local ConfirmBox = require("ui/widget/confirmbox")
local DataStorage = require("datastorage")
local Device = require("device")
local Event = require("ui/event")
local InfoMessage = require("ui/widget/infomessage")
local InputDialog = require("ui/widget/inputdialog")
local LuaSettings = require("luasettings")
local Math = require("optmath")
local NetworkMgr = require("ui/network/manager")
local SpinWidget = require("ui/widget/spinwidget")
local UIManager = require("ui/uimanager")
local WidgetContainer = require("ui/widget/container/widgetcontainer")
local json = require("json")
local logger = require("logger")
local sha2 = require("ffi/sha2")
local time = require("ui/time")
local util = require("util")
local T = require("ffi/util").template
local _ = require("gettext")

local BookhoardAPI = require("BookhoardAPI")

local SYNC_STRATEGY = {
    PROMPT = 1,
    SILENT = 2,
    DISABLE = 3,
}

local SYNC_MODE = {
    IMMEDIATE = "immediate",
    CHECKPOINT = "checkpoint",
}

local API_CALL_DEBOUNCE_DELAY = time.s(25)
local PERIODIC_PUSH_DELAY = 10

local sha256hex = sha2.sha256hex or sha2.sha256

local Bookhoard = WidgetContainer:extend({
    name = "bookhoard",
    is_doc_only = false,
    title = _("Bookhoard Server"),
    settings_key = "bookhoard",

    push_timestamp = nil,
    pull_timestamp = nil,
    page_update_counter = nil,
    last_page = nil,
    periodic_push_task = nil,
    periodic_push_scheduled = nil,
    registration_poll_scheduled = nil,

    settings = nil,
})

Bookhoard.default_settings = {
    server_url = nil,
    auth_token = nil,
    device_id = nil,
    auto_sync = false,
    pages_before_update = 50,
    sync_forward = SYNC_STRATEGY.PROMPT,
    sync_backward = SYNC_STRATEGY.DISABLE,
    sync_progress = true,
    sync_bookmarks = true,
    sync_highlights = true,
    sync_notes = true,
    sync_mode = SYNC_MODE.IMMEDIATE,
    sync_endpoints = nil,
}

function Bookhoard:init()
    self.push_timestamp = 0
    self.pull_timestamp = 0
    self.page_update_counter = 0
    self.last_page = -1
    self.periodic_push_scheduled = false
    self.registration_poll_scheduled = false

    self.periodic_push_task = function()
        self.periodic_push_scheduled = false
        self.page_update_counter = 0
        self:updateProgress(false, false)
    end

    self.settings = G_reader_settings:readSetting(self.settings_key, self.default_settings)

    if self.settings.auto_sync
        and Device:hasSeamlessWifiToggle()
        and G_reader_settings:readSetting("wifi_enable_action") ~= "turn_on" then
        self.settings.auto_sync = false
        logger.warn("Bookhoard: auto-sync disabled because wifi_enable_action is not turn_on")
    end

    self.ui.menu:registerToMainMenu(self)
end

function Bookhoard:onReaderReady()
    if self.settings.auto_sync then
        UIManager:nextTick(function()
            self:getProgress(true, false)
        end)
    end
    self:registerEvents()
    self.last_page = self.ui:getCurrentPage()
end

function Bookhoard:registerEvents()
    if self.settings.auto_sync then
        self.onCloseDocument = self._onCloseDocument
        self.onPageUpdate = self._onPageUpdate
        self.onResume = self._onResume
        self.onSuspend = self._onSuspend
        self.onNetworkConnected = self._onNetworkConnected
        self.onNetworkDisconnecting = self._onNetworkDisconnecting
    else
        self.onCloseDocument = nil
        self.onPageUpdate = nil
        self.onResume = nil
        self.onSuspend = nil
        self.onNetworkConnected = nil
        self.onNetworkDisconnecting = nil
    end
end

function Bookhoard:getAPI()
    return BookhoardAPI:new({
        server_url = self.settings.server_url,
        auth_token = self.settings.auth_token,
    })
end

function Bookhoard:isConfigured()
    return self.settings.server_url and self.settings.auth_token
end

function Bookhoard:getSyncPeriod()
    if not self.settings.auto_sync then
        return _("Not available")
    end
    local period = self.settings.pages_before_update
    if period and period > 0 then
        return period
    end
    return _("Never")
end

