## Sprint 37 — Scene-level merge-path UI flow tests (#873)
##
## Four flows that cover the critical paths through the pre-game UI.
## These tests are the merge-gate mechanism added in the Sprint 36 retro:
## regressions like #872 (New Game hang) must be caught here, not in post-merge
## smoke tests.
##
## Pattern: load scene → simulate input via button.pressed.emit() or direct
## handler call → assert terminal state. No pixel diffing, no xdotool.
##
## NOTE: Tests that end in a scene transition (change_scene_to_file) assert state
## synchronously before the deferred transition fires. The test scene is
## queue_freed in after_test() regardless.
##
## Reference: test_character_creation_sprint28.gd
## Ticket: #873 | motivating regression: #872
class_name TestMergePathFlowsSprint37
extends GdUnitTestSuite

const MAIN_MENU_SCENE_PATH := "res://scenes/main_menu.tscn"
const CHAR_CREATE_SCENE_PATH := "res://scenes/character_creation.tscn"

var _scene = null  # MainMenu or CharacterCreation — untyped, varies per test


func before_test() -> void:
	# Reset all shared state that these flows touch
	SimBridge.disconnect_from_sim()
	SimBridge._last_snapshot = null
	SimBridge._outbound_buffer.clear()
	GameState.bookmark_catalog = []
	GameState.pending_load_path = ""
	# Clear MetaStack from any leftover overlays to prevent push/pop ordering issues
	MetaStack._stack.clear()


func after_test() -> void:
	if is_instance_valid(_scene):
		_scene.queue_free()
	_scene = null
	SimBridge.disconnect_from_sim()
	SimBridge._outbound_buffer.clear()
	MetaStack._stack.clear()


# -----------------------------------------------------------------------------
# Helpers
# -----------------------------------------------------------------------------

func _load_main_menu() -> void:
	var packed := load(MAIN_MENU_SCENE_PATH) as PackedScene
	# Hard-fail on missing scene (PR #135 review T3): silent skip turns a broken
	# merge-path test into a uselessly green one.
	assert_that(packed).override_failure_message(
		"main_menu.tscn missing — merge-path coverage is broken, not skipped"
	).is_not_null()
	_scene = packed.instantiate()
	add_child(_scene)


func _load_char_create() -> void:
	var packed := load(CHAR_CREATE_SCENE_PATH) as PackedScene
	# Hard-fail on missing scene (PR #135 review T3): silent skip turns a broken
	# merge-path test into a uselessly green one.
	assert_that(packed).override_failure_message(
		"character_creation.tscn missing — merge-path coverage is broken, not skipped"
	).is_not_null()
	_scene = packed.instantiate()
	# Seed required state so Start is not disabled (guard added in PR #134 / R2-Hoshe-1).
	# Individual tests override these as needed. add_child() must run first so
	# _ready() populates @onready vars (_footer_start, etc.) that
	# _update_start_btn_state() dereferences.
	add_child(_scene)
	_scene._selected_bookmark_id = "test-bookmark"
	_scene._selected_location_id = "test-location"
	if _scene.has_method("_update_start_btn_state"):
		_scene._update_start_btn_state()


func _make_catalog_snapshot() -> Dictionary:
	## Minimal valid snapshot with a bookmark_catalog for flow-1 testing.
	## D-192: no version field required; decode accepts snapshots with or without.
	return {
		"tick": 0,
		"entities": [],
		"game_time": {"day": 0, "time_of_day": 0, "day_phase": "Morning", "tick_rate": "Full"},
		"player_facing": "North",
		"player_stance": "Walk",
		"player_inventory": [],
		"visible_tiles": [],
		"nearby_interactions": [],
		"pending_recognitions": [],
		"bookmark_catalog": {
			"bookmarks": [
				{
					"id": "bm_tycoon_arion",
					"title": "Arion Freight Broker",
					"subtitle": "Start at Arion orbital",
					"flavor": "Commodities and logistics.",
					"default_location": "arion",
					"allowed_locations": ["arion", "arion_low"],
					"allowed_locations_cultures": ["arion"],
					"career": "tycoon",
					"starting_capital_tractus": 50000,
				}
			]
		},
	}


