/* 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_At,
    TokenKind_PoundSign,
    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_And,
    TokenKind_Branch,
    TokenKind_Else,
    TokenKind_False,
    TokenKind_For,
    TokenKind_If,
    TokenKind_Jump,
    TokenKind_Or,
    TokenKind_Proc,
    TokenKind_True,
    TokenKind_Var,
    TokenKind_While,
    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;
};

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(memory_arena *Arena, token_chunk_list *List, token Token, s64 MaxTokenCountPerNode);
static token_array T_TokenArrayFromChunkList(memory_arena *Arena, token_chunk_list *List);

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

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

#endif //VN_TOKENIZER_H