#pragma once

#include <algorithm>
#include <array>
#include <cstring>
#include <cstdint>
#include <exception>
#include <sstream>
#include <string>
#include <vector>

#include "GeneralUtils.h"
#include "LevelFile.h"
#include "eReplicaComponentType.h"

/**
 * What the 3D world view draws of a zone besides its terrain: every object in its scene files (.lvl), read with LevelFile
 * (dCommon) like the world server's Level, sorted into a few kinds by the components their LOT has. Pure (bytes and
 * component lists in, objects and kinds out) so it can be unit tested; the route reads the files and the CDClient.
 */
namespace WorldScene {
	struct Object {
		LWOOBJID id{};
		uint32_t lot{};
		uint32_t templateLot{}; // what a spawner (LOT 176) spawns (spawntemplate); the object's own LOT otherwise
		float x{}, y{}, z{};
		float scale{ 1.0f };
		float qx{}, qy{}, qz{}, qw{ 1.0f }; // rotation
		bool spawner{};
		// The client draws no model for it (ObjectLoader2::LoadRenderComponent): renderDisabled or CreateNULLRender is
		// set, whatever the value (trigger volumes, markers)
		bool renderDisabled{};
		// carver_only: only carves the navigation mesh; the client never loads the object at all
		// (LWOResMgr2Interface::Run, 0x010610e5 in client 1.10.64), so it's never drawn (trigger volumes like LOT 5651)
		bool carverOnly{};
		std::string nifName;    // nif_name: the model to draw instead of its render component's
		bool clientOnly{};      // loadOnClientOnly: the client draws it, the world server never loads it
		std::string name;       // spawner_name, else respawnname, else empty
	};

	constexpr uint32_t SPAWNER_LOT = 176;

	// Every object in a scene file, as far as it could be read
	inline std::vector<Object> ReadObjects(const std::string& lvl) {
		std::istringstream stream(lvl);
		LevelFile level;
		try {
			level.Read(stream);
		} catch (const std::exception&) {
			// A damaged file: keep the objects read before the damage
		}
		std::vector<Object> objects;
		objects.reserve(level.objects.size());
		for (const auto& object : level.objects) {
			const auto setting = [&object](const std::u16string& key) {
				const auto it = object.settings.find(key);
				auto value = it == object.settings.end() || !it->second ? std::string{} : it->second->GetValueAsString();
				while (!value.empty() && (value.back() == '\r' || value.back() == ' ')) value.pop_back();
				return value;
			};
			Object out{ object.id, static_cast<uint32_t>(object.lot), static_cast<uint32_t>(object.lot),
				object.position.x, object.position.y, object.position.z, object.scale,
				object.rotation.x, object.rotation.y, object.rotation.z, object.rotation.w };
			out.spawner = object.lot == SPAWNER_LOT;
			if (out.spawner) out.templateLot = GeneralUtils::TryParse<uint32_t>(setting(u"spawntemplate")).value_or(0);
			out.clientOnly = GeneralUtils::TryParse(setting(u"loadOnClientOnly"), false);
			out.renderDisabled = object.settings.find(u"renderDisabled") != object.settings.end() || object.settings.find(u"CreateNULLRender") != object.settings.end();
			out.carverOnly = GeneralUtils::TryParse(setting(u"carver_only"), false);
			out.nifName = setting(u"nif_name");
			out.name = setting(u"spawner_name");
			if (out.name.empty()) out.name = setting(u"respawnname");
			objects.push_back(std::move(out));
		}
		return objects;
	}

	enum class eClientDraw : uint8_t {
		NO_MODEL, // nothing to draw: a spawner itself, or a model built from parts at run time
		HIDDEN,   // it has a model, but the client doesn't draw it (volumes, triggers, markers)
		DRAWN
	};

	/**
	 * Whether the client draws an object's model, given its LOT's Objects.type. As the client's
	 * ObjectLoader2::LoadRenderComponent (0x01053ca5 in client 1.10.64): nothing for renderDisabled or CreateNULLRender,
	 * blocking volumes and a few LOTs it leaves out by number (6368 is the 3D ambient sound, which gets an effect
	 * instead); and objects marked carver_only are never loaded at all (see carverOnly).
	 */
	inline eClientDraw ClientDraws(const Object& object, const std::string& type) {
		static constexpr std::array<uint32_t, 7> NOT_DRAWN{ 5937, 5938, 9741, 9742, 9862, 9863, 6368 };
		const auto lot = object.spawner ? object.templateLot : object.lot;
		if (lot == SPAWNER_LOT || lot == 0 || type == "PrimitiveModels") return eClientDraw::NO_MODEL;
		if (object.carverOnly || object.renderDisabled || type == "BlockingVolume" || std::find(NOT_DRAWN.begin(), NOT_DRAWN.end(), lot) != NOT_DRAWN.end()) return eClientDraw::HIDDEN;
		return eClientDraw::DRAWN;
	}

	/**
	 * The sky of a scene file: the first file name of its environment chunk's skydome info (the model the client draws
	 * around the camera, e.g. mesh\env\env_sky_won_ag_property.nif), empty when it has none. The chunk starts with
	 * the file offsets of its lighting, skydome and editor settings; the skydome info is length-prefixed file names.
	 */
	inline std::string ReadSkydome(const std::string& lvl) {
		std::istringstream stream(lvl);
		LevelFile level;
		try {
			level.Read(stream);
		} catch (const std::exception&) {
			// The chunk headers read before any damage are enough
		}
		const auto read32 = [&lvl](size_t offset, uint32_t& value) {
			if (offset > lvl.size() || lvl.size() - offset < 4) return false;
			std::memcpy(&value, lvl.data() + offset, 4);
			return true;
		};
		for (const auto& [id, header] : level.chunkHeaders) {
			if (id != LevelFile::SceneEnviroment) continue;
			uint32_t skydome{}, length{};
			if (!read32(header.startPosition + 4, skydome) || !read32(skydome, length) || length == 0 || length > 260 || skydome + 4 + length > lvl.size()) return {};
			return lvl.substr(skydome + 4, length);
		}
		return {};
	}

	/**
	 * The kinds objects are drawn as, most telling first: an enemy that also offers missions is an enemy. Anything with
	 * none of these components is "other" (scenery, volumes, markers). Names come from the enum (GameLabels).
	 */
	constexpr std::array<eReplicaComponentType, 8> KINDS{
		eReplicaComponentType::BASE_COMBAT_AI, eReplicaComponentType::VENDOR, eReplicaComponentType::MISSION_OFFER,
		eReplicaComponentType::QUICK_BUILD, eReplicaComponentType::ROCKET_LAUNCH, eReplicaComponentType::COLLECTIBLE,
		eReplicaComponentType::SCRIPTED_ACTIVITY, eReplicaComponentType::DESTROYABLE
	};

	// Index into KINDS of an object with these ComponentsRegistry component types, or KINDS.size() for "other"
	inline size_t Classify(const std::vector<uint32_t>& registryComponents) {
		size_t best = KINDS.size();
		for (const auto component : registryComponents) {
			const auto type = static_cast<eReplicaComponentType>(component);
			for (size_t i = 0; i < best; i++) {
				if (KINDS[i] == type) { best = i; break; }
			}
		}
		return best;
	}
}