# =============================================================================
# Flow 1: main menu → new game → loading state → catalog received → resolved
# =============================================================================
# Regression guard for #872: New Game used to hang on "Connecting to simulation..."
# because bookmark_catalog was overwritten in receive_bytes before poll_snapshot consumed it.
# This test catches that regression by verifying the full state machine:
# pressed → loading visible → catalog signal → loading dismissed.

func test_new_game_shows_loading_screen() -> void:
	## Pressing New Game must show the loading screen and set _waiting_for_catalog.
	_load_main_menu()
	if _scene == null:
		return

	assert_bool(_scene._waiting_for_catalog).override_failure_message(
		"_waiting_for_catalog must be false before New Game is pressed"
	).is_false()

	# Press New Game via the button signal (same as real player input)
	_scene._new_game_btn.pressed.emit()

	assert_bool(_scene._waiting_for_catalog).override_failure_message(
		"_waiting_for_catalog must be true after New Game pressed"
	).is_true()
	assert_that(_scene._loading_screen).override_failure_message(
		"Loading screen instance must exist after New Game pressed"
	).is_not_null()
	assert_bool(_scene._loading_screen.visible).override_failure_message(
		"Loading screen must be visible after New Game pressed"
	).is_true()


func test_new_game_catalog_snapshot_resolves_loading_state() -> void:
	## When snapshot_received fires with a bookmark_catalog, the loading state must clear.
	## This is the exact regression introduced in #872 — if the catalog is never delivered,
	## _waiting_for_catalog stays true and the screen hangs forever.
	_load_main_menu()
	if _scene == null:
		return

	# Simulate the New Game press to set up the signal subscription and loading state.
	# In test mode, connect_to_sim() immediately fires CONNECTED, which triggers
	# _on_sim_state_changed_for_new_game and connects snapshot_received.
	_scene._new_game_btn.pressed.emit()

	assert_bool(_scene._waiting_for_catalog).override_failure_message(
		"Precondition: _waiting_for_catalog must be true before catalog arrives"
	).is_true()

	# Deliver the catalog via the signal path (same path the server uses in live mode).
	# snapshot_received is emitted here directly because in test mode poll_snapshot()
	# uses the harness snapshot (no catalog). The carry-forward fix (#872) ensures
	# this signal path also works correctly in live mode when ticks batch.
	var catalog_snapshot := _make_catalog_snapshot()
	SimBridge.snapshot_received.emit(catalog_snapshot)

	# Terminal state: loading resolved
	assert_bool(_scene._waiting_for_catalog).override_failure_message(
		"_waiting_for_catalog must be false after catalog snapshot delivered — #872 regression"
	).is_false()
	# PR #135 review H4: assert the SimBridge terminus, not just the loading flag.
	# In test mode connect_to_sim() jumps state to CONNECTED synchronously; this
	# guarantees the flow reached its terminal state, not merely that the catalog
	# flag cleared.
	assert_int(SimBridge.state).override_failure_message(
		"SimBridge must be in CONNECTED terminus after catalog resolves — flow completion guard"
	).is_equal(SimBridge.ConnectionState.CONNECTED)
	assert_bool(GameState.bookmark_catalog.size() > 0).override_failure_message(
		"GameState.bookmark_catalog must be populated after catalog snapshot applied"
	).is_true()
	assert_str(GameState.bookmark_catalog[0].get("id", "")).override_failure_message(
		"Catalog entry must have the expected bookmark id"
	).is_equal("bm_tycoon_arion")


# =============================================================================
# Flow 2: main menu → load game → save picker → save selected
# =============================================================================

func test_load_game_save_picker_shows_on_browse() -> void:
	## Calling _on_load_game_browse() must show the save picker panel.
	_load_main_menu()
	if _scene == null:
		return

	assert_bool(_scene._load_panel.visible).override_failure_message(
		"Load panel must be hidden before Load Game is pressed"
	).is_false()

	_scene._on_load_game_browse()

	assert_bool(_scene._load_panel.visible).override_failure_message(
		"Load panel must be visible after _on_load_game_browse()"
	).is_true()


func test_load_game_save_selection_sets_pending_load_path() -> void:
	## Selecting a save entry must set GameState.pending_load_path for main.gd to consume.
	_load_main_menu()
	if _scene == null:
		return

	var mock_save := {
		"game_id": "20260421-120000-abc123",
		"newest_save": "quicksave.sav",
	}

