package bjc.utils.ioutils.format.directives;

import java.io.*;

import bjc.esodata.*;
import bjc.utils.ioutils.format.*;

/**
 * Implementation of the A directive.
 *
 * This is the directive that does general printing of things, and serves the
 * same general purpose as the '%s' directive for printf etc.
 *
 * @author Ben Culkin
 */
public class AestheticDirective implements Directive {
	@Override
	public Edict compile(CompileContext compCTX) {
		CLParameters params = compCTX.decr.parameters;
		CLModifiers mods = compCTX.decr.modifiers;

		// Parameter values
		CLValue mincol = CLValue.nil();
		CLValue colinc = CLValue.nil();
		CLValue minpad = CLValue.nil();

		CLValue padchar = CLValue.nil();

		// We take 0, 1 or 4 parameters
		switch (params.length()) {
		case 0:
			// Zero parameters, use all defaults
			break;
		case 1:
			params.mapIndices("mincol");

			mincol = params.resolveKey("mincol");
			break;
		case 4:
			params.mapIndices("mincol", "colinc", "minpad", "padchar");

			mincol = params.resolveKey("mincol");
			colinc = params.resolveKey("colinc");
			minpad = params.resolveKey("minpad");

			padchar = params.resolveKey("padchar");
			break;
		default:
			throw new IllegalArgumentException(
					"Must provide either zero, one or four arguments to A directive");
		}

		return new AestheticEdict(mods.atMod, padchar, mincol, colinc, minpad);
	}
}

class AestheticEdict implements Edict {
	private boolean padBefore;

	private CLValue padcharPar;
	private CLValue mincolPar;
	private CLValue colincPar;
	private CLValue minpadPar;

	public AestheticEdict(boolean padBefore, CLValue padPar, CLValue minPar,
			CLValue colPar, CLValue mpadPar) {
		this.padBefore = padBefore;

		this.padcharPar = padPar;
		this.mincolPar = minPar;
		this.colincPar = colPar;
		this.minpadPar = mpadPar;
	}

	@Override
	public void format(FormatContext formCTX) throws IOException {
		Tape<Object> itemTape = formCTX.items;

		// Check that we have an item
		CLFormatter.checkItem(itemTape.item(), 'A');

		String itemString = itemTape.item().toString();

		StringBuilder work = new StringBuilder();

		char padchar = padcharPar.asChar(itemTape,
				"padding character", "A", ' ');

		int mincol = mincolPar.asInt(itemTape,
				"minimum column count", "A", 0);
		int colinc = colincPar.asInt(itemTape,
				"padding increment", "A", 1);
		int minpad = minpadPar.asInt(itemTape,
				"minumum amount of padding", "A", 0);

		work.append(itemString);

		String padding = createPadding(work, padchar, mincol, colinc, minpad);
		if (padBefore) work.insert(0, padding);
		else           work.append(padding);

		formCTX.writer.write(work.toString());

		itemTape.right();
	}

	private static String createPadding(
			StringBuilder work,
			char padchar,
			int mincol,
			int colinc,
			int minpad) 
	{
		StringBuilder padding = new StringBuilder();
		for (int i = 0; i < minpad; i++) padding.append(padchar);

		for (int i = work.length(); i < mincol; i++) {
			for (int k = 0; k < colinc; k++) {
				padding.append(padchar);
			}
		}

		return padding.toString();
	}
}