# CORE FRAMEWORK SOURCE FILE
# Copyright (c) 2024 The StarOpenSource Project & Contributors
# Licensed under the GNU Affero General Public License v3
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
# 
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

## Initializes and manages the framework.
## 
## The [b]CORE Object[/b] is responsible for initializing, managing and
## serving the CORE Framework to the developer.
extends Node
class_name Core

# Constants
## The version number
const version_version: int = 1
## The version type
const version_type: CoreTypes.VersionType = CoreTypes.VersionType.BETA
## The version type number. Resets on every new version and version type.
const version_typerelease: int = 4

# Modules
const modules: Array[String] = [ "logger", "misc", "sms", "logui", "erm", "storage" ]
## Use this to access CORE's logging implementation.
var logger: CoreBaseModule
## Use this to access various useful functions.
var misc: CoreBaseModule
## Use this to access the scene management system.
var sms: CoreBaseModule
## Use this to access the graphical log. Serves no importance to you (probably).
var logui: CoreBaseModule
## Use this to access CORE's builtin HTTP request maker.
var erm: CoreBaseModule
## Use this to access configuration and settings files easily.
var storage: CoreBaseModule

# Variables
## Contains CORE's load path
var basepath: String
## Holds the configuration[br]
## [br]
## [b]NEVER access this yourself. To change the configuration file, use [method Core.reload_configuration] instead.[/b]
var config: CoreConfiguration
## Contains all loaded custom modules.
var custom_modules: Dictionary = {}
## Contains the custom modules node.
var custom_modules_node: Node

# Preinitialization
func _init(new_config: CoreConfiguration = CoreConfiguration.new()) -> void:
	name = "CORE"
	if !check_godot_version(): return
	if !determine_basepath(): queue_free()
	custom_modules_node = Node.new()
	reload_configuration(new_config)
	initialize_modules()
	apply_configuration()

# Initialization
func _ready() -> void:
	inject_modules()
	custom_modules_node.name = "Custom Modules"
	add_child(custom_modules_node)

# Cleanup
# Particularily useful during testing to cleanup stuff, or if you want to do some stupid stuff with CORE during runtime
func cleanup() -> void:
	logger.infof("Core", "Cleaning up")
	config.queue_free()
	var modules_reverse: Array[String] = modules.duplicate()
	modules_reverse.reverse()
	for module in modules_reverse:
		await get(module)._cleanup()
		get(module).loggeri.queue_free()
		get(module).queue_free()
	for module in custom_modules_node.get_children(): unregister_custom_module(module.name)
	remove_child(custom_modules_node)
	custom_modules_node.queue_free()
	queue_free()

# Initialize modules
## Initializes all modules during the first initialization phase.[br]
## [br]
## [b]NEVER call this yourself! You will break everything and risk a crash![/b]
func initialize_modules() -> void:
	for module in modules:
		set(module, CoreBaseModule.new())
		get(module).name = module
		get(module).set_script(load(basepath + "src/" + module + ".gd"))
		get(module).core = self
		get(module).loggeri = logger.get_instance(basepath.replace("res://", "") + "src/" + module + ".gd")
		get(module)._initialize()

# Inject modules into the SceneTree
## Injects CORE's builtin modules into the SceneTree.[br]
## [br]
## [b]NEVER call this yourself! You will break everything and risk a crash![/b]
func inject_modules() -> void: for module in modules: add_child(get(module))

# Wait for all modules to be fully initialized
## Wait for all builtin modules to be fully initialized.[br]
## [br]
## This ensures that all of CORE's builtin modules are fully initialized and ready.
## [b]Not calling this function during startup may lead to runtime issues.[/b]
func complete_init(no_success: bool = false) -> void:
	var modsinit_builtin: Array[String] = ["workaround"]
	var modsinit_custom: Array[String] = ["workaround"]
	
	while modsinit_builtin.size() != 0 and modsinit_custom.size() != 0:
		# Clear arrays
		modsinit_builtin = []
		modsinit_custom = []
		
		# Check builtin modules
		for module in modules: if !get(module).initialized: modsinit_builtin.append(module)
		
		# Check custom modules
		for module_name in custom_modules:
			if !custom_modules[module_name].initialized: modsinit_custom.append(module_name)
		
