/*!Language holders will either exist in an atom/movable or a mind. Creation of language holders happens
automatically when they are needed, for example when something tries to speak.
Where a mind is available, the mind language holder will be the one "in charge". The mind holder
will update its languages based on the atom holder, and will get updated as part of
transformations and other events that cause new languages to become available.

Every language holder has three lists of languages (and sources for each of them):
- understood_languages
- spoken_languages
- blocked_languages

Understood languages let you understand them, spoken languages lets you speak them
(if your tongue is compatible), and blocked languages will let you do neither no matter
what the source of the language is.

Language holders are designed to mostly only ever require the use the helpers in atom/movable
to achieve your goals, but it is also possible to work on them directly if needed. Any adding
and removing of languages and sources should only happen through the procs, as directly changing
these will mess something up somewhere down the line.

All atom movables have the initial_language_holder var which allows you to set the default language
holder to create. For example, /datum/language_holder/alien will give you xenocommon and a block for
galactic common. Human species also have a default language holder var that will be updated on
species change, initial_species_holder.

Key procs
* [grant_language](atom/movable.html#proc/grant_language)
* [remove_language](atom/movable.html#proc/remove_language)
* [add_blocked_language](atom/movable.html#proc/add_blocked_language)
* [remove_blocked_language](atom/movable.html#proc/remove_blocked_language)
* [grant_all_languages](atom/movable.html#proc/grant_all_languages)
* [remove_all_languages](atom/movable.html#proc/remove_all_languages)
* [has_language](atom/movable.html#proc/has_language)
* [can_speak_language](atom/movable.html#proc/can_speak_language)
* [get_selected_language](atom/movable.html#proc/get_selected_language)
* [update_atom_languages](atom/movable.html#proc/update_atom_languages)
*/

/datum/language_holder
	/// Understood languages.
	var/list/understood_languages = list(/datum/language/common = list(LANGUAGE_MIND))
	/// A list of languages that can be spoken. Tongue organ may also set limits beyond this list.
	var/list/spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM))
	/// A list of blocked languages. Used to prevent understanding and speaking certain languages, ie for certain mobs, mutations etc.
	var/list/blocked_languages = list()
	/// If true, overrides tongue limitations.
	var/omnitongue = FALSE
	/// Handles displaying the language menu UI.
	var/datum/language_menu/language_menu
	/// Currently spoken language
	var/selected_language
	/// Tracks the entity that owns the holder.
	var/owner

/// Initializes, and copies in the languages from the current atom if available.
/datum/language_holder/New(_owner)
	owner = _owner
	if(istype(owner, /datum/mind))
		var/datum/mind/M = owner
		if(M.current)
			update_atom_languages(M.current)
	get_selected_language()

/datum/language_holder/Destroy()
	QDEL_NULL(language_menu)
	return ..()

/// Grants the supplied language.
/datum/language_holder/proc/grant_language(language, understood = TRUE, spoken = TRUE, source = LANGUAGE_MIND)
	if(understood)
		if(!understood_languages[language])
			understood_languages[language] = list()
		understood_languages[language] |= source
		. = TRUE
	if(spoken)
		if(!spoken_languages[language])
			spoken_languages[language] = list()
		spoken_languages[language] |= source
		. = TRUE

/// Grants every language to understood and spoken, and gives omnitongue.
/datum/language_holder/proc/grant_all_languages(understood = TRUE, spoken = TRUE, grant_omnitongue = TRUE, source = LANGUAGE_MIND)
	for(var/language in GLOB.all_languages)
		grant_language(language, understood, spoken, source)
	if(grant_omnitongue)	// Overrides tongue limitations.
		omnitongue = TRUE
	return TRUE

/// Removes a single language or source, removing all sources returns the pre-removal state of the language.
/datum/language_holder/proc/remove_language(language, understood = TRUE, spoken = TRUE, source = LANGUAGE_ALL)
	if(understood && understood_languages[language])
		if(source == LANGUAGE_ALL)
			understood_languages -= language
		else
			understood_languages[language] -= source
			if(!length(understood_languages[language]))
				understood_languages -= language
		. = TRUE

	if(spoken && spoken_languages[language])
		if(source == LANGUAGE_ALL)
			spoken_languages -= language
		else
			spoken_languages[language] -= source
			if(!length(spoken_languages[language]))
				spoken_languages -= language
		. = TRUE