	# Call _on_save_selected directly — mirrors what the generated save-list button does.
	_scene._on_save_selected(mock_save)

	assert_str(GameState.pending_load_path).override_failure_message(
		"pending_load_path must be set to the selected save's full path"
	).is_equal("user://saves/20260421-120000-abc123/quicksave.sav")


# =============================================================================
# Flow 3: character creation → submit → sim_bridge receives correct payload
# =============================================================================

func test_character_creation_submit_sends_confirm_bookmark_action() -> void:
	## _on_start() must queue a ConfirmBookmark action with the selected bookmark
	## and location IDs. This is the payload the server uses to initialize the run.
	_load_char_create()
	if _scene == null:
		return

	# Ensure SimBridge is connected so send_named_action doesn't silently drop the action
	SimBridge.connect_to_sim()  # test mode: immediately CONNECTED

	_scene._selected_bookmark_id = "bm_tycoon_arion"
	_scene._selected_location_id = "arion"
	if _scene.has_method("_update_start_btn_state"):
		_scene._update_start_btn_state()

	SimBridge._outbound_buffer.clear()
	_scene._on_start()

	var found := false
	for entry in SimBridge._outbound_buffer:
		if entry.get("action_name") == "ConfirmBookmark":
			var data: Variant = entry.get("action_data")
			if (
				data is Dictionary
				and data.get("bookmark_id") == "bm_tycoon_arion"
				and data.get("starting_location_id") == "arion"
			):
				found = true
				break
	assert_bool(found).override_failure_message(
		"_outbound_buffer must contain ConfirmBookmark{bookmark_id='bm_tycoon_arion', starting_location_id='arion'}"
	).is_true()


# =============================================================================
# Flow 4: bookmark tab → select location → confirm → server gets bookmark action
# =============================================================================

func test_bookmark_tab_select_location_then_confirm_queues_action() -> void:
	## Exercises the full selection path: picking a bookmark, picking a location, then
	## confirming. Verifies the correct bookmark_id + starting_location_id reach the server.
	## This is the flow the player actually takes — selection handlers must propagate
	## to the outbound buffer correctly.

	# Populate catalog before scene instantiation so _build_bookmark_cards() sees it
	GameState.bookmark_catalog = [
		{
			"id": "bm_tycoon_arion",
			"title": "Arion Freight Broker",
			"subtitle": "Start at Arion orbital",
			"flavor": "Commodities and logistics.",
			"default_location": "arion",
			"allowed_locations": ["arion", "arion_low"],
			"allowed_locations_cultures": ["arion"],
			"career": "tycoon",
			"starting_capital_tractus": 50000,
		}
	]

	_load_char_create()
	if _scene == null:
		return

	SimBridge.connect_to_sim()  # test mode: immediately CONNECTED
	SimBridge._outbound_buffer.clear()

	# Simulate the player selecting the bookmark card
	var bm: Dictionary = GameState.bookmark_catalog[0]
	_scene._on_bookmark_selected(bm)

	assert_str(_scene._selected_bookmark_id).override_failure_message(
		"_on_bookmark_selected must update _selected_bookmark_id"
	).is_equal("bm_tycoon_arion")
	assert_str(_scene._selected_location_id).override_failure_message(
		"_on_bookmark_selected must populate _selected_location_id from default_location"
	).is_not_empty()

	# Simulate the player picking a specific allowed location
	_scene._on_location_selected("arion_low")

	assert_str(_scene._selected_location_id).override_failure_message(
		"_on_location_selected must update _selected_location_id"
	).is_equal("arion_low")

	# Confirm — sends the action to the server
	_scene._on_start()

	var found := false
	for entry in SimBridge._outbound_buffer:
		if entry.get("action_name") == "ConfirmBookmark":
			var data: Variant = entry.get("action_data")
			if (
				data is Dictionary
				and data.get("bookmark_id") == "bm_tycoon_arion"
				and data.get("starting_location_id") == "arion_low"
			):
				found = true
				break
	assert_bool(found).override_failure_message(
		"_outbound_buffer must contain ConfirmBookmark{bookmark_id='bm_tycoon_arion', starting_location_id='arion_low'}"
	).is_true()