extends SceneTree

const BattleSceneScript := preload("res://scripts/scenes/battle_scene.gd")

const SAVE_PATH := "user://campaign_save.json"
const MANUAL_SAVE_PATH := "user://campaign_manual_save.json"
const SETTINGS_PATH := "user://heros_settings.json"
const CAPTURE_BASE_DIR := "user://readability_captures"
const SETTLE_FRAMES := 3
const VIEWPORT_SPECS := [
	{"label": "desktop", "size": Vector2i(1280, 720)},
	{"label": "qhd", "size": Vector2i(2560, 1440)}
]


func _init() -> void:
	call_deferred("_run")


func _run() -> void:
	var save_backup := _backup_user_file(SAVE_PATH)
	var manual_backup := _backup_user_file(MANUAL_SAVE_PATH)
	var settings_backup := _backup_user_file(SETTINGS_PATH)
	var failures: Array[String] = []
	var captures: Array[Dictionary] = []
	var output_dir := ""
	_clear_user_file(SAVE_PATH)
	_clear_user_file(MANUAL_SAVE_PATH)
	_clear_user_file(SETTINGS_PATH)

	if _is_headless_display():
		failures.append("readability frame capture needs a rendering display; run without --headless")
	else:
		output_dir = _make_output_dir(failures)
		if not output_dir.is_empty():
			for spec in VIEWPORT_SPECS:
				await _capture_viewport_set(spec, output_dir, captures, failures)
			_write_manifest(output_dir, captures)

	if not _restore_user_file(SAVE_PATH, save_backup):
		failures.append("could not restore campaign save after readability capture")
	if not _restore_user_file(MANUAL_SAVE_PATH, manual_backup):
		failures.append("could not restore manual campaign save after readability capture")
	if not _restore_user_file(SETTINGS_PATH, settings_backup):
		failures.append("could not restore settings after readability capture")

	if failures.is_empty():
		print("readability frame capture ok")
		print("capture directory: %s" % ProjectSettings.globalize_path(output_dir))
		quit(0)
		return

	for failure in failures:
		push_error(failure)
	quit(1)


func _is_headless_display() -> bool:
	return DisplayServer.get_name().to_lower().contains("headless")


func _capture_viewport_set(spec: Dictionary, output_dir: String, captures: Array[Dictionary], failures: Array[String]) -> void:
	var label := str(spec.get("label", "viewport"))
	var size: Vector2i = spec.get("size", Vector2i(1280, 720))
	_set_viewport_size(size)
	var scene = BattleSceneScript.new()
	get_root().add_child(scene)
	await _settle()

	await _capture_frame(scene, output_dir, label, "01_title", captures, failures)

	scene._show_opening_prologue()
	await _settle()
	await _capture_frame(scene, output_dir, label, "02_opening_rebellion", captures, failures)

	scene.opening_prologue_index = BattleSceneScript.OPENING_PROLOGUE_PAGES.size() - 1
	scene._update_opening_prologue_page()
	await _settle()
	await _capture_frame(scene, output_dir, label, "03_opening_contact", captures, failures)

	scene._hide_opening_prologue()
	scene._hide_title_menu()
	scene._load_scenario(scene.campaign_state.get_start_scenario_id())
	scene._show_briefing()
	await _settle()
	await _capture_frame(scene, output_dir, label, "04_briefing", captures, failures)

	scene._start_battle_from_briefing()
	await _settle()
	await _capture_frame(scene, output_dir, label, "05_battle_dialogue", captures, failures)

	var guard := 0
	while scene._is_dialogue_visible() and guard < 16:
		scene._advance_dialogue()
		guard += 1
		await _settle()
	if scene.objective_notice_panel != null and scene.objective_notice_panel.visible:
		await _capture_frame(scene, output_dir, label, "06_battle_start_notice", captures, failures)
	if scene.objective_notice_panel != null:
		scene.objective_notice_panel.visible = false
	scene._update_hud()
	await _settle()
	await _capture_frame(scene, output_dir, label, "07_battle_idle", captures, failures)

	_prepare_auto_attack_hint_frame(scene)
	await _settle()
	await _capture_frame(scene, output_dir, label, "08_battle_auto_attack_hint", captures, failures)

	scene._update_threat_button()
	scene._on_command_hint_button_mouse_entered(scene.threat_button)
	await _settle()
	await _capture_frame(scene, output_dir, label, "09_battle_threat_hint", captures, failures)

	_prepare_post_move_action_frame(scene, "")
	await _settle()
	await _capture_frame(scene, output_dir, label, "10_post_move_actions", captures, failures)

	_prepare_post_move_action_frame(scene, "tactic")
	await _settle()
	await _capture_frame(scene, output_dir, label, "11_post_move_tactic_picker", captures, failures)

