///- --package .
:# hunt static =
    :< testing

:= melee_reach () : i32 = 1

:== living = vitality::vitality vitality::alive

:= attack
    (damage : i32) (hunter : geometry::position) (prey_at : geometry::position) (prey : living)
    : vitality::struck
    =
    ? geometry::within_range (melee_reach ()) hunter prey_at
    ?> vitality::strike damage prey
    |: vitality::Survived prey

:= loot (outcome : vitality::struck) (bounty : i32) (held : coins::purse) : coins::purse =
    ?= outcome ?|
    | vitality::Slain _ => coins::fewest_coins (coins::total_gold held + bounty)
    | vitality::Survived _ => held

///> c
:# adjacent_attack_lands =
    := ~damage = 40i32
    attack damage (geometry::position 100 100 7) (geometry::position 101 101 7) (vitality::spawn 100)
    |> vitality::survivor_health |> _assert_eq 60i32

///> c
:# distant_attack_misses =
    := ~damage = 40i32
    attack damage (geometry::position 100 100 7) (geometry::position 103 100 7) (vitality::spawn 100)
    |> vitality::survivor_health |> _assert_eq 100i32

///> c
:# kill_pays_bounty =
    := ~damage = 150i32
    := outcome = attack damage (geometry::position 100 100 7) (geometry::position 100 99 7) (vitality::spawn 100)
    loot outcome 250 (coins::purse 80 0 0) |> coins::total_gold |> _assert_eq 330i32

:= struck_fresh (damage : i32) : vitality::struck = vitality::strike damage (vitality::spawn 100)

:= gold_conserved (bounty : i32) (held : coins::purse) (slain : coins::purse) (kept : coins::purse) : bool =
    coins::total_gold slain = coins::total_gold held + bounty && coins::total_gold kept = coins::total_gold held

:= loot_holds (bounty : i32) (held : coins::purse) : bool =
    := slain = loot (struck_fresh 500) bounty held
    := kept = loot (struck_fresh 1) bounty held
    gold_conserved bounty held slain kept && slain::gold < 100 && slain::platinum < 100

:= case_purse (limit : i32) (i : i32) : coins::purse = coins::purse (i % limit * 37) (i / limit * 3) (i % 7)

:= loot_breaks (limit : i32) : i32 =
    :~ ^ check (i : i32) (broken : i32) : i32 =
        ? i >= limit * limit ?> broken
        |: check (i + 1) (? loot_holds (i * 53 % 997) (case_purse limit i) ?> broken |: broken + 1)
    check 0 0

///> c
:# loot_conserves_gold_and_pays_in_fewest_coins_over_1600_purses_and_bounties =
    := ~limit = 40i32
    loot_breaks limit |> _assert_eq 0i32

///> wgsl
:# kill_pays_bounty_on_gpu =
    := ~damage = 150i32
    := outcome = attack damage (geometry::position 100 100 7) (geometry::position 100 99 7) (vitality::spawn 100)
    ? (loot outcome 250 (coins::purse 80 0 0) |> coins::total_gold) = 330i32 ?> 0i32 |: 1i32