import Component from 'ember-component';
import run from 'ember-runloop';
import {
    IMAGE_MIME_TYPES,
    IMAGE_EXTENSIONS
} from 'ghost-admin/components/gh-image-uploader';

const {debounce} = run;

export default Component.extend({

    classNameBindings: [
        'isDraggedOver:-drag-over',
        'isFullScreen:gh-editor-fullscreen'
    ],

    // Public attributes
    navIsClosed: false,

    // Internal attributes
    droppedFiles: null,
    headerClass: '',
    imageExtensions: IMAGE_EXTENSIONS,
    imageMimeTypes: IMAGE_MIME_TYPES,
    isDraggedOver: false,
    isFullScreen: false,
    isSplitScreen: false,
    uploadedImageUrls: null,

    // Private
    _dragCounter: 0,
    _navIsClosed: false,
    _onResizeHandler: null,
    _viewActionsWidth: 190,

    init() {
        this._super(...arguments);
        this._onResizeHandler = (evt) => {
            debounce(this, this._setHeaderClass, evt, 100);
        };
    },

    didInsertElement() {
        this._super(...arguments);
        window.addEventListener('resize', this._onResizeHandler);
        this._setHeaderClass();
    },

    didReceiveAttrs() {
        let navIsClosed = this.get('navIsClosed');

        if (navIsClosed !== this._navIsClosed) {
            run.scheduleOnce('afterRender', this, this._setHeaderClass);
        }

        this._navIsClosed = navIsClosed;
    },

    _setHeaderClass() {
        let $editorTitle = this.$('.gh-editor-title');
        let smallHeaderClass = 'gh-editor-header-small';

        if (this.get('isSplitScreen')) {
            this.set('headerClass', smallHeaderClass);
            return;
        }

        if ($editorTitle.length > 0) {
            let boundingRect = $editorTitle[0].getBoundingClientRect();
            let maxRight = window.innerWidth - this._viewActionsWidth;

            if (boundingRect.right >= maxRight) {
                this.set('headerClass', smallHeaderClass);
                return;
            }
        }

        this.set('headerClass', '');
    },

    // dragOver is needed so that drop works
    dragOver(event) {
        if (!event.dataTransfer) {
            return;
        }

        // this is needed to work around inconsistencies with dropping files
        // from Chrome's downloads bar
        let eA = event.dataTransfer.effectAllowed;
        event.dataTransfer.dropEffect = (eA === 'move' || eA === 'linkMove') ? 'move' : 'copy';

        event.preventDefault();
        event.stopPropagation();
    },

    // dragEnter is needed so that the drag class is correctly removed
    dragEnter(event) {
        if (!event.dataTransfer) {
            return;
        }

        event.preventDefault();
        event.stopPropagation();

        // the counter technique prevents flickering of the drag class when
        // dragging across child elements
        this._dragCounter++;

        this.set('isDraggedOver', true);
    },

    dragLeave(event) {
        event.preventDefault();
        event.stopPropagation();

        this._dragCounter--;
        if (this._dragCounter === 0) {
            this.set('isDraggedOver', false);
        }
    },

    drop(event) {
        event.preventDefault();
        event.stopPropagation();

        this._dragCounter = 0;
        this.set('isDraggedOver', false);

        if (event.dataTransfer.files) {
            this.set('droppedFiles', event.dataTransfer.files);
        }
    },

    willDestroyElement() {
        this._super(...arguments);
        window.removeEventListener('resize', this._onResizeHandler);
    },

    actions: {
        toggleFullScreen() {
            this.toggleProperty('isFullScreen');
            run.scheduleOnce('afterRender', this, this._setHeaderClass);
        },

        toggleSplitScreen() {
            this.toggleProperty('isSplitScreen');
            run.scheduleOnce('afterRender', this, this._setHeaderClass);
        },

        uploadComplete(uploads) {
            this.set('uploadedImageUrls', uploads.mapBy('url'));
            this.set('droppedFiles', null);
        },

        uploadCancelled() {
            this.set('droppedFiles', null);
        }
    }
});