/* Copyright 2016 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import {
	animationStarted,
	DEFAULT_SCALE,
	DEFAULT_SCALE_VALUE,
	docStyle,
	MAX_SCALE,
	MIN_SCALE,
	noContextMenuHandler,
} from './ui_utils.js';
import { AnnotationEditorType } from 'pdfjs-dist';

const PAGE_NUMBER_LOADING_INDICATOR = 'visiblePageIsLoading';

/**
 * @typedef {Object} ToolbarOptions
 * @property {HTMLDivElement} container - Container for the secondary toolbar.
 * @property {HTMLSpanElement} numPages - Label that contains number of pages.
 * @property {HTMLInputElement} pageNumber - Control for display and user input
 *   of the current page number.
 * @property {HTMLSelectElement} scaleSelect - Scale selection control.
 *   Its width is adjusted, when necessary, on UI localization.
 * @property {HTMLOptionElement} customScaleOption - The item used to display
 *   a non-predefined scale.
 * @property {HTMLButtonElement} previous - Button to go to the previous page.
 * @property {HTMLButtonElement} next - Button to go to the next page.
 * @property {HTMLButtonElement} zoomIn - Button to zoom in the pages.
 * @property {HTMLButtonElement} zoomOut - Button to zoom out the pages.
 * @property {HTMLButtonElement} viewFind - Button to open find bar.
 * @property {HTMLButtonElement} openFile - Button to open a new document.
 * @property {HTMLButtonElement} presentationModeButton - Button to switch to
 *   presentation mode.
 * @property {HTMLButtonElement} editorNoneButton - Button to disable editing.
 * @property {HTMLButtonElement} editorFreeTextButton - Button to switch to
 *   FreeText editing.
 * @property {HTMLButtonElement} download - Button to download the document.
 * @property {HTMLAnchorElement} viewBookmark - Button to obtain a bookmark link
 *   to the current location in the document.
 */

class Toolbar {
	#wasLocalized = false;

	/**
	 * @param {ToolbarOptions} options
	 * @param {EventBus} eventBus
	 * @param {IL10n} l10n - Localization service.
	 */
	constructor(options, eventBus, l10n) {
		this.toolbar = options.container;
		this.eventBus = eventBus;
		this.l10n = l10n;
		this.buttons = [
			{ element: options.previous, eventName: 'previouspage' },
			{ element: options.next, eventName: 'nextpage' },
			{ element: options.zoomIn, eventName: 'zoomin' },
			{ element: options.zoomOut, eventName: 'zoomout' },
			{ element: options.print, eventName: 'print' },
			{ element: options.download, eventName: 'download' },
		];

		this.items = {
			numPages: options.numPages,
			pageNumber: options.pageNumber,
			scaleSelect: options.scaleSelect,
			customScaleOption: options.customScaleOption,
			previous: options.previous,
			next: options.next,
			zoomIn: options.zoomIn,
			zoomOut: options.zoomOut,
			fullscreen: options.fullscreen,
		};

		// Bind the event listeners for click and various other actions.
		this.#bindListeners(options);

		this.reset();
	}

	setPageNumber(pageNumber, pageLabel) {
		this.pageNumber = pageNumber;
		this.pageLabel = pageLabel;
		this.#updateUIState(false);
	}

	setPagesCount(pagesCount, hasPageLabels) {
		this.pagesCount = pagesCount;
		this.hasPageLabels = hasPageLabels;
		this.#updateUIState(true);
	}

	setPageScale(pageScaleValue, pageScale) {
		this.pageScaleValue = (pageScaleValue || pageScale).toString();
		this.pageScale = pageScale;
		this.#updateUIState(false);
	}

	reset() {
		this.pageNumber = 0;
		this.pageLabel = null;
		this.hasPageLabels = false;
		this.pagesCount = 0;
		this.pageScaleValue = DEFAULT_SCALE_VALUE;
		this.pageScale = DEFAULT_SCALE;
		this.#updateUIState(true);
		this.updateLoadingIndicatorState();

		// Reset the Editor buttons too, since they're document specific.
		this.eventBus.dispatch('toolbarreset', { source: this });
	}

	#bindListeners(options) {
		const { pageNumber, scaleSelect, fullscreen } = this.items;
		const self = this;

