## Visual test capture engine — boots main.tscn, runs a named scenario or flow,
## captures viewport PNGs for golden comparison or ad-hoc inspection.
##
## Usage:
##   godot --rendering-driver opengl3 --fixed-fps 60 --resolution 960x540 \
##     --path client -s res://tests/visual_capture.gd -- \
##     --scenario fog_3state --output /abs/path
##
##   godot ... -- --flow flow_dialogue --output /abs/path --interval 3
##   godot ... -- --list
##
## Follows gen_client_fixtures.gd pattern: extends SceneTree, _init -> _run, quit().
## Requires a real rendering driver (not --headless) for shader execution.
extends SceneTree

# Load VisualScenarios explicitly — class_name registry not populated in -s mode.
# Must create an instance: static methods on loaded GDScript resources aren't
# callable via variable (only via class_name, which isn't available in -s mode).
var _scenarios: RefCounted = null

var _output_dir: String = ""
var _scenario: String = ""
var _flow: String = ""
var _interval: float = 3.0
var _list_mode: bool = false
var _config: Dictionary = {}
var _is_live: bool = false


func _init():
	_run.call_deferred()


func _run():  # gdlint:disable=max-returns
	# Parse CLI args (after -- separator)
	_parse_args()

	# Load scenarios script and create instance (class_name not available in -s mode)
	var scenarios_script: GDScript = load("res://tests/visual_scenarios.gd")
	_scenarios = scenarios_script.new()

	# Load config
	_config = _load_config()
	if _config.is_empty():
		push_error("visual_capture: failed to load tests/visual.json")
		quit(1)
		return

	# List mode: print scenario/flow names and exit
	if _list_mode:
		_print_list()
		quit()
		return

	# Validate mode
	if _scenario.is_empty() and _flow.is_empty():
		push_error("visual_capture: specify --scenario NAME or --flow NAME (or --list)")
		quit(1)
		return

	if _output_dir.is_empty():
		push_error("visual_capture: --output DIR is required")
		quit(1)
		return

	# Ensure output directory exists
	DirAccess.make_dir_recursive_absolute(_output_dir)

	# Load main scene (autoloads already initialized from project.godot)
	var main_scene = load("res://scenes/main.tscn")
	if main_scene == null:
		push_error("visual_capture: failed to load res://scenes/main.tscn")
		quit(1)
		return

	var main_node = main_scene.instantiate()

	# Live mode: configure server port BEFORE main.gd._ready() calls connect_to_sim()
	_is_live = OS.get_environment("SR_LIVE") == "1"
	if _is_live:
		var sim_bridge := root.get_node("/root/SimBridge")
		var port_env := OS.get_environment("SR_PORT")
		if port_env.is_empty():
			push_error("visual_capture: SR_LIVE=1 but SR_PORT not set")
			quit(1)
			return
		sim_bridge.server_port = int(port_env)
		print("visual_capture: live mode — server port %d" % sim_bridge.server_port)

	root.add_child(main_node)

	# Wait for NoiseTexture2D async generation
	var fog_overlay = main_node.get_node_or_null("World/FogOverlay")
	if fog_overlay and not fog_overlay._noise_ready:
		print("visual_capture: waiting for fog noise texture...")
		await fog_overlay.fog_noise_ready
	print("visual_capture: fog noise ready")

	# Set deterministic shader time BEFORE settle frames
	# Autoload globals not available as identifiers in -s mode — use tree path.
	root.get_node("/root/FogState").override_time = 1.0

	# Settle frames (camera smoothing, fog uniform init, UI layout)
	var settle_count: int = _config.get("settle_frames", 30)
	print("visual_capture: settling %d frames..." % settle_count)
	for i in range(settle_count):
		await process_frame

