/*****************************************************************
 * Discovers issues in the item provided.
 * @param {object} canvasItem - Canvas item produced by the Canvas API Wrapper
 * @param {IssueItem} issueItem - The IssueItem for the item, without any issues
 * @param {object} options - Options specific to the tool selected by the user
 *****************************************************************/
function discover(canvasItem, issueItem, options) {
    let title = ``;         // the title of the card on the discovered issue
    let description = '';   // a description of the discover type that will be displayed on the issue card
    let display = ``;       // the html that will be displayed on the issue card
    let details = {};       // an object containing anything needing to be referenced in the fix function 
    let html = {
        currentHtml: canvasItem.getHtml()   // set the html for the editorTab
    };

    if (/*meets condition */true) {

        // Add new issues as needed
        issueItem.newIssue(title, display, details, html);
    }
}

/*****************************************************************
 * Fixes issues in the item provided.
 * @param {object} canvasItem - Canvas item produced by the Canvas API Wrapper
 * @param {IssueItem} issueItem - The IssueItem for the item, including its issues
 * @param {object} options - Options specific to the tool selected by the user
 * @returns {array} fixedIssues - All issues discovered.
 *****************************************************************/
function fix(canvasItem, issueItem, options) {
    return new Promise(async (resolve, reject) => {
        try {
            if (/*meets condition */true) {
                issueItem.issues.forEach(issue => {
                    if(issue.status === 'approved') {
                        // make the changes here

                        // set the issue status to 'fixed'
                        issue.status = 'fixed';
                    }
                });
                // after making the change, update the item in Canvas
                await canvasItem.update();
                resolve();
            }
        } catch (e) {
            issueItem.issues.forEach(issue => {
                if (issue.status === 'approved') {
                    issue.status = 'failed';
                }
            });
            reject(e);
        }
    });
}

const cheerio = require('cheerio');

/*****************************************************************
 * Discovers issues in the item provided.
 * @param {object} canvasItem - Canvas item produced by the Canvas API Wrapper
 * @param {IssueItem} issueItem - The IssueItem for the item, without any issues
 * @param {object} options - Options specific to the tool selected by the user
 *****************************************************************/
function discover(canvasItem, issueItem, options) {
    if (canvasItem.getHtml() === null) return;
    var $ = cheerio.load(canvasItem.getHtml());
    var images = $('img');

    images.each((i, image) => {
        image = $(image);
        var alt = image.attr('alt');

        // If the option to get ALL alt attributes is selected, move forward, else check alt it is empty/missing
        if (options.altCondition.includes('All image alt') || !alt || alt === '') {

            let title = 'Existing Alt Attribute';
            let description = 'The alt text on this image should be a good description of the image.';

            if (alt === '') {
                title = 'Empty Alt Attribute';
                description = 'The alt text on this image is empty.';
            } else if (!alt) {
                title = 'Missing Alt Attribute';
                description = 'The alt text on this image is missing.';
            }

            let display = `
                <div>${description}</div>
                <h3>Image</h3>
                <div class="navy z-depth-1" style="max-width:100%;border-radius:3px;padding:10px 10px 4px 10px;display:inline-block">
                    <img style="max-width:100%" src="${image.attr('src')}">
                </div>
            `;

            if (alt) {
                display += `
                    <h3>Current Alt Text</h3>
                    <div class="code-block">${alt}</div>
                `;
            }

            let details = {
                image: image.attr('src'),
                title,
                description
            };

            issueItem.newIssue(title, display, details);
        }
    });
}

/*****************************************************************
 * Fixes issues in the item provided.
 * @param {object} canvasItem - Canvas item produced by the Canvas API Wrapper
 * @param {IssueItem} issueItem - The IssueItem for the item, including its issues
 * @param {object} options - Options specific to the tool selected by the user
 * @returns {array} fixedIssues - All issues discovered.
 *****************************************************************/
function fix(canvasItem, issueItem, options) {
    return new Promise(async (resolve, reject) => {
        try {
            if (canvasItem.getHtml()) {
                var $ = cheerio.load(canvasItem.getHtml());

                issueItem.issues.forEach(issue => {
                    if (issue.status === 'approved') {

                        let image = $(`img[src="${issue.details.image}"]`).first();
                        if (image && issue.optionValues.newAltText) {
                            $(image).attr('alt', issue.optionValues.newAltText);
                            issue.status = 'fixed';
                        }
                    }
                });

                canvasItem.setHtml($.html());
                await canvasItem.update();
                resolve();
            }
        } catch (e) {
            issueItem.issues.forEach(issue => {
                if (issue.status === 'approved') {
                    issue.status = 'failed';
                }
            });
            reject(e);
        }
    });
}

module.exports = {
    discover,
    fix,
    id: 'alt_attributes',
    title: 'Alt Attributes',
    description: 'This tool allows you to edit image alt attributes. It can provide all images in the course, or just images that have empty or missing alt attributes. Courses with a high number of images may cause delays when navigating through issues. You will NOT be able to see any of the images if you are not signed into Canvas.',
    icon: 'text_rotation_none',
    toolType: 'fix',
    toolCategory: 'html',
    fixedMessage: 'The new alt attribute has been inserted',
    categories: [
        'pages',
        'assignments',
        'discussions',
        'quizzes',
        'quizQuestions'
    ],
    discoverOptions: [{
        title: 'Conditions',
        key: 'altCondition',
        description: 'Do you want to include all image alt attributes or just empty and missing alt attributes?',
        type: 'dropdown',
        choices: ['', 'All image alt attributes', 'Only empty and missing'],
        required: true
    }],
    fixOptions: [{
        title: 'New Alt Text',
        key: 'newAltText',
        description: 'Please enter the new alt text for this image.',
        type: 'text',
        choices: [],
        required: true
    }],
};