var tools = require("../tools/tools");

var warn = tools.warn;
var getParsedAttribute = tools.getParsedAttribute;

function withCommand (command, interpreter) {

    var container = interpreter.runVars;
    var children = command.childNodes;
    var variableName = getParsedAttribute(command, "var", interpreter);
    var i, numberOfChildren = children.length, current;

    for (i = 0; i < numberOfChildren; i += 1) {

        current = children[i];

        if (shouldBeSkipped(current, interpreter)) {
            continue;
        }

        if (isWhen(current) && !hasCondition(current)) {
            warn(interpreter.bus, "Element 'when' without a condition. Ignored.", command);
        }

        if (isElse(current) && hasCondition(current)) {
            warn(interpreter.bus, "Element 'else' with a condition. Ignored.", command);
        }

        if (isElse(current) ||
                isWhen(current) && hasCondition(current) &&
                getParsedAttribute(current, "is") === container[variableName]) {

            interpreter.pushToCallStack();
            interpreter.currentCommands = current.childNodes;
            interpreter.scenePath.push(interpreter.index);
            interpreter.scenePath.push(i);
            interpreter.index = -1;
            interpreter.currentElement = -1;

            break;
        }
    }

    return {
        doNext: true
    };
}

function shouldBeSkipped (element, interpreter) {
    return !element.tagName || !interpreter.checkIfvar(element) ||
        (element.tagName !== "when" && element.tagName !== "else");
}

function isWhen (element) {
    return tagNameIs(element, "when");
}

function isElse (element) {
    return tagNameIs(element, "else");
}

function tagNameIs (element, name) {
    return element.tagName === name;
}

function hasCondition (element) {
    return element.hasAttribute("is");
}

module.exports = withCommand;