#include "game_root.hpp"
#include <cstdint>
#include <godot_cpp/classes/global_constants.hpp>
#include <godot_cpp/classes/packed_scene.hpp>
#include <godot_cpp/classes/scene_state.hpp>
#include <godot_cpp/variant/string_name.hpp>
#include <godot_cpp/variant/utility_functions.hpp>
#include <godot_cpp/classes/input.hpp>
#include <godot_cpp/core/class_db.hpp>
#include "godot_cpp/templates/pair.hpp"
#include "utils/godot_macros.h"
#include "utils/player_input.hpp"
#include "utils/spawn_point.hpp"
#include "utils/player.hpp"
#include "game_mode.hpp"
#include "level.hpp"

namespace godot {
void GameRoot::_bind_methods() {
#define CLASSNAME GameRoot
    GDFUNCTION(reset_game_mode);
    ClassDB::add_signal("GameRoot", MethodInfo("player_connected", PropertyInfo(Variant::OBJECT, "player_input", PROPERTY_HINT_NODE_TYPE, "PlayerInput")));
    ClassDB::add_signal("GameRoot", MethodInfo("player_disconnected", PropertyInfo(Variant::OBJECT, "player_input", PROPERTY_HINT_NODE_TYPE, "PlayerInput")));
}

GameRoot *GameRoot::get_singleton() {
    return GameRoot::singleton_instance;
}

bool GameRoot::has_singleton() {
    return GameRoot::singleton_instance != nullptr;
}

void GameRoot::_enter_tree() { GDGAMEONLY();
    // TODO: Replace this with detecting input devices
    if(this->players.is_empty())
        this->player_connected();
    this->grab_singleton();
}

void GameRoot::_exit_tree() { GDGAMEONLY();
    this->release_singleton();
}

void GameRoot::set_game_mode(Ref<GameMode> mode) {
    if(mode.is_null() || !mode.is_valid()) {
        this->game_mode = Ref<GameMode>();
        return;
    }
    this->game_mode = mode;
}

Ref<GameMode> GameRoot::get_game_mode() const {
    return this->game_mode;
}

void GameRoot::player_connected() {
    PlayerInput *input = memnew(PlayerInput);
    this->add_child(input);
    this->players.insert(this->next_player_id++, {input, nullptr});
    this->emit_signal(StringName("player_connected"), input);
}

bool GameRoot::initialize_player(IPlayer *player) {
    KeyValue<uint32_t, Pair<PlayerInput*, IPlayer*>> *found{nullptr};
    // find an unassigned player input instance
    for(KeyValue<uint32_t, Pair<PlayerInput*, IPlayer*>> &pair : this->players) {
        if(pair.value.second == nullptr) {
            found = &pair;
            break;
        }
    }
    // no player slots available, notify caller
    if(!found)
        return false;
    player->player_id = found->key;
    found->value.second = player;
    player->setup_player_input(found->value.first);
    return true;
}

void GameRoot::reset_game_mode() {
    this->game_mode.unref();
}

void GameRoot::grab_singleton() {
    if(GameRoot::has_singleton()) {
        this->set_process_mode(PROCESS_MODE_DISABLED);
        UtilityFunctions::push_error("More than one GameRoot instance active");
    } else {
        GameRoot::singleton_instance = this;
    }
}

void GameRoot::release_singleton() {
    if(GameRoot::singleton_instance == this) {
        GameRoot::singleton_instance = nullptr;
    } else {
        UtilityFunctions::push_error("GameRoot instance attempted to release singleton while it is not the singleton instance");
    }
}

GameRoot *GameRoot::singleton_instance{nullptr};

#undef CLASSNAME

void GameRoot3D::_bind_methods() {
#define CLASSNAME GameRoot3D
    GDPROPERTY_HINTED(first_boot_level, Variant::OBJECT, PROPERTY_HINT_RESOURCE_TYPE, "PackedScene");
}

void GameRoot3D::_ready() { GDGAMEONLY();
    this->load_level(this->first_boot_level);
}

Level3D *GameRoot3D::load_level(Ref<PackedScene> level) {
    return this->load_level_at(level, Transform3D());
}

Level3D *GameRoot3D::load_level_at(Ref<PackedScene> level, Transform3D at) {
    if(!GameRoot3D::is_valid_level(level)) {
        return nullptr;
    }
    Level3D *instance = Object::cast_to<Level3D>(level->instantiate());
    if(instance == nullptr) {
        UtilityFunctions::push_error("Unexpected failure to instantiate level scene '", level->get_path(), "'.");
        return nullptr;
    }
    // store and add to tree at desired transform
    this->add_child(instance);
    instance->set_global_transform(at);
    this->levels.insert(level->get_path(), instance);
    // if this is the first level containing a game mode currently active use it's gamemode as a prototype
    if(this->game_mode.is_null()) {
        this->change_game_mode(instance->get_game_mode_prototype());
        instance->connect("tree_exited", Callable(this, "reset_game_mode"));
    }
    return instance;
}

void GameRoot3D::register_spawn_point(SpawnPoint3D *spawn_point) {
    if(this->spawn_points.has(spawn_point)) {
        UtilityFunctions::push_error("Duplicate attempt to register spawnpoint '", spawn_point->get_path(), "'");
        return;
    }
    this->spawn_points.insert(spawn_point);
}

void GameRoot3D::unregister_spawn_point(SpawnPoint3D *spawn_point) {
    if(!this->spawn_points.has(spawn_point)) {
        UtilityFunctions::push_error("Attempt to unregister spawnpoint '", spawn_point->get_path(), "', which is not registered.");
        return;
    }
    this->spawn_points.erase(spawn_point);
}

void GameRoot3D::set_first_boot_level(Ref<PackedScene> level) {
    if(level.is_null() || !level.is_valid()) {
        this->first_boot_level.unref();
        return;
    }
    StringName const root_type = level->get_state()->get_node_type(0);
    if(!ClassDB::is_parent_class("Level3D", root_type)) {
        UtilityFunctions::push_error("First boot level cannot be of type '", root_type, "'. First boot level has to inherit from Level3D");
        this->first_boot_level.unref();
        return;
    }
    this->first_boot_level = level;
}

Ref<PackedScene> GameRoot3D::get_first_boot_level() const {
    return this->first_boot_level;
}

bool GameRoot3D::is_valid_level(Ref<PackedScene> &level) {
    if(level.is_null() || !level.is_valid() || !level->can_instantiate()) {
        UtilityFunctions::push_error("Can't load level from invalid packed scene");
        return false;
    }
    StringName const root_type = level->get_state()->get_node_type(0);
    if(!ClassDB::is_parent_class("Level3D", root_type)) {
        UtilityFunctions::push_error("Can't load level with root type '", root_type, "'. Root node has to be of type Level3D");
        return false;
    }
    return true;
}

void GameRoot3D::change_game_mode(Ref<GameMode> prototype) {
    // free all player instances in use
    for(KeyValue<uint32_t, Pair<PlayerInput*, IPlayer*>> &pair : this->players) {
        if(pair.value.second == nullptr) continue;
        Node *node = dynamic_cast<Node*>(pair.value.second);
        if(node == nullptr) {
            UtilityFunctions::push_error("Attempt to cast player '", pair.key, "' to node failed");
        } else {
            node->queue_free();
        }
    }
    // create new gamemode instance
    this->game_mode = prototype->duplicate(true);
    Node *player_node = this->game_mode->get_player_scene()->instantiate();
    IPlayer *player = dynamic_cast<IPlayer*>(player_node);
    if(player != nullptr) {
        this->initialize_player(player);
    } else {
    }
}
}