function Bookhoard:addToMainMenu(menu_items)
    menu_items.bookhoard_sync = {
        text = _("Bookhoard sync"),
        sorting_hint = "tools",
        sub_item_table = self:buildMainMenu(),
    }
end

function Bookhoard:buildMainMenu()
    local items = {}

    table.insert(items, {
        text = _("Server URL"),
        keep_menu_open = true,
        tap_input_func = function()
            return {
                title = _("Bookhoard server URL"),
                input = self.settings.server_url or "http://",
                callback = function(input)
                    self.settings.server_url = input ~= "" and input or nil
                    G_reader_settings:saveSetting(self.settings_key, self.settings)
                end,
            }
        end,
    })

    if self:isConfigured() then
        table.insert(items, {
            text = _("Device info"),
            keep_menu_open = true,
            callback = function()
                UIManager:show(InfoMessage:new{
                    text = T(_("Device ID: %1\nServer: %2"),
                        self.settings.device_id or _("unknown"),
                        self.settings.server_url),
                })
            end,
        })
        table.insert(items, {
            text = _("Disconnect"),
            keep_menu_open = true,
            callback = function()
                UIManager:show(ConfirmBox:new{
                    text = _("Disconnect from Bookhoard server?"),
                    ok_text = _("Disconnect"),
                    ok_callback = function()
                        self.settings.auth_token = nil
                        self.settings.device_id = nil
                        self.settings.sync_endpoints = nil
                        self.settings.auto_sync = false
                        G_reader_settings:saveSetting(self.settings_key, self.settings)
                        self:registerEvents()
                        UIManager:askForRestart()
                    end,
                })
            end,
            separator = true,
        })
    else
        table.insert(items, {
            text = _("Register device"),
            keep_menu_open = true,
            callback = function()
                self:startRegistration()
            end,
            separator = true,
        })
    end

    table.insert(items, {
        text = _("Automatically keep documents in sync"),
        checked_func = function() return self.settings.auto_sync end,
        help_text = _([[This may lead to prompts about toggling WiFi on document close and suspend/resume, depending on your device's connectivity.]]),
        callback = function()
            self:toggleAutoSync()
        end,
    })

    table.insert(items, {
        text_func = function()
            return T(_("Periodically sync every # pages (%1)"), self:getSyncPeriod())
        end,
        enabled_func = function() return self.settings.auto_sync end,
        keep_menu_open = true,
        callback = function(touchmenu_instance)
            local spin = SpinWidget:new{
                text = _([[Number of page turns between progress updates. Set to 0 to disable.]]),
                value = self.settings.pages_before_update or 0,
                value_min = 0,
                value_max = 999,
                value_step = 1,
                value_hold_step = 10,
                ok_text = _("Set"),
                title_text = _("Pages before update"),
                default_value = 50,
                callback = function(spin)
                    self.settings.pages_before_update = spin.value > 0 and spin.value or nil
                    G_reader_settings:saveSetting(self.settings_key, self.settings)
                    if touchmenu_instance then touchmenu_instance:updateItems() end
                end,
            }
            UIManager:show(spin)
        end,
    })

    table.insert(items, {
        text_func = function()
            return T(_("Sync mode (%1)"),
                self.settings.sync_mode == SYNC_MODE.IMMEDIATE and _("immediate") or _("checkpoint"))
        end,
        sub_item_table = {
            {
                text = _("Immediate"),
                checked_func = function()
                    return self.settings.sync_mode == SYNC_MODE.IMMEDIATE
                end,
                callback = function()
                    self.settings.sync_mode = SYNC_MODE.IMMEDIATE
                    G_reader_settings:saveSetting(self.settings_key, self.settings)
                end,
            },
            {
                text = _("Checkpoint"),
                checked_func = function()
                    return self.settings.sync_mode == SYNC_MODE.CHECKPOINT
                end,
                callback = function()
                    self.settings.sync_mode = SYNC_MODE.CHECKPOINT
                    G_reader_settings:saveSetting(self.settings_key, self.settings)
                end,
            },
        },
        separator = true,
    })

