extends Node

# Semantic actions — NO raw key codes cross the bridge
# Movement uses hold-to-move (polled each frame in _process).
# Discrete actions (interact, stance, etc.) use press events (_unhandled_input).
#
# D-054: Mouse-relative facing and movement.
# Mouse position determines facing direction (client-side float).
# WASD is relative to facing: W = toward cursor, S = away, A/D = strafe.
# Server receives facing octant only — the full float stays client-side.
#
# Movement throttle: client-side rate limit per stance (D-053).
# Sprint=5/s, Walk=2.5/s, Careful=1.7/s, Crouch=1.25/s.
# Server cooldown is authoritative, but the client throttle prevents
# flooding and gives correct movement feel in test mode.
#
# T-1146: implant-occlusion gate. Every gameplay-sim-bound action this file can
# produce (movement, SET_FACING, and every _unhandled_input entry EXCEPT
# OPEN_MENU/BUG_REPORT/OPEN_JOURNAL, which are client-only and never reach
# send_input — see main.gd's dispatch loop) is gated on
# HudGroups.gameplay_occluded, at the POLL SITE (here), not the flush site
# (main.gd). Poll-site was T-1146's own recommendation and is also the
# structurally cleaner one: it slots into the existing dialogue_active /
# free_camera_mode early-return this file already has, and it means nothing is
# ever enqueued while occluded — a flush-site gate would still enqueue and then
# have to discard, which is exactly the kind of latent backlog this ticket is
# about. Movement is HELD-STATE polled (Input.is_action_pressed), so an
# occlusion-begin transition must be able to interrupt a key already down
# mid-press, and an occlusion-end transition must NOT silently resume a key
# still down — see _on_gameplay_occluded and _suppress_move_until_release
# below. Discrete actions (_unhandled_input) are edge-triggered per-press
# events, not held state, so there is no backlog-on-close risk for them: a
# gated press this frame simply never queues, and get_viewport() still has
# set_input_as_handled() called so the event doesn't fall through to some
# other handler either (mirrors the existing dialogue_active early-return
# already established below).
enum Action {
	MOVE_NORTH,
	MOVE_NORTHEAST,
	MOVE_EAST,
	MOVE_SOUTHEAST,
	MOVE_SOUTH,
	MOVE_SOUTHWEST,
	MOVE_WEST,
	MOVE_NORTHWEST,
	INTERACT,
	USE_PERCEPTION_MODE,
	OPEN_MENU,
	PAUSE,
	UNPAUSE,
	TOGGLE_STANCE_UP,
	TOGGLE_STANCE_DOWN,
	BUG_REPORT,  # #495: F12 WRONG button — client-only, not sent to server
	OPEN_JOURNAL,  # #264: J key — toggle knowledge journal panel, client-only
	SET_FACING,  # D-054: facing octant update (no movement)
	TELEPORT_HUB,  # #501: Home key — Gauntlet dev teleport (not production fast-travel)
	SAVE_GAME,  # #554: F5 quicksave — sends SaveGame to server with save path
	LOAD_GAME,  # #554: F6 quickload — sends LoadGame to server with save path
	DEBUG_COMMAND,  # #581: debug console command dispatch — sends DebugCommandKind to server
	CHANGE_SETTINGS,  # #646: persist a setting to server SQLite — sends {key, value} to server
	REQUEST_ALL_SETTINGS,  # #646: request full settings dump from server after handshake (unit variant)
	DELETE_SETTING,  # #646: delete a setting by key from server SQLite (struct variant)
}

# Minimum milliseconds between movement commands, per stance.
# Tuned so Walk feels like walking, Sprint feels fast but readable.
const MOVE_INTERVAL_MS := {
	"Sprint": 200,  # 5/sec — fast but trackable
	"Walk": 400,  # 2.5/sec — comfortable walking pace
	"Careful": 600,  # ~1.7/sec — deliberate, scanning
	"Crouch": 800,  # 1.25/sec — creeping
}

var input_queue: Array[Dictionary] = []

# D-054: Client-side facing angle (radians). 0=East, -PI/2=North, PI/2=South.
# Updated every frame from mouse position. EntityRenderer reads this for indicator.
var facing_angle: float = -PI / 2.0  # Default: North
var facing_octant: String = "North"  # Derived from facing_angle