	_prepare_post_move_action_frame(scene, "item")
	await _settle()
	await _capture_frame(scene, output_dir, label, "12_post_move_item_picker", captures, failures)

	scene.queue_free()
	await _settle()


func _prepare_auto_attack_hint_frame(scene) -> void:
	scene._hide_post_move_menu()
	scene._hide_post_move_picker()
	scene._hide_tactic_menu()
	scene._hide_item_menu()
	scene._hide_equip_menu()
	scene._clear_pending_move_state()
	scene.selected_skill_id = ""
	scene.selected_item_id = ""
	scene.basic_attack_targeting = false
	var cao_cao: Dictionary = scene.state.get_unit("cao_cao")
	var enemy: Dictionary = scene.state.get_unit("yellow_turban_1")
	if cao_cao.is_empty() or enemy.is_empty():
		return
	cao_cao["pos"] = Vector2i(1, 3)
	cao_cao["moved"] = false
	cao_cao["acted"] = false
	enemy["pos"] = Vector2i(4, 3)
	enemy["alive"] = true
	enemy["hp"] = maxi(1, int(enemy.get("hp", 24)))
	scene.state.select_unit("cao_cao")
	scene.hover_cell = Vector2i(4, 3)
	scene._refresh_ranges()
	scene._focus_board_on_cell(Vector2i(4, 3))
	scene._update_hud()
	scene.queue_redraw()


func _prepare_post_move_action_frame(scene, picker_mode: String) -> void:
	scene._hide_command_hint()
	scene._hide_post_move_menu()
	scene._hide_post_move_picker()
	scene._hide_tactic_menu()
	scene._hide_item_menu()
	scene._hide_equip_menu()
	scene._clear_pending_move_state()
	scene.selected_skill_id = ""
	scene.selected_item_id = ""
	scene.basic_attack_targeting = false
	scene.state.set_inventory_snapshot({"bean": 2})
	var cao_cao: Dictionary = scene.state.get_unit("cao_cao")
	var enemy: Dictionary = scene.state.get_unit("yellow_turban_1")
	var xiahou_dun: Dictionary = scene.state.get_unit("xiahou_dun")
	if cao_cao.is_empty() or enemy.is_empty() or xiahou_dun.is_empty():
		return
	cao_cao["pos"] = Vector2i(1, 3)
	cao_cao["moved"] = false
	cao_cao["acted"] = false
	cao_cao["mp"] = maxi(10, int(cao_cao.get("mp", 0)))
	enemy["pos"] = Vector2i(3, 3)
	enemy["alive"] = true
	enemy["hp"] = maxi(18, int(enemy.get("hp", 0)))
	xiahou_dun["pos"] = Vector2i(2, 4)
	xiahou_dun["alive"] = true
	xiahou_dun["hp"] = 12
	scene.state.select_unit("cao_cao")
	scene._refresh_ranges()
	scene._focus_board_on_cell(Vector2i(2, 3))
	scene._handle_board_click(_screen_for_cell(scene, Vector2i(2, 3)))
	if picker_mode == "tactic":
		scene._on_post_move_tactic_pressed()
	elif picker_mode == "item":
		scene._on_post_move_item_pressed()
	scene._update_hud()
	scene.queue_redraw()


func _screen_for_cell(scene, cell: Vector2i) -> Vector2:
	var rect: Rect2 = scene._rect_for_cell(cell)
	return rect.position + rect.size * 0.5


func _capture_frame(_scene, output_dir: String, viewport_label: String, frame_label: String, captures: Array[Dictionary], failures: Array[String]) -> void:
	var texture := get_root().get_texture()
	if texture == null:
		failures.append("viewport texture missing for %s/%s" % [viewport_label, frame_label])
		return
	var image := texture.get_image()
	if image == null or image.is_empty():
		failures.append("viewport image missing for %s/%s" % [viewport_label, frame_label])
		return
	var path := "%s/%s_%s.png" % [output_dir, viewport_label, frame_label]
	var result := image.save_png(path)
	if result != OK:
		failures.append("could not save capture %s: %s" % [path, str(result)])
		return
	captures.append({
		"viewport": viewport_label,
		"frame": frame_label,
		"path": ProjectSettings.globalize_path(path),
		"size": [image.get_width(), image.get_height()]
	})


func _settle() -> void:
	for _index in range(SETTLE_FRAMES):
		await process_frame


func _set_viewport_size(size: Vector2i) -> void:
	get_root().size = size
	DisplayServer.window_set_size(size)


func _make_output_dir(failures: Array[String]) -> String:
	var stamp := _safe_timestamp()
	var output_dir := "%s/%s" % [CAPTURE_BASE_DIR, stamp]
	var absolute_dir := ProjectSettings.globalize_path(output_dir)
	var result := DirAccess.make_dir_recursive_absolute(absolute_dir)
	if result != OK:
		failures.append("could not create capture directory %s: %s" % [absolute_dir, str(result)])
		return ""
	return output_dir


func _safe_timestamp() -> String:
	var stamp := Time.get_datetime_string_from_system(false, true)
	for token in [":", "-", "T", " "]:
		stamp = stamp.replace(token, "")
	return stamp


func _write_manifest(output_dir: String, captures: Array[Dictionary]) -> void:
	var manifest := {
		"generated_at": Time.get_datetime_string_from_system(false, true),
		"project": "Heroes of Three Kingdoms",
		"purpose": "readability QA reference frames",
		"captures": captures
	}
	var file := FileAccess.open("%s/manifest.json" % output_dir, FileAccess.WRITE)
	if file != null:
		file.store_string(JSON.stringify(manifest, "\t"))


func _backup_user_file(path: String) -> Dictionary:
	if not FileAccess.file_exists(path):
		return {"exists": false, "text": ""}
	return {
		"exists": true,
		"text": FileAccess.get_file_as_string(path)
	}


func _restore_user_file(path: String, backup: Dictionary) -> bool:
	if bool(backup.get("exists", false)):
		var file := FileAccess.open(path, FileAccess.WRITE)
		if file == null:
			return false
		file.store_string(str(backup.get("text", "")))
		return true
	return _clear_user_file(path)


func _clear_user_file(path: String) -> bool:
	if not FileAccess.file_exists(path):
		return true
	return DirAccess.remove_absolute(ProjectSettings.globalize_path(path)) == OK