/// Removes every language and optionally sets omnitongue false. If a non default source is supplied, only removes that source.
/datum/language_holder/proc/remove_all_languages(source = LANGUAGE_ALL, remove_omnitongue = FALSE)
	for(var/language in GLOB.all_languages)
		remove_language(language, TRUE, TRUE, source)
	if(remove_omnitongue)
		omnitongue = FALSE
	return TRUE

/// Adds a single language or list of languages to the blocked language list.
/datum/language_holder/proc/add_blocked_language(languages, source = LANGUAGE_MIND)
	if(!islist(languages))
		languages = list(languages)
	for(var/language in languages)
		if(!blocked_languages[language])
			blocked_languages[language] = list()
		blocked_languages[language] |= source
	return TRUE

/// Removes a single language or list of languages from the blocked language list.
/datum/language_holder/proc/remove_blocked_language(languages, source = LANGUAGE_MIND)
	if(!islist(languages))
		languages = list(languages)
	for(var/language in languages)
		if(blocked_languages[language])
			if(source == LANGUAGE_ALL)
				blocked_languages -= language
			else
				blocked_languages[language] -= source
				if(!length(blocked_languages[language]))
					blocked_languages -= language
	return TRUE

/// Checks if you have the language. If spoken is true, only checks if you can speak the language.
/datum/language_holder/proc/has_language(language, spoken = FALSE)
	if(language in blocked_languages)
		return FALSE
	if(spoken)
		return language in spoken_languages
	return language in understood_languages

/// Checks if you can speak the language. Tongue limitations should be supplied as an argument.
/datum/language_holder/proc/can_speak_language(language)
	var/atom/movable/ouratom = get_atom()
	var/tongue = ouratom.could_speak_language(language)
	if((omnitongue || tongue) && has_language(language, TRUE))
		return TRUE
	return FALSE

/// Returns selected language if it can be spoken, or decides, sets and returns a new selected language if possible.
/datum/language_holder/proc/get_selected_language()
	if(selected_language && can_speak_language(selected_language))
		return selected_language
	selected_language = null
	var/highest_priority
	for(var/lang in spoken_languages)
		var/datum/language/language = lang
		var/priority = initial(language.default_priority)
		if((!highest_priority || (priority > highest_priority)) && !(language in blocked_languages))
			if(can_speak_language(language))
				selected_language = language
				highest_priority = priority
	return selected_language

/// Gets a random understood language, useful for hallucinations and such.
/datum/language_holder/proc/get_random_understood_language()
	return pick(understood_languages)

/// Gets a random spoken language, useful for forced speech and such.
/datum/language_holder/proc/get_random_spoken_language()
	return pick(spoken_languages)

/// Opens a language menu reading from the language holder.
/datum/language_holder/proc/open_language_menu(mob/user)
	if(!language_menu)
		language_menu = new (src)
	language_menu.ui_interact(user)

/// Gets the atom, since we some times need to check if the tongue has limitations.
/datum/language_holder/proc/get_atom()
	if(owner)
		if(istype(owner, /datum/mind))
			var/datum/mind/M = owner
			return M.current
		return owner
	return FALSE

/// Empties out the atom specific languages and updates them according to the supplied atoms language holder.
/datum/language_holder/proc/update_atom_languages(atom/movable/thing)
	var/datum/language_holder/from_atom = thing.get_language_holder(FALSE)	//Gets the atoms language holder
	if(from_atom == src)	//This could happen if called on an atom without a mind.
		return FALSE
	for(var/language in understood_languages)
		remove_language(language, TRUE, FALSE, LANGUAGE_ATOM)
	for(var/language in spoken_languages)
		remove_language(language, FALSE, TRUE, LANGUAGE_ATOM)
	for(var/language in blocked_languages)
		remove_blocked_language(language, LANGUAGE_ATOM)

	copy_languages(from_atom)
	get_selected_language()
	return TRUE

/// Copies all languages from the supplied atom/language holder. Source should be overridden when you
/// do not want the language overwritten by later atom updates or want to avoid blocked languages.
/datum/language_holder/proc/copy_languages(var/datum/language_holder/from_holder, source_override)
	if(source_override)	//No blocked languages here, for now only used by ling absorb.
		for(var/language in from_holder.understood_languages)
			grant_language(language, TRUE, FALSE, source_override)
		for(var/language in from_holder.spoken_languages)
			grant_language(language, FALSE, TRUE, source_override)
	else
		for(var/language in from_holder.understood_languages)
			grant_language(language, TRUE, FALSE, from_holder.understood_languages[language])
		for(var/language in from_holder.spoken_languages)
			grant_language(language, FALSE, TRUE, from_holder.spoken_languages[language])
		for(var/language in from_holder.blocked_languages)
			add_blocked_language(language, from_holder.blocked_languages[language])
	return TRUE


