extends Control

const WorldBriefingModal = preload("res://scripts/world_briefing_modal.gd")

## World list screen — browses public worlds via GET /api/worlds.
##
## Displays a scrollable list of world cards (name + description).
## Handles loading, empty list, errors, and refresh.


# UI references
@onready var scroll_container: ScrollContainer = $VBoxContainer/ScrollContainer
@onready var world_list: VBoxContainer = $VBoxContainer/ScrollContainer/WorldList
@onready var loading_label: Label = $VBoxContainer/LoadingLabel
@onready var error_label: Label = $VBoxContainer/ErrorLabel
@onready var refresh_button: Button = $VBoxContainer/HeaderHBox/RefreshButton
@onready var back_button: Button = $VBoxContainer/HeaderHBox/BackButton
@onready var create_button: Button = $VBoxContainer/HeaderHBox/CreateButton
@onready var empty_label: Label = $VBoxContainer/EmptyLabel

## Cached so each world card can decide whether to show "Edit World"
## (docs/architecture/world_persistence_impl.md §5.3: chunk writes require
## `world.owner_id == caller`, same as `update_world`) without an extra
## round trip per card. -1 until resolved / on failure, in which case no
## card shows the edit entry point.
var _current_user_id: int = -1
var _create_modal: Control = null


func _ready() -> void:
	refresh_button.disabled = false
	back_button.disabled = false
	create_button.disabled = false
	loading_label.visible = false
	error_label.visible = false
	empty_label.visible = false
	world_list.visible = false

	_show_build_stamp()

	var me_result: Dictionary = await ApiClient.get_me()
	if me_result.ok and me_result.data is Dictionary:
		_current_user_id = int((me_result.data as Dictionary).get("id", -1))

	_refresh_worlds()



func _show_build_stamp() -> void:
	var lbl := Label.new()
	var f := FileAccess.open("res://assets/build_info.json", FileAccess.READ)
	var stamp := "dev"
	if f != null:
		var d = JSON.parse_string(f.get_as_text())
		if d is Dictionary:
			stamp = "%s %s" % [d.get("checkpoint", "?"), d.get("commit", "?")]
	lbl.text = "build %s" % stamp
	lbl.add_theme_color_override("font_color", Color(1, 1, 0.35, 1.0))
	lbl.add_theme_color_override("font_outline_color", Color(0, 0, 0, 1.0))
	lbl.add_theme_constant_override("outline_size", 6)
	lbl.add_theme_font_size_override("font_size", 18)
	lbl.mouse_filter = Control.MOUSE_FILTER_IGNORE
	add_child(lbl)

	var reposition := func() -> void:
		if is_instance_valid(lbl) and is_inside_tree():
			var vp := get_viewport().get_visible_rect().size
			lbl.position = Vector2(20, vp.y - 40)
			lbl.size = Vector2(vp.x - 40, 32)
	reposition.call()
	get_viewport().size_changed.connect(reposition)


func _on_create_button_pressed() -> void:
	if _create_modal != null and is_instance_valid(_create_modal):
		_create_modal.queue_free()
	_create_modal = _build_create_world_modal()
	add_child(_create_modal)


func _build_create_world_modal() -> Control:
	var overlay := ColorRect.new()
	overlay.name = "CreateWorldOverlay"
	overlay.color = Color(0, 0, 0, 0.75)
	overlay.set_anchors_preset(Control.PRESET_FULL_RECT)
	overlay.mouse_filter = Control.MOUSE_FILTER_STOP

	var center := CenterContainer.new()
	center.set_anchors_preset(Control.PRESET_FULL_RECT)
	overlay.add_child(center)

	var panel := PanelContainer.new()
	panel.custom_minimum_size = Vector2(480, 0)
	var style := StyleBoxFlat.new()
	style.bg_color = Color(0.18, 0.18, 0.22, 1.0)
	style.border_color = Color(0.4, 0.55, 0.8, 1.0)
	style.set_border_width_all(2)
	style.set_corner_radius_all(8)
	style.content_margin_left = 24
	style.content_margin_right = 24
	style.content_margin_top = 20
	style.content_margin_bottom = 20
	panel.add_theme_stylebox_override("panel", style)
	center.add_child(panel)

