availability.js

/*
  Solr is stale on the backend and we needed a performant way to check
  the actual availability of books (works, editions) in bulk.

  The getAvailability function hits OL's Availability API with a list
  of ocaids (archive.org item ids). It [OL] then in turn sends a http
  request to a service on Archive.org which looks up each ocaid in the
  Archive.org List API database (i.e. how lending data is currently
  stored on Archive.org for Open Library).

  Note: The plan is to move away from the List API for lending data
  (the List API is supposed to be for allowing users to create Lists
  of items, so using this data structure to support our lending is a
  bit of a hack). Instead of the List API, users lending data will be
  stored as metadata within their Archive.org user account.
*/
/* eslint-disable no-unused-vars */
// used in openlibrary/plugins/openlibrary/js/ol.js
var getAvailabilityV2, updateBookAvailability, updateWorkAvailability;
/* eslint-enable no-unused-vars */

function init() {
    var btnClassName = 'cta-btn';
    // pages still relying on legacy client-side availability checking
    var whitelist = {
        '^/account/books/[^/]+': { // readinglog
            filter: false
        },
        '^/authors/[^/]+': { // authors
            filter: true
        },
        '^/people/[^/]+': { // lists
            filter: false,
        },
        '^/stats/[^/]+': {
            filter: false
        }
    }

    getAvailabilityV2 = function(_type, _ids, callback) {
        if (!_ids.length) {
            return callback({});
        }
        var url = '/availability/v2?type=' + _type;
        $.ajax({
            url: url,
            type: "POST",
            data: JSON.stringify({
                "ids": _ids
            }),
            dataType: "json",
            contentType: "application/json",
            beforeSend: function(xhr) {
                xhr.setRequestHeader("Content-Type", "application/json");
                xhr.setRequestHeader("Accept", "application/json");
            },
            success: function(result) {
                return callback(result);
            }
        });
    };

    /*
     * Finds DOM elements for borrowable books (i.e. they have a
     * data-ocaid field and a data-key field) within the specified
     * scope of `selector` and updates the displayed borrow status
     * and ebook links to reflect correct statuses and available
     * copies.
     */
    updateBookAvailability = function(selector) {
        selector = (selector || '') + '[data-ocaid]';
        var books = {};  // lets us keep track of which ocaids came from
        // which book (i.e. edition or work). As we learn
        // ocaids are available, we'll need a way to
        // determine which edition or work this ocaid
        // comes from.
        var ocaids = [];  // a full set of ocaids spanning all books
        // which can be checked in a single request
        // to the availability API.
        $(selector).each(function(index, elem) {
            var data_ocaid = $(elem).attr('data-ocaid');
            if(data_ocaid) {
                var book_ocaids = data_ocaid.split(',')
                    .filter(function(book) { return book !== "" });
                var book_key = $(elem).attr('data-key');

                if(book_ocaids.length) {
                    books[book_key] = book_ocaids;
                    Array.prototype.push.apply(ocaids, book_ocaids);
                }
            }
        });

        getAvailabilityV2('identifier', ocaids, function(response) {
            var book_key = null;
            var book_ocaids = null;
            for (var book_ocaid in response) {
                if (response[book_ocaid].status === "borrow_available") {
                    // check all the books on this page
                    for (book_key in books) {
                        book_ocaids = books[book_key];
                        // check if available book_ocaid is in
                        // this book_key's book_ocaids
                        if (book_ocaids.indexOf(book_ocaid) > -1) {
                            // update icon, ocaid, and url (to ia:)
                            // should limit scope to `selector` ! XXX
                            $(selector + "[data-key=" + book_key  + "]")
                                .attr("href", "/borrow/ia/" + book_ocaid);
                            $(selector + "[data-key=" + book_key  + "]")
                                .addClass('cta-btn--available').addClass(btnClassName)
                            $(selector + "[data-key=" + book_key  + "]")
                                .text('Borrow');
                            // since we've found an available edition to
                            // represent this book, we can stop and remove
                            // book_ocaid from book_ocaids (one less book
                            // to check against).
                            delete books[book_key];
                        }
                    }
                } else if (response[book_ocaid].status === "borrow_unavailable"){
                    for (book_key in books) {
                        book_ocaids = books[book_key];
                        if (book_ocaids.indexOf(book_ocaid) > -1) {
                            $(selector + "[data-key=" + book_key  + "]")
                                .attr('title', 'Join waitlist');
                            $(selector + "[data-key=" + book_key  + "]")
                                .addClass('cta-btn--unavailable').addClass(btnClassName);
                            $(selector + "[data-key=" + book_key  + "]")
                                .text('Join Waitlist');
                            delete books[book_key];
                        }
                    }
                } else {
                    for (book_key in books) {
                        book_ocaids = books[book_key];
                        if (book_ocaids.indexOf(book_ocaid) > -1) {
                            $(selector + "[data-key=" + book_key  + "]")
                                .attr('href', $(selector + "[data-key=" + book_key  + "]").attr('data-key'))
                            $(selector + "[data-key=" + book_key  + "]")
                                .attr('title', 'Check Availability');
                            $(selector + "[data-key=" + book_key  + "]")
                                .removeClass('borrow-link');
                            $(selector + "[data-key=" + book_key  + "]")
                                .addClass('check-book-availability').addClass(btnClassName);
                            $(selector + "[data-key=" + book_key  + "]")
                                .text('Check Availability');
                            delete books[book_key];
                        }
                    }
                }
            }
        });
    };