	# Live mode: wait for server connection and first snapshot
	if _is_live:
		var sim_bridge := root.get_node("/root/SimBridge")
		var game_state := root.get_node("/root/GameState")
		print("visual_capture: waiting for server connection...")
		var max_frames := 300  # 5 seconds at 60fps
		var waited := 0
		while sim_bridge.state != sim_bridge.ConnectionState.CONNECTED:
			if sim_bridge.state == sim_bridge.ConnectionState.ERROR:
				push_error("visual_capture: server connection failed")
				quit(1)
				return
			await process_frame
			waited += 1
			if waited >= max_frames:
				push_error("visual_capture: connection timeout after %d frames" % waited)
				quit(1)
				return
		print("visual_capture: connected after %d frames" % waited)
		# Wait for first snapshot from server
		waited = 0
		while game_state.current_tick == 0:
			await process_frame
			waited += 1
			if waited >= max_frames:
				push_error("visual_capture: no snapshot after %d frames" % waited)
				quit(1)
				return
		print(
			"visual_capture: first snapshot tick=%d (%d frames)" % [game_state.current_tick, waited]
		)

	if not _scenario.is_empty():
		await _run_scenario(main_node)
	elif not _flow.is_empty():
		await _run_flow(main_node)

	quit()


func _run_scenario(_main_node: Node) -> void:
	var scenarios: Dictionary = _config.get("scenarios", {})
	if not scenarios.has(_scenario):
		push_error("visual_capture: unknown scenario '%s'" % _scenario)
		quit(1)
		return

	var scenario_cfg: Dictionary = scenarios[_scenario]
	var ticks: int = scenario_cfg.get("ticks", 5)

	print("visual_capture: scenario '%s' — %d ticks" % [_scenario, ticks])

	# Apply scenario setup hook (pass root for autoload access)
	if not _scenarios.apply_setup(_scenario, root):
		push_warning("visual_capture: no setup hook for '%s'" % _scenario)

	# Advance simulation ticks (each process_frame polls one snapshot)
	for i in range(ticks):
		await process_frame

	# Post-tick setup (e.g. zone tint patching)
	_scenarios.post_setup(_scenario, root)

	# Replay snapshot: inject a real server snapshot through the FULL client pipeline.
	# Loads MessagePack bytes (exact wire format from server), decodes via Protocol.gd,
	# then applies through GameState → FogState → shader — same path as live game.
	var replay_path: String = scenario_cfg.get("replay_snapshot", "")
	if not replay_path.is_empty():
		var project_root := ProjectSettings.globalize_path("res://")
		var repo_root := project_root.rstrip("/").get_base_dir()
		var abs_path := repo_root.path_join(replay_path)
		var rf := FileAccess.open(abs_path, FileAccess.READ)
		if rf == null:
			push_error("visual_capture: cannot open replay snapshot %s" % abs_path)
			quit(1)
			return
		var replay_bytes := rf.get_buffer(rf.get_length())
		rf.close()
		# Decode through Protocol.decode_snapshot() — same as live IPC receive path.
		# This exercises: msgpack decode → entity decode → tile_kind→type mapping → etc.
		# class_name `Protocol` isn't resolvable in -s mode (see header note);
		# instantiate the script and call the static decoder on the instance,
		# then free it — the decoded Dictionary is independent of the node.
		var protocol_node: Node = load("res://scripts/protocol/protocol.gd").new()
		var replay_data: Variant = protocol_node.decode_snapshot(replay_bytes)
		protocol_node.free()
		if replay_data == null or not replay_data is Dictionary:
			push_error("visual_capture: Protocol.decode_snapshot failed for %s" % abs_path)
			quit(1)
			return
		print(
			(
				"visual_capture: replaying %s (%d bytes, tick=%s, %d tiles)"
				% [
					replay_path,
					replay_bytes.size(),
					str(replay_data.get("tick", "?")),
					replay_data.get("visible_tiles", []).size()
				]
			)
		)
		var game_state := root.get_node("/root/GameState")
		var fog_state := root.get_node("/root/FogState")
		game_state.apply_snapshot(replay_data)
		fog_state.update_from_state()
		# Extra frames for fog uniform propagation
		for i in range(4):
			await process_frame

	# Extra frames for state propagation + viewport texture lag
	await process_frame
	await process_frame

	# Capture
	await _capture("%s/%s.png" % [_output_dir, _scenario])


func _run_flow(_main_node: Node) -> void:
	var flows: Dictionary = _config.get("flows", {})
	if not flows.has(_flow):
		push_error("visual_capture: unknown flow '%s'" % _flow)
		quit(1)
		return

	var flow_cfg: Dictionary = flows[_flow]
	var steps: Array = flow_cfg.get("steps", [])
	var interval: float = flow_cfg.get("interval", _interval)

	print("visual_capture: flow '%s' — %d steps, %.1fs interval" % [_flow, steps.size(), interval])