	var form := VBoxContainer.new()
	form.add_theme_constant_override("separation", 12)
	panel.add_child(form)

	var title := Label.new()
	title.text = "Create New World"
	title.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	title.add_theme_font_size_override("font_size", 22)
	title.add_theme_color_override("font_color", Color(1.0, 1.0, 1.0))
	form.add_child(title)

	var name_lbl := Label.new()
	name_lbl.text = "World Name:"
	name_lbl.add_theme_font_size_override("font_size", 14)
	form.add_child(name_lbl)

	var name_input := LineEdit.new()
	name_input.placeholder_text = "Enter world name..."
	name_input.text = "My New World"
	form.add_child(name_input)

	var desc_lbl := Label.new()
	desc_lbl.text = "Description:"
	desc_lbl.add_theme_font_size_override("font_size", 14)
	form.add_child(desc_lbl)

	var desc_input := LineEdit.new()
	desc_input.placeholder_text = "Describe your world..."
	desc_input.text = "A creative build world"
	form.add_child(desc_input)

	var tags_lbl := Label.new()
	tags_lbl.text = "Content Tags (comma separated):"
	tags_lbl.add_theme_font_size_override("font_size", 14)
	form.add_child(tags_lbl)

	var tags_input := LineEdit.new()
	tags_input.placeholder_text = "e.g. Building, Roleplay, Chill, Parkour"
	tags_input.text = "Building, Creative"
	form.add_child(tags_input)

	var guide_lbl := Label.new()
	guide_lbl.text = "World Guidelines & Rules / Disclaimer:"
	guide_lbl.add_theme_font_size_override("font_size", 14)
	form.add_child(guide_lbl)

	var guide_input := TextEdit.new()
	guide_input.custom_minimum_size = Vector2(0, 60)
	guide_input.placeholder_text = "Specify rules, content notices, or disclaimers for players..."
	guide_input.text = "Welcome! Be respectful to fellow builders and enjoy creating."
	form.add_child(guide_input)

	var err_label := Label.new()
	err_label.add_theme_font_size_override("font_size", 13)
	err_label.add_theme_color_override("font_color", Color(1.0, 0.4, 0.4))
	err_label.visible = false
	form.add_child(err_label)

	var btn_row := HBoxContainer.new()
	btn_row.alignment = BoxContainer.ALIGNMENT_END
	btn_row.add_theme_constant_override("separation", 10)
	form.add_child(btn_row)

	var cancel_btn := Button.new()
	cancel_btn.text = "Cancel"
	cancel_btn.pressed.connect(func(): overlay.queue_free())
	btn_row.add_child(cancel_btn)

	var create_btn := Button.new()
	create_btn.text = "Create World"
	btn_row.add_child(create_btn)

	var create_edit_btn := Button.new()
	create_edit_btn.text = "Create & Edit Now"
	btn_row.add_child(create_edit_btn)

	var handle_create := func(open_editor: bool) -> void:
		var wname := name_input.text.strip_edges()
		if wname.is_empty():
			err_label.text = "World name cannot be empty."
			err_label.visible = true
			return
		create_btn.disabled = true
		create_edit_btn.disabled = true
		cancel_btn.disabled = true
		err_label.text = "Creating world..."
		err_label.add_theme_color_override("font_color", Color(0.8, 0.8, 0.8))
		err_label.visible = true

		var raw_tags := tags_input.text.split(",")
		var clean_tags: Array = []
		for t in raw_tags:
			var st := t.strip_edges()
			if not st.is_empty():
				clean_tags.append(st)

		var res: Dictionary = await ApiClient.create_world(
			wname,
			desc_input.text.strip_edges(),
			"public",
			"Building",
			clean_tags,
			guide_input.text.strip_edges()
		)
		if not res.get("ok", false):
			create_btn.disabled = false
			create_edit_btn.disabled = false
			cancel_btn.disabled = false
			err_label.text = "Failed: %s" % str(res.get("detail", "unknown error"))
			err_label.add_theme_color_override("font_color", Color(1.0, 0.4, 0.4))
			return

