package de.edu.hsfulda.ciip.tdd;

import java.util.LinkedList;
import java.util.List;

public class TannenbaumRenderer {

	private static final int BOTH_DIRECTIONS = 2;
	private static final int OFFSET = 1;
	private static final int MIDDLE_BRANCH = 1;
	private static final String SYMBOL_TRUNK = "I";
	private static final String SYMBOL_BRANCH = "X";
	private static final String SYMBOL_INDENT = " ";
	private final StringRepeater symbolRepeater;

	
	public TannenbaumRenderer(StringRepeater symbolRepeater) {
		this.symbolRepeater = symbolRepeater;
	}

	public List<String> getTreeOf(int size) {
		List<String> tree = new LinkedList<>();
		renderTreeSlices(size, tree);
		renderTrunk(size, tree);
		return tree;
	}

	private void renderTrunk(int size, List<String> tree) {
		StringBuilder slice = new StringBuilder();
		symbolRepeater.repeatSymbol(slice, size - MIDDLE_BRANCH, SYMBOL_INDENT);
		symbolRepeater.repeatSymbol(slice, MIDDLE_BRANCH, SYMBOL_TRUNK);
		tree.add(slice.toString());
	}

	private void renderTreeSlices(int size, List<String> tree) {
		for (int sliceWidth = 0; sliceWidth < size; sliceWidth++) {
			renderSingleSlice(size, tree, sliceWidth);
		}
	}

	private void renderSingleSlice(int size, List<String> tree, int sliceWidth) {
		StringBuilder slice = new StringBuilder();
		symbolRepeater.repeatSymbol(slice, size - (sliceWidth + OFFSET), SYMBOL_INDENT);
		symbolRepeater.repeatSymbol(slice, sliceWidth * BOTH_DIRECTIONS + MIDDLE_BRANCH, SYMBOL_BRANCH);
		tree.add(slice.toString());
	}

}