path: root/src/openvic-simulation/scripts/Condition.hpp

#pragma once

#include <ostream>
#include <string>
#include <string_view>
#include <variant>

#include "openvic-simulation/dataloader/NodeTools.hpp"
#include "openvic-simulation/types/EnumBitfield.hpp"
#include "openvic-simulation/types/IdentifierRegistry.hpp"

/*

   ConditionType
   - execute function (taking ConditionValue's Argument + current context, e.g. THIS and FROM)

   ConditionValue
   - ConditionType
   - Arguments:
      - std::vector<ConditionValue>
      - std::string
      - ProvinceDefinition const*
      - CountryDefinition const*
      - THIS or FROM
      - bool
      - int
      - fixed_point_t
      - GovernmentType const*
      - std::string + int (or fixed_point_t?) (for check_variable)
      - CountryDefinition const* + int (or fixed_point_t?) (for diplomatic_influence and relation)
      - GoodDefinition const*
      - BuildingType const*
      - Reform const*
      - ReformGroup const* + Reform const*
      - Issue const*
      - IssueGroup const* Issue const*
      - Issue const* + fixed_point_t
      - WargoalType const*
      - Modifier const*
      - Ideology const*
      - Ideology const* + fixed_point_t (for upper_house)
      - Invention const*
      - Culture const*
      - Religion const*
      - PopType const*
      - PopType const* + fixed_point_t (for unemployment_by_type)
      - NationalValue const*
      - Strata const* + fixed_point_t
      - CountryParty const* (for ruling_party, maybe better to use std::string as parties are stored per country)
      - Continent const*
      - Crime const*
      - Region const*
      - TerrainType const*

*/

namespace OpenVic {
   enum class scope_type_t : uint8_t {
      NO_SCOPE    = 0,
      POP         = 1 << 0,
      PROVINCE    = 1 << 1,
      STATE       = 1 << 2,
      COUNTRY     = 1 << 3,
      THIS        = 1 << 4, // Indicator bit for scope switching ("use the THIS scope", not a scope in and of itself)
      FROM        = 1 << 5, // Indicator bit for scope switching ("use the FROM scope", not a scope in and of itself)
      FULL_SCOPE_MASK   = (1 << 6) - 1, // All possible scope bits (including THIS and FROM)
      ALL_SCOPES = POP | PROVINCE | STATE | COUNTRY // All real scopes (without THIS and FROM)
   };

   /* Allows enum types to be used with bitwise operators. */
   template<> struct enable_bitfield<scope_type_t> : std::true_type {};

   /* Returns true if the values have any bit in common. */
   inline constexpr bool share_scope_type(scope_type_t lhs, scope_type_t rhs) {
      return (lhs & rhs) != scope_type_t::NO_SCOPE;
   }

#define BUILD_STRING(entry) \
   if (share_scope_type(value, entry)) { \
      if (type_found) { \
         stream << " | "; \
      } else { \
         type_found = true; \
      } \
      stream << #entry; \
   }

   inline std::ostream& operator<<(std::ostream& stream, scope_type_t value) {
      using enum scope_type_t;

      if (value == NO_SCOPE) {
         return stream << "[NO_SCOPE]";
      }

      bool type_found = false;

      stream << '[';

      BUILD_STRING(COUNTRY);
      BUILD_STRING(STATE);
      BUILD_STRING(PROVINCE);
      BUILD_STRING(POP);
      BUILD_STRING(THIS);
      BUILD_STRING(FROM);

      if (!type_found) {
         stream << "INVALID SCOPE";
      }

      return stream << ']';
   }

#undef BUILD_STRING

   struct ConditionManager;
   struct ConditionScript;
   struct CountryDefinition;
   struct CountryInstance;
   struct ProvinceDefinition;
   struct ProvinceInstance;
   struct Pop;
   struct GoodDefinition;
   struct ProvinceSetModifier;
   using Continent = ProvinceSetModifier;
   struct Condition;
   struct DefinitionManager;
   struct InstanceManager;

   struct ConditionNode {
      friend struct ConditionManager;
      friend struct ConditionScript;

      // std::variant's default constructor sets it to the first type in its parameter list, so for argument_t and scope_t
      // a default-constructed instance represents no_argument_t or no_scope_t.

