/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Contains a simple window controller subclass that displays a list of `ImageCollection`s.

*/

import Cocoa

/**

    `GalleryWindowController` is a window controller that displays a list of 

    `ImageCollection`s. It creates and manages the connections between three split 

    panes in a `NSSplitViewController` setup as its `contentViewController`.

*/

class GalleryWindowController: NSWindowController {

    // MARK: Properties

    override var windowNibName: String {

        return "GalleryWindowController"

    }

    /// The identifier used for `NSSplitView`'s autosaving and state restoration.

    static let splitViewResorationIdentifier = "GallerySplitView"

    /**

        The controller that displays a list of available `ImageCollection`s in a 

        source list-style outline view. Shown as the sidebar of the main split view.

    */

    lazy var sidebarController: ImageCollectionListController = {

        let collectionController = ImageCollectionListController()

        /*

            Initialize the `imageCollections` to start with a collection referencing

            the system's desktop pictures.

        */

        let desktopPicturesURL = URL(fileURLWithPath: "/Library/Desktop Pictures/", isDirectory: true)

        let desktopPicturesCollection = ImageCollection(rootURL: desktopPicturesURL)

        desktopPicturesCollection.tableViewIcon = NSImage(named: "DesktopTemplate")!

        collectionController.imageCollections = [desktopPicturesCollection]

        /*

            When the selected collection changes, update the image list controller

            to visualize that collection.

        */

        collectionController.imageCollectionSelectionHandler = { [weak self] collections in

            self?.imageListController.imageCollections = collections

        }

        return collectionController

    }()

    /**

        The controller that displays a list of images from the selected `ImageCollection` 

        in a collection view. Shown as the content list of the main split view.

    */

    lazy var imageListController: ImageListController = {

        let imageListController = ImageListController()

        /*

            When the selected image changes, update our image viewer controller

            to visualize that image.

        */

        imageListController.imageSelectionHandler = { [weak self] imageFile in

            self?.imageViewerController.imageFile = imageFile

        }

        return imageListController

    }()

    /**

        The controller that displays a single `ImageFile` in an `NSImageView`. Shown

        as the primary cotnent of the main split view.

    */

    lazy var imageViewerController: ImageViewerController = ImageViewerController()

    /// The main split view controller used as the `contentViewController` of the window.

    lazy var splitViewController: NSSplitViewController = {

        // Create a split view controller to contain split view items.

        let splitViewController = NSSplitViewController()

        splitViewController.minimumThicknessForInlineSidebars = 992.0

        splitViewController.view.wantsLayer = true

        // Create a sidebar SplitViewItem. This has metrics and behaves like system standard sidebars.

        let sidebarSplitViewItem = NSSplitViewItem(sidebarWithViewController: self.sidebarController)

        splitViewController.addSplitViewItem(sidebarSplitViewItem)

        /*

            Create a content list `NSSplitViewItem`. This has metrics like system standard

            content lists. Even though it is a collection view rather than table

            view, it still follows the content list pattern.

        */

        let imageListControllerSplitViewItem = NSSplitViewItem(contentListWithViewController: self.imageListController)

        splitViewController.addSplitViewItem(imageListControllerSplitViewItem)

        // Create a standard `NSSplitViewItem`.

        let imageViewerSplitViewItem = NSSplitViewItem(viewController: self.imageViewerController)

        imageViewerSplitViewItem.minimumThickness = 300

        splitViewController.addSplitViewItem(imageViewerSplitViewItem)

        splitViewController.splitView.autosaveName = GalleryWindowController.splitViewResorationIdentifier

        splitViewController.splitView.identifier = GalleryWindowController.splitViewResorationIdentifier

        return splitViewController

    }()

    // MARK: Life Cycle

    override func windowDidLoad() {

        super.windowDidLoad()

        guard let window = window else {

            fatalError("`window` is expected to be non nil by this time.")

        }

        // Hide the title, so the toolbar is placed in the titlebar region.

        window.titleVisibility = .hidden

        /*

            Make sure the `contentViewController`'s view frame size matches the

            restored window size. Setting a window's `contentViewController` will

            update the window frame size from the view frame size.

        */

        let frameSize = window.contentRect(forFrameRect: window.frame).size

        splitViewController.view.setFrameSize(frameSize)

        window.contentViewController = splitViewController

    }

    // MARK: IBActions

    @IBAction func addImageCollection(_ sender: AnyObject?) {

        sidebarController.showOpenPanelToAddImageCollection(sender)

    }

}