1 files changed, 178 insertions, 0 deletions
diff --git a/src/struct/battle_action.erl b/src/struct/battle_action.erl
new file mode 100644
index 0000000..5189384
--- /dev/null
+++ b/src/struct/battle_action.erl
@@ -0,0 +1,178 @@
+-module(battle_action).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-record
+(
+   move,
+   {
+      path :: list(direction:enum())
+   }
+).
+
+-record
+(
+   switch_weapon,
+   {
+   }
+).
+
+-record
+(
+   attack,
+   {
+      target :: non_neg_integer()
+   }
+).
+
+-type category() :: ('move' | 'switch_weapon' | 'attack' | 'nothing').
+-opaque struct() :: (#move{} | #switch_weapon{} | #attack{}).
+
+-export_type([category/0, struct/0]).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-export
+(
+   [
+      decode/1,
+      handle/4,
+      can_follow/2
+   ]
+).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec decode_mov_action (map()) -> struct().
+decode_mov_action (JSONMap) ->
+   PathInBinary = maps:get(<<"p">>, JSONMap),
+   Path = lists:map(fun direction:from_binary/1, PathInBinary),
+
+   #move { path = Path }.
+
+-spec decode_atk_action (map()) -> struct().
+decode_atk_action (JSONMap) ->
+   TargetIX = maps:get(<<"tix">>, JSONMap),
+
+   #attack { target = TargetIX }.
+
+-spec decode_swp_action (map()) -> struct().
+decode_swp_action (_JSONMap) ->
+   #switch_weapon{}.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec decode (binary()) -> struct().
+decode (EncodedAction) ->
+   JSONActionMap = jiffy:decode(EncodedAction, [return_maps]),
+   ActionType = maps:get(<<"t">>, JSONActionMap),
+   case ActionType of
+      <<"mov">> -> decode_mov_action(JSONActionMap);
+      <<"atk">> -> decode_atk_action(JSONActionMap);
+      <<"swp">> -> decode_swp_action(JSONActionMap)
+   end.
+
+-spec can_follow (category(), category()) -> boolean().
+can_follow (nothing, attack) -> true;
+can_follow (nothing, switch_weapon) -> true;
+can_follow (nothing, move) -> true;
+can_follow (switch_weapon, attack) -> true;
+can_follow (move, attack) -> true;
+can_follow (_, _) -> false.
+
+-spec handle
+(
+   battle:struct(),
+   character_instance:struct(),
+   non_neg_integer(),
+   struct()
+)
+->
+{
+   list(database_diff:struct()),
+   list(turn_result:struct()),
+   battle:struct(),
+   character_instance:struct()
+}.
+handle (Battle, CharacterInstance, CharacterInstanceIX, BattleAction)
+when is_record(BattleAction, switch_weapon) ->
+   Character = character_instance:get_character(CharacterInstance),
+   CharacterAttributes = character:get_attributes(Character),
+   {PrimaryWeaponID, SecondaryWeaponID} = character:get_weapon_ids(Character),
+
+   UpdatedWeaponIDs = {SecondaryWeaponID, PrimaryWeaponID},
+   UpdatedCharacterStatistics =
+      statistics:new(CharacterAttributes, UpdatedWeaponIDs),
+   UpdatedCharacter =
+      character:set_statistics
+      (
+         UpdatedCharacterStatistics,
+         character:set_weapon_ids(UpdatedWeaponIDs, Character)
+      ),
+   UpdatedCharacterInstance =
+      character_instance:set_character(UpdatedCharacter, CharacterInstance),
+
+   {
+      % TODO: hide that into database_diff structs.
+      [
+         {character_instance, CharacterInstanceIX, wp0, SecondaryWeaponID},
+         {character_instance, CharacterInstanceIX, wp1, PrimaryWeaponID}
+         % ... statistics as well.
+      ],
+      % TODO: hide that into turn_result structs.
+      [
+         {switched_weapons, CharacterInstanceIX}
+      ],
+      UpdatedCharacterInstance,
+      Battle
+   };
+handle (Battle, CharacterInstance, CharacterInstanceIX, BattleAction)
+when is_record(BattleAction, move) ->
+   Character = character_instance:get_character(CharacterInstance),
+   CharacterStatistics = character:get_statistics(Character),
+   Battlemap = battle:get_battlemap(Battle),
+   Path = BattleAction#move.path,
+   CharacterMovementPoints =
+      statistics:get_movement_points(CharacterStatistics),
+
+   ForbiddenLocations =
+      array:foldl
+      (
+         fun (IX, CharInst, Prev) ->
+            case IX of
+               CharacterInstanceIX -> Prev;
+               _ -> [character_instance:get_location(CharInst)|Prev]
+            end
+         end,
+         [],
+         battle:get_character_instances(Battle)
+      ),
+
+   {NewLocation, Cost} =
+      movement:cross
+      (
+         Battlemap,
+         ForbiddenLocations,
+         Path,
+         character_instance:get_location(CharacterInstance)
+      ),
+
+   true = (Cost =< CharacterMovementPoints),
+
+   UpdatedCharacterInstance =
+      character_instance:set_location(NewLocation, CharacterInstance),
+
+   {
+      % TODO: hide that into database_diff structs.
+      [{character_instance, CharacterInstanceIX, loc, NewLocation}],
+      % TODO: hide that into turn_result structs.
+      [
+         {moved, Path, NewLocation}
+      ],
+      UpdatedCharacterInstance,
+      Battle
+   }.