## D-030 Layer 1: Protocol bridge tests for ObserverSnapshot features.
## Validates player_stance (D-053) and player_inventory (D-065) decode,
## GameState storage, SimBridge test mode, input encoding for stance toggles,
## protocol version checks, and fixture round-trips.
## Spec refs: D-053, D-065, D-020, #449
class_name TestProtocolBridge
extends GdUnitTestSuite

const FIXTURE_DIR = "res://tests/fixtures/msgpack/"
# TODO: Add .msgpack fixture files for v6 stance/inventory variations.
# Current fixtures (snapshot_one_npc, snapshot_empty, etc.) only cover default
# Walk stance with empty inventory. Missing fixtures:
#   - snapshot with player_stance = Sprint, Careful, Crouch
#   - snapshot with populated player_inventory (1-item, 9-item full grid)
#   - combined stance + inventory variations
# Stance/inventory decode is tested via in-memory Messagepack.encode() above,
# but regression-safe .msgpack fixtures are needed for bridge contract coverage.


func _load_fixture(name: String) -> PackedByteArray:
	var path = FIXTURE_DIR + name + ".msgpack"
	var file = FileAccess.open(path, FileAccess.READ)
	assert_that(file).is_not_null()
	return file.get_buffer(file.get_length())


# -- Protocol version upgrade -------------------------------------------------

func test_protocol_version_is_8() -> void:
	assert_that(Protocol.PROTOCOL_VERSION).is_equal(8)


func test_fixtures_at_protocol_version_8() -> void:
	# All regenerated fixtures should be at v8
	for fixture_name in ["snapshot_one_npc", "snapshot_empty", "snapshot_player", "snapshot_multi_entity"]:
		var bytes = _load_fixture(fixture_name)
		var snapshot = Protocol.decode_snapshot(bytes)
		assert_that(snapshot).is_not_null()
		assert_that(snapshot.version).is_equal(8)


func test_rejects_version_6() -> void:
	var raw := {"tick": 1, "version": 6, "entities": []}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)
	assert_that(snapshot).is_null()


# -- player_stance decode (D-053) ---------------------------------------------

func test_decode_player_stance_walk() -> void:
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
		"player_stance": "Walk",
		"player_inventory": [],
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)
	assert_that(snapshot).is_not_null()
	assert_that(snapshot.player_stance).is_equal("Walk")


func test_decode_player_stance_sprint() -> void:
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
		"player_stance": "Sprint",
		"player_inventory": [],
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)
	assert_that(snapshot.player_stance).is_equal("Sprint")


func test_decode_player_stance_careful() -> void:
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
		"player_stance": "Careful",
		"player_inventory": [],
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)
	assert_that(snapshot.player_stance).is_equal("Careful")


func test_decode_player_stance_crouch() -> void:
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
		"player_stance": "Crouch",
		"player_inventory": [],
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)
	assert_that(snapshot.player_stance).is_equal("Crouch")


func test_decode_player_stance_missing_defaults_to_walk() -> void:
	# v6 snapshot without player_stance → should default to "Walk"
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)
	assert_that(snapshot).is_not_null()
	assert_that(snapshot.player_stance).is_equal("Walk")


# -- player_inventory decode (D-065) ------------------------------------------

func test_decode_empty_inventory() -> void:
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
		"player_stance": "Walk",
		"player_inventory": [],
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)
	assert_that(snapshot.player_inventory.size()).is_equal(0)


func test_decode_smuggler_inventory_3_items() -> void:
	# D-065: smuggler carries 3 specific items
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
		"player_stance": "Walk",
		"player_inventory": [
			{"item_id": 100, "name": "Manifest Copy", "slot": 0},
			{"item_id": 101, "name": "Access Token", "slot": 1},
			{"item_id": 102, "name": "Comm Log", "slot": 2},
		],
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)

	assert_that(snapshot.player_inventory.size()).is_equal(3)
	assert_that(snapshot.player_inventory[0].item_id).is_equal(100)
	assert_that(snapshot.player_inventory[0].name).is_equal("Manifest Copy")
	assert_that(snapshot.player_inventory[0].slot).is_equal(0)
	assert_that(snapshot.player_inventory[1].name).is_equal("Access Token")
	assert_that(snapshot.player_inventory[1].slot).is_equal(1)
	assert_that(snapshot.player_inventory[2].name).is_equal("Comm Log")
	assert_that(snapshot.player_inventory[2].slot).is_equal(2)


func test_decode_full_9_slot_inventory() -> void:
	# D-065: 3x3 grid = 9 slots universal
	var items: Array = []
	for i in range(9):
		items.append({"item_id": 100 + i, "name": "Item %d" % i, "slot": i})
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
		"player_inventory": items,
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)

