#include "Expr.h"
#include <stdio.h>
#include <string.h>

namespace hsql {

    Expr::Expr(ExprType type) :
        type(type),
        expr(NULL),
        expr2(NULL),
        name(NULL),
        table(NULL),
        alias(NULL) {};

    Expr::~Expr() {
        delete expr;
        delete expr2;
        delete name;
        delete table;
    }

    Expr* Expr::makeOpUnary(OperatorType op, Expr* expr) {
        Expr* e = new Expr(kExprOperator);
        e->op_type = op;
        e->expr = expr;
        e->expr2 = NULL;
        return e;
    }

    Expr* Expr::makeOpBinary(Expr* expr1, OperatorType op, Expr* expr2) {
        Expr* e = new Expr(kExprOperator);
        e->op_type = op;
        e->op_char = 0;
        e->expr = expr1;
        e->expr2 = expr2;
        return e;
    }

    Expr* Expr::makeOpBinary(Expr* expr1, char op, Expr* expr2) {
        Expr* e = new Expr(kExprOperator);
        e->op_type = SIMPLE_OP;
        e->op_char = op;
        e->expr = expr1;
        e->expr2 = expr2;
        return e;
    }

    Expr* Expr::makeLiteral(int64_t val) {
        Expr* e = new Expr(kExprLiteralInt);
        e->ival = val;
        return e;
    }

    Expr* Expr::makeLiteral(double value) {
        Expr* e = new Expr(kExprLiteralFloat);
        e->fval = value;
        return e;
    }

    Expr* Expr::makeLiteral(char* string) {
        Expr* e = new Expr(kExprLiteralString);
        e->name = string;
        return e;
    }


    Expr* Expr::makeColumnRef(char* name) {
        Expr* e = new Expr(kExprColumnRef);
        e->name = name;
        return e;
    }

    Expr* Expr::makeColumnRef(char* table, char* name) {
        Expr* e = new Expr(kExprColumnRef);
        e->name = name;
        e->table = table;
        return e;
    }

    Expr* Expr::makeFunctionRef(char* func_name, Expr* expr, bool distinct) {
        Expr* e = new Expr(kExprFunctionRef);
        e->name = func_name;
        e->expr = expr;
        e->distinct = distinct;
        return e;
    }

    Expr* Expr::makePlaceholder(int id) {
        Expr* e = new Expr(kExprPlaceholder);
        e->ival = id;
        return e;
    }

    bool Expr::isType(ExprType e_type) {
        return e_type == type;
    }

    bool Expr::isLiteral() {
        return isType(kExprLiteralInt) || isType(kExprLiteralFloat) || isType(kExprLiteralString) || isType(kExprPlaceholder);
    }

    bool Expr::hasAlias() {
        return alias != NULL;
    }

    bool Expr::hasTable() {
        return table != NULL;
    }

    char* Expr::getName() {
        if (alias != NULL) return alias;
        else return name;
    }

    bool Expr::isSimpleOp() {
        return op_type == SIMPLE_OP;
    }

    bool Expr::isSimpleOp(char op) {
        return isSimpleOp() && op_char == op;
    }
    
    char* substr(const char* source, int from, int to) {
        int len = to-from;
        char* copy = new char[len+1];
        strncpy(copy, source+from, len);
        copy[len] = '\0';
        return copy;
    }
} // namespace hsql