local UIManager = require("ui/uimanager")
local WidgetContainer = require("ui/widget/container/widgetcontainer")
local logger = require("logger")
local _ = require("gettext")
local BookInfoManager = require("bookinfomanager")

--[[
    This plugin provides additional display modes to file browsers (File Manager
    and History).
    It does that by dynamically replacing some methods code to their classes
    or instances.
--]]

-- We need to save the original methods early here as locals.
-- For some reason, saving them as attributes in init() does not allow
-- us to get back to classic mode
local FileChooser = require("ui/widget/filechooser")
local _FileChooser__recalculateDimen_orig = FileChooser._recalculateDimen
local _FileChooser_updateItems_orig = FileChooser.updateItems
local _FileChooser_onCloseWidget_orig = FileChooser.onCloseWidget

local FileManagerHistory = require("apps/filemanager/filemanagerhistory")
local _FileManagerHistory_updateItemTable_orig = FileManagerHistory.updateItemTable

local FileManagerCollection = require("apps/filemanager/filemanagercollection")
local _FileManagerCollection_updateItemTable_orig = FileManagerCollection.updateItemTable

local FileManager = require("apps/filemanager/filemanager")
local _FileManager_tapPlus_orig = FileManager.tapPlus

-- Available display modes
local DISPLAY_MODES = {
    -- nil or ""                -- classic : filename only
    mosaic_image        = true, -- 3x3 grid covers with images
    mosaic_text         = true, -- 3x3 grid covers text only
    list_image_meta     = true, -- image with metadata (title/authors)
    list_only_meta      = true, -- metadata with no image
    list_image_filename = true, -- image with filename (no metadata)
}

-- Store some states as locals, to be permanent across instantiations
local init_done = false
local filemanager_display_mode = false -- not initialized yet
local history_display_mode = false -- not initialized yet
local collection_display_mode = false -- not initialized yet
local series_mode = nil -- defaults to not display series

local CoverBrowser = WidgetContainer:extend{
    name = "coverbrowser",
}

function CoverBrowser:init()
    self.ui.menu:registerToMainMenu(self)

    if init_done then -- things already patched according to current modes
        return
    end

    -- Set up default display modes on first launch
    if not G_reader_settings:isTrue("coverbrowser_initial_default_setup_done") then
        -- Only if no display mode has been set yet
        if not BookInfoManager:getSetting("filemanager_display_mode")
            and not BookInfoManager:getSetting("history_display_mode") then
            logger.info("CoverBrowser: setting default display modes")
            BookInfoManager:saveSetting("filemanager_display_mode", "list_image_meta")
            BookInfoManager:saveSetting("history_display_mode", "mosaic_image")
        end
        G_reader_settings:makeTrue("coverbrowser_initial_default_setup_done")
    end

    self:setupFileManagerDisplayMode(BookInfoManager:getSetting("filemanager_display_mode"))
    self:setupHistoryDisplayMode(BookInfoManager:getSetting("history_display_mode"))
    self:setupCollectionDisplayMode(BookInfoManager:getSetting("collection_display_mode"))
    series_mode = BookInfoManager:getSetting("series_mode")

    init_done = true
    BookInfoManager:closeDbConnection() -- will be re-opened if needed
end

function CoverBrowser:addToMainMenu(menu_items)
    -- We add it only to FileManager menu
    if self.ui.view then -- Reader
        return
    end

