#include <ctype.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <stdio.h>

#include "lex.h"

String collect_identifier(char* input, size_t* pos) {
    String id_buf = make_String(256);
    while (input[*pos] == '_' || isalnum(input[*pos])) {
        push_to_String(&id_buf, input[(*pos)++]);
    }
    return id_buf;
}

String collect_single_quoted_section(char* input, size_t* pos) {
    (*pos)++;      // Consume quote mark
    String chunk_str = make_String(256);
    while (input[*pos] != '\'') {
        if (input[*pos] == '\0') exit(42);
        push_to_String(&chunk_str, input[(*pos)++]);
    }
    (*pos)++;       // Consume closing quote
    return chunk_str;
}

TokenVec lex_region(char* input, size_t* pos, char until);


void expect_char(char* input, size_t* pos, char expected) {
    if (input[*pos] != expected) exit(42);     // TODO: nicer handling
    (*pos)++;
}


void lex_double_quoted_section(char* input, size_t* pos, ChunkVec* coll, RegionVec* reg_arena) {
    (*pos)++;
    String accum = make_String(256);
    while (input[*pos] != '\"') {
        if (input[*pos] == '\0') exit(42);

        if (input[*pos] == '$') {
            (*pos)++;
            if (input[*pos] == '(') {
                if (input[*pos] == '(') {
                    TokenVec inner_toks = lex_region(input, pos, ')');
                    expect_char(input, pos, ')');
                    expect_char(input, pos, ')');
                    push_to_RegionVec(reg_arena, (Region){.})
                    push_to_ChunkVec(coll, (Chunk){.mode = DOUBLE_Q, .kind = ARITHM, .as.arithm_expr_region = inner_toks});
                }
            } else {
                String id_name = collect_identifier(input, pos);
                if (id_name.count > 0) {
                    push_to_ChunkVec(coll, (Chunk){.mode = DOUBLE_Q, .kind = VAR_EXP, .as.param_string = inner(id_name)});
                }
                continue;
            }
        } else {

        }
    }
}




typedef struct {
    Region root_reg;
    RegionVec reg_arena;
} LexResult;
// TODO: maybe make an input+pos struct 

TokenVec lex_region(char* input, size_t* pos, char until) {
    TokenVec tokens = make_TokenVec(256);    
    RegionVec reg_arena;

    while (input[*pos] != until) {
        // Getting a token

        if (input[*pos] == ' ') {
            (*pos)++;
            continue;
        }

        ChunkVec chunks = make_ChunkVec(256);
        
        switch (input[*pos]) {
            case '\'':
                String qstring = get_single_quoted_chunk(input, pos);
                push_to_ChunkVec(&chunks, (Chunk){.mode=SINGLE_Q, .kind = LITERAL, .as.lit_str = qstring.items});
                break;
                
        }

    }
    return tokens;
}

TokenVec lex(char* input) {
    size_t pos = 0;
    return lex_region(input, &pos, '\0');
}