var SETTINGS = {
    navBarTravelling: false,
    navBarTravelDirection: "",
	 navBarTravelDistance: 150
}

var colours = {
    0: "#867100",
    1: "#7F4200",
    2: "#99813D",
    3: "#40FEFF",
    4: "#14CC99",
    5: "#00BAFF",
    6: "#0082B2",
    7: "#B25D7A",
    8: "#00FF17",
    9: "#006B49",
    10: "#00B27A",
    11: "#996B3D",
    12: "#CC7014",
    13: "#40FF8C",
    14: "#FF3400",
    15: "#ECBB5E",
    16: "#ECBB0C",
    17: "#B9D912",
    18: "#253A93",
    19: "#125FB9",
}

document.documentElement.classList.remove("no-js");
document.documentElement.classList.add("js");

// Out advancer buttons
var pnAdvancerLeft = document.getElementById("pnAdvancerLeft");
var pnAdvancerRight = document.getElementById("pnAdvancerRight");
// the indicator
var pnIndicator = document.getElementById("pnIndicator");

var pnProductNav = document.getElementById("pnProductNav");
var pnProductNavContents = document.getElementById("pnProductNavContents");

pnProductNav.setAttribute("data-overflowing", determineOverflow(pnProductNavContents, pnProductNav));

// Set the indicator
moveIndicator(pnProductNav.querySelector("[aria-selected=\"true\"]"), colours[0]);

// Handle the scroll of the horizontal container
var last_known_scroll_position = 0;
var ticking = false;

function doSomething(scroll_pos) {
    pnProductNav.setAttribute("data-overflowing", determineOverflow(pnProductNavContents, pnProductNav));
}

pnProductNav.addEventListener("scroll", function() {
    last_known_scroll_position = window.scrollY;
    if (!ticking) {
        window.requestAnimationFrame(function() {
            doSomething(last_known_scroll_position);
            ticking = false;
        });
    }
    ticking = true;
});


pnAdvancerLeft.addEventListener("click", function() {
	// If in the middle of a move return
    if (SETTINGS.navBarTravelling === true) {
        return;
    }
    // If we have content overflowing both sides or on the left
    if (determineOverflow(pnProductNavContents, pnProductNav) === "left" || determineOverflow(pnProductNavContents, pnProductNav) === "both") {
        // Find how far this panel has been scrolled
        var availableScrollLeft = pnProductNav.scrollLeft;
        // If the space available is less than two lots of our desired distance, just move the whole amount
        // otherwise, move by the amount in the settings
        if (availableScrollLeft < SETTINGS.navBarTravelDistance * 2) {
            pnProductNavContents.style.transform = "translateX(" + availableScrollLeft + "px)";
        } else {
            pnProductNavContents.style.transform = "translateX(" + SETTINGS.navBarTravelDistance + "px)";
        }
        // We do want a transition (this is set in CSS) when moving so remove the class that would prevent that
        pnProductNavContents.classList.remove("pn-ProductNav_Contents-no-transition");
        // Update our settings
        SETTINGS.navBarTravelDirection = "left";
        SETTINGS.navBarTravelling = true;
    }
    // Now update the attribute in the DOM
    pnProductNav.setAttribute("data-overflowing", determineOverflow(pnProductNavContents, pnProductNav));
});

pnAdvancerRight.addEventListener("click", function() {
    // If in the middle of a move return
    if (SETTINGS.navBarTravelling === true) {
        return;
    }
    // If we have content overflowing both sides or on the right
    if (determineOverflow(pnProductNavContents, pnProductNav) === "right" || determineOverflow(pnProductNavContents, pnProductNav) === "both") {
        // Get the right edge of the container and content
        var navBarRightEdge = pnProductNavContents.getBoundingClientRect().right;
        var navBarScrollerRightEdge = pnProductNav.getBoundingClientRect().right;
        // Now we know how much space we have available to scroll
        var availableScrollRight = Math.floor(navBarRightEdge - navBarScrollerRightEdge);
        // If the space available is less than two lots of our desired distance, just move the whole amount
        // otherwise, move by the amount in the settings
        if (availableScrollRight < SETTINGS.navBarTravelDistance * 2) {
            pnProductNavContents.style.transform = "translateX(-" + availableScrollRight + "px)";
        } else {
            pnProductNavContents.style.transform = "translateX(-" + SETTINGS.navBarTravelDistance + "px)";
        }
        // We do want a transition (this is set in CSS) when moving so remove the class that would prevent that
        pnProductNavContents.classList.remove("pn-ProductNav_Contents-no-transition");
        // Update our settings
        SETTINGS.navBarTravelDirection = "right";
        SETTINGS.navBarTravelling = true;
    }
    // Now update the attribute in the DOM
    pnProductNav.setAttribute("data-overflowing", determineOverflow(pnProductNavContents, pnProductNav));
});

pnProductNavContents.addEventListener(
    "transitionend",
    function() {
        // get the value of the transform, apply that to the current scroll position (so get the scroll pos first) and then remove the transform
        var styleOfTransform = window.getComputedStyle(pnProductNavContents, null);
        var tr = styleOfTransform.getPropertyValue("-webkit-transform") || styleOfTransform.getPropertyValue("transform");
        // If there is no transition we want to default to 0 and not null
        var amount = Math.abs(parseInt(tr.split(",")[4]) || 0);
        pnProductNavContents.style.transform = "none";
        pnProductNavContents.classList.add("pn-ProductNav_Contents-no-transition");
        // Now lets set the scroll position
        if (SETTINGS.navBarTravelDirection === "left") {
            pnProductNav.scrollLeft = pnProductNav.scrollLeft - amount;
        } else {
            pnProductNav.scrollLeft = pnProductNav.scrollLeft + amount;
        }
        SETTINGS.navBarTravelling = false;
    },
    false
);

// Handle setting the currently active link
pnProductNavContents.addEventListener("click", function(e) {
	var links = [].slice.call(document.querySelectorAll(".pn-ProductNav_Link"));
	links.forEach(function(item) {
		item.setAttribute("aria-selected", "false");
	})
	e.target.setAttribute("aria-selected", "true");
	// Pass the clicked item and it's colour to the move indicator function
	moveIndicator(e.target, colours[links.indexOf(e.target)]);
	console.log(colours[links.indexOf(e.target)]);
});

function moveIndicator(item, color) {
    var textPosition = item.getBoundingClientRect();
    var container = pnProductNavContents.getBoundingClientRect().left;
    var distance = textPosition.left - container;
    pnIndicator.style.transform = "translateX(" + (distance + pnProductNavContents.scrollLeft) + "px) scaleX(" + textPosition.width * 0.01 + ")";
    if (color) {
        pnIndicator.style.backgroundColor = color;
    }
}

function determineOverflow(content, container) {
    var containerMetrics = container.getBoundingClientRect();
    var containerMetricsRight = Math.floor(containerMetrics.right);
    var containerMetricsLeft = Math.floor(containerMetrics.left);
    var contentMetrics = content.getBoundingClientRect();
    var contentMetricsRight = Math.floor(contentMetrics.right);
    var contentMetricsLeft = Math.floor(contentMetrics.left);
	 if (containerMetricsLeft > contentMetricsLeft && containerMetricsRight < contentMetricsRight) {
        return "both";
    } else if (contentMetricsLeft < containerMetricsLeft) {
        return "left";
    } else if (contentMetricsRight > containerMetricsRight) {
        return "right";
    } else {
        return "none";
    }
}