/* date = July 9th 2023 8:04 pm */

#ifndef VN_TOKENIZER_H
#define VN_TOKENIZER_H

////////////////////////////////
//~ sixten: Token Types
enum token_kind
{
	TokenKind_None,
	
	// sixten: labels
	TokenKind_Identifier,
	TokenKind_Numeric,
	TokenKind_StringLiteral,
	
	// sixten: symbols
	TokenKind_SymbolsBegin,
	// sixten: (single char)
	TokenKind_CurlyOpen,
	TokenKind_CurlyClose,
	TokenKind_ParenthesisOpen,
	TokenKind_ParenthesisClose,
	TokenKind_Comma,
	TokenKind_Dot,
	TokenKind_DollarSign,
	TokenKind_Semicolon,
	TokenKind_Plus,
	TokenKind_Minus,
	TokenKind_Star,
	TokenKind_Slash,
	// sixten: (one or two chars)
	TokenKind_Bang,
	TokenKind_BangEqual,
	TokenKind_Equal,
	TokenKind_EqualEqual,
	TokenKind_Greater,
	TokenKind_GreaterEqual,
	TokenKind_Less,
	TokenKind_LessEqual,
	TokenKind_SymbolsEnd,
	
	// sixten: keywords
	TokenKind_KeywordsBegin,
	TokenKind_Branch,
	TokenKind_Else,
	TokenKind_False,
	TokenKind_If,
    TokenKind_Then,
	TokenKind_While,
	TokenKind_Jump,
	TokenKind_Proc,
	TokenKind_True,
	TokenKind_Let,
	TokenKind_Call,
	TokenKind_Wait,
	TokenKind_End,
	TokenKind_KeywordsEnd,
    
	// sixten: whitespace
	TokenKind_Whitespace,
	TokenKind_Newline,
	TokenKind_Comment,
	
	// sixten: invalid kinds
	TokenKind_BrokenComment,
	TokenKind_BrokenStringLiteral,
	TokenKind_BadCharacter,
};

typedef b32 tokenizer_filter_function(token_kind Kind);

struct token
{
	token_kind Kind;
	range1_s64 Range;
	s64 Line;
};

global read_only token T_EmptyToken = {};

struct token_chunk_node
{
	token *Tokens;
	s64 MaxCount;
	s64 Count;
	token_chunk_node *Next;
};

struct token_chunk_list
{
	token_chunk_node *First;
	token_chunk_node *Last;
	s64 Count;
};

struct token_array
{
	token *Tokens;
	s64 Count;
};

////////////////////////////////
//~ sixten: Tokenizer Message Types
enum tokenizer_message_kind
{
	T_MessageKind_Invalid,
	T_MessageKind_Note,
	T_MessageKind_Warning,
	T_MessageKind_Error,
};

struct tokenizer_message
{
	tokenizer_message *Next;
	tokenizer_message_kind Kind;
	s64 Offset;
	string String;
};

struct tokenizer_message_list
{
	tokenizer_message *First;
	tokenizer_message *Last;
	s64 Count;
};

////////////////////////////////
//~ sixten: Text -> Token Types
struct tokenize_result
{
	token_array Tokens;
	tokenizer_message_list Messages;
};

////////////////////////////////
//~ sixten: Token Filter Helper Functions
inline b32 T_IsComment(token_kind Kind)    { return(Kind == TokenKind_Comment); }
inline b32 T_IsWhitespace(token_kind Kind) { return(Kind == TokenKind_Whitespace ||
                                                    Kind == TokenKind_Newline); }
inline b32 T_IsIrregular(token_kind Kind)  { return(T_IsComment(Kind) ||
                                                    T_IsWhitespace(Kind)); }
inline b32 T_IsRegular(token_kind Kind)    { return(!T_IsIrregular(Kind)); }
inline b32 T_IsInvalid(token_kind Kind)    { return(Kind == TokenKind_None ||
                                                    Kind == TokenKind_BrokenComment ||
                                                    Kind == TokenKind_BrokenStringLiteral ||
                                                    Kind == TokenKind_BadCharacter); }

////////////////////////////////
//~ sixten: Token Type Functions
static string T_StringFromToken(string Text, token Token);
static void T_TokenChunkListPush(arena *Arena, token_chunk_list *List, token Token, s64 MaxTokenCountPerNode);
static token_array T_TokenArrayFromChunkList(arena *Arena, token_chunk_list *List);

////////////////////////////////
//~ sixten: Tokenizer Message Functions
static void T_MessageListPush(arena *Arena, tokenizer_message_list *List, tokenizer_message_kind Kind, s64 Offset, string String);

////////////////////////////////
//~ sixten: Text -> Token Functions
static tokenize_result T_TokenizeFromText(arena *Arena, string Text, tokenizer_filter_function *ExcludeFilter = 0);

#endif //VN_TOKENIZER_H