		var new_world: Dictionary = res.get("data", {})
		var new_world_id: int = int(new_world.get("id", 0))
		overlay.queue_free()

		if open_editor and new_world_id > 0:
			Session.begin_edit(new_world_id)
			get_tree().change_scene_to_file("res://scenes/game.tscn")
		else:
			_refresh_worlds()

	create_btn.pressed.connect(handle_create.bind(false))
	create_edit_btn.pressed.connect(handle_create.bind(true))

	return overlay



func _on_refresh_button_pressed() -> void:
	_refresh_worlds()


func _on_back_button_pressed() -> void:
	get_tree().change_scene_to_file("res://scenes/main_menu.tscn")


func _on_discover_button_pressed() -> void:
	get_tree().change_scene_to_file("res://scenes/discovery_ui.tscn")



## Fetch the world list from the backend and update the UI.
func _refresh_worlds() -> void:
	# Reset UI state
	loading_label.visible = true
	error_label.visible = false
	empty_label.visible = false
	world_list.visible = false
	refresh_button.disabled = true

	# Clear previous world cards
	for child in world_list.get_children():
		child.queue_free()

	var result := await ApiClient.get_worlds()

	loading_label.visible = false
	refresh_button.disabled = false

	if not result.ok:
		# Show error message (401, network failure, etc.)
		error_label.text = "Error: %s" % result.detail
		error_label.visible = true
		empty_label.visible = false
		world_list.visible = false
		return

	var data = result.data
	if not data is Array:
		error_label.text = "Unexpected response format."
		error_label.visible = true
		empty_label.visible = false
		world_list.visible = false
		return

	if data.is_empty():
		empty_label.text = "No worlds yet. Check back later!"
		empty_label.visible = true
		error_label.visible = false
		world_list.visible = false
		return

	# Render world cards
	world_list.visible = true
	empty_label.visible = false
	error_label.visible = false

	for world_dict in data:
		if not world_dict is Dictionary:
			continue
		var card := _create_world_card(world_dict)
		world_list.add_child(card)


## Create a visual card for a single world entry.
func _create_world_card(world_dict: Dictionary) -> Control:
	# PanelContainer for the background, not a ColorRect moved to child index
	# 0 of a VBoxContainer -- a VBoxContainer lays out ALL its children in a
	# vertical sequence, it has no concept of "float this one child behind
	# the others as an overlay". That version rendered as an empty dark bar
	# sitting above the text, not a background behind it.
	var panel := PanelContainer.new()
	panel.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	panel.custom_minimum_size = Vector2(0, 80)
	var style := StyleBoxFlat.new()
	style.bg_color = Color(0.15, 0.15, 0.15, 1.0)
	style.content_margin_left = 12
	style.content_margin_right = 12
	style.content_margin_top = 8
	style.content_margin_bottom = 8
	panel.add_theme_stylebox_override("panel", style)

	var card := VBoxContainer.new()
	card.size_flags_horizontal = Control.SIZE_EXPAND_FILL
	card.add_theme_constant_override("separation", 4)
	panel.add_child(card)

	var owner_id := int(world_dict.get("owner_id", -1))
	var is_owner := (_current_user_id != -1 and owner_id == _current_user_id)

	var name_label := Label.new()
	var raw_name: String = world_dict.get("name", "Unnamed World")
	if is_owner:
		name_label.text = "%s  ★ [Your World]" % raw_name
		name_label.add_theme_color_override("font_color", Color(1.0, 0.9, 0.4, 1.0))
		style.border_color = Color(0.7, 0.6, 0.2, 0.8)
		style.set_border_width_all(2)
	else:
		name_label.text = raw_name
	name_label.autowrap_mode = TextServer.AUTOWRAP_WORD
	name_label.size_flags_horizontal = Control.SIZE_FILL
	name_label.size_flags_vertical = Control.SIZE_SHRINK_BEGIN
	name_label.add_theme_font_size_override("font_size", 18)


