#include <pproc_expand.h>
#include <scc_lexer.h>
#include <scc_lexer_utils.h>
#include <scc_pproc.h>

static int pproc_next_one_file(scc_pproc_t *pp, scc_lexer_tok_t *out) {
    scc_lexer_tok_ring_t *stream = null;
    scc_lexer_tok_t tok = {0};
    int ok = 0;
CONTINUE:
    stream = pp->cur_ring;
    if (pp->expanded_ring.cap) {
        scc_ring_next_consume(pp->expanded_ring, *out, ok);
        if (ok == false) {
            scc_ring_free(pp->expanded_ring);
            goto CONTINUE;
        } else {
            return true;
        }
    }
    scc_ring_peek(*stream, tok, ok);
    if (ok == false) {
        return false;
    }

    if (pp->at_line_start) {
        if (tok.type == SCC_TOK_SHARP) {
            // parse to #
            scc_pproc_handle_directive(pp);
            pp->at_line_start = true;
            goto CONTINUE;
        } else if (tok.type == SCC_TOK_BLANK) {
            scc_ring_next(*stream, *out, ok);
            scc_ring_peek(*stream, tok, ok);
            if (ok && tok.type == SCC_TOK_SHARP) {
                scc_lexer_tok_drop(out);
                scc_pproc_handle_directive(pp);
                pp->at_line_start = true;
                goto CONTINUE;
            }
            scc_ring_back(*stream, ok);
            Assert(ok == true);
            scc_ring_peek(*stream, tok, ok);
        }
    }
    if (pp->enable == false) {
        scc_lexer_skip_until_newline(stream);
        pp->at_line_start = true;
        goto CONTINUE;
    }

    if (tok.type == SCC_TOK_ENDLINE) {
        scc_ring_next_consume(*stream, *out, ok);
        pp->at_line_start = true;
        return true;
    } else if (scc_get_tok_subtype(tok.type) == SCC_TOK_SUBTYPE_IDENTIFIER) {
        // maybe expanded
        scc_pproc_macro_t *macro =
            scc_pproc_macro_table_get(&pp->macro_table, &tok.lexeme);
        if (macro == null) {
            scc_ring_next_consume(*stream, *out, ok);
            return ok;
        }
        scc_pproc_expand_by_src(&pp->macro_table, pp->cur_ring,
                                &pp->expanded_ring, macro,
                                pp->config.keep_original_pos);
        goto CONTINUE;
    } else {
        // continue
        scc_ring_next_consume(*stream, *out, ok);
        return ok;
    }
    return false;
}

static int pproc_next(scc_pproc_t *pp, scc_lexer_tok_t *tok) {
    int ret = 0;
CONTINUE:
    ret = pproc_next_one_file(pp, tok);
    if (ret != 0) {
        return true;
    }

    if (scc_vec_size(pp->file_stack) == 0) {
        return false;
    }

    scc_pproc_file_t *file = scc_vec_pop(pp->file_stack);
    Assert(file->ring == pp->cur_ring);
    scc_lexer_drop_ring(file->ring);
    scc_lexer_drop(&(file->lexer));
    scc_sstream_drop(&(file->sstream));
    scc_free(file);

    if (scc_vec_size(pp->file_stack) == 0) {
        pp->cur_ring = pp->org_ring;
    } else {
        pp->cur_ring =
            scc_vec_at(pp->file_stack, scc_vec_size(pp->file_stack) - 1)->ring;
    }
    goto CONTINUE;
}

void scc_pproc_init(scc_pproc_t *pp, scc_lexer_tok_ring_t *input) {
    Assert(pp != null && input != null);
    pp->org_ring = input;
    pp->cur_ring = pp->org_ring;
    scc_ring_init(pp->expanded_ring, 0, 0, 0);
    scc_pproc_marco_table_init(&pp->macro_table);
    scc_vec_init(pp->include_paths);
    scc_vec_init(pp->if_stack);
    scc_vec_init(pp->file_stack);
    pp->at_line_start = true;
    pp->enable = true;

    pp->config.max_include_depth = 32;
    pp->config.keep_original_pos = true;
}

void scc_pproc_add_builtin_macros() {
    // TODO
}

static cbool fill_token(scc_lexer_tok_t *tok, void *userdata) {
    scc_pproc_t *pp = userdata;
    cbool ret = false;
CONTINUE:
    ret = pproc_next(pp, tok);
    // FIXME Hack the token
    if (ret && tok->type >= SCC_TOK_DISABLED) {
        tok->type -= SCC_TOK_DISABLED;
    }

    if (ret && scc_get_tok_subtype(tok->type) == SCC_TOK_SUBTYPE_INVALID) {
        PanicFmt("Invalid token: %s", scc_cstring_as_cstr(&tok->lexeme));
    }
    if (ret && !pp->ring_need_comment &&
        scc_get_tok_subtype(tok->type) == SCC_TOK_SUBTYPE_COMMENT) {
        scc_lexer_tok_drop(tok);
        goto CONTINUE;
    }
    if (ret && !pp->ring_need_empty &&
        scc_get_tok_subtype(tok->type) == SCC_TOK_SUBTYPE_EMPTYSPACE) {
        scc_lexer_tok_drop(tok);
        goto CONTINUE;
    }
    return ret;
}

scc_lexer_tok_ring_t *scc_pproc_to_ring(scc_pproc_t *pp, int ring_size,
                                        cbool need_empty, cbool need_comment) {
    scc_ring_init(pp->ring, ring_size, fill_token, pp);
    pp->ring_need_comment = need_comment;
    pp->ring_need_empty = need_empty;
    pp->ring_ref_count++;
    return &pp->ring;
}

// 销毁预处理器
void scc_pproc_drop(scc_pproc_t *pp) {
    if (pp == null)
        return;
    Assert(pp->cur_ring == pp->org_ring);
    scc_lexer_drop_ring(pp->org_ring);
    scc_pproc_macro_table_drop(&pp->macro_table);
    scc_ring_free(pp->expanded_ring);

    scc_vec_foreach(pp->include_paths, i) {
        scc_cstring_free(&scc_vec_at(pp->include_paths, i));
    }
    scc_vec_free(pp->include_paths);

    Assert(scc_vec_size(pp->if_stack) == 0);
    scc_vec_free(pp->if_stack);

    Assert(scc_vec_size(pp->file_stack) == 0);
    scc_vec_free(pp->file_stack);
}