#ifndef LEXER_H
#define LEXER_H

#include <stdbool.h>
#include <stddef.h>

typedef enum {
    TokenTypeEof,

    TokenTypeInvalidChar,
    TokenTypeMalformedMultilineComment,
    TokenTypeMalformedChar,
    TokenTypeMalformedString,

    TokenTypeId,
    TokenTypeInt,
    TokenTypeIntDoubleDot,
    TokenTypeHex,
    TokenTypeBinary,
    TokenTypeFloat,
    TokenTypeChar,
    TokenTypeString,

    TokenTypeIf,
    TokenTypeElse,
    TokenTypeLoop,
    TokenTypeWhile,
    TokenTypeFor,
    TokenTypeIn,
    TokenTypeBreak,
    TokenTypeLet,
    TokenTypeMatch,
    TokenTypeFalse,
    TokenTypeTrue,
    TokenTypeNot,
    TokenTypeAnd,
    TokenTypeOr,
    TokenTypeFn,
    TokenTypeReturn,
    TokenTypeMut,
    TokenTypeDefer,

    TokenTypeLParen,
    TokenTypeRParen,
    TokenTypeLBrace,
    TokenTypeRBrace,
    TokenTypeLBracket,
    TokenTypeRBracket,
    TokenTypeComma,
    TokenTypeColon,
    TokenTypeDoubleColon,
    TokenTypeDoubleColonLt,
    TokenTypeSemicolon,
    TokenTypeAmpersand,
    TokenTypeUnderscore,
    TokenTypeDot,
    TokenTypeDoubleDot,
    TokenTypeDoubleDotEqual,
    TokenTypeDoubleDotLt,

    TokenTypePlusEqual,
    TokenTypeMinusEqual,
    TokenTypeAsteriskEqual,
    TokenTypeSlashEqual,
    TokenTypePercentEqual,
    TokenTypeDoubleEqual,
    TokenTypeExclamationEqual,
    TokenTypeLtEqual,
    TokenTypeGtEqual,

    TokenTypePlus,
    TokenTypeMinus,
    TokenTypeAsterisk,
    TokenTypeSlash,
    TokenTypePercent,
    TokenTypeEqual,
    TokenTypeExclamation,
    TokenTypeLt,
    TokenTypeGt,
} TokenType;

const char* token_type_to_string(TokenType type);

typedef struct {
    size_t index;
    int line, column;
} Position;

typedef struct {
    TokenType type;
    Position position;
    size_t length;
} Token;

char* token_string(const Token* token, const char* text);
char* token_to_string(const Token* token, const char* text);

typedef struct {
    const char* text;
    size_t index, length;
    int line, column;
} Lexer;

void lexer_create(Lexer* lexer, const char* text, size_t text_length);
Token lexer_next(Lexer* lexer);
char* lexer_token_string(const Lexer* lexer, const Token* token);

Token lexer_skip_whitespace(Lexer* lexer);
Token lexer_make_int_or_float(Lexer* lexer);
Token lexer_make_id(Lexer* lexer);
bool lexer_span_matches(const Lexer* lexer, Position begin, const char* value);
Token lexer_make_static_token(Lexer* lexer);
Token lexer_make_int_hex_binary_or_float(Lexer* lexer);
Token lexer_make_char(Lexer* lexer);
Token lexer_make_string(Lexer* lexer);
void lexer_skip_literal_char(Lexer* lexer);
Token lexer_make_single_char_token(Lexer* lexer, TokenType type);
Token lexer_make_dot_token(Lexer* lexer);
Token lexer_make_colon_token(Lexer* lexer);
Token lexer_make_slash_token(Lexer* lexer);
Token lexer_skip_singleline_comment(Lexer* lexer);
Token lexer_make_single_or_double_char_token(Lexer* lexer,
    TokenType single_type, char second_char, TokenType double_type);
Token lexer_skip_multiline_comment(Lexer* lexer);
Token lexer_make_invalid_char(Lexer* lexer);
Position lexer_position(const Lexer* lexer);
Token lexer_token(const Lexer* lexer, TokenType type, Position begin);
bool lexer_done(const Lexer* lexer);
char lexer_current(const Lexer* lexer);
void lexer_step(Lexer* lexer);

#endif