# T-1088 (design §9): 3D facing seam. A 3D scene installs a provider returning
# sim-space radians (0=East, +PI/2=South — same convention as facing_angle), or
# NAN = no update (deadzone/degenerate ray). While installed it fully replaces the
# 2D canvas-transform path in _update_facing_from_mouse(); unset (default) leaves
# the 2D path unchanged. Untyped Callable per the autoload parse-order rule.
var facing_angle_provider = Callable()

# gdlint class-definitions-order: all public vars above this line, all
# private (underscore-prefixed) vars below — reordered while touching this
# file for T-1146 (pre-existing violation on main, unrelated to this ticket:
# facing_angle_provider used to sit after _last_sent_octant/_last_move_msec).
var _last_sent_octant: String = "North"  # Track to avoid redundant sends
var _last_move_msec: int = 0

# T-1146: local mirror of HudGroups.gameplay_occluded, updated by the signal
# handler below. Deliberately NOT HudGroups.is_implant_active() / is_app_active()
# — those are true for BOTH FULLSCREEN and INSERT mode (e.g. main.gd opens
# "implant/economics" in INSERT mode, a small overlay alongside still-visible,
# still-playable gameplay — D-181/#824), whereas gameplay_occluded (and this
# mirror) is only ever true for FULLSCREEN, which is the actual "the player is
# not looking at their character" condition this gate exists for. Read directly
# in the hot _process() poll instead of calling HudGroups.get_active_mode()
# every frame — the signal already tells us exactly when it changes.
var _gameplay_occluded: bool = false

# T-1146: latch set the instant gameplay becomes occluded WHILE a movement key
# is already held. Cleared only once the poll observes ALL movement keys
# released (raw_dir == ZERO) at least one frame after occlusion ends — a
# player who forgot their finger on W when the map closes must re-press, not
# lurch forward on the very next frame. Facing updates are exempt (see
# _process) — turning to look is not "movement" and re-syncing facing the
# instant the implant closes is expected, not a lurch.
var _suppress_move_until_release: bool = false


func _ready() -> void:
	# Autoload-to-autoload signal wiring is fine at _ready (both are autoloads,
	# so both are already fully constructed by the time either _ready() body
	# runs) — the parse-order rule that bites autoloads only applies to
	# referencing a class_name TYPE, not calling a method / connecting a
	# signal on another autoload singleton.
	HudGroups.gameplay_occluded.connect(_on_gameplay_occluded)


# T-1146: fires on BOTH the open transition (occluded=true) and the close
# transition (occluded=false). Open: mirror the flag — the very next
# _process() poll already gates on _gameplay_occluded below and simply stops
# producing, so a key held at the moment of opening is dropped this frame with
# no separate latch needed. Close: mirror the flag AND arm the release-latch so
# a key still held at the moment of closing cannot resume movement without an
# intervening release — see _suppress_move_until_release's own doc.
func _on_gameplay_occluded(occluded: bool) -> void:
	_gameplay_occluded = occluded
	if not occluded:
		_suppress_move_until_release = true


# Hold-to-move: poll held direction keys each frame, throttled by stance.
# D-054: WASD is now mouse-relative. W = toward cursor, A/D = strafe.
# Server-side cooldown (D-053) is authoritative; this prevents client flooding.
# D-064: movement suppressed during dialogue (walk-away handled by dialogue_box).
# T-1146: SET_FACING and movement are both gated on gameplay_occluded — an
# implant screen open means the player is not looking at their character, so
# neither "I turned to face something" nor "I walked" should reach the server.
# Facing-angle tracking itself (facing_angle/facing_octant, purely client-side)
# still updates every frame regardless — only the SEND to the server is gated,
# same as the existing test_mode split in sim_bridge.gd's send_input().
func _process(_delta: float) -> void:
	# D-054: Update facing angle from mouse position every frame
	_update_facing_from_mouse()

	if GameState.dialogue_active or GameState.free_camera_mode:
		return

	if _gameplay_occluded:
		return

	# D-054: Send facing octant to server when it changes (even without movement)
	if facing_octant != _last_sent_octant:
		_last_sent_octant = facing_octant
		(
			input_queue
			. append(
				{
					"action": Action.SET_FACING,
					"timestamp_msec": Time.get_ticks_msec(),
					"action_data": {"facing": facing_octant},
				}
			)
		)

