extends SceneTree

## Runs every writer/reader save-restart pair as two real child Godot processes
## (distinct PIDs) from this one suite, so a script-level regression roster also
## proves the new-PID halves. Each child's complete stdout+stderr and exit code
## are kept under user://pair-evidence/ (inside the run's private profile);
## summaries printed here avoid completion-marker wording on purpose.
const PAIRS: Array[String] = [
	"res://tests/s2/test_mana_reserve_new_pid.gd",
	"res://tests/s2/test_mana_recovery_new_pid.gd",
	"res://tests/transport/test_runtime_warp.gd",
	"res://tests/mvp/test_whole_tower_outage.gd",
	"res://tests/transport/test_route_wait_choice.gd",
]
const EVIDENCE_DIR := "user://pair-evidence"
var _checks := 0
var _failures := 0


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


func _run() -> void:
	var engine := OS.get_executable_path()
	var project := ProjectSettings.globalize_path("res://")
	DirAccess.make_dir_recursive_absolute(ProjectSettings.globalize_path(EVIDENCE_DIR))
	print("New-PID pairs: parent pid %d engine %s" % [OS.get_process_id(), engine])
	for script: String in PAIRS:
		var pids := {}
		for mode: String in ["writer", "reader"]:
			var output: Array = []
			var code := OS.execute(engine, ["--headless", "--path", project, "--script", script, "--", mode], output, true)
			var text := "".join(output)
			var name := "%s.%s" % [script.get_file().get_basename(), mode]
			var file := FileAccess.open(EVIDENCE_DIR.path_join(name + ".log"), FileAccess.WRITE)
			file.store_string(text)
			file.close()
			var pid := _child_pid(text)
			pids[mode] = pid
			var passed := code == 0 and _child_marker_passed(text)
			print("  pair %s %s exit=%d child_pid=%d bytes=%d sha256=%s" % [script.get_file(), mode, code, pid, text.to_utf8_buffer().size(), text.sha256_text()])
			_expect(passed, "%s %s child completes with zero failures" % [script.get_file(), mode])
		_expect(int(pids["writer"]) > 0 and int(pids["reader"]) > 0 and pids["writer"] != pids["reader"] and pids["reader"] != OS.get_process_id(), "%s writer and reader ran in distinct processes" % script.get_file())
	print("%s: %d checks" % ["PASS" if _failures == 0 else "FAIL", _checks])
	quit(_failures)


## Each pair script prints its own pid on its first line ("... pid N" or "(pid N)").
static func _child_pid(text: String) -> int:
	var regex := RegEx.new()
	regex.compile("pid (\\d+)")
	var found := regex.search(text)
	return int(found.get_string(1)) if found != null else -1


static func _child_marker_passed(text: String) -> bool:
	var regex := RegEx.new()
	regex.compile("(?m)^PASS: (\\d+) checks$")
	var found := regex.search(text)
	return found != null and int(found.get_string(1)) > 0 and not text.contains("FAIL:") and not text.contains("SCRIPT ERROR")


func _expect(condition: bool, label: String) -> void:
	_checks += 1
	if not condition:
		_failures += 1
		push_error("  ✗ %s" % label)