	assert_that(snapshot.player_inventory.size()).is_equal(9)
	assert_that(snapshot.player_inventory[0].slot).is_equal(0)
	assert_that(snapshot.player_inventory[8].slot).is_equal(8)
	assert_that(snapshot.player_inventory[8].item_id).is_equal(108)


func test_decode_inventory_missing_defaults_to_empty() -> void:
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)
	assert_that(snapshot.player_inventory.size()).is_equal(0)


func test_decode_inventory_skips_malformed_items() -> void:
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
		"player_inventory": [
			{"item_id": 100, "name": "Valid Item", "slot": 0},
			{"broken": true},  # Missing item_id and name
			{"item_id": 101},  # Missing name
			{"name": "No ID"},  # Missing item_id
			{"item_id": 102, "name": "Also Valid", "slot": 3},
		],
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)
	# Only items with both item_id and name should decode
	assert_that(snapshot.player_inventory.size()).is_equal(2)
	assert_that(snapshot.player_inventory[0].name).is_equal("Valid Item")
	assert_that(snapshot.player_inventory[1].name).is_equal("Also Valid")


func test_decode_inventory_item_slot_defaults_to_zero() -> void:
	var raw := {
		"tick": 1,
		"version": Protocol.PROTOCOL_VERSION,
		"entities": [],
		"player_inventory": [
			{"item_id": 100, "name": "No Slot"},
		],
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)
	assert_that(snapshot.player_inventory[0].slot).is_equal(0)


# -- GameState: v6 field storage -----------------------------------------------

func test_game_state_stores_player_stance() -> void:
	GameState.apply_snapshot({"tick": 1, "entities": [], "player_stance": "Sprint"})
	assert_that(GameState.player_stance).is_equal("Sprint")
	GameState.player_stance = "Walk"  # Reset


func test_game_state_stores_player_inventory() -> void:
	var inv := [
		{"item_id": 100, "name": "Manifest Copy", "slot": 0},
		{"item_id": 101, "name": "Access Token", "slot": 1},
	]
	GameState.apply_snapshot({"tick": 1, "entities": [], "player_inventory": inv})
	assert_that(GameState.player_inventory.size()).is_equal(2)
	assert_that(GameState.player_inventory[0].name).is_equal("Manifest Copy")
	GameState.player_inventory = []  # Reset


func test_game_state_clears_inventory_when_absent() -> void:
	var inv := [{"item_id": 100, "name": "Item", "slot": 0}]
	GameState.apply_snapshot({"tick": 1, "entities": [], "player_inventory": inv})
	assert_that(GameState.player_inventory.size()).is_equal(1)
	GameState.apply_snapshot({"tick": 2, "entities": []})
	assert_that(GameState.player_inventory.size()).is_equal(0)


func test_game_state_stance_persists_when_absent() -> void:
	# Stance should NOT reset when field is missing — keep last known value
	GameState.apply_snapshot({"tick": 1, "entities": [], "player_stance": "Careful"})
	assert_that(GameState.player_stance).is_equal("Careful")
	GameState.apply_snapshot({"tick": 2, "entities": []})
	# Stance persists (no explicit reset to Walk when absent)
	assert_that(GameState.player_stance).is_equal("Careful")
	GameState.player_stance = "Walk"  # Reset


func test_game_state_defaults() -> void:
	# Default values before any snapshot
	var gs_stance = GameState.player_stance
	var gs_inv = GameState.player_inventory
	assert_that(gs_stance).is_equal("Walk")
	assert_that(gs_inv.size()).is_equal(0)


# -- SimBridge test mode: v6 fields -------------------------------------------

func test_sim_bridge_test_snapshot_has_player_stance() -> void:
	SimBridge.reset_test_state()
	var snap = SimBridge._test_snapshot()
	assert_that(snap.has("player_stance")).is_true()
	assert_that(snap.player_stance).is_equal("Walk")


func test_sim_bridge_test_snapshot_has_player_inventory() -> void:
	SimBridge.reset_test_state()
	var snap = SimBridge._test_snapshot()
	assert_that(snap.has("player_inventory")).is_true()
	assert_that(snap.player_inventory is Array).is_true()


func test_sim_bridge_test_snapshot_version_8() -> void:
	SimBridge.reset_test_state()
	var snap = SimBridge._test_snapshot()
	assert_that(snap.version).is_equal(8)


# -- Fixture: v6 snapshots include new fields ----------------------------------

func test_fixture_snapshots_have_v6_defaults() -> void:
	# All regenerated fixtures should have player_stance=Walk and empty inventory
	for fixture_name in ["snapshot_one_npc", "snapshot_empty", "snapshot_player"]:
		var bytes = _load_fixture(fixture_name)
		var snapshot = Protocol.decode_snapshot(bytes)
		assert_that(snapshot).is_not_null()
		assert_that(snapshot.player_stance).is_equal("Walk")
		assert_that(snapshot.player_inventory.size()).is_equal(0)