	# Poll held WASD keys
	var raw_dir := Vector2i.ZERO
	if Input.is_action_pressed("move_north"):
		raw_dir.y -= 1
	if Input.is_action_pressed("move_south"):
		raw_dir.y += 1
	if Input.is_action_pressed("move_east"):
		raw_dir.x += 1
	if Input.is_action_pressed("move_west"):
		raw_dir.x -= 1

	# T-1146: a key still held at the exact moment the implant closed must not
	# resume movement on its own — the latch (armed in _on_gameplay_occluded)
	# stays up until this poll observes every movement key released at least
	# once, at which point a fresh press is required to move again.
	if _suppress_move_until_release:
		if raw_dir == Vector2i.ZERO:
			_suppress_move_until_release = false
		return

	if raw_dir != Vector2i.ZERO:
		var now := Time.get_ticks_msec()
		var interval: int = MOVE_INTERVAL_MS.get(GameState.player_stance, 200)
		if now - _last_move_msec >= interval:
			_last_move_msec = now
			# D-054: Transform WASD input relative to mouse facing
			var world_dir := _wasd_to_world_dir(raw_dir)
			var action: Action = _dir_to_action(world_dir)
			(
				input_queue
				. append(
					{
						"action": action,
						"timestamp_msec": now,
					}
				)
			)


# Discrete actions: fire once on key press (not held).
# T-1146: OPEN_MENU/BUG_REPORT/OPEN_JOURNAL are checked and queued BEFORE the
# implant-occlusion gate — they are the implant/app-level keys the ticket
# explicitly carves out. OPEN_MENU is how the implant CLOSES (Esc/#528's
# priority chain in main.gd — HudGroups.close_app() before anything else), so
# gating it on occlusion would make the implant impossible to close with Esc.
# BUG_REPORT and OPEN_JOURNAL are client-only (main.gd's dispatch loop
# `continue`s on both before ever reaching SimBridge.send_input) — neither is
# gameplay-sim-bound, so neither belongs behind a gameplay-occlusion gate.
# Every other action in this function (INTERACT, USE_PERCEPTION_MODE,
# PAUSE/UNPAUSE, TOGGLE_STANCE_*, TELEPORT_HUB, SAVE_GAME, LOAD_GAME) reaches
# send_input unconditionally once queued (sim_bridge.gd's action_enum_to_wire
# has a wire case for every one of them) and IS gated below.
func _unhandled_input(event: InputEvent) -> void:
	if GameState.dialogue_active or GameState.free_camera_mode:
		return

	# Implant/app-level keys — never gated on occlusion, checked first so they
	# always win regardless of implant state.
	var action: Action = -1
	if event.is_action_pressed("open_menu"):
		action = Action.OPEN_MENU
	elif event.is_action_pressed("bug_report"):
		action = Action.BUG_REPORT
	elif event.is_action_pressed("open_journal"):
		action = Action.OPEN_JOURNAL

	# Gameplay-sim-bound keys — gated: skip the whole block while an implant
	# screen is occluding gameplay, so none of these can even be recognized,
	# let alone queued, while the player isn't looking at their character.
	if action == -1 and not _gameplay_occluded:
		if event.is_action_pressed("interact"):
			action = Action.INTERACT
		elif event.is_action_pressed("perception_mode"):
			action = Action.USE_PERCEPTION_MODE
		elif event.is_action_pressed("pause"):
			var tick_rate = GameState.game_time.get("tick_rate", "Full")
			action = Action.UNPAUSE if tick_rate == "Paused" else Action.PAUSE
		elif event.is_action_pressed("stance_up"):
			action = Action.TOGGLE_STANCE_UP
		elif event.is_action_pressed("stance_down"):
			action = Action.TOGGLE_STANCE_DOWN
		elif event.is_action_pressed("teleport_hub"):
			if GameState.gauntlet_mode:
				action = Action.TELEPORT_HUB
		elif event.is_action_pressed("quicksave"):
			action = Action.SAVE_GAME
		elif event.is_action_pressed("quickload"):
			action = Action.LOAD_GAME

