-module(blc_weapon).

-include("tacticians/attributes.hrl").

-define(WEAPON_ATTRIBUTE_RANGE_MIN,       0).
-define(WEAPON_ATTRIBUTE_RANGE_MAX,       2).
-define(WEAPON_ATTRIBUTE_RANGE_DEFAULT,   0).
-define(WEAPON_ATTRIBUTE_RANGE_COST,      1).

-define
(
   BASE_SPENDABLE_WEAPON_POINTS,
   (
      (
         ?ATTRIBUTE_ACCURACY_COST
         * (?ATTRIBUTE_ACCURACY_DEFAULT - ?ATTRIBUTE_ACCURACY_MIN)
      )
      +
      (
         ?ATTRIBUTE_CRITICAL_HIT_CHANCE_COST
         *
         (
            ?ATTRIBUTE_CRITICAL_HIT_CHANCE_DEFAULT
            - ?ATTRIBUTE_CRITICAL_HIT_CHANCE_MIN
         )
      )
      +
      (
         ?ATTRIBUTE_DOUBLE_HIT_CHANCE_COST
         *
         (
            ?ATTRIBUTE_DOUBLE_HIT_CHANCE_DEFAULT
            - ?ATTRIBUTE_DOUBLE_HIT_CHANCE_MIN
         )
      )
      +
      (
         ?ATTRIBUTE_ATTACK_SCORE_COST
         * (?ATTRIBUTE_ATTACK_SCORE_DEFAULT - ?ATTRIBUTE_ATTACK_SCORE_MIN)
      )
      +
      (
         ?WEAPON_ATTRIBUTE_RANGE_COST
         * (?WEAPON_ATTRIBUTE_RANGE_DEFAULT - ?WEAPON_ATTRIBUTE_RANGE_MIN)
      )
   )
).

-define
(
   MELEE_SPENDABLE_WEAPON_POINTS,
   (
      ?BASE_SPENDABLE_WEAPON_POINTS
      +
      (
         ?ATTRIBUTE_PARRY_CHANCE_COST
         * (?ATTRIBUTE_PARRY_CHANCE_DEFAULT - ?ATTRIBUTE_PARRY_CHANCE_MIN)
      )
   )
).

-define(RANGED_SPENDABLE_WEAPON_POINTS, ?BASE_SPENDABLE_WEAPON_POINTS).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-type range_type() :: (melee | ranged).

-record
(
   proto_weapon,
   {
      range :: non_neg_integer(),
      range_type :: range_type(),
      omnimods :: shr_omnimods:type(),
      attack_coef :: list(blc_damage_type:coefficient()),
      attack_score :: non_neg_integer(),
      remaining_points :: non_neg_integer()
   }
).

-opaque type() :: #proto_weapon{}.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-export_type([type/0,range_type/0]).

-export
(
   [
      increase_range_by/2,
      increase_parry_chance_by/2,
      increase_accuracy_by/2,
      increase_critical_hit_chance_by/2,
      increase_double_hit_chance_by/2,
      increase_attack_score_by/2,
      increase_range_for/2,
      increase_parry_chance_for/2,
      increase_accuracy_for/2,
      increase_critical_hit_chance_for/2,
      increase_double_hit_chance_for/2,
      increase_attack_score_for/2,
      set_attack_coefficients/2
   ]
).

-export
(
   [
      new/2,
      get_remaining_points/1
   ]
).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec increase_attribute_by
   (
      shr_attributes:enum(),
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_attribute_by (Attribute, S0Amount, Weapon) ->
   CurrentOmnimods = Weapon#proto_weapon.omnimods,
   CurrentValue =
      shr_omnimods:get_attribute_modifier(Attribute, CurrentOmnimods),

   {_AttMin, _AttDef, AttMax, AttCost} = blc_attribute:get_info(Attribute),

   S1Amount =
      case ((CurrentValue + S0Amount) > AttMax) of
         true -> (AttMax - CurrentValue);
         false -> S0Amount
      end,

   Cost = (S1Amount * AttCost),
   RemainingPoints = Weapon#proto_weapon.remaining_points,

   case (Cost > RemainingPoints) of
      true -> {error, balance, RemainingPoints, Cost};
      false ->
         {
            ok,
            Weapon#proto_weapon
            {
               remaining_points = (RemainingPoints - Cost),
               omnimods =
                  shr_omnimods:mod_attribute_modifier
                  (
                     Attribute,
                     S1Amount,
                     Weapon#proto_weapon.omnimods
                  )
            }
         }
   end.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec increase_accuracy_by
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_accuracy_by (Amount, Weapon) ->
   increase_attribute_by(?ATTRIBUTE_ACCURACY, Amount, Weapon).

-spec increase_range_by
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_range_by (Amount, Weapon) ->
   increase_attribute_by(?ATTRIBUTE_ACCURACY, Amount, Weapon).

-spec increase_parry_chance_by
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_parry_chance_by (Amount, Weapon) ->
   case (Weapon#proto_weapon.range_type) of
      ranged -> {error, incompatible};
      _ -> increase_attribute_by(?ATTRIBUTE_PARRY_CHANCE, Amount, Weapon)
   end.

-spec increase_critical_hit_chance_by
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_critical_hit_chance_by (Amount, Weapon) ->
   increase_attribute_by(?ATTRIBUTE_CRITICAL_HIT_CHANCE, Amount, Weapon).

-spec increase_double_hit_chance_by
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_double_hit_chance_by (Amount, Weapon) ->
   increase_attribute_by(?ATTRIBUTE_DOUBLE_HIT_CHANCE, Amount, Weapon).

