--[[ ---------------------------------------------------------------------------
Folder Cover patch (custom .cover.* + auto cover fallback) with item-count badge
bottom-right and with consistent edge inset (same offset logic in both axes).

This version changes ONLY the nbitems_widget placement logic:
- Keeps the badge in the bottom-right
- Applies Folder.face.nb_items_margin as an inset from BOTH the right and bottom
----------------------------------------------------------------------------- ]]

local AlphaContainer = require("ui/widget/container/alphacontainer")
local BD = require("ui/bidi")
local Blitbuffer = require("ffi/blitbuffer")
local BottomContainer = require("ui/widget/container/bottomcontainer")
local CenterContainer = require("ui/widget/container/centercontainer")
local Device = require("device")
local FileChooser = require("ui/widget/filechooser")
local Font = require("ui/font")
local FrameContainer = require("ui/widget/container/framecontainer")
local ImageWidget = require("ui/widget/imagewidget")
local LineWidget = require("ui/widget/linewidget")
local OverlapGroup = require("ui/widget/overlapgroup")
local RightContainer = require("ui/widget/container/rightcontainer")
local Size = require("ui/size")
local TextBoxWidget = require("ui/widget/textboxwidget")
local TextWidget = require("ui/widget/textwidget")
local TopContainer = require("ui/widget/container/topcontainer")
local VerticalGroup = require("ui/widget/verticalgroup")
local VerticalSpan = require("ui/widget/verticalspan")
local userpatch = require("userpatch")
local util = require("util")

local _ = require("gettext")
local Screen = Device.screen
local logger = require("logger")

--========================== [[ Folder Cover Tuning ]] ==========================

-- Edge bars (above cover)
local EDGE_THICKNESS       = Screen:scaleBySize(4.5)    -- thickness of the top/bottom edge bars
local EDGE_MARGIN          = Size.line.medium           -- space between edge bars and other elements
local EDGE_COLOR           = Blitbuffer.COLOR_GRAY_4    -- color of the edge bars
local EDGE_WIDTH_RATIO     = 0.97                       -- width of the edge bars relative to the cover width

-- Cover face
local COVER_BORDER_SIZE    = Size.border.thin           -- thickness of the cover border around the image
local COVER_BANNER_ALPHA   = 0.6                        -- transparency of the folder name banner overlay
local DIR_MAX_FONT_SIZE    = 20                         -- maximum font size for the folder name text

--========================== [[ Number Badge Tuning ]] ==========================

local NB_ITEMS_FONT_SIZE   = 18                        -- font size of the number badge text
local NB_ITEMS_MARGIN      = Screen:scaleBySize(5)     -- inset distance of number badge from right & bottom edges
local NB_BADGE_SIZE        = Screen:scaleBySize(18)    -- default size of the badge (width and height)
local NB_BADGE_PADDING     = Screen:scaleBySize(2)     -- padding inside the badge frame
local NB_BADGE_RADIUS      = 6                         -- corner radius for the badge
local NB_BADGE_BG_COLOR    = Blitbuffer.COLOR_WHITE    -- background color of the badge
local NB_BADGE_MARGIN      = Screen:scaleBySize(5)     -- inset from right and bottom edges

--===============================================================================

local FolderCover = {
    name = ".cover",
    exts = { ".jpg", ".jpeg", ".png", ".webp", ".gif" },
}

local function findCover(dir_path)
    local path = dir_path .. "/" .. FolderCover.name
    for i, ext in ipairs(FolderCover.exts) do
        local fname = path .. ext
        if util.fileExists(fname) then return fname end
    end
end

local function getMenuItem(menu, ...) -- path
    local function findItem(sub_items, texts)
        local find = {}
        local texts = type(texts) == "table" and texts or { texts }
        for i, text in ipairs(texts) do find[text] = true end
        for i, item in ipairs(sub_items) do
            local text = item.text or (item.text_func and item.text_func())
            if text and find[text] then return item end
        end
    end

    local sub_items, item
    for i, texts in ipairs { ... } do -- walk path
        sub_items = (item or menu).sub_item_table
        if not sub_items then return end
        item = findItem(sub_items, texts)
        if not item then return end
    end
    return item
end

local function toKey(...)
    local keys = {}
    for i, key in pairs { ... } do
        if type(key) == "table" then
            table.insert(keys, "table")
            for k, v in pairs(key) do
                table.insert(keys, tostring(k))
                table.insert(keys, tostring(v))
            end
        else
            table.insert(keys, tostring(key))
        end
    end
    return table.concat(keys, "")
end

local orig_FileChooser_getListItem = FileChooser.getListItem
local cached_list = {}

function FileChooser:getListItem(dirpath, f, fullpath, attributes, collate)
    local key = toKey(dirpath, f, fullpath, attributes, collate, self.show_filter.status)
    cached_list[key] = cached_list[key] or orig_FileChooser_getListItem(self, dirpath, f, fullpath, attributes, collate)
    return cached_list[key]
end

