// We want to remember how far we were scrolled on each 'tab'.
// To do so, we need to save away the old position of the
// scrollbar when we switch to a new tab (and restore it
// when we switch back.)
var scroll_positions = {};

function register_onclick(message_row, message_id) {
    message_row.find(".messagebox").click(function (e) {
        if (!(clicking && mouse_moved)) {
            // Was a click (not a click-and-drag).
            select_message_by_id(message_id);
            respond_to_message();
        }
        mouse_moved = false;
        clicking = false;
    });
}

function focus_on(field_id) {
    // Call after autocompleting on a field, to advance the focus to
    // the next input field.

    // Bootstrap's typeahead does not expose a callback for when an
    // autocomplete selection has been made, so we have to do this
    // manually.
    $("#" + field_id).focus();
}

/* We use 'visibility' rather than 'display' and jQuery's show() / hide(),
   because we want to reserve space for the email address.  This avoids
   things jumping around slightly when the email address is shown. */

function hide_email() {
    $('.sender_email').addClass('invisible');
}

function show_email(message_id) {
    hide_email();
    get_message_row(message_id).find('.sender_email').removeClass('invisible');
}

function report_error(response, xhr, status_box) {
    if (xhr.status.toString().charAt(0) === "4") {
        // Only display the error response for 4XX, where we've crafted
        // a nice response.
        response += ": " + $.parseJSON(xhr.responseText).msg;
    }

    status_box.removeClass(status_classes).addClass('alert-error')
              .text(response).stop(true).fadeTo(0, 1);
    status_box.show();
}

function report_success(response, status_box) {
    status_box.removeClass(status_classes).addClass('alert-success')
              .text(response).stop(true).fadeTo(0, 1);
    status_box.show();
}

var clicking = false;
var mouse_moved = false;

function mousedown() {
    mouse_moved = false;
    clicking = true;
}

function mousemove() {
    if (clicking) {
        mouse_moved = true;
    }
}

function resizehandler(e) {
    var sidebar = $("#sidebar");
    var sidebar_nav = $(".sidebar-nav");
    var composebox = $("#compose");
    var top_statusbar = $("#top_statusbar");
    if (viewport.width() <= 767) {
        sidebar.removeClass('nav-stacked');

        var space_taken_up_by_navbar = sidebar_nav.outerHeight(true);
        $("#nav_whitespace").height(space_taken_up_by_navbar); // .visible-phone only, so doesn't need undoing
        top_statusbar.css('top', space_taken_up_by_navbar);

        var message_list_width = $("#main_div").outerWidth();
        composebox.width(message_list_width);
        top_statusbar.width(message_list_width);
        sidebar_nav.width(message_list_width);
    } else {
        sidebar.addClass('nav-stacked');
        top_statusbar.css('top', 0);
        top_statusbar.width('');
        composebox.width('');
        sidebar_nav.width('');
    }

    // This function might run onReady (if we're in a narrow window),
    // but before we've loaded in the messages; in that case, don't
    // try to scroll to one.
    if (selected_message_id !== -1) {
        scroll_to_selected();
    }
}

var autocomplete_needs_update = false;

function update_autocomplete() {
    stream_list.sort();
    people_list.sort(function (x, y) {
        if (x.email === y.email) return 0;
        if (x.email < y.email) return -1;
        return 1;
    });

    var huddle_typeahead_list = $.map(people_list, function (person) {
        return person.full_name + " <" + person.email + ">";
    });

    // We need to muck with the internal state of Typeahead in order to update
    // its data source
    $("#stream").data("typeahead").source = stream_list;
    $("#huddle_recipient").data("typeahead").source = huddle_typeahead_list;

    autocomplete_needs_update = false;
}

var old_label;
var is_floating_recipient_bar_showing = false;
function replace_floating_recipient_bar(desired_label) {
    if (desired_label !== old_label) {
        if (desired_label.children(".message_newstyle_stream").length !== 0) {
            $("#current_label_stream td:first").replaceWith(desired_label.children(".message_newstyle_stream").clone());
            $("#current_label_stream td:last").replaceWith(desired_label.children(".message_newstyle_subject").clone());
            $("#current_label_huddle").css('display', 'none');
            $("#current_label_stream").css('display', 'table-row');
        } else {
            $("#current_label_huddle td:first").replaceWith(desired_label.children(".message_newstyle_pm").clone());
            $("#current_label_stream").css('display', 'none');
            $("#current_label_huddle").css('display', 'table-row');
        }
        old_label = desired_label;
    }
    if (!is_floating_recipient_bar_showing) {
        $(".floating_recipient_bar").css('visibility', 'visible');
        is_floating_recipient_bar_showing = true;
    }
}

