<RenderMatchList>,
	val rules: Map<String, RenderRuleList>,
) {
	init {
		for (value in matches) {
			value.resolve(this)
		}
	}

	companion object {
		val ADAPTER = FactoryAdapter.Builder(RenderTemplate::class)
			.mapAsObject(RenderTemplate::pieces, RenderPiece::class.java)
			.auto(RenderTemplate::representativePiece)
			.list(RenderTemplate::matches, RenderMatchList::class.java)
			.mapAsObject(RenderTemplate::rules, RenderRuleList::class.java)
			.build()

		fun registerGson(gsonBuilder: GsonBuilder) {
			gsonBuilder.registerTypeAdapter(RenderPiece.ADAPTER)
			gsonBuilder.registerTypeAdapter(RenderRuleList.ADAPTER)
			gsonBuilder.registerTypeAdapter(RenderMatch.ADAPTER)
			gsonBuilder.registerTypeAdapter(RenderMatch.PIECE_ADAPTER)
			gsonBuilder.registerTypeAdapter(RenderMatch.MATCHER_ADAPTER)
			gsonBuilder.registerTypeAdapter(RenderMatchList.ADAPTER)

			gsonBuilder.registerTypeAdapter(RenderRuleList.Entry.ADAPTER)

			gsonBuilder.registerTypeAdapter(ADAPTER)

			gsonBuilder.registerTypeAdapter(EnumAdapter(RenderRuleList.Combination::class.java))
		}

		private val cache = ConcurrentHashMap<String, RenderTemplate>()

		val CACHE = object : TypeAdapter<RenderTemplate>() {
			override fun write(out: JsonWriter, value: RenderTemplate) {
				ADAPTER.write(out, value)
			}

			override fun read(reader: JsonReader): RenderTemplate {
				if (reader.peek() != JsonToken.STRING) {
					throw JsonSyntaxException("Expected string as input for render template cache retriever")
				}

				var path = reader.nextString()

				if (path[0] != '/') {
					// относительный путь

					val readingFolder = Starbound.assetFolder ?: throw NullPointerException("Currently read folder is not specified")
					path = "$readingFolder/$path"
				}

				return cache.computeIfAbsent(path) {
					return@computeIfAbsent Starbound.GSON.fromJson(Starbound.locate(it).reader(), RenderTemplate::class.java)
				}
			}
		}
	}
}