import * as DOM from '../services/dom';
import {Component} from './component';
import {copyTextToClipboard} from '../services/clipboard';

export class Pointer extends Component {

    setup() {
        this.container = this.$el;
        this.input = this.$refs.input;
        this.button = this.$refs.button;
        this.pageId = this.$opts.pageId;

        // Instance variables
        this.showing = false;
        this.isSelection = false;
        this.pointerModeLink = true;
        this.pointerSectionId = '';

        this.setupListeners();
    }

    setupListeners() {
        // Copy on copy button click
        this.button.addEventListener('click', event => {
            copyTextToClipboard(this.input.value);
        });

        // Select all contents on input click
        this.input.addEventListener('click', event => {
            this.input.select();
            event.stopPropagation();
        });

        // Prevent closing pointer when clicked or focused
        DOM.onEvents(this.container, ['click', 'focus'], event => {
            event.stopPropagation();
        });

        // Pointer mode toggle
        DOM.onChildEvent(this.container, 'span.icon', 'click', (event, icon) => {
            event.stopPropagation();
            this.pointerModeLink = !this.pointerModeLink;
            icon.querySelector('[data-icon="include"]').style.display = (!this.pointerModeLink) ? 'inline' : 'none';
            icon.querySelector('[data-icon="link"]').style.display = (this.pointerModeLink) ? 'inline' : 'none';
            this.updateForTarget();
        });

        // Hide pointer when clicking away
        DOM.onEvents(document.body, ['click', 'focus'], event => {
            if (!this.showing || this.isSelection) return;
            this.hidePointer();
        });

        // Show pointer when selecting a single block of tagged content
        const pageContent = document.querySelector('.page-content');
        DOM.onEvents(pageContent, ['mouseup', 'keyup'], event => {
            event.stopPropagation();
            const targetEl = event.target.closest('[id^="bkmrk"]');
            if (targetEl) {
                this.showPointerAtTarget(targetEl, event.pageX);
            }
        });
    }

    hidePointer() {
        this.container.style.display = null;
        this.showing = false;
    }

    /**
     * Move and display the pointer at the given element, targeting the given screen x-position if possible.
     * @param {Element} element
     * @param {Number} xPosition
     */
    showPointerAtTarget(element, xPosition) {
        const selection = window.getSelection();
        if (selection.toString().length === 0) return;

        // Show pointer and set link
        this.pointerSectionId = element.id;
        this.updateForTarget(element);

        this.container.style.display = 'block';
        const targetBounds = element.getBoundingClientRect();
        const pointerBounds = this.container.getBoundingClientRect();

        const xTarget = Math.min(Math.max(xPosition, targetBounds.left), targetBounds.right);
        const xOffset = xTarget - (pointerBounds.width / 2);
        const yOffset = (targetBounds.top - pointerBounds.height) - 16;

        this.container.style.left = `${xOffset}px`;
        this.container.style.top = `${yOffset}px`;

        this.showing = true;
        this.isSelection = true;

        setTimeout(() => {
            this.isSelection = false;
        }, 100);

        const scrollListener = () => {
            this.hidePointer();
            window.removeEventListener('scroll', scrollListener, {passive: true});
        };
        window.addEventListener('scroll', scrollListener, {passive: true});
    }

    /**
     * Update the pointer inputs/content for the given target element.
     * @param {?Element} element
     */
    updateForTarget(element) {
        let inputText = this.pointerModeLink ? window.baseUrl(`/link/${this.pageId}#${this.pointerSectionId}`) : `{{@${this.pageId}#${this.pointerSectionId}}}`;
        if (this.pointerModeLink && !inputText.startsWith('http')) {
            inputText = `${window.location.protocol}//${window.location.host}${inputText}`;
        }

        this.input.value = inputText;

        // Update anchor if present
        const editAnchor = this.container.querySelector('#pointer-edit');
        if (editAnchor && element) {
            const {editHref} = editAnchor.dataset;
            const elementId = element.id;

            // get the first 50 characters.
            const queryContent = element.textContent && element.textContent.substring(0, 50);
            editAnchor.href = `${editHref}?content-id=${elementId}&content-text=${encodeURIComponent(queryContent)}`;
        }
    }

}