/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2007 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package alterrs.asm.commons;

import alterrs.asm.Label;
import alterrs.asm.MethodAdapter;
import alterrs.asm.MethodVisitor;
import alterrs.asm.Opcodes;

/**
 * A {@link MethodAdapter} that can be used to approximate method size.
 * 
 * @author Eugene Kuleshov
 */
public class CodeSizeEvaluator extends MethodAdapter implements Opcodes {

	private int minSize;

	private int maxSize;

	public CodeSizeEvaluator(final MethodVisitor mv) {
		super(mv);
	}

	public int getMinSize() {
		return this.minSize;
	}

	public int getMaxSize() {
		return this.maxSize;
	}

	public void visitInsn(final int opcode) {
		minSize += 1;
		maxSize += 1;
		if (mv != null) {
			mv.visitInsn(opcode);
		}
	}

	public void visitIntInsn(final int opcode, final int operand) {
		if (opcode == SIPUSH) {
			minSize += 3;
			maxSize += 3;
		} else {
			minSize += 2;
			maxSize += 2;
		}
		if (mv != null) {
			mv.visitIntInsn(opcode, operand);
		}
	}

	public void visitVarInsn(final int opcode, final int var) {
		if (var < 4 && opcode != RET) {
			minSize += 1;
			maxSize += 1;
		} else if (var >= 256) {
			minSize += 4;
			maxSize += 4;
		} else {
			minSize += 2;
			maxSize += 2;
		}
		if (mv != null) {
			mv.visitVarInsn(opcode, var);
		}
	}

	public void visitTypeInsn(final int opcode, final String type) {
		minSize += 3;
		maxSize += 3;
		if (mv != null) {
			mv.visitTypeInsn(opcode, type);
		}
	}

	public void visitFieldInsn(final int opcode, final String owner,
			final String name, final String desc) {
		minSize += 3;
		maxSize += 3;
		if (mv != null) {
			mv.visitFieldInsn(opcode, owner, name, desc);
		}
	}

	public void visitMethodInsn(final int opcode, final String owner,
			final String name, final String desc) {
		if (opcode == INVOKEINTERFACE || opcode == INVOKEDYNAMIC) {
			minSize += 5;
			maxSize += 5;
		} else {
			minSize += 3;
			maxSize += 3;
		}
		if (mv != null) {
			mv.visitMethodInsn(opcode, owner, name, desc);
		}
	}

	public void visitJumpInsn(final int opcode, final Label label) {
		minSize += 3;
		if (opcode == GOTO || opcode == JSR) {
			maxSize += 5;
		} else {
			maxSize += 8;
		}
		if (mv != null) {
			mv.visitJumpInsn(opcode, label);
		}
	}

	public void visitLdcInsn(final Object cst) {
		if (cst instanceof Long || cst instanceof Double) {
			minSize += 3;
			maxSize += 3;
		} else {
			minSize += 2;
			maxSize += 3;
		}
		if (mv != null) {
			mv.visitLdcInsn(cst);
		}
	}

	public void visitIincInsn(final int var, final int increment) {
		if (var > 255 || increment > 127 || increment < -128) {
			minSize += 6;
			maxSize += 6;
		} else {
			minSize += 3;
			maxSize += 3;
		}
		if (mv != null) {
			mv.visitIincInsn(var, increment);
		}
	}

	public void visitTableSwitchInsn(final int min, final int max,
			final Label dflt, final Label[] labels) {
		minSize += 13 + labels.length * 4;
		maxSize += 16 + labels.length * 4;
		if (mv != null) {
			mv.visitTableSwitchInsn(min, max, dflt, labels);
		}
	}

	public void visitLookupSwitchInsn(final Label dflt, final int[] keys,
			final Label[] labels) {
		minSize += 9 + keys.length * 8;
		maxSize += 12 + keys.length * 8;
		if (mv != null) {
			mv.visitLookupSwitchInsn(dflt, keys, labels);
		}
	}

	public void visitMultiANewArrayInsn(final String desc, final int dims) {
		minSize += 4;
		maxSize += 4;
		if (mv != null) {
			mv.visitMultiANewArrayInsn(desc, dims);
		}
	}
}