		# Print and sleep
		if modsinit_builtin.size() != 0 or modsinit_custom.size() != 0:
			print("Waiting for modules to finish initialization:")
			if modsinit_builtin.size() != 0: print("  Builtin: " + str(modsinit_builtin))
			if modsinit_custom.size() != 0: print("  Custom: " + str(modsinit_custom))
			await get_tree().create_timer(1).timeout
	
	# Initialization complete
	await get_tree().process_frame
	if !no_success: logger.infof("Core", "Initialized CORE successfully")

# Registers a custom module
## Registers a new custom module.
func register_custom_module(module_name: String, module_origin: String, module_class: CoreBaseModule) -> bool:
	logger.verbf("Core", "Registering new custom module \"" + module_name + "\"")
	if !config.custom_modules:
		logger.errorf("Core", "Registering module failed: Custom module support is disabled.")
		return false
	if custom_modules.has(module_name):
		logger.errorf("Core", "Registering module failed: A custom module with the name \"" + module_name + "\" already exists.")
		return false
	logger.diagf("Core", "Updating variables")
	module_class.name = module_name
	module_class.core = self
	module_class.loggeri = logger.get_instance(module_origin)
	logger.diagf("Core", "Adding module to SceneTree")
	custom_modules_node.add_child(module_class)
	logger.diagf("Core", "Merging module with custom_modules")
	custom_modules.merge({ module_name: module_class })
	logger.diagf("Core", "Initializing custom module")
	module_class._initialize()
	logger.diagf("Core", "Updating custom module configuration")
	module_class._pull_config()
	return true

# Unregisters a custom module
## Unregisters a custom module, making it no longer function.
func unregister_custom_module(module_name: String) -> void:
	logger.verbf("Core", "Unregistering custom module \"" + module_name + "\"")
	if !custom_modules.has(module_name):
		logger.errorf("Core", "Unregistering module failed: A custom module with the name \"" + module_name + "\" does not exist.")
		return
	var module: Node = get_custom_module(module_name)
	await module._cleanup()
	module.loggeri.queue_free()
	custom_modules_node.remove_child(module)
	custom_modules.erase(module_name)
	module.queue_free()

# Returns a custom module
## Returns a loaded custom module for access.
func get_custom_module(module_name: String) -> CoreBaseModule:
	logger.diagf("Core", "Getting custom module \"" + module_name + "\"")
	if !custom_modules.has(module_name):
		logger.errorf("Core", "Getting module failed: A custom module with the name \"" + module_name + "\" does not exist.")
		return null
	return custom_modules[module_name]

# (Re-)Load configuration
## Loads a (new) configuration file and applies it to all modules.
func reload_configuration(new_config: CoreConfiguration = CoreConfiguration.new()) -> void:
	var initialized = config != null
	if initialized: logger.verbf("Core", "Reloading CORE's configuration")
	if config != null: config.queue_free()
	config = new_config
	if is_devmode(): # Override configuration in development mode
		config.logger_level = CoreTypes.LoggerLevel.VERB
		if initialized: logger.verbf("Core", "Overrode configuration (development mode)")
	if initialized: apply_configuration()

# Call _pull_config() functions
## Applies the newly applied configuration.[br]
## [br]
## [b]NEVER call this yourself unless you know what you are doing![/b]
func apply_configuration() -> void:
	logger.verbf("Core", "Applying configuration")
	if is_devmode(): logger.warnf("Core", "The CORE Framework is in development mode. Here be dragons!")
	if config.headless: logger.warnf("Core", "CORE is in headless mode. Certain modules will not work as expected.")
	if !config.custom_modules:
		logger.verbf("Core", "Removing all custom modules (custom modules support is disabled)")
		for module in custom_modules: unregister_custom_module(module)
	for module in modules: get(module)._pull_config()
	if config.custom_modules:
		for module in custom_modules:
			logger.diagf("Core", "Updating configuration for custom module \"" + module.name + "\"")
			module._pull_config()

# Return development mode status
## Returns if the CORE Framework is in development mode.
func is_devmode() -> bool:
	return config.debugging and basepath == "res://" and OS.is_debug_build()