    menu_items.filemanager_display_mode = {
        text = _("Display mode"),
        sub_item_table = {
            -- selecting these does not close menu, which may be nice
            -- so one can see how they look below the menu
            {
                text = _("Classic (filename only)"),
                checked_func = function() return not filemanager_display_mode end,
                callback = function()
                   self:setupFileManagerDisplayMode("")
                end,
            },
            {
                text = _("Mosaic with cover images"),
                checked_func = function() return filemanager_display_mode == "mosaic_image" end,
                callback = function()
                   self:setupFileManagerDisplayMode("mosaic_image")
                end,
            },
            {
                text = _("Mosaic with text covers"),
                checked_func = function() return filemanager_display_mode == "mosaic_text" end,
                callback = function()
                   self:setupFileManagerDisplayMode("mosaic_text")
                end,
            },
            {
                text = _("Detailed list with cover images and metadata"),
                checked_func = function() return filemanager_display_mode == "list_image_meta" end,
                callback = function()
                   self:setupFileManagerDisplayMode("list_image_meta")
                end,
            },
            {
                text = _("Detailed list with metadata, no images"),
                checked_func = function() return filemanager_display_mode == "list_only_meta" end,
                callback = function()
                   self:setupFileManagerDisplayMode("list_only_meta")
                end,
            },
            {
                text = _("Detailed list with cover images and filenames"),
                checked_func = function() return filemanager_display_mode == "list_image_filename" end,
                callback = function()
                   self:setupFileManagerDisplayMode("list_image_filename")
                end,
                separator = true,
            },
            -- Plug the same choices for History here as a submenu
            -- (Any other suitable place for that ?)
            {
                text = _("History display mode"),
                sub_item_table = {
                    {
                        text = _("Classic (filename only)"),
                        checked_func = function() return not history_display_mode end,
                        callback = function()
                           self:setupHistoryDisplayMode("")
                        end,
                    },
                    {
                        text = _("Mosaic with cover images"),
                        checked_func = function() return history_display_mode == "mosaic_image" end,
                        callback = function()
                           self:setupHistoryDisplayMode("mosaic_image")
                        end,
                    },
                    {
                        text = _("Mosaic with text covers"),
                        checked_func = function() return history_display_mode == "mosaic_text" end,
                        callback = function()
                           self:setupHistoryDisplayMode("mosaic_text")
                        end,
                    },
                    {
                        text = _("Detailed list with cover images and metadata"),
                        checked_func = function() return history_display_mode == "list_image_meta" end,
                        callback = function()
                           self:setupHistoryDisplayMode("list_image_meta")
                        end,
                    },
                    {
                        text = _("Detailed list with metadata, no images"),
                        checked_func = function() return history_display_mode == "list_only_meta" end,
                        callback = function()
                           self:setupHistoryDisplayMode("list_only_meta")
                        end,
                    },
                    {
                        text = _("Detailed list with cover images and filenames"),
                        checked_func = function() return history_display_mode == "list_image_filename" end,
                        callback = function()
                           self:setupHistoryDisplayMode("list_image_filename")
                        end,
                    },
                },
            },
            {
                text = _("Favorites display mode"),
                sub_item_table = {
                    {
                        text = _("Classic (filename only)"),
                        checked_func = function() return not collection_display_mode end,
                        callback = function()
                            self:setupCollectionDisplayMode("")
                        end,
                    },
                    {
                        text = _("Mosaic with cover images"),
                        checked_func = function() return collection_display_mode == "mosaic_image" end,
                        callback = function()
                            self:setupCollectionDisplayMode("mosaic_image")
                        end,
                    },
                    {
                        text = _("Mosaic with text covers"),
                        checked_func = function() return collection_display_mode == "mosaic_text" end,
                        callback = function()
                            self:setupCollectionDisplayMode("mosaic_text")
                        end,
                    },
                    {
                        text = _("Detailed list with cover images and metadata"),
                        checked_func = function() return collection_display_mode == "list_image_meta" end,
                        callback = function()
                            self:setupCollectionDisplayMode("list_image_meta")
                        end,
                    },
                    {
                        text = _("Detailed list with metadata, no images"),
                        checked_func = function() return collection_display_mode == "list_only_meta" end,
                        callback = function()
                            self:setupCollectionDisplayMode("list_only_meta")
                        end,
                    },
                    {
                        text = _("Detailed list with cover images and filenames"),
                        checked_func = function() return collection_display_mode == "list_image_filename" end,
                        callback = function()
                            self:setupCollectionDisplayMode("list_image_filename")
                        end,
                    },
                },
            },
        },
    }

