#ifndef GRAMMAR_BASIC_H
#define GRAMMAR_BASIC_H

#include "../lexer/lexer.h"
#include "../utils/ast/ast.h"

// === Functions

/* @brief: parses a list of [and_or] rules separated by semicolons and that
 *         ends by a newline
 *
 * @code list = and_or { ';' and_or } [ ';' ] ;
 *
 * @first first(and_or)
 */
struct ast *parse_list(struct lexer_context *ctx);

/* @brief Only parses a pipeline rule for the moment
 *
 * @code and_or = pipeline { ( '&&' | '||' ) {'\n'} pipeline } ;
 *
 * @first first(pipeline)
 */
struct ast *parse_and_or(struct lexer_context *ctx);

/* @brief Only parses a command rule for the moment
 *
 * @code pipeline = command ;
 *
 * @first first(command)
 */
struct ast *parse_pipeline(struct lexer_context *ctx);

/* @brief Parses a simple command rule or a shell command rule depending on
 *        the first token.
 * @note
 *        TOKEN_WORD => simple_command
 *        TOKEN_IF => shell_command
 *
 * @code command = simple_command
 *               | shell_command
 *               ;
 * @first first(simple_command), first(shell_command)
 */
struct ast *parse_command(struct lexer_context *ctx);

/* @brief Parses a simple list of words (command and arguments)
 *        ending by a separator
 *
 * @code simple_command = WORD { element } ;
 *
 * @first WORD
 */
struct ast *parse_simple_command(struct lexer_context *ctx);

/* @brief Only parses if rules for the moment
 *
 * @code shell_command = if_rule ;
 *
 * @first first(if_rule)
 */
struct ast *parse_shell_command(struct lexer_context *ctx);

/* @brief Parses a if rule (condition, then-clause, elif-clause, else-clause)
 *
 * @code if_rule = 'if' compound_list 'then' compound_list [else_clause] 'fi' ;
 *
 * @first TOKEN_IF
 */
struct ast *parse_if_rule(struct lexer_context *ctx);

/* @brief parses commands inside if/else clauses and returns the corresponding
 * AST list
 *
 * @code compound_list = {'\n'} and_or { ( ';' | '\n' ) {'\n'} and_or } [';']
 * {'\n'} ;
 *
 * @first TOKEN_NEWLINE, first(and_or)
 */
struct ast *parse_compound_list(struct lexer_context *ctx);

/* @brief
 *
 * @code else_clause = 'else' compound_list
 *                   | 'elif' compound_list 'then' compound_list [else_clause]
 *                   ;
 *
 * @first TOKEN_ELSE, TOKEN_ELIF
 */
struct ast *parse_else_clause(struct lexer_context *ctx);

#endif /* ! GRAMMAR_BASIC_H */