-module(btl_condition).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-include("tacticians/conditions.hrl").

-type update_action() ::
   (
      none
      | remove
      | {update, ataxic:basic()}
   ).

-record
(
   btl_cond,
   {
      category :: shr_condition:id(),
      triggers :: ordset:ordset(shr_condition:trigger()),
      occurrences :: (non_neg_integer() | -1),
      duration :: (non_neg_integer() | -1),
      parameters :: tuple()
   }
).

-opaque type() :: #btl_cond{}.
-opaque collection() :: orddict:orddict(non_neg_integer(), type()).

-export_type([type/0, collection/0, update_action/0]).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-export
(
   [
      get_category/1,
      get_triggers/1,
      get_remaining_occurrences/1,
      get_duration/1,
      get_parameters/1,

      set_triggers/2,
      set_remaining_occurrences/2,
      set_duration/2,
      set_parameters/2,

      ataxia_set_triggers/2,
      ataxia_set_remaining_occurrences/2,
      ataxia_set_duration/2,
      ataxia_set_parameters/2,

      ataxia_set_triggers/3,
      ataxia_set_parameters/3,

      get_category_field/0,
      get_triggers_field/0,
      get_remaining_occurrences_field/0,
      get_duration_field/0,
      get_parameters_field/0
   ]
).

-export
(
   [
      ataxia_apply_trigger/3
   ]
).

-export
(
   [
      encode/1
   ]
).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec encode_parameters
   (
      shr_condition:id(),
      tuple()
   )
   -> {list({binary(), any()})}.
encode_parameters (_Category, _Parameters) -> {[]}. % TODO.

-spec update_actions_to_ataxic_update
   (
      list({non_neg_integer(), update_action()})
   )
   -> ataxic:basic().
update_actions_to_ataxic_update (Updates) ->
   AtaxicSequence =
      lists:foldl
      (
         fun ({IX, Update}, AtaxicUpdates) ->
            case Update of
               none -> AtaxicUpdates;
               remove ->
                  [
                     ataxic:apply_function
                     (
                        orddict,
                        erase,
                        [ataxic:constant(IX), ataxic:current_value()]
                     )
                     |AtaxicUpdates
                  ];

               {update, Ataxic} ->
                  [
                     ataxic_sugar:update_orddict_element(IX, Ataxic)
                     |AtaxicUpdates
                  ]
            end
         end,
         [],
         Updates
      ),

   ataxic:sequence(AtaxicSequence).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

-spec get_category (type()) -> shr_condition:id().
get_category (Condition) -> Condition#btl_cond.category.

-spec get_triggers (type()) -> ordset:ordset(shr_condition:trigger()).
get_triggers (Condition) -> Condition#btl_cond.triggers.

-spec get_remaining_occurrences (type()) -> (non_neg_integer() | -1).
get_remaining_occurrences (Condition) -> Condition#btl_cond.occurrences.

-spec get_duration (type()) -> (non_neg_integer() | -1).
get_duration (Condition) -> Condition#btl_cond.duration.

-spec get_parameters (type()) -> tuple().
get_parameters (Condition) -> Condition#btl_cond.parameters.

-spec set_triggers (ordset:ordset(shr_condition:trigger()), type()) -> type().
set_triggers (Triggers, Condition) -> Condition#btl_cond{ triggers = Triggers }.

-spec set_remaining_occurrences ((non_neg_integer() | -1), type()) -> type().
set_remaining_occurrences (Value, Condition) ->
   Condition#btl_cond{ occurrences = Value }.

-spec set_duration ((non_neg_integer() | -1), type()) -> type().
set_duration (Value, Condition) ->
   Condition#btl_cond{ duration = Value }.

-spec set_parameters (tuple(), type()) -> type().
set_parameters (Value, Condition) -> Condition#btl_cond{ parameters = Value }.

-spec ataxia_set_triggers
   (
      ordset:ordset(shr_condition:trigger()),
      type()
   )
   -> {type(), ataxic:basic()}.
ataxia_set_triggers (Triggers, Condition) ->
   {
      set_triggers(Triggers, Condition),
      ataxic:update_field
      (
         get_triggers_field(),
         ataxic:constant(Triggers)
      )
   }.