    -- add Mosaic / Detailed list mode settings to File browser Settings submenu
    -- next to Classic mode settings
    if menu_items.filebrowser_settings == nil then return end
    table.insert (menu_items.filebrowser_settings.sub_item_table, 4, {
        text = _("Mosaic and detailed list settings"),
        separator = true,
        sub_item_table = {
            {
                text = _("Items per page"),
                help_text = _([[This sets the number of files and folders per page in display modes other than classic.]]),
                -- Best to not "keep_menu_open = true", to see how this apply on the full view
                callback = function()
                    local SpinWidget = require("ui/widget/spinwidget")
                    -- "files_per_page" should have been saved with an adequate value
                    -- the first time Detailed list was shown. Fallback to a start
                    -- value of 10 if it hasn't.
                    local curr_items = BookInfoManager:getSetting("files_per_page") or 10
                    local items = SpinWidget:new{
                        value = curr_items,
                        value_min = 4,
                        value_max = 20,
                        default_value = 10,
                        keep_shown_on_apply = true,
                        title_text =  _("Items per page"),
                        callback = function(spin)
                            BookInfoManager:saveSetting("files_per_page", spin.value)
                            self.ui:onRefresh()
                        end
                    }
                    UIManager:show(items)
                end,
            },
            {
                text = _("Display hints"),
                sub_item_table = {
                    {
                        text = _("Show hint for books with description"),
                        checked_func = function() return not BookInfoManager:getSetting("no_hint_description") end,
                        callback = function()
                            if BookInfoManager:getSetting("no_hint_description") then
                                BookInfoManager:saveSetting("no_hint_description", false)
                            else
                                BookInfoManager:saveSetting("no_hint_description", true)
                            end
                            self:refreshFileManagerInstance()
                        end,
                    },
                    {
                        text = _("Show hint for opened books in history"),
                        checked_func = function() return BookInfoManager:getSetting("history_hint_opened") end,
                        callback = function()
                            if BookInfoManager:getSetting("history_hint_opened") then
                                BookInfoManager:saveSetting("history_hint_opened", false)
                            else
                                BookInfoManager:saveSetting("history_hint_opened", true)
                            end
                            self:refreshFileManagerInstance()
                        end,
                    },
                    {
                        text = _("Show hint for opened books in favorites"),
                        checked_func = function() return BookInfoManager:getSetting("collections_hint_opened") end,
                        callback = function()
                            if BookInfoManager:getSetting("collections_hint_opened") then
                                BookInfoManager:saveSetting("collections_hint_opened", false)
                            else
                                BookInfoManager:saveSetting("collections_hint_opened", true)
                            end
                            self:refreshFileManagerInstance()
                        end,
                    }
                }
            },
            {
                text = _("Series"),
                sub_item_table = {
                    {
                        text = _("Append series metadata to authors"),
                        checked_func = function() return series_mode == "append_series_to_authors" end,
                        callback = function()
                            if series_mode == "append_series_to_authors" then
                                series_mode = nil
                            else
                                series_mode = "append_series_to_authors"
                            end
                            BookInfoManager:saveSetting("series_mode", series_mode)
                            self:refreshFileManagerInstance()
                        end,
                    },
                    {
                        text = _("Append series metadata to title"),
                        checked_func = function() return series_mode == "append_series_to_title" end,
                        callback = function()
                            if series_mode == "append_series_to_title" then
                                series_mode = nil
                            else
                                series_mode = "append_series_to_title"
                            end
                            BookInfoManager:saveSetting("series_mode", series_mode)
                            self:refreshFileManagerInstance()
                        end,
                    },
                    {
                        text = _("Show series metadata in separate line"),
                        checked_func = function() return series_mode == "series_in_separate_line" end,
                        callback = function()
                            if series_mode == "series_in_separate_line" then
                                series_mode = nil
                            else
                                series_mode = "series_in_separate_line"
                            end
                            BookInfoManager:saveSetting("series_mode", series_mode)
                            self:refreshFileManagerInstance()
                        end,
                    },
                },
                separator = true
