# Displays a Lesson ressource and a list a button to start each practice in a

# lesson.

#

# When pressing a practice button, emits an event so the navigation can

# transition to the practice screen.

class_name UILesson

extends UINavigatablePage

const ContentBlockScene := preload("screens/lesson/UIContentBlock.tscn")

const QuizInputFieldScene := preload("screens/lesson/quizzes/UIQuizInputField.tscn")

const QuizChoiceScene := preload("screens/lesson/quizzes/UIQuizChoice.tscn")

const PracticeButtonScene := preload("screens/lesson/UIPracticeButton.tscn")

const AUTOSCROLL_PADDING := 20

const AUTOSCROLL_DURATION := 0.24

export var test_lesson: Resource

var _lesson: Lesson

# Resource used to highlight glossary entries in the lesson text.

var _glossary: Glossary

var _visible_index := -1

var _quizzes_done := -1 # Start with -1 because we will always autoincrement at least once.

var _quizz_count := 0

var _base_text_font_size := preload("res://ui/theme/fonts/font_text.tres").size

onready var _scroll_container := $OuterMargin/ScrollContainer as ScrollContainer

onready var _scroll_content := $OuterMargin/ScrollContainer/InnerMargin as Control

onready var _title := $OuterMargin/ScrollContainer/InnerMargin/Content/Title as Label

onready var _content_blocks := $OuterMargin/ScrollContainer/InnerMargin/Content/ContentBlocks as VBoxContainer

onready var _content_container := $OuterMargin/ScrollContainer/InnerMargin/Content as VBoxContainer

onready var _practices_visibility_container := $OuterMargin/ScrollContainer/InnerMargin/Content/PracticesContainer as VBoxContainer

onready var _practices_container := $OuterMargin/ScrollContainer/InnerMargin/Content/PracticesContainer/Practices as VBoxContainer

onready var _debounce_timer := $DebounceTimer as Timer

onready var _tweener := $Tween as Tween

onready var _glossary_popup := $GlossaryPopup

onready var _start_content_width := _content_container.rect_size.x

func _ready() -> void:

Events.connect("font_size_scale_changed", self, "_update_content_container_width")

_update_content_container_width(UserProfiles.get_profile().font_size_scale)

_scroll_container.get_v_scrollbar().connect("value_changed", self, "_on_content_scrolled")

_debounce_timer.connect("timeout", self, "_emit_read_content")

TranslationManager.connect("translation_changed", self, "_on_translation_changed")

_glossary = load("res://course/glossary.tres")

if test_lesson and get_parent() == get_tree().root:

setup(test_lesson, null)

for child in _content_blocks.get_children():

child.show()

_practices_container.show()

_scroll_container.grab_focus()

func _notification(what: int) -> void:

if what == NOTIFICATION_TRANSLATION_CHANGED:

_update_labels()

func setup(lesson: Lesson, course: Course) -> void:

if not is_inside_tree():

yield(self, "ready")

_lesson = lesson

_title.text = tr(_lesson.title)

var user_profile := UserProfiles.get_profile()

# If this was the last lesson the student interacted with before, we will try to restore

# their reading position.

var is_returning := false

if course:

var last_lesson := user_profile.get_last_started_lesson(course.resource_path)

is_returning = _lesson.resource_path == last_lesson

var restore_node: Control

var restore_id := ""

if course:

# We have 4 possible situations:

# - We are returning to the last visited lesson and must set the position to the last content

# block the user has seen.

# - We are opening a lesson for the first time and must remain at the top.

# - We are opening a lesson that is completed, at least the reading part, and must remain at

# the top.

# - We are opening a lesson that we were in the middle of, but not the last one; we must set

# the position to the first unread block.

if is_returning:

restore_id = user_profile.get_last_visited_lesson_block(

course.resource_path, lesson.resource_path

)

var reading_done := user_profile.is_lesson_reading_completed(

course.resource_path, lesson.resource_path

)

var reading_started := user_profile.has_lesson_blocks_read(

course.resource_path, lesson.resource_path

)

if restore_id.empty() and not reading_done and reading_started:

for block in lesson.content_blocks:

var block_id := ""

if block is Quiz:

block_id = block.quiz_id

else:

block_id = block.content_id

if user_profile.is_lesson_block_read(

course.resource_path, lesson.resource_path, block_id

):

continue

restore_id = block_id

break

for block in lesson.content_blocks:

if block is ContentBlock:

var instance: UIContentBlock = ContentBlockScene.instance()

instance.name = block.content_id.get_file().get_basename()

_content_blocks.add_child(instance)

instance.setup(block)

instance.hide()

if restore_id == block.content_id:

restore_node = instance

elif block is Quiz:

var scene = QuizInputFieldScene if block is QuizInputField else QuizChoiceScene

var instance = scene.instance()

instance.name = block.quiz_id.get_file().get_basename()

