/*
 * Copyright (C) 2023 Johnny Richard
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#ifndef AST_H
#define AST_H
#include "string_view.h"
#include "vector.h"
#include <stdint.h>

#define ast_visitor_visit(visitor, node) ast_node_accept_visitor(node, (ast_visitor_t *)visitor);

typedef enum
{
  TYPE_I32
} type_t;

typedef struct ast_visitor_t ast_visitor_t;
typedef struct ast_node_t ast_node_t;

typedef struct ast_return_stmt_t
{
  ast_node_t *argument;
} ast_return_stmt_t;

typedef struct ast_function_declaration_t
{
  string_view_t name;
  type_t return_type;
  vector_t *body;
} ast_function_declaration_t;

typedef struct ast_binary_operation_t
{
  // FIXME: We want to use enum to distinguish operators
  string_view_t op;
  ast_node_t *left;
  ast_node_t *right;
} ast_binary_operation_t;

typedef enum
{
  AST_LITERAL_INTEGER
} ast_literal_kind_t;

typedef union
{
  uint32_t integer;
} ast_literal_value_t;

typedef struct ast_literal_t
{
  ast_literal_kind_t kind;
  ast_literal_value_t value;
} ast_literal_t;

typedef struct ast_identifier_t
{
  string_view_t name;
} ast_identifier_t;

typedef struct ast_variable_declaration_t
{
  string_view_t name;
  type_t type;
  ast_node_t *value;
} ast_variable_declaration_t;

typedef struct ast_visitor_t
{
  void (*visit_function)(struct ast_visitor_t *, ast_function_declaration_t *);
  void (*visit_return_stmt)(struct ast_visitor_t *, ast_return_stmt_t *);
  void (*visit_literal)(struct ast_visitor_t *, ast_literal_t *);
  void (*visit_binary_operation)(struct ast_visitor_t *, ast_binary_operation_t *);
} ast_visitor_t;

typedef enum
{
  AST_BINARY_OPERATION,
  AST_FUNCTION_DECLARATION,
  AST_IDENTIFIER,
  AST_LITERAL,
  AST_RETURN_STMT,
  AST_UNKOWN_NODE,
  AST_VARIABLE_DECLARATION,
} ast_node_kind_t;

typedef union
{
  ast_binary_operation_t binary_operation;
  ast_function_declaration_t function;
  ast_literal_t literal;
  ast_return_stmt_t return_stmt;
  ast_variable_declaration_t variable;
  ast_identifier_t identifier;
} ast_node_data_t;

typedef struct ast_node_t
{
  void (*accept_visitor)(ast_node_t *, ast_visitor_t *);
  ast_node_kind_t kind;
  ast_node_data_t data;
} ast_node_t;

void
ast_node_accept_visitor(ast_node_t *node, ast_visitor_t *visitor);

ast_node_t *
ast_node_new();
void
ast_node_destroy(ast_node_t *node);

void
ast_node_init_binary_operation(ast_node_t *node, string_view_t op, ast_node_t *left, ast_node_t *right);
void
ast_node_init_function_declaration(ast_node_t *node, string_view_t name, type_t return_type, vector_t *body);
void
ast_node_init_identifier(ast_node_t *node, string_view_t name);
void
ast_node_init_return_stmt(ast_node_t *node, ast_node_t *argument);
void
ast_node_init_variable_declaration(ast_node_t *node, string_view_t variable_name, type_t type, ast_node_t *value);
// FIXME: use the naming convention
void
ast_literal_integer_create(ast_node_t *node, uint32_t number);

#endif /* AST_H */