/*
 * Copyright 2004-2013 H2 Group. Multiple-Licensed under the H2 License,
 * Version 1.0, and under the Eclipse Public License, Version 1.0
 * (http://h2database.com/html/license.html).
 * Initial Developer: H2 Group
 */
package org.h2.value;

import java.sql.PreparedStatement;
import java.sql.SQLException;
import org.h2.constant.ErrorCode;
import org.h2.message.DbException;
import org.h2.util.MathUtils;

/**
 * Implementation of the INT data type.
 */
public class ValueInt extends Value {

    /**
     * The precision in digits.
     */
    public static final int PRECISION = 10;

    /**
     * The maximum display size of an int.
     * Example: -2147483648
     */
    public static final int DISPLAY_SIZE = 11;

    private static final int STATIC_SIZE = 128;
    // must be a power of 2
    private static final int DYNAMIC_SIZE = 256;
    private static final ValueInt[] STATIC_CACHE = new ValueInt[STATIC_SIZE];
    private static final ValueInt[] DYNAMIC_CACHE = new ValueInt[DYNAMIC_SIZE];

    private final int value;

    static {
        for (int i = 0; i < STATIC_SIZE; i++) {
            STATIC_CACHE[i] = new ValueInt(i);
        }
    }

    private ValueInt(int value) {
        this.value = value;
    }

    /**
     * Get or create an int value for the given int.
     *
     * @param i the int
     * @return the value
     */
    public static ValueInt get(int i) {
        if (i >= 0 && i < STATIC_SIZE) {
            return STATIC_CACHE[i];
        }
        ValueInt v = DYNAMIC_CACHE[i & (DYNAMIC_SIZE - 1)];
        if (v == null || v.value != i) {
            v = new ValueInt(i);
            DYNAMIC_CACHE[i & (DYNAMIC_SIZE - 1)] = v;
        }
        return v;
    }

    @Override
    public Value add(Value v) {
        ValueInt other = (ValueInt) v;
        return checkRange((long) value + (long) other.value);
    }

    private static ValueInt checkRange(long x) {
        if (x < Integer.MIN_VALUE || x > Integer.MAX_VALUE) {
            throw DbException.get(ErrorCode.NUMERIC_VALUE_OUT_OF_RANGE_1, Long.toString(x));
        }
        return ValueInt.get((int) x);
    }

    @Override
    public int getSignum() {
        return Integer.signum(value);
    }

    @Override
    public Value negate() {
        return checkRange(-(long) value);
    }

    @Override
    public Value subtract(Value v) {
        ValueInt other = (ValueInt) v;
        return checkRange((long) value - (long) other.value);
    }

    @Override
    public Value multiply(Value v) {
        ValueInt other = (ValueInt) v;
        return checkRange((long) value * (long) other.value);
    }

    @Override
    public Value divide(Value v) {
        ValueInt other = (ValueInt) v;
        if (other.value == 0) {
            throw DbException.get(ErrorCode.DIVISION_BY_ZERO_1, getSQL());
        }
        return ValueInt.get(value / other.value);
    }

    @Override
    public Value modulus(Value v) {
        ValueInt other = (ValueInt) v;
        if (other.value == 0) {
            throw DbException.get(ErrorCode.DIVISION_BY_ZERO_1, getSQL());
        }
        return ValueInt.get(value % other.value);
    }

    @Override
    public String getSQL() {
        return getString();
    }

    @Override
    public int getType() {
        return Value.INT;
    }

    @Override
    public int getInt() {
        return value;
    }

    @Override
    public long getLong() {
        return value;
    }

    @Override
    protected int compareSecure(Value o, CompareMode mode) {
        ValueInt v = (ValueInt) o;
        return MathUtils.compareInt(value, v.value);
    }

    @Override
    public String getString() {
        return String.valueOf(value);
    }

    @Override
    public long getPrecision() {
        return PRECISION;
    }

    @Override
    public int hashCode() {
        return value;
    }

    @Override
    public Object getObject() {
        return value;
    }

    @Override
    public void set(PreparedStatement prep, int parameterIndex) throws SQLException {
        prep.setInt(parameterIndex, value);
    }

    @Override
    public int getDisplaySize() {
        return DISPLAY_SIZE;
    }

    @Override
    public boolean equals(Object other) {
        return other instanceof ValueInt && value == ((ValueInt) other).value;
    }

}