local function capitalize(sentence)
    local words = {}
    for word in sentence:gmatch("%S+") do
        table.insert(words, word:sub(1, 1):upper() .. word:sub(2):lower())
    end
    return table.concat(words, " ")
end

local Folder = {
    edge = {
        thick  = EDGE_THICKNESS,
        margin = EDGE_MARGIN,
        color  = EDGE_COLOR,
        width  = EDGE_WIDTH_RATIO,
    },
    face = {
        border_size       = COVER_BORDER_SIZE,
        alpha             = COVER_BANNER_ALPHA,
        nb_items_font_size = NB_ITEMS_FONT_SIZE,
        nb_items_margin   = NB_ITEMS_MARGIN,
        dir_max_font_size = DIR_MAX_FONT_SIZE,
    },
}

local function patchCoverBrowser(plugin)
    local MosaicMenu = require("mosaicmenu")
    local MosaicMenuItem = userpatch.getUpValue(MosaicMenu._updateItemsBuildUI, "MosaicMenuItem")
    if not MosaicMenuItem then return end -- Protect against remnants of project title
    local BookInfoManager = userpatch.getUpValue(MosaicMenuItem.update, "BookInfoManager")
    local original_update = MosaicMenuItem.update

    -- setting
    function BooleanSetting(text, name, default)
        self = { text = text }
        self.get = function()
            local setting = BookInfoManager:getSetting(name)
            if default then return not setting end -- false is stored as nil, so we need our own logic for boolean default
            return setting
        end
        self.toggle = function() return BookInfoManager:toggleSetting(name) end
        return self
    end

    local settings = {
        crop_to_fit = BooleanSetting(_("Crop folder custom image"), "folder_crop_custom_image", true),
        name_centered = BooleanSetting(_("Folder name centered"), "folder_name_centered", true),
        show_folder_name = BooleanSetting(_("Show folder name"), "folder_name_show", true),
    }

    -- cover item
    function MosaicMenuItem:update(...)
        original_update(self, ...)
        if self._foldercover_processed or self.menu.no_refresh_covers or not self.do_cover_image then return end

        if self.entry.is_file or self.entry.file or not self.mandatory then return end -- it's a file
        local dir_path = self.entry and self.entry.path
        if not dir_path then return end

        self._foldercover_processed = true

        local cover_file = findCover(dir_path) -- custom
        if cover_file then
            local success, w, h = pcall(function()
                local tmp_img = ImageWidget:new { file = cover_file, scale_factor = 1 }
                tmp_img:_render()
                local orig_w = tmp_img:getOriginalWidth()
                local orig_h = tmp_img:getOriginalHeight()
                tmp_img:free()
                return orig_w, orig_h
            end)
            if success then
                self:_setFolderCover { file = cover_file, w = w, h = h, scale_to_fit = settings.crop_to_fit.get() }
                return
            end
        end

        self.menu._dummy = true
        local entries = self.menu:genItemTableFromPath(dir_path) -- sorted
        self.menu._dummy = false
        if not entries then return end

        for _, entry in ipairs(entries) do
            if entry.is_file or entry.file then
                local bookinfo = BookInfoManager:getBookInfo(entry.path, true)
                if
                    bookinfo
                    and bookinfo.cover_bb
                    and bookinfo.has_cover
                    and bookinfo.cover_fetched
                    and not bookinfo.ignore_cover
                    and not BookInfoManager.isCachedCoverInvalid(bookinfo, self.menu.cover_specs)
                then
                    self:_setFolderCover { data = bookinfo.cover_bb, w = bookinfo.cover_w, h = bookinfo.cover_h }
                    break
                end
            end
        end
    end

    function MosaicMenuItem:_setFolderCover(img)
        local top_h = 2 * (Folder.edge.thick + Folder.edge.margin)
        local target = {
            w = self.width - 2 * Folder.face.border_size,
            h = self.height - 2 * Folder.face.border_size - top_h,
        }

        local img_options = { file = img.file, image = img.data }
        if img.scale_to_fit then
            img_options.scale_factor = math.max(target.w / img.w, target.h / img.h)
            img_options.width = target.w
            img_options.height = target.h
        else
            img_options.scale_factor = math.min(target.w / img.w, target.h / img.h)
        end

        local image = ImageWidget:new(img_options)
        local size = image:getSize()
        local dimen = { w = size.w + 2 * Folder.face.border_size, h = size.h + 2 * Folder.face.border_size }

        local image_widget = FrameContainer:new {
            padding = 0,
            bordersize = Folder.face.border_size,
            image,
            overlap_align = "center",
        }