# -- Input encoding: stance toggle actions (D-053) ----------------------------

func test_encode_toggle_stance_up() -> void:
	var inputs: Array = [{"tick": 10, "action_name": "ToggleStanceUp"}]
	var bytes := Protocol.encode_player_inputs(inputs)
	var raw = Messagepack.decode(bytes)
	assert_that(raw.status == null).is_true()
	assert_that(raw.value[0]["action"]).is_equal("ToggleStanceUp")


func test_encode_toggle_stance_down() -> void:
	var inputs: Array = [{"tick": 10, "action_name": "ToggleStanceDown"}]
	var bytes := Protocol.encode_player_inputs(inputs)
	var raw = Messagepack.decode(bytes)
	assert_that(raw.status == null).is_true()
	assert_that(raw.value[0]["action"]).is_equal("ToggleStanceDown")


func test_encode_decode_stance_toggle_roundtrip() -> void:
	for action_name in ["ToggleStanceUp", "ToggleStanceDown"]:
		var bytes = Protocol.encode_player_input(50, action_name)
		assert_that(bytes.size()).is_greater(0)
		var decoded = Protocol.decode_player_input(bytes)
		assert_that(decoded).is_not_null()
		assert_that(decoded.tick).is_equal(50)
		assert_that(decoded.action.variant).is_equal(action_name)
		assert_that(decoded.action.data).is_null()


# -- Integration: full v6 snapshot round-trip ----------------------------------

func test_full_v6_snapshot_decode() -> void:
	# Simulate a realistic v6 snapshot with all fields populated
	var raw := {
		"tick": 100,
		"version": Protocol.PROTOCOL_VERSION,
		"game_time": {"day": 1, "time_of_day": 720, "day_phase": "Evening", "tick_rate": "Full"},
		"player_facing": "Southeast",
		"player_stance": "Careful",
		"player_inventory": [
			{"item_id": 100, "name": "Manifest Copy", "slot": 0},
			{"item_id": 101, "name": "Access Token", "slot": 1},
			{"item_id": 102, "name": "Comm Log", "slot": 2},
		],
		"entities": [
			{"entity_id": 1, "x": 10.0, "y": 10.0, "z": 0, "kind": "Player",
			 "visibility": "Forward", "relationship": "Unknown", "observation": "Visible"},
		],
		"visible_tiles": [
			{"x": 10, "y": 10, "z": 0, "visibility": "Forward", "tile_kind": "Floor"},
		],
		"nearby_interactions": [{
			"entity_id": 2,
			"entity_type": "Npc",
			"distance": 1,
			"verbs": [{"kind": "Talk", "label": "Talk", "priority": 1, "available": true}],
		}],
		"current_monologue": {
			"id": "test_001",
			"text": "Sova Transit. The usual crowd.",
			"duration_seconds": 4.0,
		},
	}
	var encoded = Messagepack.encode(raw)
	var snapshot = Protocol.decode_snapshot(encoded.value)

	assert_that(snapshot).is_not_null()
	assert_that(snapshot.tick).is_equal(100)
	assert_that(snapshot.version).is_equal(Protocol.PROTOCOL_VERSION)
	assert_that(snapshot.player_facing).is_equal("Southeast")
	assert_that(snapshot.player_stance).is_equal("Careful")
	assert_that(snapshot.player_inventory.size()).is_equal(3)
	assert_that(snapshot.entities.size()).is_equal(1)
	assert_that(snapshot.nearby_interactions.size()).is_equal(1)
	assert_that(snapshot.current_monologue).is_not_null()
	assert_that(snapshot.current_monologue.text).is_equal("Sova Transit. The usual crowd.")


func test_full_v6_snapshot_to_game_state() -> void:
	var snapshot := {
		"tick": 50,
		"player_stance": "Crouch",
		"player_inventory": [
			{"item_id": 200, "name": "Access Token", "slot": 4},
		],
		"entities": [
			{"entity_id": 1, "x": 5.0, "y": 5.0, "z": 0, "kind": {"variant": "Player", "data": null}},
		],
	}
	GameState.apply_snapshot(snapshot)

	assert_that(GameState.current_tick).is_equal(50)
	assert_that(GameState.player_stance).is_equal("Crouch")
	assert_that(GameState.player_inventory.size()).is_equal(1)
	assert_that(GameState.player_inventory[0].name).is_equal("Access Token")
	assert_that(GameState.player_inventory[0].slot).is_equal(4)
	assert_that(GameState.player_position).is_equal(Vector2(5, 5))

	# Reset
	GameState.player_stance = "Walk"
	GameState.player_inventory = []