    updateWorkAvailability = function() {

        // Determine whether availability check necessary for page
        var checkAvailability = false;
        var filter = false;
        for (var page in whitelist) {
            if (window.location.pathname.match(page)) {
                checkAvailability = true;
                filter = whitelist[page].filter;
            }
        }
        if(!checkAvailability) {
            return;
        }

        if (localStorage.getItem('mode') === "printdisabled") {
            var daisies = $('.print-disabled-only');
            $.each(daisies, function() {
                $(this).removeClass('hidden');
            });
            return;
        }

        var editions = [];
        var works = [];
        var results = $('a.results');
        $.each(results, function(index, e) {
            var href = $(e).attr('href');
            var _type_key_slug = href.split('/')
            var _type = _type_key_slug[1];
            var key = _type_key_slug[2];
            if (_type === 'works') {
                works.push(key);
            } else if (_type === 'books') {
                editions.push(key);
            }
        });

        getAvailabilityV2('openlibrary_edition', editions, function(editions_response) {
            getAvailabilityV2('openlibrary_work', works, function(works_response) {
                var response = {'books': editions_response, 'works': works_response};
                $.each(results, function(index, e) {
                    var href = $(e).attr('href');
                    var _type_key_slug = href.split('/')
                    var _type = _type_key_slug[1];
                    var key = _type_key_slug[2];
                    if (response[_type]) {
                        var work = response[_type][key];
                        var li = $(e).closest("li");
                        var cta = li.find(".searchResultItemCTA-lending");
                        var msg = '';
                        var link = '';
                        var annotation = '';
                        var tag = 'a';

                        var mode = filter ? localStorage.getItem('mode') : 'everything';

                        if (mode !== "printdisabled") {
                            if (work.status === 'error' || work.status === 'private') {
                                if (mode === "ebooks") {
                                    li.remove();
                                }
                            } else {
                                var cls = 'borrow_available borrow-link';
                                link = ' href="/books/' + work.openlibrary_edition + '/x/borrow" ';

                                if (work.status === 'open') {
                                    cls = 'cta-btn--available';
                                    msg = 'Read';
                                } else if (work.status === 'borrow_available') {
                                    cls = 'cta-btn--available';
                                    msg = 'Borrow';
                                } else if (work.status === 'borrow_unavailable') {
                                    tag = 'span';
                                    link = '';
                                    cls = 'cta-btn--unavailable';
                                    msg = '<form method="POST" action="/books/' + work.openlibrary_edition + '/x/borrow?action=join-waitinglist" class="join-waitlist waitinglist-form"><input type="hidden" name="action" value="join-waitinglist">';
                                    if (work.num_waitlist !== '0') {
                                        msg += 'Join Waitlist <span class="cta-btn__badge">' + work.num_waitlist + '</span></form>';

                                    } else {
                                        msg += 'Join Waitlist</form>';
                                        annotation = '<div class="waitlist-msg">You will be first in line!</div>';
                                    }
                                }
                                $(cta).append(
                                    '<' + tag + ' ' + link + ' class="' + cls +
                                        ' ' + btnClassName + '" data-ol-link-track="' +
                                        work.status
                                        + '">' + msg + '</' + tag + '>'
                                );

                                if (annotation) {
                                    $(cta).append(annotation);
                                }
                            }
                        }
                    }
                });
            });
        })
        /* eslint-disable no-unused-vars */
        // event object is passed to this function
        $('.searchResultItemCTA-lending form.join-waitlist').on('click', function(e) {
            // consider submitting form async and refreshing search results page
            $(this).submit()
        })
        /* eslint-enable no-unused-vars */
        updateBookAvailability();
    }
}

init();
export { getAvailabilityV2, updateBookAvailability, updateWorkAvailability };