#include "elna/gcc/elna-tree.h"
#include "elna/gcc/elna-diagnostic.h"

#include "stor-layout.h"
#include "fold-const.h"
#include "diagnostic-core.h"

tree elna_global_trees[ELNA_TI_MAX];

namespace elna
{
namespace gcc
{
    void init_ttree()
    {
        elna_string_type_node = build_pointer_type(
                build_qualified_type(char_type_node, TYPE_QUAL_CONST)); /* const char* */
    }

    bool is_pointer_type(tree type)
    {
        gcc_assert(TYPE_P(type));
        return TREE_CODE(type) == POINTER_TYPE;
    }

    bool is_integral_type(tree type)
    {
        gcc_assert(TYPE_P(type));
        return TREE_CODE(type) == INTEGER_TYPE;
    }

    bool are_compatible_pointers(tree lhs, tree rhs)
    {
        return (lhs == null_pointer_node || rhs == null_pointer_node)
            && is_pointer_type(TREE_TYPE(lhs)) && is_pointer_type(TREE_TYPE(rhs));
    }

    tree tree_chain_base::head()
    {
        return first;
    }

    void tree_chain_base::append(tree t)
    {
        gcc_assert(t != NULL_TREE);

        if (this->first == NULL_TREE)
        {
            this->first = this->last = t;
        }
        else
        {
            chain(t);
            this->last = t;
        }
    }

    void tree_chain::chain(tree t)
    {
        TREE_CHAIN(this->last) = t;
    }

    tree_symbol_mapping::tree_symbol_mapping(tree bind_expression, tree block)
        : m_bind_expression(bind_expression), m_block(block)
    {
    }

    tree tree_symbol_mapping::bind_expression()
    {
        return m_bind_expression;
    }

    tree tree_symbol_mapping::block()
    {
        return m_block;
    }

    std::shared_ptr<boot::symbol_table<tree>> builtin_symbol_table()
    {
        std::shared_ptr<boot::symbol_table<tree>> initial_table =
            std::make_shared<boot::symbol_table<tree>>();

        initial_table->enter("Int", long_integer_type_node);
        initial_table->enter("Word", size_type_node);
        initial_table->enter("Bool", boolean_type_node);
        initial_table->enter("Float", double_type_node);
        initial_table->enter("Char", unsigned_char_type_node);
        initial_table->enter("Byte", make_unsigned_type(8));
        initial_table->enter("String", elna_string_type_node);

        return initial_table;
    }

    tree do_pointer_arithmetic(boot::binary_operator binary_operator, tree left, tree right)
    {
        if (binary_operator == boot::binary_operator::sum)
        {
            tree pointer{ NULL_TREE };
            tree offset{ NULL_TREE };

            if (is_pointer_type(TREE_TYPE(left)) && is_integral_type(TREE_TYPE(right)))
            {
                pointer = left;
                offset = right;
            }
            else if (is_integral_type(TREE_TYPE(left)) && is_pointer_type(TREE_TYPE(right)))
            {
                pointer = right;
                offset = left;
            }
            else
            {
                return error_mark_node;
            }
            tree size_exp = fold_convert(TREE_TYPE(offset), size_in_bytes(TREE_TYPE(TREE_TYPE(pointer))));

            offset = fold_build2(MULT_EXPR, TREE_TYPE(offset), offset, size_exp);
            offset = fold_convert(sizetype, offset);

            return fold_build2(POINTER_PLUS_EXPR, TREE_TYPE(pointer), pointer, offset);
        }
        else if (binary_operator == boot::binary_operator::subtraction)
        {
            if (is_pointer_type(TREE_TYPE(left)) && is_integral_type(TREE_TYPE(right)))
            {
                tree pointer_type = TREE_TYPE(left);
                tree offset_type = TREE_TYPE(right);
                tree size_exp = fold_convert(offset_type, size_in_bytes(TREE_TYPE(pointer_type)));

                tree convert_expression = fold_build2(MULT_EXPR, offset_type, right, size_exp);
                convert_expression = fold_convert(sizetype, convert_expression);

                convert_expression = fold_build1(NEGATE_EXPR, sizetype, convert_expression);
                return fold_build2(POINTER_PLUS_EXPR, pointer_type, left, convert_expression);
            } else if (is_pointer_type(TREE_TYPE(left)) && is_pointer_type(TREE_TYPE(right))
                    && TREE_TYPE(left) == TREE_TYPE(right))
            {
                return fold_build2(POINTER_DIFF_EXPR, ssizetype, left, right);
            }
        }
        return error_mark_node;
    }

    tree build_binary_operation(bool condition, boot::binary_expression *expression,
            tree_code operator_code, tree left, tree right, tree target_type)
    {
        location_t expression_location = get_location(&expression->position());
        tree left_type = TREE_TYPE(left);
        tree right_type = TREE_TYPE(right);

        if (condition)
        {
            return build2_loc(expression_location, operator_code, target_type, left, right);
        }
        else
        {
            error_at(expression_location,
                    "invalid operands of type %s and %s for operator %s",
                    print_type(left_type), print_type(right_type),
                    elna::boot::print_binary_operator(expression->operation()));
            return error_mark_node;
        }
    }
}
}