extends Library

const ItchClient := preload("res://plugins/itch/core/itch_client.gd")
const _apps_cache_file: String = "apps.json"

var settings_manager := load("res://core/global/settings_manager.tres") as SettingsManager

@onready var itch: ItchClient = get_tree().get_first_node_in_group("itch_client")

## The item currently being installed/updated/uninstalled. OGPU's InstallManager
## only runs one install at a time, so a single slot is enough to map butlerd's
## install_progressed/app_* signals back to the LibraryLaunchItem.
var _active_item: LibraryLaunchItem


func _ready() -> void:
	super()
	library_id = "itch"
	logger_name = "itch"
	logger = Log.get_logger(logger_name, log_level)
	logger.info("itch.io library loaded")
	itch.logged_in.connect(_on_logged_in)
	itch.install_progressed.connect(_on_install_progressed)


func get_library_launch_items() -> Array[LibraryLaunchItem]:
	return await _load_library(Cache.FLAGS.LOAD | Cache.FLAGS.SAVE)


func install_to(item: LibraryLaunchItem, _location: InstallLocation = null, _options: Dictionary = {}) -> void:
	var game := (item.metadata.get("game", {}) as Dictionary)
	_active_item = item
	var success: bool = await itch.install(game)
	_active_item = null
	install_completed.emit(item, success)
	logger.info("Install of '" + item.name + "' completed with status: " + str(success))


func update(item: LibraryLaunchItem) -> void:
	var game := (item.metadata.get("game", {}) as Dictionary)
	_active_item = item
	var success: bool = await itch.install(game, item.provider_app_id)
	_active_item = null
	update_completed.emit(item, success)
	logger.info("Update of '" + item.name + "' completed with status: " + str(success))


func uninstall(item: LibraryLaunchItem) -> void:
	_active_item = item
	var success: bool = await itch.uninstall(item.provider_app_id)
	_active_item = null
	uninstall_completed.emit(item, success)
	logger.info("Uninstall of '" + item.name + "' completed with status: " + str(success))


## itch.io's CheckUpdate call is async (and rate-limited), so we don't poll it
## synchronously here. LibraryManager is expected to periodically call
## get_library_launch_items() again, which re-fetches from butlerd's cache.
func has_update(_item: LibraryLaunchItem) -> bool:
	return false


func _on_logged_in(status: ItchClient.LOGIN_STATUS, _profile: Dictionary) -> void:
	if status != ItchClient.LOGIN_STATUS.OK:
		return
	logger.info("Logged in. Refreshing itch.io library.")
	var items: Array = await _load_library(Cache.FLAGS.SAVE)
	for i in items:
		var item: LibraryLaunchItem = i
		if not library_manager.has_app(item.name):
			logger.debug("App '" + item.name + "' was not loaded. Reloading library.")
			library_manager.reload_library()
			return


## Forwards butlerd's install progress (current/total are percentage points,
## 0-100) to the base [Library] install_progressed contract (a fraction,
## 0.0-1.0) that OGPU's InstallManager and launch menu render as a progress
## bar.
func _on_install_progressed(_id: String, current: int, total: int) -> void:
	if _active_item == null:
		return
	if total <= 0:
		return
	logger.info("Install progressing: " + str(current) + "/" + str(total))
	install_progressed.emit(_active_item, float(current) / float(total))


## Returns true unless the "only show games available on this platform"
## filter is enabled and the game's platforms don't include the OS
## OpenGamepadUI is running on. Installed games always pass: they were
## installed on this machine, so they're runnable regardless of what
## platform info butlerd reported. Everything else needs an explicit
## platform match, so games with no platform info at all (e.g. HTML5) are
## hidden while the filter is on.
func _game_available_on_current_platform(game: Dictionary, installed := false) -> bool:
	if not _filter_unsupported():
		return true
	if installed:
		return true
	var platforms: Dictionary = game.get("platforms", {})
	if platforms.is_empty():
		return false
	var current := "windows"
	if OS.get_name() == "Linux":
		current = "linux"
	elif OS.get_name() == "macOS":
		current = "osx"
	return not (platforms.get(current, "") as String).is_empty()


func _filter_unsupported() -> bool:
	return settings_manager.get_value("plugin.itch", "filter_unsupported", true) as bool


