extends MarginContainer

const Brand := preload("res://scripts/ui/medmind_style.gd")
const Style := preload("res://scripts/ui/ui_style.gd")
const DonationAmount := preload("res://scripts/ui/donation_amount.gd")
const MINIMUM_CENTS := 500
const MAXIMUM_CENTS := 1000000
const DEFAULT_CENTS := 2500

var main: Control
var content_grid: GridContainer
var mission_panel: PanelContainer
var contribution_panel: PanelContainer
var preset_grid: GridContainer
var amount_buttons: Array[Button] = []
var amount_group := ButtonGroup.new()
var custom_amount: LineEdit
var donate_button: Button
var status_label: Label
var selected_amount_cents := DEFAULT_CENTS
var donation_service: Node


func _ready() -> void:
	donation_service = get_node("/root/DonationService")
	set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	add_theme_constant_override("margin_bottom", 8)
	_build_ui()
	resized.connect(_update_layout)
	donation_service.checkout_started.connect(_on_checkout_started)
	donation_service.donation_status_changed.connect(_on_donation_status_changed)
	donation_service.donation_failed.connect(_on_donation_failed)
	UIThemeService.theme_changed.connect(_on_theme_changed)
	_update_layout()
	_update_donate_button()
	refresh_theme_controls()


func _build_ui() -> void:
	var scroll := ScrollContainer.new()
	scroll.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	scroll.size_flags_vertical = Control.SIZE_EXPAND_FILL
	scroll.horizontal_scroll_mode = ScrollContainer.SCROLL_MODE_DISABLED
	add_child(scroll)

	var page := VBoxContainer.new()
	page.custom_minimum_size = Vector2(0, 0)
	page.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	page.add_theme_constant_override("separation", 24)
	scroll.add_child(page)

	var title := Label.new()
	title.text = "Support MedMind"
	title.add_theme_font_override("font", Brand.font)
	title.add_theme_font_size_override("font_size", 36)
	page.add_child(title)

	var subtitle := Label.new()
	subtitle.text = "Help us build accessible, clinically grounded tools for Step 3 learners."
	subtitle.add_theme_font_override("font", Brand.font)
	subtitle.add_theme_font_size_override("font_size", 18)
	subtitle.add_theme_color_override("font_color", Brand.muted_color(UIThemeService.is_dark_mode()))
	subtitle.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
	page.add_child(subtitle)

	content_grid = GridContainer.new()
	content_grid.columns = 2
	content_grid.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	content_grid.add_theme_constant_override("h_separation", 24)
	content_grid.add_theme_constant_override("v_separation", 24)
	page.add_child(content_grid)

	mission_panel = _panel()
	mission_panel.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	content_grid.add_child(mission_panel)
	var mission := VBoxContainer.new()
	mission.add_theme_constant_override("separation", 18)
	mission_panel.add_child(mission)
	mission.add_child(_heading("Our mission", 26))
	mission.add_child(_body("MedMind exists to make rigorous, clinically grounded medical education more accessible. We are building an independent Step 3 study experience that helps learners develop clinical judgment through original questions, realistic CCS cases, transparent explanations, and continuous improvement driven by learner feedback."))
	mission.add_child(HSeparator.new())
	mission.add_child(_heading("What your support makes possible", 20))
	for item_text in [
		"Original question and CCS case development",
		"Clinical source review and content verification",
		"Reliable hosting and continued pre-alpha access",
		"Accessibility, usability, and learning-tool improvements"
	]:
		var row := HBoxContainer.new()
		row.add_theme_constant_override("separation", 12)
		var marker := Label.new()
		marker.text = "-"
		marker.add_theme_font_size_override("font_size", 20)
		marker.add_theme_color_override("font_color", Brand.TEAL)
		row.add_child(marker)
		var item := _body(item_text)
		item.size_flags_horizontal = Control.SIZE_EXPAND_FILL
		row.add_child(item)
		mission.add_child(row)

	contribution_panel = _panel()
	contribution_panel.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	content_grid.add_child(contribution_panel)
	var contribution := VBoxContainer.new()
	contribution.add_theme_constant_override("separation", 18)
	contribution_panel.add_child(contribution)
	contribution.add_child(_heading("Make a one-time contribution", 26))
	contribution.add_child(_body("Choose an amount. Secure payment and email receipts are handled by Stripe."))

