#ifndef AST_H
#define AST_H

#include <stdbool.h>

#include "../lists/lists.h"

enum ast_type
{
    AST_END,
    AST_LIST,
    AST_IF,
    AST_CMD
};

struct ast_cmd
{
    struct list *cmd; // A list of words (char*)
};

struct ast_if
{
    struct ast *condition;
    struct ast *then_clause;
    struct ast *else_clause;
};

struct ast
{
    enum ast_type type;

    /**
     * Data associated with this AST node. It can be one of the following:
     * - NULL (AST_END)
     * - struct ast_if* (AST_IF)
     * - struct ast_cmd* (AST_CMD)
     */
    void *data;
};

struct ast_list
{
    struct list *children; // A list of ASTs (ast*)
};

/**
 * Checks if the given AST node is an if statement.
 */
bool ast_is_if(struct ast *node);

/**
 * Checks if the given AST node is a command.
 */
bool ast_is_cmd(struct ast *node);

/**
 * Checks if the given AST node is a command.
 */
bool ast_is_list(struct ast *node);

/**
 * Retrieves the if statement data from the given AST node.
 * Assumes that the node is of type AST_IF.
 */
struct ast_if *ast_get_if(struct ast *node);

/**
 * Retrieves the command data from the given AST node.
 * Assumes that the node is of type AST_CMD.
 */
struct ast_cmd *ast_get_cmd(struct ast *node);

/**
 * Retrieves the command data from the given AST node.
 * Assumes that the node is of type AST_LIST.
 */
struct ast_list *ast_get_list(struct ast *node);

/**
 * Creates a new AST node representing an if statement.
 */
struct ast *ast_create_if(struct ast *condition, struct ast *then_clause,
                          struct ast *else_clause);

/**
 * Creates a new AST node representing a command.
 */
struct ast *ast_create_cmd(struct list *cmd);

/**
 * Creates a new AST node representing a list of ASTs
 */
struct ast* ast_create_list(struct list* ast_list);

#endif /* ! AST_H */