load("parser.js")

Program.prototype.compile = function() {
	for (var h in this.hats) {
		this.hats[h].compile();
		this.hats[h].program = this;
	}
}

function Context() {
	this.position = 0;
	this.applys = [];
}

function Code() {
	this.indentation = "";
	this.text = "";
	this.fresh_line = true;

	this.indent = function() {
		this.indentation += "    ";
	}

	this.unindent = function() {
		this.indentation = this.indentation.substring(0, this.indentation.length - 4);
	}

	this.put = function(x) {
		if (this.fresh_line)
			this.text += this.indentation;
		this.text += x;
		this.fresh_line = false;
	}

	this.putl = function(x) {
		this.put(x + "\n");
		this.fresh_line = true;
	}
}

Hat.prototype.compile = function() {
	var nop = function() {};

	this.stacks = [[]];
	this.suspended_contexts = [];
	this.compiled_magic = {init: nop, in: nop, out: nop};
	this.compiled_magic_code = [];
	this.program = null;

	this.push = function(x) {
		this.stacks[0].unshift(x);
		this.compiled_magic["in"].call(this);
	}

	this.pop = function(x) {
		this.compiled_magic["out"].call(this);
		if (this.stacks[0].length > 0)
			return this.stacks[0].shift();
		else
			throw 'empty argument stack';
	}

	for (var m in this.magic) {
		var code = new Code();
		var position = 0;
		code.putl("(function() {");
		code.indent();

		if (m == "in") {
			code.putl("if (this.suspended_contexts.length > 0)");
			code.putl("    var context = this.suspended_contexts.pop();");
			code.putl("else");
			code.put("    ");
		}
		
		code.putl("var context = new Context();");
		code.putl("");

		if (m == "in") {
			code.putl("switch (context.position) {");
			code.indent();
			code.putl("case 0:");
			code.indent();
		}

		for (var n in this.magic[m]) {
			var move = this.magic[m][n];
			var sourcecode, destcode;
			code.putl("// " + move);

			switch (move.source.type) {
				case "stack":
					this.stacks[move.source.id] = [];
					if (move.source.id=="0" && m=="in") {
						// This is a suspension point.
						position++;
						code.putl("context.position = " + position + ";");
						code.unindent();
						code.putl("");
						code.putl("case " + position + ":");
						code.indent();
						code.putl("if (this.stacks[0].length == 0) {");
						code.putl("    this.suspended_contexts.push(context);");
						code.putl("    return;");
						code.putl("}");
					}
	
					else {
						code.putl("if (this.stacks[" + move.source.id + "].length == 0)");
						code.putl("   throw 'Empty stack!';");
					}
				
					sourcecode = "this.stacks[" + move.source.id + "].pop()";
					break;
			
				case "hat":
					sourcecode = "this.program.hats['" + move.source.id + "'].pop()";
					break;

				case "apply":
					code.putl("if (!context.applys[" + move.source.id + "])");
					code.putl("    throw 'Using uninitialized apply!';");
					sourcecode = "context.applys[" + move.source.id + "].pop()";
					break;

				case "number":
					//if (!inbounds(move.source.id))
					//	throw "Compile error: number " + move.source.id + " out of range";
					sourcecode = "wraparound(" + move.source.id + ")";
					break;

				case "hatid":
					//sourcecode = this.program.hats[move.source.id].hatid;
					// Late binding, just because.
					// (Makes it possible to add the environment after compilation.)
					sourcecode = "this.program.hats['" + move.source.id + "'].hatid";
					break;

				default:
					throw 'Hwaet!';
			}

			var outcode;
			switch (move.dest.type) {
				case "hat":
					code.putl("this.program.hats['" + move.dest.id + "'].push(" + sourcecode + ");");
					break;

				case "stack":
					code.putl("this.stacks[" + move.dest.id + "].push(" + sourcecode + ");");
					this.stacks[move.dest.id] = [];
					break;

				case "apply":
					code.putl("if (!context.applys[" + move.dest.id + "]) {");
					code.putl("    context.applys[" + move.dest.id + "] = this.program.get_by_hatid(" + sourcecode + ");");
					code.putl("    if (context.applys[" + move.dest.id + "].name == 'apply')");
					code.putl("        context.applys[" + move.dest.id + "] = null;");
					code.putl("}");
					code.putl("else");
					code.putl("    context.applys[" + move.dest.id + "].push(" + sourcecode + ");");
					break;

				case "number":
				case "hatid":
					code.putl(sourcecode + ";");
					break;

				default:
					throw "Argh!";
			}
			
			code.putl("");
		}

		if (m == "in") {
			code.putl("break;");
			code.unindent();
			code.putl("default:");
			code.putl("    throw 'Jumping to non-existent label!' + context.position;");
			code.unindent();
			code.putl("}");
		}

		code.unindent();
		code.putl("})");

		this.compiled_magic_code[m] = code.text;
		this.compiled_magic[m] = eval(code.text);
	}

	this.compiled_magic['init'].call(this);
}