            },
            {
                text = _("Show progress % in mosaic mode"),
                checked_func = function() return BookInfoManager:getSetting("show_progress_in_mosaic") end,
                callback = function()
                    if BookInfoManager:getSetting("show_progress_in_mosaic") then
                        BookInfoManager:saveSetting("show_progress_in_mosaic", false)
                    else
                        BookInfoManager:saveSetting("show_progress_in_mosaic", true)
                    end
                    self:refreshFileManagerInstance()
                end,
            },
            {
                text = _("Show number of pages read instead of progress %"),
                checked_func = function() return BookInfoManager:getSetting("show_pages_read_as_progress") end,
                callback = function()
                    if BookInfoManager:getSetting("show_pages_read_as_progress") then
                        BookInfoManager:saveSetting("show_pages_read_as_progress", false)
                    else
                        BookInfoManager:saveSetting("show_pages_read_as_progress", true)
                    end
                    self:refreshFileManagerInstance()
                end,
            },
            {
                text = _("Show number of pages left to read"),
                checked_func = function() return BookInfoManager:getSetting("show_pages_left_in_progress") end,
                callback = function()
                    if BookInfoManager:getSetting("show_pages_left_in_progress") then
                        BookInfoManager:saveSetting("show_pages_left_in_progress", false)
                    else
                        BookInfoManager:saveSetting("show_pages_left_in_progress", true)
                    end
                    self:refreshFileManagerInstance()
                end,
                separator = true,
            },
            {
                text = _("Book info cache management"),
                sub_item_table = {
                    {
                        text_func = function() -- add current db size to menu text
                            local sstr = BookInfoManager:getDbSize()
                            return _("Current cache size: ") .. sstr
                        end,
                        keep_menu_open = true,
                        callback = function() end, -- no callback, only for information
                    },
                    {
                        text = _("Prune cache of removed books"),
                        keep_menu_open = true,
                        callback = function()
                            local ConfirmBox = require("ui/widget/confirmbox")
                            UIManager:close(self.file_dialog)
                            UIManager:show(ConfirmBox:new{
                                -- Checking file existences is quite fast, but deleting entries is slow.
                                text = _("Are you sure that you want to prune cache of removed books?\n(This may take a while.)"),
                                ok_text = _("Prune cache"),
                                ok_callback = function()
                                    local InfoMessage = require("ui/widget/infomessage")
                                    local msg = InfoMessage:new{ text = _("Pruning cache of removed books…") }
                                    UIManager:show(msg)
                                    UIManager:nextTick(function()
                                        local summary = BookInfoManager:removeNonExistantEntries()
                                        UIManager:close(msg)
                                        UIManager:show( InfoMessage:new{ text = summary } )
                                    end)
                                end
                            })
                        end,
                    },
                    {
                        text = _("Compact cache database"),
                        keep_menu_open = true,
                        callback = function()
                            local ConfirmBox = require("ui/widget/confirmbox")
                            UIManager:close(self.file_dialog)
                            UIManager:show(ConfirmBox:new{
                                text = _("Are you sure that you want to compact cache database?\n(This may take a while.)"),
                                ok_text = _("Compact database"),
                                ok_callback = function()
                                    local InfoMessage = require("ui/widget/infomessage")
                                    local msg = InfoMessage:new{ text = _("Compacting cache database…") }
                                    UIManager:show(msg)
                                    UIManager:nextTick(function()
                                        local summary = BookInfoManager:compactDb()
                                        UIManager:close(msg)
                                        UIManager:show( InfoMessage:new{ text = summary } )
                                    end)
                                end
                            })
                        end,
                    },
                    {
                        text = _("Delete cache database"),
                        keep_menu_open = true,
                        callback = function()
                            local ConfirmBox = require("ui/widget/confirmbox")
                            UIManager:close(self.file_dialog)
                            UIManager:show(ConfirmBox:new{
                                text = _("Are you sure that you want to delete cover and metadata cache?\n(This will also reset your display mode settings.)"),
                                ok_text = _("Purge"),
                                ok_callback = function()
                                    BookInfoManager:deleteDb()
                                end
                            })
                        end,
                    },
                },
            },
        },
    })
end

