#include "parser.h"
#include "type.h"
#include "ast/ast.h"

int poptok(struct Parser* parser) {
    if (parser->size == 0) {
        return -1;
    }
    int idx = parser->cur_idx;
    parser->cur_idx = (idx + 1) % PARSER_MAX_TOKEN_QUEUE;
    parser->size--;
    return 0;
}

void flushpeektok(struct Parser* parser) {
    parser->peek_idx = parser->cur_idx;
}

struct Token* peektok(struct Parser* parser) {
    int idx = parser->peek_idx;
    idx = (idx + 1) % PARSER_MAX_TOKEN_QUEUE;
    if (parser->size >= PARSER_MAX_TOKEN_QUEUE) {
        warn("peek maybe too deep");
    }
    if (parser->peek_idx == parser->end_idx) {
        if (parser->size == PARSER_MAX_TOKEN_QUEUE) {
            // FIXME
            error("buffer overflow");
        }
        get_valid_token(parser->lexer, &(parser->TokenBuffer[idx]));
        parser->size++;
        parser->end_idx = idx;
    }
    
    parser->peek_idx = idx;
    return &(parser->TokenBuffer[idx]);
}

enum TokenType peektoktype(struct Parser* parser) {
    return peektok(parser)->type;
}

void expecttok(struct Parser* parser, enum TokenType type) {
    struct Token* tok = peektok(parser);
    if (tok->type != type) {
        error("expected tok: %s, got %s", get_token_name(type), get_token_name(tok->type));
    } else {
        poptok(parser);
    }
}

void init_parser(struct Parser* parser, struct Lexer* lexer, struct SymbolTable* symtab) {
    parser->cur_node = NULL;
    parser->root = NULL;

    parser->cur_idx = 0;
    parser->peek_idx = 0;
    parser->end_idx = 0;
    parser->size = 0;
    parser->lexer = lexer;
    parser->symtab = symtab;
    // TODO
}

void run_parser(struct Parser* parser) {
    parse_prog(parser);
}