///- --package .

world_port (test)

///- --test static --symbol

:< testing

:< sm'_operators

:== world_programs =
    {
        directory : string
        server : string
        server_args : list string
        log : string
        online_line : string
    }

:== world = { running : process::started; programs : world_programs }

:= world_started (programs : world_programs) : world =
    {
        running = process::start_logging programs::directory programs::server programs::server_args programs::log
        programs = programs
    }

:= world_online (w : world) : bool =
    file_system::read_all_text w::programs::log |> sm'::contains w::programs::online_line

:= world_event_within (w : world) (ms : i32) : option arena_host::host_event =
    ?= process::await_exit_within w::running ms ?|
    | Some _ => Some arena_host::WorldCrashed
    | None => ? world_online w ?> Some arena_host::WorldReady |: None

:= world_stopped (w : world) : () = process::kill_tree_of_pid (process::started_pid w::running)

:= stopped_if_running (current : option world) : () =
    ?= current ?|
    | Some w => world_stopped w
    | None => ()

:= restarted (programs : world_programs) (current : option world) : option world =
    stopped_if_running current
    Some (world_started programs)

:= released (current : option world) : option world =
    stopped_if_running current
    None

:= world_changed (programs : world_programs) (current : option world) (c : arena_host::host_command) : option world =
    ? c = arena_host::RestartWorld ?> restarted programs current
    |? c = arena_host::ReleaseWindow ?> released current
    |: current

:= world_obeyed (programs : world_programs) (current : option world) (c : arena_host::host_command) : option world =
    ? c = arena_host::StartWorld ?> Some (world_started programs) |: world_changed programs current c

:= exited (s : process::started) (ms : i32) : bool =
    ?= process::await_exit_within s ms ?|
    | Some _ => !+
    | None => !-

:= absent (current : option world) : bool =
    ?= current ?|
    | Some _ => !-
    | None => !+

:= fake_server_args (line : string) : list string =
    [ "-u"; "-c"; "import time; print('" ++# line ++# "'); time.sleep(30)" ]

:= fake_log () : string = file_system::get_temp_path () ++# "/tibia-world-port-fake.log"

:= fake_server (line : string) : world_programs =
    {
        directory = "."
        server = "python"
        server_args = fake_server_args line
        log = fake_log ()
        online_line = ">> server online!"
    }

:~ ^ settled (w : world) (tries : i32) : option arena_host::host_event =
    ?= world_event_within w 50i32 ?|
    | Some e => Some e
    | None => ? tries > 0i32 ?> settled w (tries - 1i32) |: None

:= ready_within (w : world) (tries : i32) : bool = settled w tries = Some arena_host::WorldReady

:= crashed_within (w : world) (ms : i32) : bool = world_event_within w ms = Some arena_host::WorldCrashed

:= exits_within (w : world) : bool = exited w::running 10000i32

:= expect_world (current : option world) : world =
    ?= current ?|
    | Some w => w
    | None => failwith "world_port: a start command left no world"

:= obeyed_world (p : world_programs) (current : option world) (c : arena_host::host_command) : world =
    expect_world (world_obeyed p current c)

:= cycled (p : world_programs) : world * world * option world =
    := first = obeyed_world p None arena_host::StartWorld
    := second = obeyed_world p (Some first) arena_host::RestartWorld
    first, second, world_obeyed p (Some second) arena_host::ReleaseWindow

a_world_reports_online_then_crashed_after_a_kill (test)

///- --test --symbol
///> gleam

:= w = world_started (fake_server ">> server online!")
ready_within w 400i32 |> _assert_eq !+
world_stopped w
crashed_within w 10000i32 |> _assert_eq !+

__assert_eq { expected = true }
__assert_eq { expected = true }

the_world_owner_restarts_and_releases_its_server (test)

///- --test --symbol
///> gleam

:= first, second, released = cycled (fake_server ">> server online!")
(exits_within first, exits_within second, absent released) |> _assert_eq (!+, !+, !+)

__assert_eq { expected = (true, true, true) }