function CoverBrowser:refreshFileManagerInstance(cleanup, post_init)
    local fm = FileManager.instance
    if fm then
        local fc = fm.file_chooser
        if cleanup then -- clean instance properties we may have set
            if fc.showFileDialog_orig then
                -- remove our showFileDialog that extended file_dialog with new buttons
                fc.showFileDialog = fc.showFileDialog_orig
                fc.showFileDialog_orig = nil
                fc.showFileDialog_ours = nil
            end
        end
        if filemanager_display_mode then
            if post_init then
                -- FileBrowser was initialized in classic mode, but we changed
                -- display mode: items per page may have changed, and we want
                -- to re-position on the focused_file
                fc:_recalculateDimen()
                fc:changeToPath(fc.path, fc.prev_focused_path)
            else
                fc:updateItems()
            end
        else -- classic file_chooser needs this for a full redraw
            fc:refreshPath()
        end
    end
end

function CoverBrowser:setupFileManagerDisplayMode(display_mode)
    if not DISPLAY_MODES[display_mode] then
        display_mode = nil -- unknow mode, fallback to classic
    end
    if init_done and display_mode == filemanager_display_mode then -- no change
        return
    end
    if init_done then -- save new mode in db
        BookInfoManager:saveSetting("filemanager_display_mode", display_mode)
    end
    -- remember current mode in module variable
    filemanager_display_mode = display_mode
    logger.dbg("CoverBrowser: setting FileManager display mode to:", display_mode or "classic")

    if not init_done and not display_mode then
        return -- starting in classic mode, nothing to patch
    end

    if not display_mode then -- classic mode
        -- Put back original methods
        FileChooser.updateItems = _FileChooser_updateItems_orig
        FileChooser.onCloseWidget = _FileChooser_onCloseWidget_orig
        FileChooser._recalculateDimen = _FileChooser__recalculateDimen_orig
        FileManager.tapPlus = _FileManager_tapPlus_orig
        -- Also clean-up what we added, even if it does not bother original code
        FileChooser._updateItemsBuildUI = nil
        FileChooser._do_cover_images = nil
        FileChooser._do_filename_only = nil
        FileChooser._do_hint_opened = nil
        FileChooser._do_center_partial_rows = nil
        self:refreshFileManagerInstance(true)
        return
    end

    -- In both mosaic and list modes, replace original methods with those from
    -- our generic CoverMenu
    local CoverMenu = require("covermenu")
    FileChooser.updateItems = CoverMenu.updateItems
    FileChooser.onCloseWidget = CoverMenu.onCloseWidget

    if display_mode == "mosaic_image" or display_mode == "mosaic_text" then -- mosaic mode
        -- Replace some other original methods with those from our MosaicMenu
        local MosaicMenu = require("mosaicmenu")
        FileChooser._recalculateDimen = MosaicMenu._recalculateDimen
        FileChooser._updateItemsBuildUI = MosaicMenu._updateItemsBuildUI
        -- Set MosaicMenu behaviour:
        FileChooser._do_cover_images = display_mode ~= "mosaic_text"
        FileChooser._do_hint_opened = true -- dogear at bottom
        -- Don't have "../" centered in empty directories
        FileChooser._do_center_partial_rows = false
        -- One could override default 3x3 grid here (put that as settings ?)
        -- FileChooser.nb_cols_portrait = 4
        -- FileChooser.nb_rows_portrait = 4
        -- FileChooser.nb_cols_landscape = 6
        -- FileChooser.nb_rows_landscape = 3

    elseif display_mode == "list_image_meta" or display_mode == "list_only_meta" or
                                     display_mode == "list_image_filename" then -- list modes
        -- Replace some other original methods with those from our ListMenu
        local ListMenu = require("listmenu")
        FileChooser._recalculateDimen = ListMenu._recalculateDimen
        FileChooser._updateItemsBuildUI = ListMenu._updateItemsBuildUI
        -- Set ListMenu behaviour:
        FileChooser._do_cover_images = display_mode ~= "list_only_meta"
        FileChooser._do_filename_only = display_mode == "list_image_filename"
        FileChooser._do_hint_opened = true -- dogear at bottom
    end