# Replaces variables with human-friendly strings
## Replaces placeholders with human-friendly strings You can use the following placeholders:[br]
## - [code]%release%[/code]: Returns the release number.[br]
## - [code]%release_type%[/code]: Returns the typerelease number[br]
## - [code]%release_semantic%[/code]: Returns the result of [method Core.get_version_semantic], example [i]5.2.3[/i][br]
## - [code]%type%[/code]: Returns the release type as a word, for example [i]Release Candidate[/i][br]
## - [code]%type_technical%[/code]: Returns the release type as one or two lowercase letters, for example [i]rc[/i][br]
## - [code]%devmode%[/code]: Returns the development mode status[br]
## - [code]%headless%[/code]: Returns the headless mode status
func get_formatted_string(string: String) -> String:
	# Version strings
	string = string.replace("%version%", str(version_version))
	string = string.replace("%version_type%", str(version_typerelease))
	var semantic_version: Array[int] = get_version_semantic()
	string = string.replace("%version_semantic%", str(semantic_version[0]) + "." + str(semantic_version[1]) + "." + str(semantic_version[2]))
	match(version_type):
		CoreTypes.VersionType.RELEASE:
			string = string.replace("%type%", "Release")
			string = string.replace("%type_technical%", "r")
		CoreTypes.VersionType.RELEASECANDIDATE:
			string = string.replace("%type%", "Release Candidate")
			string = string.replace("%type_technical%", "rc")
		CoreTypes.VersionType.BETA:
			string = string.replace("%type%", "Beta")
			string = string.replace("%type_technical%", "b")
		CoreTypes.VersionType.ALPHA:
			string = string.replace("%type%", "Alpha")
			string = string.replace("%type_technical%", "a")
		_: await logger.crashf("Core", "Invalid version type " + str(version_type), true)
	# Development mode
	if is_devmode(): string = string.replace("%devmode%", "Enabled")
	else: string = string.replace("%devmode%", "Disabled")
	# Headless mode
	if config.headless: string = string.replace("%headless%", "Enabled")
	else: string = string.replace("%headless%", "Disabled")
	# Custom module support
	if config.custom_modules: string = string.replace("%custommodules%", "Enabled")
	else: string = string.replace("%custommodules%", "Disabled")
	return string

# Return CORE's version in the semantic versioning scheme
## Returns CORE's versioning scheme into the semantic versioning scheme.[br]
## The first integer contains the release number, the second integer contains the release type ([code]0[/code] for alpha, [code]1[/code] for beta, [code]2[/code] for rc and [code]3[/code] for release and the last integer contains the typerelease number.
func get_version_semantic() -> Array[int]:
	var version_type_int: int
	match(version_type):
		CoreTypes.VersionType.RELEASE: version_type_int = 3
		CoreTypes.VersionType.RELEASECANDIDATE: version_type_int = 2
		CoreTypes.VersionType.BETA: version_type_int = 1
		CoreTypes.VersionType.ALPHA: version_type_int = 0
	return [version_version, version_type_int, version_typerelease]

# Determines CORE's installation/base path
## Determines CORE's installation/base path[br]
## [br]
## [b]Calling this function is likely to be safe, but shouldn't be done nonetheless![/b]
func determine_basepath() -> bool:
	if FileAccess.file_exists("res://.corebasepath"):
		basepath = "res://"
	elif FileAccess.file_exists("res://CORE/.corebasepath"):
		basepath = "res://CORE/"
	elif FileAccess.file_exists("res://addons/CORE/.corebasepath"):
		basepath = "res://addons/CORE/"
	else:
		assert(false, "CORE is not located at 'res://CORE/', aborting initialization")
		return false
	return true

# Checks Godot's version
## Checks compatibility with the running version.
func check_godot_version() -> bool:
	var version: Dictionary = Engine.get_version_info()
	match(version["major"]):
		4: pass
		_:
			printerr("The CORE Framework does not support Godot versions older or newer than 4.x.x")
			return false
	match(version["minor"]):
		0: printerr("The CORE Framework does not support Godot versions older than 4.2.x. Please update to Godot 4.2.x to ensure full compatibility.")
		1: printerr("The CORE Framework does not support Godot versions older than 4.2.x. Please update to Godot 4.2.x to ensure full compatibility.")
		2: pass
		_:
			printerr("The CORE Framework does not support Godot versions newer than 4.2.x. Please downgrade to Godot 4.2.x.")
			return false
	if version["status"] != "stable":
		printerr("The CORE Framework does not support unstable Godot versions. Please switch to Godot stable 4.2.x.")
		return false
	return true