import autosize from "autosize";
import $ from "jquery";

import * as blueslip from "./blueslip";
import * as condense from "./condense";
import * as message_lists from "./message_lists";
import * as message_viewport from "./message_viewport";
import * as navbar_alerts from "./navbar_alerts";
import * as navigate from "./navigate";
import * as popovers from "./popovers";
import * as ui from "./ui";
import {user_settings} from "./user_settings";
import * as util from "./util";

let narrow_window = false;

function confine_to_range(lo, val, hi) {
    if (val < lo) {
        return lo;
    }
    if (val > hi) {
        return hi;
    }
    return val;
}

function size_blocks(blocks, usable_height) {
    let sum_height = 0;

    for (const block of blocks) {
        sum_height += block.real_height;
    }

    for (const block of blocks) {
        let ratio = block.real_height / sum_height;
        ratio = confine_to_range(0.05, ratio, 0.85);
        block.max_height = confine_to_range(80, usable_height * ratio, 1.2 * block.real_height);
    }
}

function get_new_heights() {
    const res = {};
    const viewport_height = message_viewport.height();
    const top_navbar_height = $("#top_navbar").safeOuterHeight(true);
    const right_sidebar_shorcuts_height = $(".right-sidebar-shortcuts").safeOuterHeight(true) || 0;
    const add_streams_link_height = $("#add-stream-link").safeOuterHeight(true) || 0;

    res.bottom_whitespace_height = viewport_height * 0.4;

    res.main_div_min_height = viewport_height - top_navbar_height;

    res.stream_filters_max_height =
        viewport_height -
        Number.parseInt($("#left-sidebar").css("marginTop"), 10) -
        Number.parseInt($(".narrows_panel").css("marginTop"), 10) -
        Number.parseInt($(".narrows_panel").css("marginBottom"), 10) -
        $("#global_filters").safeOuterHeight(true) -
        $("#streams_header").safeOuterHeight(true) -
        add_streams_link_height;

    // Don't let us crush the stream sidebar completely out of view
    res.stream_filters_max_height = Math.max(80, res.stream_filters_max_height);

    // RIGHT SIDEBAR

    const usable_height =
        viewport_height -
        Number.parseInt($("#right-sidebar").css("marginTop"), 10) -
        $("#userlist-header").safeOuterHeight(true) -
        $("#user_search_section").safeOuterHeight(true) -
        right_sidebar_shorcuts_height;

    res.buddy_list_wrapper_max_height = Math.max(80, usable_height);

    return res;
}

function left_userlist_get_new_heights() {
    const res = {};
    const viewport_height = message_viewport.height();
    const viewport_width = message_viewport.width();
    res.viewport_height = viewport_height;
    res.viewport_width = viewport_width;

    // main div
    const top_navbar_height = $(".header").safeOuterHeight(true);
    res.bottom_whitespace_height = viewport_height * 0.4;
    res.main_div_min_height = viewport_height - top_navbar_height;

    // left sidebar
    const stream_filters = $("#stream_filters").expectOne();
    const buddy_list_wrapper = $("#buddy_list_wrapper").expectOne();

    const stream_filters_real_height = stream_filters.prop("scrollHeight");
    const user_list_real_height = ui.get_scroll_element(buddy_list_wrapper).prop("scrollHeight");

    res.total_leftlist_height =
        viewport_height -
        Number.parseInt($("#left-sidebar").css("marginTop"), 10) -
        Number.parseInt($(".narrows_panel").css("marginTop"), 10) -
        Number.parseInt($(".narrows_panel").css("marginBottom"), 10) -
        $("#global_filters").safeOuterHeight(true) -
        $("#streams_header").safeOuterHeight(true) -
        $("#userlist-header").safeOuterHeight(true) -
        $("#user_search_section").safeOuterHeight(true) -
        Number.parseInt(stream_filters.css("marginBottom"), 10);

    const blocks = [
        {
            real_height: stream_filters_real_height,
        },
        {
            real_height: user_list_real_height,
        },
    ];

    size_blocks(blocks, res.total_leftlist_height);

    res.stream_filters_max_height = blocks[0].max_height;
    res.buddy_list_wrapper_max_height = blocks[1].max_height;

    return res;
}

export function watch_manual_resize(element) {
    const box = document.querySelector(element);

    if (!box) {
        blueslip.error("Bad selector in watch_manual_resize: " + element);
        return undefined;
    }

    const meta = {
        box,
        height: null,
        mousedown: false,
    };

    const box_handler = function () {
        meta.mousedown = true;
        meta.height = meta.box.clientHeight;
    };
    meta.box.addEventListener("mousedown", box_handler);

    // If the user resizes the textarea manually, we use the
    // callback to stop autosize from adjusting the height.
    // It will be re-enabled when this component is next opened.
    const body_handler = function () {
        if (meta.mousedown === true) {
            meta.mousedown = false;
            if (meta.height !== meta.box.clientHeight) {
                meta.height = meta.box.clientHeight;
                autosize.destroy($(element)).height(meta.height + "px");
            }
        }
    };
    document.body.addEventListener("mouseup", body_handler);

    return [box_handler, body_handler];
}

export function reset_compose_textarea_max_height(bottom_whitespace_height) {
    // If the compose-box is open, we set the `max-height` property of
    // `compose-textarea` and `preview-textarea`, so that the
    // compose-box's maximum extent does not overlap the last message
    // in the current stream.  We also leave a tiny bit of space after
    // the last message of the current stream.