        local directory, nbitems = self:_getTextBoxes { w = size.w, h = size.h }
        local size_nb = nbitems:getSize()
        local nb_size = math.max(size_nb.w, size_nb.h)

        local folder_name_widget
        if settings.show_folder_name.get() then
            folder_name_widget = (settings.name_centered.get() and CenterContainer or TopContainer):new {
                dimen = dimen,
                FrameContainer:new {
                    padding = 0, -- Makes text container larger than image if expanded
                    bordersize = Folder.face.border_size,
                    AlphaContainer:new { alpha = Folder.face.alpha, directory },
                },
                overlap_align = "center",
            }
        else
            folder_name_widget = VerticalSpan:new { width = 0 }
        end

        local nbitems_widget
        if tonumber(nbitems.text) ~= 0 then
            -- Inset from edges (right AND bottom) using the same margin value
            local inset = NB_BADGE_MARGIN

            nbitems_widget = BottomContainer:new {
                dimen = {
                    w = dimen.w,
                    h = dimen.h
                },

                RightContainer:new {
                    dimen = {
                        w = dimen.w - inset,
                        h = NB_BADGE_SIZE + inset * 2 + math.ceil(NB_BADGE_SIZE * 0.125),
                    },

                    FrameContainer:new {
                        padding = NB_BADGE_PADDING,
                        radius = NB_BADGE_RADIUS,
                        background = NB_BADGE_BG_COLOR,
                        CenterContainer:new { dimen = { w = NB_BADGE_SIZE, h = NB_BADGE_SIZE }, nbitems },
                    },
                },

                overlap_align = "center",
            }
        else
            nbitems_widget = VerticalSpan:new { width = 0 }
        end

        local widget = CenterContainer:new {
            dimen = { w = self.width, h = self.height },
            VerticalGroup:new {
                VerticalSpan:new { width = math.max(0, math.ceil((self.height - (top_h + dimen.h)) * 0.5)) },
                LineWidget:new {
                    background = Folder.edge.color,
                    dimen = { w = math.floor(dimen.w * (Folder.edge.width ^ 2)), h = Folder.edge.thick },
                },
                VerticalSpan:new { width = Folder.edge.margin },
                LineWidget:new {
                    background = Folder.edge.color,
                    dimen = { w = math.floor(dimen.w * Folder.edge.width), h = Folder.edge.thick },
                },
                VerticalSpan:new { width = Folder.edge.margin },
                OverlapGroup:new {
                    dimen = { w = self.width, h = self.height - top_h },
                    image_widget,
                    folder_name_widget,
                    nbitems_widget,
                },
            },
        }

        if self._underline_container[1] then
            local previous_widget = self._underline_container[1]
            previous_widget:free()
        end
        self._underline_container[1] = widget
    end

    function MosaicMenuItem:_getTextBoxes(dimen_in)
        local nbitems = TextWidget:new {
            text = self.mandatory:match("(%d+)") or "", -- nb books
            face = Font:getFace("cfont", Folder.face.nb_items_font_size),
            bold = true,
            padding = 0,
        }

        local text = self.text
        if text:match("/$") then text = text:sub(1, -2) end -- remove "/"
        text = BD.directory(capitalize(text))
        local available_height = dimen_in.h - 2 * nbitems:getSize().h
        local dir_font_size = Folder.face.dir_max_font_size
        local directory

        while true do
            if directory then directory:free(true) end
            directory = TextBoxWidget:new {
                text = text,
                face = Font:getFace("cfont", dir_font_size),
                width = dimen_in.w,
                alignment = "center",
                bold = true,
            }
            if directory:getSize().h <= available_height then break end
            dir_font_size = dir_font_size - 1
            if dir_font_size < 10 then -- don't go too low
                directory:free()
                directory.height = available_height
                directory.height_adjust = true
                directory.height_overflow_show_ellipsis = true
                directory:init()
                break
            end
        end

        return directory, nbitems
    end

    -- menu
    local orig_CoverBrowser_addToMainMenu = plugin.addToMainMenu

    function plugin:addToMainMenu(menu_items)
        orig_CoverBrowser_addToMainMenu(self, menu_items)
        if menu_items.filebrowser_settings == nil then return end

        local item = getMenuItem(menu_items.filebrowser_settings, _("Mosaic and detailed list settings"))
        if item then
            item.sub_item_table[#item.sub_item_table].separator = true
            for i, setting in pairs(settings) do
                if not getMenuItem(menu_items.filebrowser_settings, _("Mosaic and detailed list settings"), setting.text) then
                    table.insert(item.sub_item_table, {
                        text = setting.text,
                        checked_func = function() return setting.get() end,
                        callback = function()
                            setting.toggle()
                            self.ui.file_chooser:updateItems()
                        end,
                    })
                end
            end
        end
    end
end

userpatch.registerPatchPluginFunc("coverbrowser", patchCoverBrowser)