## Builds a LibraryLaunchItem for a game, or null when the entry isn't an
## actual game (itch.io also hosts tools, assets, soundtracks, comics, ...)
## or is filtered out by the "available on this platform" setting.
func _make_item(game: Dictionary, caves_by_game_id: Dictionary) -> Variant:
	if game.is_empty():
		return null
	if game.get("classification", "game") != "game":
		return null
	var game_id: int = game.get("id", 0)
	var cave: Dictionary = caves_by_game_id.get(game_id, {})
	if not _game_available_on_current_platform(game, not cave.is_empty()):
		return null

	var item := LibraryLaunchItem.new()
	item.provider_app_id = cave.get("id", "")
	item.name = game.get("title", "Unknown itch.io game")
	item.tags = ["itch"]
	item.categories = ["Game"]
	item.installed = not cave.is_empty()
	item.metadata = {"game": game}

	if not cave.is_empty():
		var install_folder: String = cave.get("installInfo", {}).get("installFolder", "")
		var exe := _find_executable(install_folder)
		item.command = exe
		item.args = []
		item.cwd = install_folder
	return item


## Builds the full itch.io library: owned games merged with install state
## from Fetch.Caves. Uses the standard Cache system so we don't hammer
## butlerd (and, transitively, the itch.io API) on every library refresh.
func _load_library(caching_flags: int = Cache.FLAGS.LOAD | Cache.FLAGS.SAVE) -> Array[LibraryLaunchItem]:
	if caching_flags & Cache.FLAGS.LOAD and Cache.is_cached(_cache_dir, _apps_cache_file):
		var json_items = Cache.get_json(_cache_dir, _apps_cache_file)
		if json_items != null:
			logger.info("itch.io apps found in cache. Using cache.")
			var items := [] as Array[LibraryLaunchItem]
			for i in json_items:
				var item := LibraryLaunchItem.from_dict(i)
				var game: Dictionary = item.metadata.get("game", {})
				if not _game_available_on_current_platform(game, item.installed):
					continue
				items.append(item)
			_queue_boxart(items)
			return items

	if not itch.is_logged_in:
		logger.info("itch.io client is not logged in yet.")
		return []

	logger.info("Fetching itch.io library...")
	var owned: Array = await itch.get_owned_games()
	var caves: Array = await itch.get_caves()
	var collection_games: Array = await itch.get_collection_games()

	var caves_by_game_id := {}
	for c in caves:
		var cave: Dictionary = c
		var game_id: int = cave.get("game", {}).get("id", 0)
		caves_by_game_id[game_id] = cave

	var items := [] as Array[LibraryLaunchItem]
	var seen_game_ids := {}
	for o in owned:
		var owned_entry: Dictionary = o
		var game: Dictionary = owned_entry.get("game", {})
		var item := _make_item(game, caves_by_game_id)
		if item == null:
			continue
		seen_game_ids[game.get("id", 0)] = true
		items.append(item)

	# Collection games aren't necessarily owned (e.g. a free game the user
	# bookmarked), so merge them in too, deduped against owned games.
	for g in collection_games:
		var game: Dictionary = g
		var game_id: int = game.get("id", 0)
		if game_id in seen_game_ids:
			continue
		var item := _make_item(game, caves_by_game_id)
		if item == null:
			continue
		seen_game_ids[game_id] = true
		items.append(item)

	if caching_flags & Cache.FLAGS.SAVE:
		logger.debug("Saving itch.io apps to cache.")
		var json_items := []
		for i in items:
			var item: LibraryLaunchItem = i
			json_items.append(item.to_dict())
		if Cache.save_json(_cache_dir, _apps_cache_file, json_items) != OK:
			logger.warn("Unable to save itch.io apps cache")

	_queue_boxart(items)

	return items


## Queues background downloads of each game's cover art into OGPU's local
## boxart directory (user://boxart/local/). The built-in "local" BoxArtProvider
## picks those files up by <game name>-<layout>.png, so games show their real
## cover instead of the placeholder. Covers are only downloaded once (the task
## bails out if a layout file already exists). For games with an animated GIF
## cover, itch.io provides a stillCoverUrl (a static frame, served as PNG) which
## we prefer, since Godot has no GIF decoder.
func _queue_boxart(items: Array) -> void:
	for i in items:
		var item: LibraryLaunchItem = i
		var game: Dictionary = item.metadata.get("game", {})
		var title: String = game.get("title", "")
		var cover_url := _cover_url(game)
		if title.is_empty() or cover_url.is_empty():
			continue
		if FileAccess.file_exists("/".join([_boxart_dir(), title + "-portrait.png"])):
			continue
		itch.thread_group.scheduled_exec(_ensure_boxart.bind(game), 0)