function hide_floating_recipient_bar() {
    if (is_floating_recipient_bar_showing) {
        $(".floating_recipient_bar").css('visibility', 'hidden');
        is_floating_recipient_bar_showing = false;
    }
}

function update_floating_recipient_bar() {
    var top_statusbar = $("#top_statusbar");
    var top_statusbar_top = top_statusbar.offset().top;
    var top_statusbar_bottom = top_statusbar_top + top_statusbar.height();

    // Find the last message where the top of the recipient
    // row is at least partially occluded by our box.
    // Start with the pointer's current location.
    var candidate = selected_message;
    while (true) {
        candidate = candidate.prev();
        if (candidate.length === 0) {
            // We're at the top of the page and no labels are above us.
            hide_floating_recipient_bar();
            return;
        }
        if (candidate.is(".focused_table .recipient_row")) {
            if (candidate.offset().top < top_statusbar_bottom) {
                break;
            }
        }
    }
    var current_label = candidate;

    // We now know what the floating stream/subject bar should say.
    // Do we show it?

    // Hide if the bottom of our floating stream/subject label is not
    // lower than the bottom of current_label (since that means we're
    // covering up a label that already exists).
    if (top_statusbar_bottom <=
        (current_label.offset().top + current_label.height())) {
        hide_floating_recipient_bar();
        return;
    }

    // Hide if our bottom is in our bookend (or one bookend-height
    // above it). This means we're not showing any useful part of the
    // message above us, so why bother showing the label?)
    var current_label_bookend = current_label.nextUntil(".bookend_tr")
                                             .next(".bookend_tr");
    // (The last message currently doesn't have a bookend, which is why this might be 0).
    if (current_label_bookend.length > 0) {
        var my_bookend = $(current_label_bookend[0]);
        if (top_statusbar_bottom >
            (my_bookend.offset().top - my_bookend.height())) {
            hide_floating_recipient_bar();
            return;
        }
    }

    // If we've gotten this far, well, show it.
    replace_floating_recipient_bar(current_label);
}
function hack_for_floating_recipient_bar() {
    // So, as of this writing, Firefox respects visibility: collapse,
    // but WebKit does not (at least, my Chrome doesn't.)  Instead it
    // renders it basically as visibility: hidden, which leaves a
    // slight gap that our messages peek through as they scroll
    // by. This hack fixes this by programmatically measuring how big
    // the gap is, and then moving our table up to compensate.
    var gap = $("#floating_recipient_layout_row").outerHeight(true);
    var floating_recipient = $(".floating_recipient");
    var offset = floating_recipient.offset();
    offset.top = offset.top - gap;
    floating_recipient.offset(offset);
}

$(function () {
    // NB: This just binds to current elements, and won't bind to elements
    // created after ready() is called.

    $('#message-type-tabs a[href="#stream-message"]').on('shown', function (e) {
        $('#personal-message').hide();
        $('#stream-message').show();
        $('#new_message_type').val('stream');
        $("#send-status").removeClass(status_classes).hide();
        focus_on("stream");
    });
    $('#message-type-tabs a[href="#personal-message"]').on('shown', function (e) {
        $('#personal-message').show();
        $('#stream-message').hide();
        $('#new_message_type').val('personal');
        $("#send-status").removeClass(status_classes).hide();
        focus_on("huddle_recipient");
    });

    // Prepare the click handler for subbing to a new stream to which
    // you have composed a message.
    $('#create-it').click(function () {
        sub_from_home(compose_stream_name(), $('#stream-dne'));
    });

    // Prepare the click handler for subbing to an existing stream.
    $('#sub-it').click(function () {
        sub_from_home(compose_stream_name(), $('#stream-nosub'));
    });

    var throttled_scrollhandler = $.throttle(50, function(e) {
        if ($('#home').hasClass('active')) {
            keep_pointer_in_view();
            update_floating_recipient_bar();
        }
    });
    $(window).scroll(throttled_scrollhandler);

    var throttled_mousewheelhandler = $.throttle(50, function(e) {
        // Most of the mouse wheel's work will be handled by the
        // scroll handler, but when we're at the top or bottom of the
        // page, the pointer may still need to move.
        move_pointer_at_page_top_and_bottom();
    });
    $(window).mousewheel(throttled_mousewheelhandler);

    var throttled_resizehandler = $.throttle(50, resizehandler);
    $(window).resize(throttled_resizehandler);