    // Compute bottom_whitespace_height if not provided by caller.
    if (bottom_whitespace_height === undefined) {
        const h = narrow_window ? left_userlist_get_new_heights() : get_new_heights();
        bottom_whitespace_height = h.bottom_whitespace_height;
    }

    // Take properties of the whichever message area is visible.
    const visible_textarea = $("#compose-textarea:visible, #preview_message_area:visible");
    const compose_height = Number.parseInt($("#compose").outerHeight(), 10);
    const compose_textarea_height = Number.parseInt(visible_textarea.outerHeight(), 10);
    const compose_non_textarea_height = compose_height - compose_textarea_height;

    // The `preview_message_area` can have a slightly different height
    // than `compose-textarea` based on operating system. We just
    // ensure that the last message is not overlapped by compose box.
    visible_textarea.css(
        "max-height",
        // The 10 here leaves space for the selected message border.
        bottom_whitespace_height - compose_non_textarea_height - 10,
    );
}

export function resize_bottom_whitespace(h) {
    $("#bottom_whitespace").height(h.bottom_whitespace_height);

    // The height of the compose box is tied to that of
    // bottom_whitespace, so update it if necessary.
    //
    // reset_compose_textarea_max_height cannot compute the right
    // height correctly while compose is hidden. This is OK, because
    // we also resize compose every time it is opened.
    if ($(".message_comp").is(":visible")) {
        reset_compose_textarea_max_height(h.bottom_whitespace_height);
    }
}

export function resize_stream_filters_container(h) {
    h = narrow_window ? left_userlist_get_new_heights() : get_new_heights();
    resize_bottom_whitespace(h);
    $("#stream-filters-container").css("max-height", h.stream_filters_max_height);
}

export function resize_sidebars() {
    let sidebar;

    if (user_settings.left_side_userlist) {
        const css_narrow_mode = message_viewport.is_narrow();

        $("#top_navbar").removeClass("rightside-userlist");

        const right_items = $(".right-sidebar-items").expectOne();

        if (css_narrow_mode && !narrow_window) {
            // move stuff to the left sidebar (skinny mode)
            narrow_window = true;
            popovers.set_userlist_placement("left");
            sidebar = $("#left-sidebar").expectOne();
            sidebar.append(right_items);
            $("#buddy_list_wrapper").css("margin", "0px");
            $("#userlist-toggle").css("display", "none");
            $("#invite-user-link").hide();
        } else if (!css_narrow_mode && narrow_window) {
            // move stuff to the right sidebar (wide mode)
            narrow_window = false;
            popovers.set_userlist_placement("right");
            sidebar = $("#right-sidebar").expectOne();
            sidebar.append(right_items);
            $("#buddy_list_wrapper").css("margin", "");
            $("#userlist-toggle").css("display", "");
            $("#invite-user-link").show();
        }
    }

    const h = narrow_window ? left_userlist_get_new_heights() : get_new_heights();

    $("#buddy_list_wrapper").css("max-height", h.buddy_list_wrapper_max_height);
    $("#stream-filters-container").css("max-height", h.stream_filters_max_height);

    return h;
}

export function resize_page_components() {
    navbar_alerts.resize_app();
    const h = resize_sidebars();
    resize_bottom_whitespace(h);
}

let _old_width = $(window).width();

export function handler() {
    const new_width = $(window).width();

    // On mobile web, we want to avoid hiding a popover here on height change,
    // especially if this resize was triggered by a virtual keyboard
    // popping up when the user opened that very popover.
    const mobile = util.is_mobile();
    if (!mobile || new_width !== _old_width) {
        popovers.hide_all();
    }

    if (new_width !== _old_width) {
        _old_width = new_width;
        condense.clear_message_content_height_cache();
    }
    resize_page_components();

    // Re-compute and display/remove [More] links to messages
    condense.condense_and_collapse($(".message_table .message_row"));

    // 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 (message_lists.current.selected_id() !== -1) {
        if (mobile) {
            popovers.set_suppress_scroll_hide();
        }

        navigate.scroll_to_selected();
    }
}