-spec increase_attack_score_by
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_attack_score_by (S0Amount, Weapon) ->
   CurrentValue = Weapon#proto_weapon.attack_score,
   S0NewValue = CurrentValue + S0Amount,
   {S1Amount, S1NewValue} =
      case (S0NewValue > ?ATTRIBUTE_ATTACK_SCORE_MAX) of
         false -> {S0Amount, S0NewValue};
         true ->
            {
               (?ATTRIBUTE_ATTACK_SCORE_MAX - CurrentValue),
               ?ATTRIBUTE_ATTACK_SCORE_MAX
            }
      end,

   Cost = (S1Amount * ?ATTRIBUTE_ATTACK_SCORE_COST),
   RemainingPoints = Weapon#proto_weapon.remaining_points,

   case (Cost > RemainingPoints) of
      true -> {error, balance, RemainingPoints, Cost};
      false ->
         {
            ok,
            Weapon#proto_weapon
            {
               remaining_points = (RemainingPoints - Cost),
               attack_score = S1NewValue,
               omnimods =
                  shr_omnimods:set_attack_modifiers
                  (
                     blc_damage_type:generate_entries_from_score
                     (
                        S1NewValue,
                        Weapon#proto_weapon.attack_coef
                     ),
                     Weapon#proto_weapon.omnimods
                  )
            }
         }
   end.

-spec set_attack_coefficients
   (
      list(blc_damage_type:coefficient()),
      type()
   )
   -> type().
set_attack_coefficients (Coefficients, Weapon) ->
   NewCoefs = blc_damage_type:sort_entries(Coefficients),

   Weapon#proto_weapon
   {
      attack_coef = NewCoefs,
      omnimods =
         shr_omnimods:set_attack_modifiers
         (
            blc_damage_type:generate_entries_from_score
            (
               Weapon#proto_weapon.attack_score,
               NewCoefs
            ),
            Weapon#proto_weapon.omnimods
         )
   }.

-spec new (range_type(), list(blc_damage_type:coefficient())) -> type().
new (RangeType, Coefficients) ->
   SortedCoefficients = blc_damage_type:sort_entries(Coefficients),

   #proto_weapon
   {
      range = ?WEAPON_ATTRIBUTE_RANGE_MIN,
      range_type = RangeType,
      omnimods =
         shr_omnimods:new
         (
            [
               {?ATTRIBUTE_ACCURACY, ?ATTRIBUTE_ACCURACY_MIN},
               {?ATTRIBUTE_PARRY_CHANCE, ?ATTRIBUTE_PARRY_CHANCE_MIN},
               {
                  ?ATTRIBUTE_CRITICAL_HIT_CHANCE,
                  ?ATTRIBUTE_CRITICAL_HIT_CHANCE_MIN
               },
               {
                  ?ATTRIBUTE_DOUBLE_HIT_CHANCE,
                  ?ATTRIBUTE_DOUBLE_HIT_CHANCE_MIN
               }
            ],
            blc_damage_type:generate_entries_from_score
            (
               ?ATTRIBUTE_ATTACK_SCORE_MIN,
               SortedCoefficients
            ),
            []
         ),

      attack_coef = SortedCoefficients,
      attack_score = ?ATTRIBUTE_ATTACK_SCORE_MIN,
      remaining_points =
         case RangeType of
            melee -> ?MELEE_SPENDABLE_WEAPON_POINTS;
            ranged -> ?RANGED_SPENDABLE_WEAPON_POINTS
         end
   }.

-spec increase_range_for
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_range_for (GivenPoints, Weapon) ->
   AmountOfIncrease = trunc(GivenPoints / ?WEAPON_ATTRIBUTE_RANGE_COST),
   increase_range_by(AmountOfIncrease, Weapon).

-spec increase_parry_chance_for
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_parry_chance_for (GivenPoints, Weapon) ->
   AmountOfIncrease = trunc(GivenPoints / ?ATTRIBUTE_PARRY_CHANCE_COST),
   increase_parry_chance_by(AmountOfIncrease, Weapon).

-spec increase_accuracy_for
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_accuracy_for (GivenPoints, Weapon) ->
   AmountOfIncrease = trunc(GivenPoints / ?ATTRIBUTE_ACCURACY_COST),
   increase_accuracy_by(AmountOfIncrease, Weapon).

-spec increase_critical_hit_chance_for
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_critical_hit_chance_for (GivenPoints, Weapon) ->
   AmountOfIncrease = trunc(GivenPoints / ?ATTRIBUTE_CRITICAL_HIT_CHANCE_COST),
   increase_critical_hit_chance_by(AmountOfIncrease, Weapon).

-spec increase_double_hit_chance_for
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_double_hit_chance_for (GivenPoints, Weapon) ->
   AmountOfIncrease = trunc(GivenPoints / ?ATTRIBUTE_DOUBLE_HIT_CHANCE_COST),
   increase_double_hit_chance_by(AmountOfIncrease, Weapon).


-spec increase_attack_score_for
   (
      non_neg_integer(),
      type()
   )
   -> ({ok, type()} | blc_error:type()).
increase_attack_score_for (GivenPoints, Weapon) ->
   AmountOfIncrease = trunc(GivenPoints / ?ATTRIBUTE_ATTACK_SCORE_COST),
   increase_attack_score_by(AmountOfIncrease, Weapon).


-spec get_remaining_points (type()) -> non_neg_integer().
get_remaining_points (Weapon) -> Weapon#proto_weapon.remaining_points.