#include "forth.h"

// Input tokenizer (unchanged)
char* next_token(void) {
    if (input_ptr == NULL) return NULL;
    while (*input_ptr != '\0' && isspace((unsigned char)*input_ptr)) {
        input_ptr++;
    }
    if (*input_ptr == '\0') return NULL;
    char* start = input_ptr;
    while (*input_ptr != '\0' && !isspace((unsigned char)*input_ptr)) {
        input_ptr++;
    }
    if (*input_ptr != '\0') {
        *input_ptr = '\0';
        input_ptr++;
    }
    return start;
}

// Ensure compile_buf has room for at least 'needed' more cells
int ensure_compile_cap(int32_t needed) {
    if (compile_idx + needed > compile_cap) {
        forth_printf("Compile buffer overflow\n");
        return 0;
    }
    return 1;
}

// Inner interpreter (unchanged)
void inner_interpreter(void) {
    while (ip != NULL) {
        Cell current = *ip;
        ip++;
        current.word->code(current.word);
    }
}

void process_token(const char* token) {
    Word* w = lookup_word(token);
    if (w != NULL) {
        if (state == 0) { // Interpret mode
            if (w->code == do_docolon) {
                ret_push_ip(NULL);
                ip = w->body;
                inner_interpreter();
            } else {
                w->code(w);
            }
        } else { // Compile mode
            if (w->flags & (1 << 7)) { // Immediate word
                if (w->code == do_docolon) {
                    ret_push_ip(NULL);
                    ip = w->body;
                    inner_interpreter();
                } else {
                    w->code(w);
                }
            } else { // Compile normal word
                if (!ensure_compile_cap(1)) return;
                compile_buf[compile_idx++] = (Cell){.word = w};
            }
        }
    } else { // Try to parse as number
        char* end;
        long long v = strtoll(token, &end, 10);
        if (end != token && *end == '\0') {
            if (state == 0) {
                data_push((int64_t)v);
            } else { // Compile lit + number
                if (!w_lit) {
                    forth_printf("Fatal: lit word not found\n");
                    return;
                }
                if (!ensure_compile_cap(2)) return;
                compile_buf[compile_idx++] = (Cell){.word = w_lit};
                compile_buf[compile_idx++] = (Cell){.num = (int64_t)v};
            }
        } else {
            forth_printf("Unknown word: '%s'\n", token);
        }
    }
}

void outer_interpreter(void) {
    static char line_buf[256];
    while (1) {
        forth_printf("ok ");
        forth_fflush();
        if (fgets(line_buf, sizeof(line_buf), stdin) == NULL) {
            break;
        }
        input_buf = line_buf;
        input_buf_cap = sizeof(line_buf);
        size_t n = strlen(input_buf);
        if (n > 0 && input_buf[n - 1] == '\n') {
            input_buf[n - 1] = '\0';
        }
        input_ptr = input_buf;
        char* tok;
        while ((tok = next_token()) != NULL) {
            process_token(tok);
        }
    }
    forth_printf("\n");
}