## Downloads the given game's cover (blocking, runs on the shared thread) and
## writes it to every boxart layout. itch.zone only serves one fixed landscape
## image per game, and OGPU's boxart slots all keep-aspect (scale + crop), so a
## single image is reused for portrait, landscape, banner and logo.
func _ensure_boxart(game: Dictionary) -> void:
	var title: String = game.get("title", "")
	var cover_url := _cover_url(game)
	if title.is_empty() or cover_url.is_empty():
		return
	var dir := _boxart_dir()
	if FileAccess.file_exists("/".join([dir, title + "-portrait.png"])):
		return

	var body := _download_cover(cover_url)
	if body.is_empty():
		logger.warn("Unable to download cover art for '" + title + "'")
		return
	if not _is_raster_image(body):
		# OGPU's local provider only loads png/jpg. If itch.io didn't give us a
		# still for an animated cover, skip rather than write an unloadable file.
		logger.warn("Skipping unsupported cover format for '" + title + "'")
		return

	DirAccess.make_dir_recursive_absolute(dir)
	for layout in ["portrait", "landscape", "banner", "logo"]:
		var path := "/".join([dir, title + "-" + layout + ".png"])
		var file := FileAccess.open(path, FileAccess.WRITE)
		if file:
			file.store_buffer(body)
			file.close()
	logger.info("Downloaded boxart for '" + title + "'")


func _boxart_dir() -> String:
	return ProjectSettings.globalize_path("user://boxart/local")


## itch.io exposes stillCoverUrl for games whose cover is an animated GIF: a
## static frame that the CDN serves as PNG. Prefer it over coverUrl so those
## games still get art (Godot can't decode GIFs at runtime).
func _cover_url(game: Dictionary) -> String:
	var still: String = game.get("stillCoverUrl", "")
	if not still.is_empty():
		return still
	return game.get("coverUrl", "")


## Blocking HTTPS GET of a single cover image, for use on a background thread.
func _download_cover(url: String) -> PackedByteArray:
	var parts := url.split("/")
	var use_tls := parts[0] == "https:"
	var http := HTTPClient.new()
	var err: int = http.connect_to_host(parts[2], 443 if use_tls else 80, TLSOptions.client() if use_tls else null)
	if err != OK:
		return PackedByteArray()
	var deadline := Time.get_ticks_msec() + 15000
	while http.get_status() == HTTPClient.STATUS_CONNECTING or http.get_status() == HTTPClient.STATUS_RESOLVING:
		http.poll()
		if Time.get_ticks_msec() > deadline:
			http.close()
			return PackedByteArray()
		OS.delay_msec(50)
	if http.get_status() != HTTPClient.STATUS_CONNECTED:
		http.close()
		return PackedByteArray()

	http.request(HTTPClient.METHOD_GET, "/" + "/".join(parts.slice(3)), PackedStringArray())
	deadline = Time.get_ticks_msec() + 15000
	while http.get_status() == HTTPClient.STATUS_REQUESTING:
		http.poll()
		if Time.get_ticks_msec() > deadline:
			http.close()
			return PackedByteArray()
		OS.delay_msec(10)

	var body := PackedByteArray()
	while http.get_status() == HTTPClient.STATUS_BODY:
		http.poll()
		var chunk: PackedByteArray = http.read_response_body_chunk()
		if chunk.is_empty():
			if Time.get_ticks_msec() > deadline:
				http.close()
				return PackedByteArray()
			OS.delay_msec(10)
			continue
		body.append_array(chunk)

	var code: int = http.get_response_code()
	http.close()
	if code != 200:
		return PackedByteArray()
	return body


## Returns true if the bytes look like a PNG or JPEG (the only formats OGPU's
## local boxart provider can load).
func _is_raster_image(body: PackedByteArray) -> bool:
	if body.size() < 12:
		return false
	var png_magic := [0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]
	var is_png := true
	for i in png_magic.size():
		if body[i] != png_magic[i]:
			is_png = false
			break
	if is_png:
		return true
	return body[0] == 0xff and body[1] == 0xd8 and body[2] == 0xff


## Best-effort discovery of the game's launch executable inside its install
## folder. butlerd doesn't hand back a ready-to-exec command the way a
## "gog://" or "steam://" URI does, so we look at what's actually on disk.
## TODO: parse .itch/receipt.json.gz for the authoritative launch target
## and any declared manifest Actions instead of guessing.
func _find_executable(install_folder: String) -> String:
	if install_folder == "":
		return ""
	var out := []
	OS.execute("bash", [
		"-c",
		"find " + install_folder.c_escape() + " -maxdepth 2 -type f -executable | head -n 1"
	], out)
	if out.is_empty():
		return ""
	return (out[0] as String).strip_edges()