	var desc_label := Label.new()
	var description: String = str(world_dict.get("description", ""))
	desc_label.text = description if description != "" else "No description."
	desc_label.autowrap_mode = TextServer.AUTOWRAP_WORD
	desc_label.size_flags_horizontal = Control.SIZE_FILL
	desc_label.size_flags_vertical = Control.SIZE_EXPAND_FILL
	desc_label.add_theme_font_size_override("font_size", 14)
	desc_label.add_theme_color_override("font_color", Color(0.7, 0.7, 0.7, 1.0))

	var meta_label := Label.new()
	var visibility: String = str(world_dict.get("visibility", "public"))
	var created: String = str(world_dict.get("created_at", ""))
	meta_label.text = "Visibility: %s%s" % [visibility, " | Created: " + created if created != "" else ""]
	meta_label.autowrap_mode = TextServer.AUTOWRAP_WORD
	meta_label.size_flags_horizontal = Control.SIZE_FILL
	meta_label.size_flags_vertical = Control.SIZE_SHRINK_BEGIN
	meta_label.add_theme_font_size_override("font_size", 12)
	meta_label.add_theme_color_override("font_color", Color(0.5, 0.5, 0.5, 1.0))

	# "Enter World" asks the backend to host this world (POST /join) and then
	# loads scenes/game.tscn networked. If the backend has no game-server
	# orchestration (a plain dev instance), it falls back to local
	# single-player. All worlds still load the same test level -- per-world
	# content is a later milestone.
	var world_id := int(world_dict.get("id", 0))
	var enter_button := Button.new()
	enter_button.text = "Enter World"
	enter_button.size_flags_horizontal = Control.SIZE_SHRINK_BEGIN
	enter_button.pressed.connect(func(): _show_world_briefing(world_dict, enter_button))

	var buttons_row := HBoxContainer.new()
	buttons_row.add_child(enter_button)

	# "Edit World" (world_persistence_impl.md §6 D4): a non-joined entry
	# point into the in-game editor -- it does NOT call POST /join. Only
	# shown for the world's owner, matching the write-side authorization the
	# save path itself enforces (§5.3), so a non-owner never sees a button
	# that would just 403 on the first save.
	if is_owner:
		var edit_button := Button.new()
		edit_button.text = "Edit World"
		edit_button.size_flags_horizontal = Control.SIZE_SHRINK_BEGIN
		edit_button.pressed.connect(_on_edit_world_pressed.bind(world_id))
		buttons_row.add_child(edit_button)

	card.add_child(name_label)
	card.add_child(desc_label)
	card.add_child(meta_label)
	card.add_child(buttons_row)

	return panel


func _show_world_briefing(world_dict: Dictionary, button: Button) -> void:
	var modal := WorldBriefingModal.new()
	var wid: int = int(world_dict.get("id", 0))
	modal.setup_world_data(
		wid,
		str(world_dict.get("name", "World")),
		str(world_dict.get("owner_username", "")),
		str(world_dict.get("content_guidelines", "")),
		world_dict.get("tags", []),
		int(world_dict.get("play_count", 0))
	)
	modal.entered_confirmed.connect(func(target_wid: int): _on_enter_world_pressed(target_wid, button))
	add_child(modal)


func _on_enter_world_pressed(world_id: int, button: Button) -> void:

	button.disabled = true
	button.text = "Joining…"

	var result := await ApiClient.join_world(world_id)

	if result.ok and result.data is Dictionary:
		var d: Dictionary = result.data
		Session.begin(world_id, str(d.get("host", "")), int(d.get("port", 0)))
		get_tree().change_scene_to_file("res://scenes/game.tscn")
		return

	if result.status == 503:
		# This backend can't host game servers -- go in local single-player.
		Session.clear()
		get_tree().change_scene_to_file("res://scenes/game.tscn")
		return

	button.disabled = false
	button.text = "Enter World"
	error_label.text = "Couldn't join: %s" % result.detail
	error_label.visible = true


## Enter build mode for this world without joining it
## (world_persistence_impl.md §6 D4). No /join call, no ENet connection, no
## dedicated server -- game.gd loads/saves the world's chunks over HTTP.
func _on_edit_world_pressed(world_id: int) -> void:
	Session.begin_edit(world_id)
	get_tree().change_scene_to_file("res://scenes/game.tscn")