extends SceneTree
const E = preload("res://world/owniverse/math/exact.gd")

var failures: int = 0
var checks: int = 0
var completions: Array = []

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

func check(value: bool, message: String) -> void:
    checks = E.add(checks, 1)
    if (not value):
        failures = E.add(failures, 1)
        push_error(message)

func run() -> void:
    var manager = load("res://autoload/save_manager.gd").new()
    var directory: String = ("/tmp/owniverse-async-%s-%s" % [OS.get_process_id(), Time.get_ticks_usec()])
    DirAccess.make_dir_recursive_absolute(directory)
    manager.save_directory = directory
    root.add_child(manager)
    manager.save_completed.connect(func ( filename , success , error ) : completions.append([filename, success, error]))
    var world = load("res://world/owniverse/owniverse.gd").new()
    world.state.energy = E.subtract(world.state.energy, 1)
    world.state.time = preload("res://world/owniverse/simulation_time.gd").advance({"datetime": E.of("1e27")}, 0.000000001, 1)
    var data: Dictionary = {"state": world.state, "ui": {"current_page": 1}}
    var initial_energy: Variant = world.state.energy
    var global: Node = root.get_node("Global")
    var old_plaintext: bool = global.save_plaintext_copy
    global.save_plaintext_copy = true
    check(manager.request_save("snapshot", "test-password", data), "Snapshot queued")
    data.state.energy = 99
    data.ui.current_page = 2
    var frames: int = 0
    var deadline: int = E.add(Time.get_ticks_msec(), 10000)
    while (manager.is_saving() and E.lt(Time.get_ticks_msec(), deadline)):
        frames = E.add(frames, 1)
        await process_frame
    check(((not manager.is_saving()) and E.gt(frames, 0)), "Frames continue while save is pending")
    var saved: Dictionary = manager.load_data("snapshot", "test-password")
    check((E.eq(saved.state.energy, initial_energy) and E.eq(saved.ui.current_page, 1)), "Worker owns a deep snapshot")
    check(E.eq(saved.state.time, world.state.time), "Encrypted save preserves exact ticks at huge age")
    var plain: Dictionary = JSON.parse_string(FileAccess.get_file_as_string(directory.path_join("snapshot.adventure.json")))
    check(E.eq(E.decode(plain.state.energy), initial_energy), "Diagnostic JSON uses same snapshot")
    check(E.eq(E.decode(plain.state.time), saved.state.time), "Diagnostic JSON preserves fractional time")
    check((E.eq(completions.size(), 1) and completions[0][1]), "Completion reports successful write")

    completions.clear()
    data.state.energy = 1
    manager.request_save("latest", "test-password", data)
    data.state.energy = 2
    manager.request_save("latest", "test-password", data)
    data.state.energy = 3
    manager.request_save("latest", "test-password", data)
    data.state.energy = 4
    manager.flush_saves()
    check(E.eq(completions.size(), 2), "Repeated requests coalesce behind active write")
    check(E.eq(manager.load_data("latest", "test-password").state.energy, 3), "Last queued snapshot wins")

    var incompatible_path: String = directory.path_join("incompatible.adventure")
    var incompatible = FileAccess.open_encrypted_with_pass(incompatible_path, FileAccess.WRITE, "test-password")
    incompatible.store_var({"format_version": E.neg(1), "state": {"unknown": true}}, false)
    incompatible.close()
    var original: PackedByteArray = FileAccess.get_file_as_bytes(incompatible_path)
    var previous_archive = FileAccess.open(E.add(incompatible_path, ".incompatible.bak"), FileAccess.WRITE)
    previous_archive.store_string("keep previous backup")
    previous_archive.close()
    manager.blocked_saves.incompatible = true
    check((manager.load_data("incompatible", "test-password").is_empty() and E.eq(manager.last_error, "")), "Unsupported format permits a fresh session")
    check(((not manager.blocked_saves.has("incompatible")) and (not FileAccess.file_exists(incompatible_path))), "Incompatible file no longer blocks saving")
    check(E.eq(FileAccess.get_file_as_bytes(E.add(incompatible_path, ".incompatible.bak.1")), original), "Unsupported save archived without losing bytes")
    check(E.eq(FileAccess.get_file_as_string(E.add(incompatible_path, ".incompatible.bak")), "keep previous backup"), "Earlier archive preserved")
    check(manager.request_save("incompatible", "test-password", data), "New session can queue a save")
    manager.flush_saves()
    check(E.eq(manager.load_data("incompatible", "test-password").state, data.state), "New format saves and reloads after incompatible file")

    # Expected failures below must leave the last good encrypted file intact.
    data.state.energy = E.neg(1)
    manager.request_save("latest", "test-password", data)
    manager.flush_saves()
    check(((not completions.back()[1]) and manager.last_error.contains("Invalid save")), "Worker validation error reaches main thread")
    check(E.eq(manager.load_data("latest", "test-password").state.energy, 3), "Invalid snapshot preserves previous save")
    manager.blocked_saves.latest = true
    check((not manager.request_save("latest", "test-password", data)), "Unreadable save protection also applies to queue")
    # A valid snapshot exercises an actual I/O failure, not validation.
    data.state.energy = 5
    manager.request_save("missing/failure", "test-password", data)
    manager.flush_saves()
    check(manager.last_error.contains("Cannot write"), "I/O error reported without hanging queue")

    manager.request_save("shutdown", "test-password", data)
    data.state.energy = 6
    manager.request_save("shutdown", "test-password", data)
    manager.free()
    var reader = load("res://autoload/save_manager.gd").new()
    reader.save_directory = directory
    check(E.eq(reader.load_data("shutdown", "test-password").state.energy, 6), "Teardown drains final pending snapshot")
    reader.free()
    world.free()
    # Exercise the stage entry point too: manager tests alone do not catch a
    # regression back to the synchronous API in stage.gd.
    var shared_manager: Node = root.get_node("SaveManager")
    var original_directory: String = shared_manager.save_directory
    shared_manager.save_directory = directory
    var stage = load("res://stage/stage.gd").new()
    stage.pending_page = 2
    stage.owniverse.state.energy = 42
    stage.save_data()
    check(shared_manager.is_saving(), "Stage queues a background save instead of waiting for disk")
    stage.owniverse.state.energy = 43
    shared_manager.flush_saves()
    check(E.eq(shared_manager.load_data("owniverse", "qwerty").state.energy, 42), "Stage save writes an independent snapshot")
    stage.owniverse.free()
    stage.free()
    shared_manager.save_directory = original_directory
    global.save_plaintext_copy = old_plaintext
    for filename in DirAccess.get_files_at(directory):
        DirAccess.remove_absolute(directory.path_join(filename))
    DirAccess.remove_absolute(directory)
    print(("Async save: %d checks, %d failures (validation/block/I/O errors above are intentional)" % [checks, failures]))
    quit((0 if E.eq(failures, 0) else 1))