    -- Replace this FileManager method with the one from CoverMenu
    -- (but first, make the original method saved here as local available
    -- to CoverMenu)
    CoverMenu._FileManager_tapPlus_orig = _FileManager_tapPlus_orig
    FileManager.tapPlus = CoverMenu.tapPlus

    if init_done then
        self:refreshFileManagerInstance()
    else
        -- If KOReader has started directly to FileManager, the FileManager
        -- instance is being init()'ed and there is no FileManager.instance yet,
        -- but there'll be one at next tick.
        UIManager:nextTick(function()
            self:refreshFileManagerInstance(false, true)
        end)
    end

end

local function _FileManagerHistory_updateItemTable(self)
    -- 'self' here is the single FileManagerHistory instance
    -- FileManagerHistory has just created a new instance of Menu as 'hist_menu'
    -- at each display of History. Soon after instantiation, this method
    -- is called. The first time it is called, we replace some methods.
    local display_mode = self.display_mode
    local hist_menu = self.hist_menu

    if not hist_menu._coverbrowser_overridden then
        hist_menu._coverbrowser_overridden = true

        -- In both mosaic and list modes, replace original methods with those from
        -- our generic CoverMenu
        local CoverMenu = require("covermenu")
        hist_menu.updateItems = CoverMenu.updateItems
        hist_menu.onCloseWidget = CoverMenu.onCloseWidget
        -- Also replace original onMenuHold (it will use original method, so remember it)
        hist_menu.onMenuHold_orig = hist_menu.onMenuHold
        hist_menu.onMenuHold = CoverMenu.onHistoryMenuHold

        if display_mode == "mosaic_image" or display_mode == "mosaic_text" then -- mosaic mode
            -- Replace some other original methods with those from our MosaicMenu
            local MosaicMenu = require("mosaicmenu")
            hist_menu._recalculateDimen = MosaicMenu._recalculateDimen
            hist_menu._updateItemsBuildUI = MosaicMenu._updateItemsBuildUI
            -- Set MosaicMenu behaviour:
            hist_menu._do_cover_images = display_mode ~= "mosaic_text"
            hist_menu._do_center_partial_rows = true -- nicer looking when few elements

        elseif display_mode == "list_image_meta" or display_mode == "list_only_meta" or
                                 display_mode == "list_image_filename" then -- list modes
            -- Replace some other original methods with those from our ListMenu
            local ListMenu = require("listmenu")
            hist_menu._recalculateDimen = ListMenu._recalculateDimen
            hist_menu._updateItemsBuildUI = ListMenu._updateItemsBuildUI
            -- Set ListMenu behaviour:
            hist_menu._do_cover_images = display_mode ~= "list_only_meta"
            hist_menu._do_filename_only = display_mode == "list_image_filename"

        end
        hist_menu._do_hint_opened = BookInfoManager:getSetting("history_hint_opened")
    end

    -- And do now what the original does
    _FileManagerHistory_updateItemTable_orig(self)
end

function CoverBrowser:setupHistoryDisplayMode(display_mode)
    if not DISPLAY_MODES[display_mode] then
        display_mode = nil -- unknow mode, fallback to classic
    end
    if init_done and display_mode == history_display_mode then -- no change
        return
    end
    if init_done then -- save new mode in db
        BookInfoManager:saveSetting("history_display_mode", display_mode)
    end
    -- remember current mode in module variable
    history_display_mode = display_mode
    logger.dbg("CoverBrowser: setting History display mode to:", display_mode or "classic")

    if not init_done and not display_mode then
        return -- starting in classic mode, nothing to patch
    end