	if action != -1:
		var entry := {
			"action": action,
			"timestamp_msec": Time.get_ticks_msec(),
		}
		# #554: Attach save path for SaveGame/LoadGame actions
		if action == Action.SAVE_GAME or action == Action.LOAD_GAME:
			var game_id := GameState.current_game_id
			if game_id.is_empty():
				get_viewport().set_input_as_handled()
				return  # No active session — ignore save/load
			entry["action_data"] = {"path": "user://saves/" + game_id + "/quicksave.sav"}
		input_queue.append(entry)
		get_viewport().set_input_as_handled()


func flush_queue() -> Array[Dictionary]:
	var queue = input_queue.duplicate()
	input_queue.clear()
	return queue


# T-1088 click-to-move seam (design §9 / D-248): queue ONE 8-direction step from a
# sim tile delta (e.g. Vector2i(1, 0) = East, Vector2i(1, 1) = Southeast), gated by
# the SAME per-stance throttle held-WASD uses (_last_move_msec + MOVE_INTERVAL_MS).
# The sandbox path follower calls this once per frame while walking a client-planned
# path; the shared throttle paces it to the exact stance cadence (no duplicated
# interval table) and interleaves cleanly with WASD — a held key and a queued step
# can never both fire inside one window. Returns true when the step was queued,
# false when throttled or input-suppressed. Ordinary Move* actions only: zero
# protocol change, no client prediction, the server validates every step (D-010).
func queue_move_step(tile_delta: Vector2i) -> bool:
	# T-1146: same suppression predicate as the _process poll — all three
	# input_queue producers in this module share it, so the occlusion gate is
	# self-contained here rather than delegated to seam callers (today the
	# sandbox freezes the path follower itself, but Phase 5/T-962 lifts
	# click-to-move into the shared session driver).
	if GameState.dialogue_active or GameState.free_camera_mode or _gameplay_occluded:
		return false
	if tile_delta == Vector2i.ZERO:
		return false
	var now := Time.get_ticks_msec()
	var interval: int = MOVE_INTERVAL_MS.get(GameState.player_stance, 200)
	if now - _last_move_msec < interval:
		return false
	_last_move_msec = now
	input_queue.append(
		{
			"action": _dir_to_action(tile_delta),
			"timestamp_msec": now,
		}
	)
	return true


# T-1088 double-RMB sprint-there seam: queue ONE ordinary stance toggle (up = toward
# Sprint, down = toward Crouch) through the same input_queue movement rides. Discrete,
# so no throttle — the server's handle_toggle_stance has no cooldown, so the sandbox
# follower can burst the exact ladder distance and trust it (server validates). No-op
# while input is suppressed (dialogue / free camera / occlusion), matching movement.
func queue_stance_toggle(up: bool) -> void:
	if GameState.dialogue_active or GameState.free_camera_mode or _gameplay_occluded:
		return
	input_queue.append(
		{
			"action": Action.TOGGLE_STANCE_UP if up else Action.TOGGLE_STANCE_DOWN,
			"timestamp_msec": Time.get_ticks_msec(),
		}
	)


## Reset facing state to default (North). Use in tests per D-030 testability.
func reset_facing_state() -> void:
	facing_angle = -PI / 2.0
	facing_octant = "North"
	_last_sent_octant = "North"


