# system_test.ludic - the runner: init, reset, save and load in the order added, tick phase by
# phase, each system its own save section, and a missing section is a reset
import "ludic.base"
program SystemTest {
  numbers float
  state SystemTestState {
    trail: string = ""
    apples: int = 0
    hours: float = 0.0
  }

  function draw_tick(system_test_st: mut SystemTestState, t: Tick) -> void { system_test_st.trail = system_test_st.trail + "d" }
  function think_tick(system_test_st: mut SystemTestState, t: Tick) -> void { system_test_st.trail = system_test_st.trail + "t" }
  function input_tick(system_test_st: mut SystemTestState, t: Tick) -> void { system_test_st.trail = system_test_st.trail + "i" }
  function commit_tick(system_test_st: mut SystemTestState, t: Tick) -> void { system_test_st.trail = system_test_st.trail + "c" }
  function apples_init(system_test_st: mut SystemTestState) -> void { system_test_st.trail = system_test_st.trail + "A" }
  function apples_reset(system_test_st: mut SystemTestState) -> void { system_test_st.apples = 0 }
  function apples_tick(system_test_st: mut SystemTestState, t: Tick) -> void { system_test_st.apples += 1 }
  function apples_save(system_test_st: SystemTestState) -> Val {
    let v = Value.object()
    sv_put_int(v, "n", system_test_st.apples)
    return v
  }
  function apples_load(system_test_st: mut SystemTestState, v: Val, version: int) -> void { system_test_st.apples = sv_int(v, "n", 0) * version }
  function clock_reset(system_test_st: mut SystemTestState) -> void { system_test_st.hours = 6.0 }
  function clock_tick(system_test_st: mut SystemTestState, t: Tick) -> void { system_test_st.hours = system_test_st.hours + t.hours }
  function clock_save(system_test_st: SystemTestState) -> Val {
    let v = Value.object()
    sv_put_float(v, "h", system_test_st.hours)
    return v
  }
  function clock_load(system_test_st: mut SystemTestState, v: Val, version: int) -> void { system_test_st.hours = sv_float(v, "h", 6.0) }

  function sys(key: string, phase: int, tick: fn(Tick) -> void) -> System {
    let s = system_new(key, phase)
    s.tick = tick
    return s
  }

  function setup(base_st: mut BaseState, system_test_st: mut SystemTestState) -> void {
    core_clear(base_st)
    system_test_st.trail = ""
    core_add(base_st, sys("draw", PH_PRESENT, fn draw_tick))
    core_add(base_st, sys("think", PH_SIMULATE, fn think_tick))
    let a = sys("apples", PH_SIMULATE, fn apples_tick)
    a.init = fn apples_init
    a.reset = fn apples_reset
    a.save = fn apples_save
    a.load = fn apples_load
    a.version = 2
    core_add(base_st, a)
    core_add(base_st, sys("input", PH_INPUT, fn input_tick))
    core_add(base_st, sys("commit", PH_COMMIT, fn commit_tick))
    let c = sys("clock", PH_SIMULATE, fn clock_tick)
    c.reset = fn clock_reset
    c.save = fn clock_save
    c.load = fn clock_load
    core_add(base_st, c)
  }

  test "tick runs phase by phase, in the order added within a phase" (base_st: mut BaseState, system_test_st: mut SystemTestState) {
    setup(base_st, system_test_st)
    core_tick_all(base_st, tick_new(1.0 / 60.0, 0, 0.0))
    expect(system_test_st.trail == "itcd")
    expect_eq(system_test_st.apples, 1)
  }

  test "init and reset run in the order added and skip a null verb" (base_st: mut BaseState, system_test_st: mut SystemTestState) {
    setup(base_st, system_test_st)
    core_init_all(base_st)
    expect(system_test_st.trail == "A")
    system_test_st.apples = 9
    core_reset_all(base_st)
    expect_eq(system_test_st.apples, 0)
    expect(system_test_st.hours == 6.0)
    expect_eq(core_count(base_st), 6)
  }

  test "save writes each system under its key with its version, and load reads it back" (base_st: mut BaseState, system_test_st: mut SystemTestState) {
    setup(base_st, system_test_st)
    core_reset_all(base_st)
    system_test_st.apples = 4
    core_tick_all(base_st, tick_new(0.016, 1, 0.5))
    let root = core_save_all(base_st)
    expect_eq(Value.count(root), 2)
    expect_eq(load_section(root, "apples").version, 2)
    expect_eq(load_section(root, "clock").version, 1)
    let text = save_encode(root)
    core_reset_all(base_st)
    core_load_all(base_st, save_decode(text))
    expect_eq(system_test_st.apples, 10)
    expect(system_test_st.hours == 6.5)
  }

  test "a system with no section in the save is reset" (base_st: mut BaseState, system_test_st: mut SystemTestState) {
    setup(base_st, system_test_st)
    system_test_st.apples = 3
    system_test_st.hours = 11.0
    let root = save_tree()
    let v = Value.object()
    sv_put_float(v, "h", 20.25)
    save_section(root, "clock", 1, v)
    core_load_all(base_st, root)
    expect_eq(system_test_st.apples, 0)
    expect(system_test_st.hours == 20.25)
  }
}