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

/**
 * 0 false
 * 1 true
 */
int peek_decl(struct Parser* parser) {
    flushpeektok(parser);
    switch (peektoktype(parser)) {
        case TOKEN_STATIC:
        case TOKEN_EXTERN:
        case TOKEN_REGISTER:
        case TOKEN_TYPEDEF:
            error("not impliment");
            break;
        default:
            flushpeektok(parser);
    }

    switch (peektoktype(parser)) {
        case TOKEN_VOID:
        case TOKEN_CHAR:
        case TOKEN_SHORT:
        case TOKEN_INT:
        case TOKEN_LONG:
        case TOKEN_FLOAT:
        case TOKEN_DOUBLE:
            return 1;
        default:
            flushpeektok(parser);
    }
}

struct ASTNode* parse_decl_val(struct Parser* parser) {
    flushpeektok(parser);
    // parse_type
    enum TokenType ttype;
    struct ASTNode* node;

    struct ASTNode* type_node = parse_type(parser);
    struct ASTNode* name_node = parser_ident_without_pop(parser);
    
    node = new_ast_node();
    node->decl_val.type = type_node;
    node->decl_val.name = name_node;
    node->type = NT_DECL_VAR;
    symtab_add_symbol(parser->symtab, name_node->syms.tok.constant.str, node);
    
    ttype = peektoktype(parser);
    if (ttype == TOKEN_ASSIGN) {
        node->decl_val.expr_stmt = parse_stmt(parser);
        if (node->decl_val.expr_stmt->type != NT_STMT_EXPR) {
            error("parser_decl_val want stmt_expr");
        }
    } else if (ttype == TOKEN_SEMICOLON) {
        poptok(parser);
        expecttok(parser, TOKEN_SEMICOLON);
    } else {
        error("parser_decl_val syntax error");
    }
    return node;
}

// 类型解析入口改进
struct ASTNode* parse_decl(struct Parser* parser) {
    flushpeektok(parser);
    int idx;
    enum TokenType ttype;
    struct ASTNode* node;
    
    if (peek_decl(parser) == 0) {
        error("syntax error expect decl_val TYPE");
    }
    if (peektoktype(parser) != TOKEN_IDENT) {
        error("syntax error expect decl_val IDENT");
    }

    ttype = peektoktype(parser);
    switch (ttype) {
        case TOKEN_L_PAREN: // (
            node = parse_func(parser);
            break;
        case TOKEN_ASSIGN:
        case TOKEN_SEMICOLON:
            node = parse_decl_val(parser);
            break;
        default:
            error("syntax error expect decl_val ASSIGN or SEMICOLON");
            return NULL;
    }
    return node;
}