      struct no_argument_t {};
      struct this_argument_t {};
      struct from_argument_t {};
      using integer_t = int64_t;
      using argument_t = std::variant<
         // No argument
         no_argument_t,
         // Script reference arguments
         this_argument_t, from_argument_t,
         // List argument
         std::vector<ConditionNode>,
         // Value arguments
         bool, std::string, integer_t, fixed_point_t,
         // Game object arguments
         CountryDefinition const*, ProvinceDefinition const*, GoodDefinition const*, Continent const*
      >;

      static constexpr bool is_this_argument(argument_t const& argument) {
         return std::holds_alternative<this_argument_t>(argument);
      }

      static constexpr bool is_from_argument(argument_t const& argument) {
         return std::holds_alternative<from_argument_t>(argument);
      }

      struct no_scope_t {};
      using scope_t = std::variant<
         no_scope_t,
         CountryInstance const*,
         ProvinceInstance const*,
         Pop const*
      >;

      static constexpr bool is_no_scope(scope_t const& scope) {
         return std::holds_alternative<no_scope_t>(scope);
      }

   private:
      Condition const* PROPERTY(condition);
      argument_t PROPERTY(argument);

      ConditionNode(
         Condition const* new_condition = nullptr, argument_t&& new_argument = no_argument_t {}
      );

   public:
      ConditionNode(ConditionNode&&) = default;
      ConditionNode& operator=(ConditionNode&&) = default;

      constexpr bool is_initialised() const {
         return condition != nullptr;
      }

      bool execute(
         InstanceManager const& instance_manager, scope_t const& current_scope, scope_t const& this_scope,
         scope_t const& from_scope
      ) const;
   };

   struct Condition : HasIdentifier {
      friend struct ConditionManager;

      using parse_callback_t = NodeTools::callback_t<
         // bool(definition_manager, current_scope, this_scope, from_scope, node, callback)
         DefinitionManager const&, scope_type_t, scope_type_t, scope_type_t, ast::NodeCPtr,
         NodeTools::callback_t<ConditionNode::argument_t&&>
      >;
      using execute_callback_t = NodeTools::callback_t<
         // bool(instance_manager, current_scope, this_scope, from_scope, argument)
         InstanceManager const&, ConditionNode::scope_t const&, ConditionNode::scope_t const&,
         ConditionNode::scope_t const&, ConditionNode::argument_t const&
      >;

   private:
      parse_callback_t PROPERTY(parse_callback);
      execute_callback_t PROPERTY(execute_callback);

      Condition(
         std::string_view new_identifier,
         parse_callback_t&& new_parse_callback,
         execute_callback_t&& new_execute_callback
      );

   public:
      Condition(Condition&&) = default;
   };

   struct ConditionManager {
   private:
      CaseInsensitiveIdentifierRegistry<Condition> IDENTIFIER_REGISTRY(condition);
      Condition const* PROPERTY(root_condition);

      bool add_condition(
         std::string_view identifier,
         Condition::parse_callback_t&& parse_callback,
         Condition::execute_callback_t&& execute_callback
      );

      template<
         scope_type_t CHANGE_SCOPE = scope_type_t::NO_SCOPE,
         scope_type_t ALLOWED_SCOPES = scope_type_t::ALL_SCOPES,
         bool TOP_SCOPE = false
      >
      static bool _parse_condition_node_list_callback(
         DefinitionManager const& definition_manager, scope_type_t current_scope, scope_type_t this_scope,
         scope_type_t from_scope, ast::NodeCPtr node, NodeTools::callback_t<ConditionNode::argument_t&&> callback
      );

      NodeTools::Callback<Condition const&, ast::NodeCPtr> auto expect_condition_node(
         DefinitionManager const& definition_manager, scope_type_t current_scope, scope_type_t this_scope,
         scope_type_t from_scope, NodeTools::Callback<ConditionNode&&> auto callback
      ) const;

      NodeTools::NodeCallback auto expect_condition_node_list_and_length(
         DefinitionManager const& definition_manager, scope_type_t current_scope, scope_type_t this_scope,
         scope_type_t from_scope, NodeTools::Callback<ConditionNode&&> auto callback,
         NodeTools::LengthCallback auto length_callback, bool top_scope = false
      ) const;

      NodeTools::NodeCallback auto expect_condition_node_list(
         DefinitionManager const& definition_manager, scope_type_t current_scope, scope_type_t this_scope,
         scope_type_t from_scope, NodeTools::Callback<ConditionNode&&> auto callback, bool top_scope = false
      ) const;

   public:
      ConditionManager();

      bool setup_conditions(DefinitionManager const& definition_manager);

      NodeTools::node_callback_t expect_condition_script(
         DefinitionManager const& definition_manager, scope_type_t initial_scope, scope_type_t this_scope,
         scope_type_t from_scope, NodeTools::callback_t<ConditionNode&&> callback
      ) const;
   };
}