#include "type.hpp"
#include "error.hpp"

namespace lily {
    type_data::constructor* type_data::create_constructor(const std::string& name,
            std::vector<type*>&& params) {
        auto new_constructor = std::unique_ptr<constructor>(new constructor());
        new_constructor->id = constructors.size();
        new_constructor->parent = this;
        new_constructor->params = std::move(params);

        constructor* raw_ptr = new_constructor.get();
        constructors[name] = std::move(new_constructor);
        return raw_ptr;
    }

    bool try_unify_pram(type* substitute_with, type* substitute_in) {
        type_parameter* param = dynamic_cast<type_parameter*>(substitute_in);
        if(!param) return false;
        if(!param->actual_type) {
            param->actual_type = substitute_with;
            return true;
        } else {
            return substitute_with->unify_with(param->actual_type);
        }
    }

    bool type_internal::unify_with(type* other) {
        type_internal* other_int = dynamic_cast<type_internal*>(other);
        if(other_int && other_int->type_id == type_id) return true;
        if(try_unify_pram(this, other)) return true;
        return false;
    }

    bool type_parameter::unify_with(type* other) {
        if(this == other) return true;
        if(!actual_type) {
            actual_type = other;
            return true;
        }
        if(try_unify_pram(this, other)) return true;
        if(actual_type->unify_with(other)) return true;
        return false;
    }

    bool type_data::unify_with(type* other) {
        type_data* other_data = dynamic_cast<type_data*>(other);
        if(other_data && other_data->type_id == type_id) return true;
        if(try_unify_pram(this, other)) return true;
        return false;
    }

    bool type_func::unify_with(type* other) {
        type_func* other_func = dynamic_cast<type_func*>(other);
        if(try_unify_pram(this, other)) return true;
        if(other_func &&
                left->unify_with(other_func->left) &&
                right->unify_with(other_func->right)) return true;
        return false;
    }
}