/*
 * Copyright (c) 2026, Chloe M.
 * Provided under the BSD-3 clause
 */

#include <stdint.h>
#include <errno.h>
#include "cescal/log.h"
#include "cescal/parser.h"
#include "cescal/state.h"
#include "cescal/lexer.h"

/* Symbolic token */
#define symtok(tok) \
    "[" tok "]"

/* Quoted token */
#define qtok(tok) \
    "'" tok "'"

/* Convert token to string */
#define tokstr1(tt) \
    toktab[(tt)]

/* Convert token to string */
#define tokstr(tok) \
    toktab[(tok)->type]

/*
 * Converts numeric tokens into human readable strings
 */
static const char *toktab[] = {
    [TT_NONE]    = symtok("none"),
    [TT_IDENT]   = symtok("ident"),
    [TT_COMMENT] = symtok("comment"),
    [TT_INTLIT]  = symtok("number"),
    [TT_LPAREN]  = qtok("("),
    [TT_RPAREN]  = qtok(")"),
    [TT_COMMA]   = qtok(","),
    [TT_COLON]   = qtok(":"),
    [TT_ARROW]   = qtok("->"),
    [TT_PLUS]    = qtok("+"),
    [TT_MINUS]   = qtok("-"),
    [TT_SLASH]   = qtok("/"),
    [TT_STAR]    = qtok("*"),
    [TT_EQUALS]  = qtok("="),
    [TT_DEFINE]  = qtok("#define"),
    [TT_IFNDEF]  = qtok("#ifndef"),
    [TT_IFDEF]   = qtok("#ifdef"),
    [TT_RETURN]  = qtok("return"),
    [TT_PUB]     = qtok("pub"),
    [TT_PROC]    = qtok("proc"),
    [TT_BEGIN]   = qtok("begin"),
    [TT_END]     = qtok("end"),
    [TT_U8]      = qtok("u8"),
    [TT_U16]     = qtok("u16"),
    [TT_U32]     = qtok("u32"),
    [TT_U64]     = qtok("u64")
};

/*
 * Push a token to the token buffer in the preprocessing stage
 *
 * @tokbuf: Token buffer to push to
 * @tok:    Token to push
 *
 * Returns zero on success
 */
static int
preprocessor_push(struct tokbuf *tokbuf, struct token *tok)
{
    if (tokbuf == NULL || tok == NULL) {
        return -1;
    }

    switch (tok->type) {
    case TT_IFNDEF:
    case TT_IFDEF:
    case TT_DEFINE:
        break;
    default:
        if (tokbuf_push(tokbuf, tok) < 0) {
            return -1;
        }
    }

    return 0;
}

static int
parser_nom(struct cescal_state *state, struct token *res)
{
    struct token tok;

    if (state == NULL || res == NULL) {
        errno = EINVAL;
        return -1;
    }

    switch (state->pass) {
    case 0:     /* Pre-processor */
        if (lexer_nom(state, &tok) < 0) {
            return -1;
        }

        printf("* %s\n", tokstr(&tok));
        if (preprocessor_push(&state->tokbuf, &tok) < 0) {
            return -1;
        }

        break;
    case 1:     /* Parse */
        if (tokbuf_pop(&state->tokbuf, &tok) < 0) {
            return -1;
        }

        break;
    }

    *res = tok;
    return 0;
}

int
parser_parse(struct cescal_state *state)
{
    struct token tok;

    if (state == NULL) {
        errno = EINVAL;
        return -1;
    }

    while (parser_nom(state, &tok) == 0) {
        cc_trace("got token %s\n", tokstr(&tok));
    }

    ++state->pass;
    return 0;
}