#ifndef PARSE_H
#define PARSE_H

#include "collection.h"
#include <stddef.h>

char* read_textfile(const char* filename);

// phases:
// https://en.cppreference.com/c/language/translation_phases

// phase 1 - source chars

typedef struct {
    char ch;
    int line;
    int col;
} Char;

typedef struct {
    const char* text;
    size_t i;
    int line;
    int col;
} SourceIter;

void source_iter_init(SourceIter* r, const char* text);
Char source_iter_next(SourceIter* r);

// phase 2 - logical source lines

typedef struct {
    SourceIter* source_char_iter;
    Char curr;
} LslIter;

void lsl_iter_init(LslIter* r, SourceIter* source_iter);
Char lsl_iter_next(LslIter* r);

// phase 3 - preprocessor tokens

typedef enum {
    Tok_Eof,
    Tok_Ident,
    Tok_Int,
    Tok_Str,
    Tok_Char,
    Tok_Whitespace,
    Tok_HeaderName,
    Tok_Eol = '\n', // NOTE: has value 10
    Tok_Semicolon = ';',
    Tok_LParen = '(',
    Tok_RParen = ')',
    Tok_LBrace = '{',
    Tok_RBrace = '}',
    Tok_Comma = ',',
    Tok_Asterisk = '*',
    Tok_Hashtag = '#',

    // used internally in preprocessor
    Tok_EndOfMacroInvocation,
} TokTy;

const char* tokty_str(TokTy ty);

typedef struct {
    TokTy ty;
    char* text;
    int line;
    int col;
} Tok;

typedef struct {
    LslIter* lsl_iter;
    Arena* arena;
    Char curr;
    bool lex_whitespace;
    bool lex_headername;
} Lexer;

void lexer_init(Lexer* r, LslIter* lsl_iter, Arena* arena);
Tok lexer_next(Lexer* l);

// phase 4 - preprocessor

typedef struct Preproc Preproc;

void preproc_init(Preproc** p, char* filename, char* text, Arena* arena);
void preproc_deinit(Preproc* p);
Tok preproc_next(Preproc* p);

// phase 5, 6 - preprocessor cleanup, concat strings

typedef struct {
    Preproc* preproc;
    Arena* arena;
    Tok curr;
} TokStream;

void tokstream_init(TokStream* s, Preproc* preproc, Arena* arena);
Tok tokstream_next(TokStream* s);

#endif