	preset_grid = GridContainer.new()
	preset_grid.columns = 4
	preset_grid.add_theme_constant_override("h_separation", 10)
	preset_grid.add_theme_constant_override("v_separation", 10)
	contribution.add_child(preset_grid)
	for amount in [500, 1000, 2500, 5000]:
		var button := Button.new()
		button.text = "$%d" % int(amount / 100.0)
		button.toggle_mode = true
		button.button_group = amount_group
		button.custom_minimum_size = Vector2(64, 48)
		button.size_flags_horizontal = Control.SIZE_EXPAND_FILL
		button.set_meta("amount_cents", amount)
		button.pressed.connect(_select_preset.bind(button))
		preset_grid.add_child(button)
		amount_buttons.append(button)
		if amount == DEFAULT_CENTS:
			button.set_pressed_no_signal(true)

	var custom_label := Label.new()
	custom_label.text = "Custom amount (USD)"
	custom_label.add_theme_font_override("font", Brand.font)
	custom_label.add_theme_font_size_override("font_size", 16)
	contribution.add_child(custom_label)

	custom_amount = LineEdit.new()
	custom_amount.placeholder_text = "$5.00 minimum"
	custom_amount.max_length = 12
	custom_amount.virtual_keyboard_type = LineEdit.KEYBOARD_TYPE_NUMBER_DECIMAL
	custom_amount.custom_minimum_size = Vector2(0, 56)
	custom_amount.text_changed.connect(_on_custom_amount_changed)
	contribution.add_child(custom_amount)

	donate_button = Button.new()
	donate_button.text = "Donate $25 securely"
	donate_button.custom_minimum_size = Vector2(0, 58)
	donate_button.pressed.connect(_on_donate_pressed)
	contribution.add_child(donate_button)

	status_label = Label.new()
	status_label.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
	status_label.add_theme_font_override("font", Brand.font)
	status_label.add_theme_font_size_override("font_size", 15)
	status_label.add_theme_color_override("font_color", Brand.muted_color(UIThemeService.is_dark_mode()))
	status_label.custom_minimum_size.y = 44
	contribution.add_child(status_label)

	var disclosure := _body("Contributions are voluntary, one-time, and not tax-deductible. Card details are entered only on Stripe's secure checkout page.")
	disclosure.add_theme_font_size_override("font_size", 14)
	contribution.add_child(disclosure)


func on_show(_payload: Variant = null) -> void:
	donate_button.disabled = donation_service.checkout_pending
	if donation_service.active_donation_id.is_empty():
		status_label.text = ""
	else:
		donation_service.resume_polling()


func on_hide() -> void:
	donation_service.stop_polling()


static func parse_amount_cents(value: String) -> int:
	return DonationAmount.parse_cents(value)


func _select_preset(button: Button) -> void:
	selected_amount_cents = int(button.get_meta("amount_cents", DEFAULT_CENTS))
	custom_amount.text = ""
	_set_validation_state("")
	_update_donate_button()
	refresh_theme_controls()


func _on_custom_amount_changed(value: String) -> void:
	if value.strip_edges().is_empty():
		return
	for button in amount_buttons:
		button.set_pressed_no_signal(false)
	selected_amount_cents = parse_amount_cents(value)
	_set_validation_state("")
	_update_donate_button()
	refresh_theme_controls()


func _on_donate_pressed() -> void:
	if selected_amount_cents < MINIMUM_CENTS:
		_set_validation_state("Enter an amount of at least $5.00.", true)
		return
	if selected_amount_cents > MAXIMUM_CENTS:
		_set_validation_state("The maximum contribution is $10,000.00.", true)
		return
	donate_button.disabled = true
	_set_validation_state("Opening secure checkout...")
	donation_service.begin_checkout(selected_amount_cents)


func _on_checkout_started(_donation_id: String, _checkout_url: String) -> void:
	donate_button.disabled = false
	_set_validation_state("Checkout opened in your browser. This page will confirm when Stripe completes the payment.")