-spec ataxia_set_remaining_occurrences
   (
      (non_neg_integer() | -1),
      type()
   )
   -> {type(), ataxic:basic()}.
ataxia_set_remaining_occurrences (Value, Condition) ->
   {
      set_remaining_occurrences(Value, Condition),
      ataxic:update_field
      (
         get_remaining_occurrences_field(),
         ataxic:constant(Value)
      )
   }.


-spec ataxia_set_duration
   (
      (non_neg_integer() | -1),
      type()
   )
   -> {type(), ataxic:basic()}.
ataxia_set_duration (Value, Condition) ->
   {
      set_duration(Value, Condition),
      ataxic:update_field
      (
         get_duration_field(),
         ataxic:constant(Value)
      )
   }.

-spec ataxia_set_parameters (tuple(), type()) -> {type(), ataxic:basic()}.
ataxia_set_parameters (Value, Condition) ->
   {
      set_parameters(Value, Condition),
      ataxic:update_field
      (
         get_parameters_field(),
         ataxic:constant(Value)
      )
   }.

-spec ataxia_set_triggers
   (
      ordset:ordset(shr_condition:trigger()),
      ataxic:basic(),
      type()
   )
   -> {type(), ataxic:basic()}.
ataxia_set_triggers (Triggers, Update, Condition) ->
   {
      set_triggers(Triggers, Condition),
      ataxic:update_field
      (
         get_triggers_field(),
         Update
      )
   }.

-spec ataxia_set_parameters
   (
      tuple(),
      ataxic:basic(),
      type()
   )
   -> {type(), ataxic:basic()}.
ataxia_set_parameters (Value, Update, Condition) ->
   {
      set_parameters(Value, Condition),
      ataxic:update_field
      (
         get_parameters_field(),
         Update
      )
   }.

-spec triggers_on (shr_condition:trigger(), type()) -> boolean().
triggers_on (Trigger, Type) ->
   ordset:is_element(Trigger, Type#btl_cond.triggers).

-spec get_category_field () -> non_neg_integer().
get_category_field () -> #btl_cond.category.

-spec get_triggers_field () -> non_neg_integer().
get_triggers_field () -> #btl_cond.triggers.

-spec get_remaining_occurrences_field () -> non_neg_integer().
get_remaining_occurrences_field () -> #btl_cond.occurrences.

-spec get_duration_field () -> non_neg_integer().
get_duration_field () -> #btl_cond.duration.

-spec get_parameters_field () -> non_neg_integer().
get_parameters_field () -> #btl_cond.parameters.

-spec ataxia_apply_trigger
   (
      shr_condition:context(_ReadOnlyDataType, VolatileDataType),
      btl_character_turn_update:type(),
      collection()
   )
   ->
   {
      VolatileDataType,
      ataxic:basic(),
      btl_character_turn_update:type()
   }.
ataxia_apply_trigger (Context, S0Update, Conditions) ->
   {Trigger, ReadOnlyData, S0VolatileData} = Context,

   RelevantConditions =
      orddict:filter
      (
         fun (_IX, Condition) -> triggers_on(Trigger, Condition) end,
         Conditions
      ),

   {LastVolatileData, LastUpdate, AllUpdateActions} =
      orddict:fold
      (
         fun
         (
            IX,
            Condition,
            {
               CurrentVolatileData,
               CurrentUpdate,
               UpdateActions
            }
         ) ->
            Module = shr_condition_selector:get_module(get_category(Condition)),
            {NextVolatileData, NextUpdate, UpdateAction} =
               erlang:apply
               (
                  Module,
                  apply,
                  [
                     Condition,
                     CurrentUpdate,
                     {Trigger, ReadOnlyData, CurrentVolatileData}
                  ]
               ),

            {
               NextVolatileData,
               NextUpdate,
               case UpdateAction of
                  none -> UpdateActions;
                  _ -> [{IX, UpdateAction}|UpdateActions]
               end
            }
         end,
         {S0VolatileData, S0Update, []},
         RelevantConditions
      ),

   ConditionsAtaxiaUpdate = update_actions_to_ataxic_update(AllUpdateActions),

   {LastVolatileData, ConditionsAtaxiaUpdate, LastUpdate}.

-spec encode (type()) -> {list({binary(), any()})}.
encode (Condition) -> {[]}. % TODO