#include "lookup.h"
#include "messages.h"
#include "types.h"
#include "Node.h"
#include "SyntaxTree.h"
#include "Symbol.h"
#include "SymbolTable.h"
#include <assert.h>

/* declared in comp.l */
extern int lineno;

/* declared in comp.y */
extern SyntaxTree *tree;
extern SymbolTable *symtab;
extern Messages messages;
extern string mainScopeName;

Symbol *lookup(const string& id, SymbolType default_type)
{
    /* Lookup ID */
    Symbol *symbol = symtab->GetSymbol(id);
    if (symbol == NULL) {
        /* Symbol not found */
        messages.UndeclaredIdError(lineno, id);

        /* Add ID with return type error to avoid triggering error again */
        symbol = new Symbol();
        symbol->SetSymbolType(default_type);
        symbol->SetName(id);
        symbol->SetLine(lineno);
        symbol->SetReturnType(RT_ERROR);
        symtab->AddSymbol(symbol);
    }
    return symbol;
}

/* Checks if the id already exists and gives an error if it does */
void check_id(const string& id)
{
    /* check for program name */
    if (id == mainScopeName) {
        messages.DeclaredIdError(lineno, id, 0);
        return;
    }
    /* check for local identifiers */
    Symbol *symbol = symtab->GetSymbol(symtab->GetCurrentScopeName(), id, false);
    if (symbol != NULL) {
        messages.DeclaredIdError(lineno, id, symbol->GetLine());
        return;
    }
    /* check for global identifiers */
    symbol = symtab->GetSymbol(id);
    if (symbol != NULL) {
        SymbolType symboltype = symbol->GetSymbolType();
        if (symboltype == ST_FUNCTION || symboltype == ST_PROCEDURE) {
            messages.DeclaredIdError(lineno, id, symbol->GetLine());
            return;
        }
    }
}