	# Create output subdirectory for flow frames
	var flow_dir := "%s/%s" % [_output_dir, _flow]
	DirAccess.make_dir_recursive_absolute(flow_dir)

	var manifest_lines: PackedStringArray = []
	var frame_idx: int = 0

	for step in steps:
		if not step is Dictionary:
			continue
		var action: String = step.get("action", "wait")
		var label: String = step.get("label", action)

		# Apply action
		_scenarios.apply_flow_action(action, root)

		# Wait for interval (timer yields back to main loop — frames keep rendering)
		await create_timer(interval).timeout

		# Extra frames for viewport texture to catch up
		await process_frame
		await process_frame

		# Capture frame
		var frame_name := "%s_%03d.png" % [_flow, frame_idx]
		await _capture("%s/%s" % [flow_dir, frame_name])

		# Build manifest line
		var total_seconds: int = int((frame_idx + 1) * interval)
		var timecode := "%d:%02d" % [total_seconds / 60, total_seconds % 60]
		manifest_lines.append("%03d %s %s" % [frame_idx, timecode, label])

		frame_idx += 1

	# Write manifest sidecar
	var manifest_path := "%s/%s_manifest.txt" % [flow_dir, _flow]
	var f := FileAccess.open(manifest_path, FileAccess.WRITE)
	if f:
		f.store_string("\n".join(manifest_lines) + "\n")
		f.close()
		print("visual_capture: manifest -> %s" % manifest_path)


func _capture(path: String) -> void:
	# Wait for GPU to finish rendering current frame
	await RenderingServer.frame_post_draw

	var image := root.get_viewport().get_texture().get_image()
	if image == null:
		push_error("visual_capture: viewport image is null — GPU rendering may not be available")
		quit(1)
		return

	var err := image.save_png(path)
	if err != OK:
		push_error("visual_capture: failed to save PNG to %s (error %d)" % [path, err])
		quit(1)
		return

	print("visual_capture: captured -> %s (%dx%d)" % [path, image.get_width(), image.get_height()])


func _load_config() -> Dictionary:
	# Config is at tests/visual.json relative to repo root.
	# Repo root = parent of Godot project root (client/).
	var project_root := ProjectSettings.globalize_path("res://")
	var repo_root := project_root.rstrip("/").get_base_dir()
	var config_path := repo_root.path_join("tests/visual.json")

	var f := FileAccess.open(config_path, FileAccess.READ)
	if f == null:
		push_error("visual_capture: cannot open %s" % config_path)
		return {}

	var json_text := f.get_as_text()
	f.close()

	var parsed = JSON.parse_string(json_text)
	if parsed == null or not parsed is Dictionary:
		push_error("visual_capture: invalid JSON in %s" % config_path)
		return {}

	return parsed


func _parse_args() -> void:
	var args := OS.get_cmdline_user_args()
	var i := 0
	while i < args.size():
		match args[i]:
			"--scenario":
				i += 1
				if i < args.size():
					_scenario = args[i]
			"--flow":
				i += 1
				if i < args.size():
					_flow = args[i]
			"--output":
				i += 1
				if i < args.size():
					_output_dir = args[i]
			"--interval":
				i += 1
				if i < args.size():
					_interval = float(args[i])
			"--list":
				_list_mode = true
			_:
				push_warning("visual_capture: unknown arg '%s'" % args[i])
		i += 1


func _print_list() -> void:
	var scenarios: Dictionary = _config.get("scenarios", {})
	var flows: Dictionary = _config.get("flows", {})
	print("scenarios:")
	for name in scenarios:
		var desc: String = scenarios[name].get("description", "")
		print("  %s — %s" % [name, desc])
	print("flows:")
	for name in flows:
		var steps: Array = flows[name].get("steps", [])
		print("  %s — %d steps" % [name, steps.size()])