    -- We only need to replace one FileManagerHistory method
    if not display_mode then -- classic mode
        -- Put back original methods
        FileManagerHistory.updateItemTable = _FileManagerHistory_updateItemTable_orig
        FileManagerHistory.display_mode = nil
    else
        -- Replace original method with the one defined above
        FileManagerHistory.updateItemTable = _FileManagerHistory_updateItemTable
        -- And let it know which display_mode we should use
        FileManagerHistory.display_mode = display_mode
    end
end

local function _FileManagerCollections_updateItemTable(self)
    -- 'self' here is the single FileManagerCollections instance
    -- FileManagerCollections has just created a new instance of Menu as 'coll_menu'
    -- at each display of Collection/Favorites. Soon after instantiation, this method
    -- is called. The first time it is called, we replace some methods.
    local display_mode = self.display_mode
    local coll_menu = self.coll_menu

    if not coll_menu._coverbrowser_overridden then
        coll_menu._coverbrowser_overridden = true

        -- In both mosaic and list modes, replace original methods with those from
        -- our generic CoverMenu
        local CoverMenu = require("covermenu")
        coll_menu.updateItems = CoverMenu.updateItems
        coll_menu.onCloseWidget = CoverMenu.onCloseWidget
        -- Also replace original onMenuHold (it will use original method, so remember it)
        coll_menu.onMenuHold_orig = coll_menu.onMenuHold
        coll_menu.onMenuHold = CoverMenu.onCollectionsMenuHold

        if display_mode == "mosaic_image" or display_mode == "mosaic_text" then -- mosaic mode
            -- Replace some other original methods with those from our MosaicMenu
            local MosaicMenu = require("mosaicmenu")
            coll_menu._recalculateDimen = MosaicMenu._recalculateDimen
            coll_menu._updateItemsBuildUI = MosaicMenu._updateItemsBuildUI
            -- Set MosaicMenu behaviour:
            coll_menu._do_cover_images = display_mode ~= "mosaic_text"
            coll_menu._do_center_partial_rows = true -- nicer looking when few elements

        elseif display_mode == "list_image_meta" or display_mode == "list_only_meta" or
            display_mode == "list_image_filename" then -- list modes
            -- Replace some other original methods with those from our ListMenu
            local ListMenu = require("listmenu")
            coll_menu._recalculateDimen = ListMenu._recalculateDimen
            coll_menu._updateItemsBuildUI = ListMenu._updateItemsBuildUI
            -- Set ListMenu behaviour:
            coll_menu._do_cover_images = display_mode ~= "list_only_meta"
            coll_menu._do_filename_only = display_mode == "list_image_filename"

        end
        coll_menu._do_hint_opened = BookInfoManager:getSetting("collections_hint_opened")
    end

    -- And do now what the original does
    _FileManagerCollection_updateItemTable_orig(self)
end


function CoverBrowser:setupCollectionDisplayMode(display_mode)
    if not DISPLAY_MODES[display_mode] then
        display_mode = nil -- unknow mode, fallback to classic
    end
    if init_done and display_mode == collection_display_mode then -- no change
        return
    end
    if init_done then -- save new mode in db
        BookInfoManager:saveSetting("collection_display_mode", display_mode)
    end
    -- remember current mode in module variable
    collection_display_mode = display_mode
    logger.dbg("CoverBrowser: setting Collection display mode to:", display_mode or "classic")

    if not init_done and not display_mode then
        return -- starting in classic mode, nothing to patch
    end

    -- We only need to replace one FileManagerCollection method
    if not display_mode then -- classic mode
        -- Put back original methods
        FileManagerCollection.updateItemTable = _FileManagerCollection_updateItemTable_orig
        FileManagerCollection.display_mode = nil
    else
        -- Replace original method with the one defined above
        FileManagerCollection.updateItemTable = _FileManagerCollections_updateItemTable
        -- And let it know which display_mode we should use
        FileManagerCollection.display_mode = display_mode
    end
end

return CoverBrowser