_content_blocks.add_child(instance)

instance.setup(block)

instance.hide()

var completed_before := false

if course:

completed_before = user_profile.is_lesson_quiz_completed(

course.resource_path, lesson.resource_path, block.quiz_id

)

if completed_before:

_quizzes_done += 1

instance.completed_before = completed_before

instance.connect("quiz_passed", Events, "emit_signal", ["quiz_completed", block])

instance.connect("quiz_passed", self, "_reveal_up_to_next_quiz")

instance.connect("quiz_skipped", self, "_reveal_up_to_next_quiz")

if restore_id == block.quiz_id:

restore_node = instance

var highlighted_next := false

var practice_index := 0

for practice in lesson.practices:

var button: UIPracticeButton = PracticeButtonScene.instance()

button.setup(practice, practice_index)

if course:

button.completed_before = user_profile.is_lesson_practice_completed(

course.resource_path, lesson.resource_path, practice.practice_id

)

if not highlighted_next and not button.completed_before:

highlighted_next = true

button.is_highlighted = true

_practices_container.add_child(button)

practice_index += 1

_practices_visibility_container.hide()

_quizz_count = lesson.get_quizzes_count()

_reveal_up_to_next_quiz()

# Wait until the lesson is considered loaded by the system, and then update the size of

# the scroll container and its content.

yield(Events, "lesson_started")

if restore_node and restore_node.is_visible_in_tree():

var scroll_offset = abs(

_scroll_content.rect_global_position.y - _content_blocks.rect_global_position.y

)

var scroll_target = restore_node.rect_position.y + scroll_offset - AUTOSCROLL_PADDING

_tweener.stop_all()

_tweener.interpolate_method(

_scroll_container,

"set_v_scroll", # So it plays nice with our smooth scroller

_scroll_container.scroll_vertical,

scroll_target,

AUTOSCROLL_DURATION,

Tween.TRANS_QUAD,

Tween.EASE_IN_OUT

)

_tweener.start()

_underline_glossary_entries()

# Call this immediately to update for the blocks that are already visible.

_emit_read_content()

func _underline_glossary_entries() -> void:

_glossary.setup()

# Underline glossary entries

for rtl in get_tree().get_nodes_in_group("rich_text_label"):

rtl.bbcode_text = _glossary.replace_matching_terms(rtl.bbcode_text)

if not rtl.is_connected("meta_clicked", self, "_open_glossary_popup"):

rtl.connect("meta_clicked", self, "_open_glossary_popup")

func _update_labels() -> void:

if not _lesson:

return

_title.text = tr(_lesson.title)

func get_screen_resource() -> Lesson:

return _lesson

func _reveal_up_to_next_quiz() -> void:

_quizzes_done += 1

var child_count := _content_blocks.get_child_count()

while _visible_index < child_count - 1:

_visible_index += 1

var child = _content_blocks.get_child(_visible_index)

child.show()

if child is UIBaseQuiz and not child.completed_before:

break

if _visible_index >= child_count - 1 and _quizzes_done >= _quizz_count:

_practices_visibility_container.show()

func _on_content_scrolled(_value: float) -> void:

_debounce_timer.start()

func _emit_read_content() -> void:

var scroll_offset = abs(

_scroll_content.rect_global_position.y - _content_blocks.rect_global_position.y

)

var scroll_distance = _scroll_container.scroll_vertical - scroll_offset - AUTOSCROLL_PADDING

var content_index := 0

var content_blocks := []

for child_node in _content_blocks.get_children():

var control_node := child_node as Control

if not control_node:

continue

# We reached the end of visible blocks.

if not control_node.visible:

break

if content_index < _lesson.content_blocks.size():

content_blocks.append(_lesson.content_blocks[content_index])

var content_offset := control_node.rect_position.y

if content_offset > scroll_distance:

break

content_index += 1

if content_blocks.size() > 0:

var last_block = content_blocks.pop_back()

Events.emit_signal("lesson_reading_block", last_block, content_blocks)

func _update_content_container_width(new_font_scale: int) -> void:

var font_size_multiplier := (

float(_base_text_font_size + new_font_scale * 2)

/ _base_text_font_size

)

_content_container.rect_min_size.x = _start_content_width * font_size_multiplier

func _on_translation_changed() -> void:

_underline_glossary_entries()

func _open_glossary_popup(meta: String) -> void:

var entry: Glossary.Entry = _glossary.get_match(meta)

if entry == null:

return

_glossary_popup.setup(entry.term, entry.explanation)

_glossary_popup.call_deferred("align_with_mouse", get_global_mouse_position())

_glossary_popup.appear()