//************************************************
//*        Specific language holders              *
//*      Use atom language sources only.           *
//************************************************/


/datum/language_holder/alien
	understood_languages = list(/datum/language/xenocommon = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/xenocommon = list(LANGUAGE_ATOM))
	blocked_languages = list(/datum/language/common = list(LANGUAGE_ATOM))

/datum/language_holder/clockmob
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/ratvar = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/ratvar = list(LANGUAGE_ATOM))

/datum/language_holder/construct
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/narsie = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/narsie = list(LANGUAGE_ATOM))

/datum/language_holder/drone
	understood_languages = list(/datum/language/drone = list(LANGUAGE_ATOM),
								/datum/language/machine = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/drone = list(LANGUAGE_ATOM))
	blocked_languages = list(/datum/language/common = list(LANGUAGE_ATOM))

/datum/language_holder/drone/syndicate
	blocked_languages = list()

/datum/language_holder/jelly
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/slime = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/slime = list(LANGUAGE_ATOM))

/datum/language_holder/lightbringer
	understood_languages = list(/datum/language/slime = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/slime = list(LANGUAGE_ATOM))
	blocked_languages = list(/datum/language/common = list(LANGUAGE_ATOM))

/datum/language_holder/lizard
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/draconic = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/draconic = list(LANGUAGE_ATOM))

/datum/language_holder/lizard/ash
	selected_language = /datum/language/draconic

/datum/language_holder/monkey
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/monkey = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/monkey = list(LANGUAGE_ATOM))

/datum/language_holder/mushroom
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/mushroom = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/mushroom = list(LANGUAGE_ATOM))

/datum/language_holder/slime
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/slime = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/slime = list(LANGUAGE_ATOM))

/datum/language_holder/venus
	understood_languages = list(/datum/language/sylvan = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/sylvan = list(LANGUAGE_ATOM))
	blocked_languages = list(/datum/language/common = list(LANGUAGE_ATOM))

/datum/language_holder/swarmer
	understood_languages = list(/datum/language/swarmer = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/swarmer = list(LANGUAGE_ATOM))
	blocked_languages = list(/datum/language/common = list(LANGUAGE_ATOM))

/datum/language_holder/synthetic
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/machine = list(LANGUAGE_ATOM),
								/datum/language/draconic = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/machine = list(LANGUAGE_ATOM),
							/datum/language/draconic = list(LANGUAGE_ATOM))

/datum/language_holder/plant
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/sylvan = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/sylvan = list(LANGUAGE_ATOM))

/datum/language_holder/plasmaman
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/bonespeak = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/bonespeak = list(LANGUAGE_ATOM))

/datum/language_holder/pod
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/sylvan = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/sylvan = list(LANGUAGE_ATOM))

/datum/language_holder/preternis
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/machine = list(LANGUAGE_ATOM),)
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/machine = list(LANGUAGE_ATOM),)

/datum/language_holder/polysmorph
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/polysmorph = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/polysmorph = list(LANGUAGE_ATOM))

/datum/language_holder/mothmen
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/mothian = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/mothian = list(LANGUAGE_ATOM))

/datum/language_holder/ethereal
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/etherean = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/etherean = list(LANGUAGE_ATOM))

/datum/language_holder/clockwork
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/ratvar = list(LANGUAGE_ATOM),)
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/ratvar = list(LANGUAGE_ATOM),)

/datum/language_holder/empty
	understood_languages = list()
	spoken_languages = list()

/datum/language_holder/universal/New()
	..()
	grant_all_languages()

/datum/language_holder/mouse
	understood_languages = list(/datum/language/mouse = list(LANGUAGE_ATOM))
	spoken_languages = list(/datum/language/mouse = list(LANGUAGE_ATOM))

/datum/language_holder/egg
	understood_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
								/datum/language/egg = list(LANGUAGE_ATOM),)
	spoken_languages = list(/datum/language/common = list(LANGUAGE_ATOM),
							/datum/language/egg = list(LANGUAGE_ATOM),)