    $('#sidebar a[data-toggle="pill"]').on('show', function (e) {
        // Save the position of our old tab away, before we switch
        var old_tab = $(e.relatedTarget).attr('href');
        scroll_positions[old_tab] = viewport.scrollTop();
    });
    $('#sidebar a[data-toggle="pill"]').on('shown', function (e) {
        // Right after we show the new tab, restore its old scroll position
        var target_tab = $(e.target).attr('href');
        if (scroll_positions.hasOwnProperty(target_tab)) {
            viewport.scrollTop(scroll_positions[target_tab]);
        } else {
            viewport.scrollTop(0);
        }

        // Hide all our error messages when switching tabs
        $('.alert-error').hide();
        $('.alert-success').hide();
        $('.alert-info').hide();
        $('.alert').hide();

        // Set the URL bar title to show the sub-page you're currently on.
        var browser_url = $(e.target).attr('href');
        if (browser_url === "#home") {
            browser_url = "#";
        }
        window.history.pushState("object or string", "Title", browser_url);
    });

    $('.button-slide').click(function () {
        show_compose('stream', $("#stream"));
    });

    $('#sidebar a[href="#subscriptions"]').click(fetch_subs);

    var settings_status = $('#settings-status');
    $("#current_settings form").ajaxForm({
        dataType: 'json', // This seems to be ignored. We still get back an xhr.
        success: function (resp, statusText, xhr, form) {
            var message = "Updated settings!";
            var result = $.parseJSON(xhr.responseText);
            if ((result.full_name !== undefined) || (result.short_name !== undefined)) {
                message = "Updated settings!  You will need to reload the page for your changes to take effect.";
            }
            settings_status.removeClass(status_classes)
                .addClass('alert-success')
                .text(message).stop(true).fadeTo(0,1);
            // TODO: In theory we should auto-reload or something if
            // you changed the email address or other fields that show
            // up on all screens
        },
        error: function (xhr, error_type, xhn) {
            var response = "Error changing settings";
            if (xhr.status.toString().charAt(0) === "4") {
                // Only display the error response for 4XX, where we've crafted
                // a nice response.
                response += ": " + $.parseJSON(xhr.responseText).msg;
            }
            settings_status.removeClass(status_classes)
                .addClass('alert-error')
                .text(response).stop(true).fadeTo(0,1);
        }
    });

    // A little hackish, because it doesn't seem to totally get us
    // the exact right width for the top_statusbar and compose box,
    // but, close enough for now.
    resizehandler();
    hack_for_floating_recipient_bar();

    // limit number of items so the list doesn't fall off the screen
    $( "#stream" ).typeahead({
        source: [], // will be set in update_autocomplete()
        items: 3
    });
    $( "#subject" ).typeahead({
        source: function (query, process) {
            var stream_name = $("#stream").val();
            if (subject_dict.hasOwnProperty(stream_name)) {
                return subject_dict[stream_name];
            }
            return [];
        },
        items: 2
    });
    $( "#huddle_recipient" ).typeahead({
        source: [], // will be set in update_autocomplete()
        items: 4,
        matcher: function (item) {
            // Assumes email addresses don't have commas or semicolons in them
            var current_recipient = $(this.query.split(/[,;] */)).last()[0];
            // Case-insensitive (from Bootstrap's default matcher).
            return (item.toLowerCase().indexOf(current_recipient.toLowerCase()) !== -1);
        },
        updater: function (item) {
            var previous_recipients = this.query.split(/[,;] */);
            previous_recipients.pop();
            previous_recipients = previous_recipients.join(", ");
            if (previous_recipients.length !== 0) {
                previous_recipients += ", ";
            }
            // Extracting the email portion via regex is icky, but the Bootstrap
            // typeahead widget doesn't seem to be flexible enough to pass
            // objects around
            var email_re = /<[^<]*>$/;
            var email = email_re.exec(item)[0];
            return previous_recipients + email.substring(1, email.length - 1) + ", ";
        }

    });

    $( "#huddle_recipient" ).blur(function (event) {
        var val = $(this).val();
        $(this).val(val.replace(/[,;] *$/, ''));
    });

    update_autocomplete();
});