# D-054: Compute facing angle from mouse position relative to player screen position.
# Uses viewport canvas transform to convert world coords to screen coords.
# Intentional coupling: reads GameState.player_position directly — InputMapper is an
# autoload that runs before game loop rendering, so position is always current-tick.
func _update_facing_from_mouse() -> void:
	# T-1088 (design §9): provider seam. In a 3D scene the canvas-transform anchor
	# below is a far-off-screen point, and the screen-space mouse angle is not a
	# sim-space angle under the 45° map rotation + ortho pitch — an installed
	# provider (e.g. SandboxMouseAimProvider) replaces this whole path.
	if facing_angle_provider.is_valid():
		var a: float = facing_angle_provider.call()
		if is_finite(a):
			facing_angle = a
			facing_octant = _angle_to_octant(a)
		return
	var vp := get_viewport()
	if vp == null:
		return
	var canvas_xf := vp.get_canvas_transform()
	var C := load("res://scripts/constants.gd")
	var player_world_px: Vector2 = GameState.player_position * C.TILE_SIZE
	var player_screen: Vector2 = canvas_xf * player_world_px
	var mouse_screen: Vector2 = vp.get_mouse_position()
	var delta: Vector2 = mouse_screen - player_screen
	# Only update if mouse is meaningfully distant from player (avoid jitter at center)
	if delta.length_squared() > 4.0:
		facing_angle = delta.angle()
		facing_octant = _angle_to_octant(facing_angle)


# D-054: Transform raw WASD input (screen-space) to world direction relative to mouse facing.
# W (+Y up in input, mapped to forward), S (backward), A (strafe left), D (strafe right).
# Raw input: W=(-Y), S=(+Y), A=(-X), D=(+X) in screen coords.
# Forward = facing_angle direction. Output: nearest octant direction vector.
func _wasd_to_world_dir(raw_dir: Vector2i) -> Vector2i:
	# Build a continuous direction vector relative to facing.
	# raw_dir.y: -1 = W (forward), +1 = S (backward)
	# raw_dir.x: -1 = A (strafe left), +1 = D (strafe right)
	var forward := Vector2(cos(facing_angle), sin(facing_angle))
	var right := Vector2(-forward.y, forward.x)  # 90° clockwise

	# Combine: forward/back from W/S, strafe from A/D
	var world_float := forward * float(-raw_dir.y) + right * float(raw_dir.x)

	# Snap to nearest octant direction
	return _snap_to_octant_dir(world_float)


# Snap a floating-point direction vector to the nearest of 8 cardinal/diagonal directions.
static func _snap_to_octant_dir(dir: Vector2) -> Vector2i:
	if dir.length_squared() < 0.001:
		return Vector2i.ZERO
	var angle := dir.angle()
	# Quantize to nearest 45° (PI/4)
	var octant := roundi(angle / (PI / 4.0))
	match octant:
		0:
			return Vector2i(1, 0)  # East
		1:
			return Vector2i(1, 1)  # Southeast
		2, -6:
			return Vector2i(0, 1)  # South
		3, -5:
			return Vector2i(-1, 1)  # Southwest
		4, -4:
			return Vector2i(-1, 0)  # West
		-3, 5:
			return Vector2i(-1, -1)  # Northwest
		-2:
			return Vector2i(0, -1)  # North
		-1:
			return Vector2i(1, -1)  # Northeast
		_:
			return Vector2i.ZERO


# D-054: Convert a facing angle (radians) to the nearest octant name.
# Godot 2D: 0=East, PI/2=South, -PI/2=North.
static func _angle_to_octant(angle: float) -> String:
	var octant := roundi(angle / (PI / 4.0))
	match octant:
		0:
			return "East"
		1:
			return "Southeast"
		2, -6:
			return "South"
		3, -5:
			return "Southwest"
		4, -4:
			return "West"
		-3, 5:
			return "Northwest"
		-2:
			return "North"
		-1:
			return "Northeast"
		_:
			return "East"


# Map a direction vector to the corresponding movement Action.
# Handles all 8 directions via composite W+D, W+A, etc.
static func _dir_to_action(dir: Vector2i) -> Action:
	match dir:
		Vector2i(0, -1):
			return Action.MOVE_NORTH
		Vector2i(1, -1):
			return Action.MOVE_NORTHEAST
		Vector2i(1, 0):
			return Action.MOVE_EAST
		Vector2i(1, 1):
			return Action.MOVE_SOUTHEAST
		Vector2i(0, 1):
			return Action.MOVE_SOUTH
		Vector2i(-1, 1):
			return Action.MOVE_SOUTHWEST
		Vector2i(-1, 0):
			return Action.MOVE_WEST
		Vector2i(-1, -1):
			return Action.MOVE_NORTHWEST
		_:
			return Action.MOVE_NORTH