		// The buttons within the toolbar.
		for (const { element, eventName, eventDetails } of this.buttons) {
			for (let i = 0; i < element.length; i++) {
				element[i].addEventListener('click', (evt) => {
					if (eventName !== null) {
						const details = { source: this };
						if (eventDetails) {
							for (const property in eventDetails) {
								details[property] = eventDetails[property];
							}
						}

						this.eventBus.dispatch(eventName, details);
					}
				});
			}
		}
		for (let i = 0; i < pageNumber.length; i++) {
			pageNumber[i].addEventListener('click', function () {
				this.select();
			});
			pageNumber[i].addEventListener('change', function () {
				self.eventBus.dispatch('pagenumberchanged', {
					source: self,
					value: this.value,
				});
			});
		}
		for (let i = 0; i < scaleSelect.length; i++) {
			scaleSelect[i].addEventListener('change', function () {
				if (this.value === 'custom') {
					return;
				}
				self.eventBus.dispatch('scalechanged', {
					source: self,
					value: this.value,
				});
			});
		}

		for (let i = 0; i < fullscreen.length; i++) {
			fullscreen[i].addEventListener('click', function (evt) {
				const target = evt.target;
				let pdf_target_id = target.getAttribute('data-pdf-id');
				let frame = window.parent.document.querySelector(
					'#wppdf-emb-iframe-' + pdf_target_id,
				);

				let container = window.parent.document.querySelector(
					'#wppdfemb-frame-container-' + pdf_target_id,
				);

				if (frame.classList.contains('wppdf-fullscreen')) {
					container.append(frame);
					frame.classList.remove('wppdf-fullscreen');
				} else {
					frame.classList.add('wppdf-fullscreen');
					parent.document.body.append(frame);
				}
			});
			let deboune;
			window.parent.document.addEventListener('keyup', function (e) {
				switch (e.keyCode) {
					case 27: // Escape
						let pdf_target_id =
							fullscreen[i].getAttribute('data-pdf-id');

						let frame = window.parent.document.getElementById(
							'wppdf-emb-iframe-' + pdf_target_id,
						);

						let container = window.parent.document.querySelector(
							'#wppdfemb-frame-container-' + pdf_target_id,
						);

						if (frame.classList.contains('wppdf-fullscreen')) {
							frame.classList.remove('wppdf-fullscreen');
							container.appendChild(frame);
						}
						break;
				}
			});
			document.addEventListener('keyup', function (e) {
				switch (e.keyCode) {
					case 27: // Escape
						let pdf_target_id =
							fullscreen[i].getAttribute('data-pdf-id');

						let frame = window.parent.document.getElementById(
							'wppdf-emb-iframe-' + pdf_target_id,
						);

						let container = window.parent.document.querySelector(
							'#wppdfemb-frame-container-' + pdf_target_id,
						);

						if (frame.classList.contains('wppdf-fullscreen')) {
							frame.classList.remove('wppdf-fullscreen');
							container.appendChild(frame);
						}
						break;
				}
			});
		}
		// Here we depend on browsers dispatching the "click" event *after* the
		// "change" event, when the <select>-element changes.
		for (let i = 0; i < scaleSelect.length; i++) {
			scaleSelect[i].addEventListener('click', function (evt) {
				const target = evt.target;
				// Remove focus when an <option>-element was *clicked*, to improve the UX
				// for mouse users (fixes bug 1300525 and issue 4923).
				if (
					this.value === self.pageScaleValue &&
					target.tagName.toUpperCase() === 'OPTION'
				) {
					this.blur();
				}
			});
			// Suppress context menus for some controls.
			scaleSelect[i].oncontextmenu = noContextMenuHandler;
		}

		this.eventBus._on('localized', () => {
			this.#wasLocalized = true;
			this.#adjustScaleWidth();
			this.#updateUIState(true);
		});
	}