func _on_donation_status_changed(status: String, _donation: Dictionary) -> void:
	match status:
		"paid": _set_validation_state("Thank you for supporting MedMind. Your contribution has been confirmed.", false, Brand.SUCCESS)
		"failed": _set_validation_state("Stripe could not complete the contribution. No payment was confirmed.", true)
		"expired": _set_validation_state("The checkout session expired. Start a new checkout when you are ready.", true)


func _on_donation_failed(message: String) -> void:
	donate_button.disabled = false
	_set_validation_state(message, true)


func _update_donate_button() -> void:
	donate_button.disabled = selected_amount_cents < MINIMUM_CENTS or selected_amount_cents > MAXIMUM_CENTS
	if selected_amount_cents >= MINIMUM_CENTS and selected_amount_cents <= MAXIMUM_CENTS:
		donate_button.text = "Donate %s securely" % _format_amount(selected_amount_cents)
	else:
		donate_button.text = "Donate securely"


func _format_amount(amount_cents: int) -> String:
	return "$%d.%02d" % [int(amount_cents / 100.0), amount_cents % 100]


func _set_validation_state(message: String, is_error: bool = false, color: Color = Color.TRANSPARENT) -> void:
	status_label.text = message
	var text_color := color
	if text_color == Color.TRANSPARENT:
		text_color = Style.RED if is_error else Brand.muted_color(UIThemeService.is_dark_mode())
	status_label.add_theme_color_override("font_color", text_color)


func _panel() -> PanelContainer:
	var panel := PanelContainer.new()
	var box := Brand.content_card_box(UIThemeService.is_dark_mode(), false)
	box.content_margin_left = 28
	box.content_margin_right = 28
	box.content_margin_top = 28
	box.content_margin_bottom = 28
	panel.add_theme_stylebox_override("panel", box)
	return panel


func _heading(value: String, font_size: int) -> Label:
	var label := Label.new()
	label.text = value
	label.add_theme_font_override("font", Brand.font)
	label.add_theme_font_size_override("font_size", font_size)
	label.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
	return label


func _body(value: String) -> Label:
	var label := Label.new()
	label.text = value
	label.add_theme_font_override("font", Brand.font)
	label.add_theme_font_size_override("font_size", 17)
	label.add_theme_color_override("font_color", Brand.muted_color(UIThemeService.is_dark_mode()))
	label.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
	return label


func _update_layout() -> void:
	if content_grid != null:
		content_grid.columns = 1 if size.x < 1050.0 else 2
	if preset_grid != null:
		preset_grid.columns = 2 if size.x < 520.0 else 4


func refresh_theme_controls() -> void:
	var dark := UIThemeService.is_dark_mode()
	for panel in [mission_panel, contribution_panel]:
		if panel != null:
			var box := Brand.content_card_box(dark, false)
			box.content_margin_left = 28
			box.content_margin_right = 28
			box.content_margin_top = 28
			box.content_margin_bottom = 28
			panel.add_theme_stylebox_override("panel", box)
	if custom_amount != null:
		custom_amount.add_theme_stylebox_override("normal", Brand.field_box(dark))
		custom_amount.add_theme_stylebox_override("focus", Brand.field_box(dark, true))
		custom_amount.add_theme_color_override("font_color", Brand.text_color(dark))
		custom_amount.add_theme_color_override("font_placeholder_color", Brand.muted_color(dark))
	for button in amount_buttons:
		var selected := button.button_pressed
		var normal := Brand.secondary_button_box(dark, selected)
		if selected:
			normal.bg_color = Color(Brand.ROYAL_BLUE, 0.22 if dark else 0.10)
			normal.border_color = Brand.ROYAL_BLUE
		button.add_theme_stylebox_override("normal", normal)
		button.add_theme_stylebox_override("pressed", normal)
		button.add_theme_color_override("font_color", Brand.text_color(dark))
		button.add_theme_color_override("font_pressed_color", Brand.text_color(dark))
	if donate_button != null:
		donate_button.add_theme_stylebox_override("normal", Brand.gradient_button_box())
		donate_button.add_theme_stylebox_override("hover", Brand.gradient_button_box())
		donate_button.add_theme_color_override("font_color", Color.WHITE)
		donate_button.add_theme_color_override("font_hover_color", Color.WHITE)


func _on_theme_changed(_is_dark_mode: bool) -> void:
	refresh_theme_controls()