	#bindEditorToolsListener({
		editorNoneButton,
		editorFreeTextButton,
		editorFreeTextParamsToolbar,
		editorInkButton,
		editorInkParamsToolbar,
	}) {
		const editorModeChanged = (evt, disableButtons = false) => {
			const editorButtons = [
				{ mode: AnnotationEditorType.NONE, button: editorNoneButton },
				{
					mode: AnnotationEditorType.FREETEXT,
					button: editorFreeTextButton,
					toolbar: editorFreeTextParamsToolbar,
				},
				{
					mode: AnnotationEditorType.INK,
					button: editorInkButton,
					toolbar: editorInkParamsToolbar,
				},
			];

			for (const { mode, button, toolbar } of editorButtons) {
				const checked = mode === evt.mode;
				button.classList.toggle('toggled', checked);
				button.setAttribute('aria-checked', checked);
				button.disabled = disableButtons;
				if (toolbar) {
					toolbar.classList.toggle('hidden', !checked);
				}
			}
		};
		this.eventBus._on('annotationeditormodechanged', editorModeChanged);

		this.eventBus._on('toolbarreset', (evt) => {
			if (evt.source === this) {
				editorModeChanged(
					{ mode: AnnotationEditorType.NONE },
					/* disableButtons = */ true,
				);
			}
		});
	}

	#updateUIState(resetNumPages = false) {
		if (!this.#wasLocalized) {
			// Don't update the UI state until we localize the toolbar.
			return;
		}
		const { pageNumber, pagesCount, pageScaleValue, pageScale, items } =
			this;

		if (resetNumPages) {
			if (this.hasPageLabels) {
				items.pageNumber.type = 'text';
			} else {
				items.pageNumber.type = 'number';
				this.l10n.get('of_pages', { pagesCount }).then((msg) => {
					items.numPages.textContent = msg;
				});
			}
			items.pageNumber.max = pagesCount;
		}

		if (this.hasPageLabels) {
			items.pageNumber.value = this.pageLabel;
			this.l10n
				.get('page_of_pages', { pageNumber, pagesCount })
				.then((msg) => {
					items.numPages.textContent = msg;
				});
		} else {
			items.pageNumber.value = pageNumber;
		}

		items.previous.disabled = pageNumber <= 1;
		items.next.disabled = pageNumber >= pagesCount;

		items.zoomOut.disabled = pageScale <= MIN_SCALE;
		items.zoomIn.disabled = pageScale >= MAX_SCALE;

		this.l10n
			.get('page_scale_percent', {
				scale: Math.round(pageScale * 10000) / 100,
			})
			.then((msg) => {
				let predefinedValueFound = false;
				for (const option of items.scaleSelect.options) {
					if (option.value !== pageScaleValue) {
						option.selected = false;
						continue;
					}
					option.selected = true;
					predefinedValueFound = true;
				}
				if (!predefinedValueFound) {
					items.customScaleOption.textContent = msg;
					items.customScaleOption.selected = true;
				}
			});
	}

	updateLoadingIndicatorState(loading = false) {
		const { pageNumber } = this.items;
		for (let i = 0; i < pageNumber.length; i++) {
			let pageNumberID = document.getElementById(pageNumber[i].id);
			pageNumberID.classList.toggle(
				PAGE_NUMBER_LOADING_INDICATOR,
				loading,
			);
		}
	}

	/**
	 * Increase the width of the zoom dropdown DOM element if, and only if, it's
	 * too narrow to fit the *longest* of the localized strings.
	 */
	async #adjustScaleWidth() {
		const { items, l10n } = this;

		const predefinedValuesPromise = Promise.all([
			l10n.get('page_scale_auto'),
			l10n.get('page_scale_actual'),
			l10n.get('page_scale_fit'),
			l10n.get('page_scale_width'),
		]);
		await animationStarted;

		const style = getComputedStyle(items.scaleSelect),
			scaleSelectContainerWidth = parseInt(
				style.getPropertyValue('--scale-select-container-width'),
				10,
			),
			scaleSelectOverflow = parseInt(
				style.getPropertyValue('--scale-select-overflow'),
				10,
			);

		// The temporary canvas is used to measure text length in the DOM.
		const canvas = document.createElement('canvas');
		const ctx = canvas.getContext('2d', { alpha: false });
		ctx.font = `${style.fontSize} ${style.fontFamily}`;

		let maxWidth = 0;
		for (const predefinedValue of await predefinedValuesPromise) {
			const { width } = ctx.measureText(predefinedValue);
			if (width > maxWidth) {
				maxWidth = width;
			}
		}
		maxWidth += 2 * scaleSelectOverflow;

		if (maxWidth > scaleSelectContainerWidth) {
			docStyle.setProperty(
				'--scale-select-container-width',
				`${maxWidth}px`,
			);
		}
		// Zeroing the width and height cause Firefox to release graphics resources
		// immediately, which can greatly reduce memory consumption.
		canvas.width = 0;
		canvas.height = 0;
	}
}

export { Toolbar };