    table.insert(items, {
        text = _("Sync behavior"),
        sub_item_table = {
            {
                text_func = function()
                    return T(_("Sync to a newer state (%1)"),
                        self:getStrategyName(self.settings.sync_forward))
                end,
                sub_item_table = {
                    {
                        text = _("Silently"),
                        checked_func = function()
                            return self.settings.sync_forward == SYNC_STRATEGY.SILENT
                        end,
                        callback = function()
                            self.settings.sync_forward = SYNC_STRATEGY.SILENT
                            G_reader_settings:saveSetting(self.settings_key, self.settings)
                        end,
                    },
                    {
                        text = _("Prompt"),
                        checked_func = function()
                            return self.settings.sync_forward == SYNC_STRATEGY.PROMPT
                        end,
                        callback = function()
                            self.settings.sync_forward = SYNC_STRATEGY.PROMPT
                            G_reader_settings:saveSetting(self.settings_key, self.settings)
                        end,
                    },
                    {
                        text = _("Never"),
                        checked_func = function()
                            return self.settings.sync_forward == SYNC_STRATEGY.DISABLE
                        end,
                        callback = function()
                            self.settings.sync_forward = SYNC_STRATEGY.DISABLE
                            G_reader_settings:saveSetting(self.settings_key, self.settings)
                        end,
                    },
                },
            },
            {
                text_func = function()
                    return T(_("Sync to an older state (%1)"),
                        self:getStrategyName(self.settings.sync_backward))
                end,
                sub_item_table = {
                    {
                        text = _("Silently"),
                        checked_func = function()
                            return self.settings.sync_backward == SYNC_STRATEGY.SILENT
                        end,
                        callback = function()
                            self.settings.sync_backward = SYNC_STRATEGY.SILENT
                            G_reader_settings:saveSetting(self.settings_key, self.settings)
                        end,
                    },
                    {
                        text = _("Prompt"),
                        checked_func = function()
                            return self.settings.sync_backward == SYNC_STRATEGY.PROMPT
                        end,
                        callback = function()
                            self.settings.sync_backward = SYNC_STRATEGY.PROMPT
                            G_reader_settings:saveSetting(self.settings_key, self.settings)
                        end,
                    },
                    {
                        text = _("Never"),
                        checked_func = function()
                            return self.settings.sync_backward == SYNC_STRATEGY.DISABLE
                        end,
                        callback = function()
                            self.settings.sync_backward = SYNC_STRATEGY.DISABLE
                            G_reader_settings:saveSetting(self.settings_key, self.settings)
                        end,
                    },
                },
            },
        },
        separator = true,
    })

    table.insert(items, {
        text = _("What to sync"),
        sub_item_table = {
            {
                text = _("Reading progress"),
                checked_func = function() return self.settings.sync_progress end,
                callback = function()
                    self.settings.sync_progress = not self.settings.sync_progress
                    G_reader_settings:saveSetting(self.settings_key, self.settings)
                end,
            },
            {
                text = _("Bookmarks"),
                checked_func = function() return self.settings.sync_bookmarks end,
                callback = function()
                    self.settings.sync_bookmarks = not self.settings.sync_bookmarks
                    G_reader_settings:saveSetting(self.settings_key, self.settings)
                end,
            },
            {
                text = _("Highlights"),
                checked_func = function() return self.settings.sync_highlights end,
                callback = function()
                    self.settings.sync_highlights = not self.settings.sync_highlights
                    G_reader_settings:saveSetting(self.settings_key, self.settings)
                end,
            },
            {
                text = _("Notes"),
                checked_func = function() return self.settings.sync_notes end,
                callback = function()
                    self.settings.sync_notes = not self.settings.sync_notes
                    G_reader_settings:saveSetting(self.settings_key, self.settings)
                end,
            },
        },
        separator = true,
    })

    table.insert(items, {
        text = _("Sync now"),
        enabled_func = function() return self:isConfigured() end,
        callback = function()
            self:updateProgress(true, true)
            self:getProgress(true, true)
        end,
    })

    table.insert(items, {
        text = _("Push progress from this device"),
        enabled_func = function() return self:isConfigured() end,
        callback = function()
            self:updateProgress(true, true)
        end,
    })

    table.insert(items, {
        text = _("Pull progress from server"),
        enabled_func = function() return self:isConfigured() end,
        callback = function()
            self:getProgress(true, true)
        end,
        separator = true,
    })

    table.insert(items, {
        text = _("Setup OPDS catalog"),
        keep_menu_open = true,
        enabled_func = function() return self:isConfigured() end,
        callback = function()
            if self:setupOPDS() then
                UIManager:show(InfoMessage:new{
                    text = _("Bookhoard OPDS catalog added! Find it in Home → OPDS Catalog."),
                    timeout = 3,
                })
            else
                UIManager:show(InfoMessage:new{
                    text = _("Please configure and register your device first."),
                    timeout = 3,
                })
            end
        end,
    })

    return items
end

function Bookhoard:getStrategyName(strategy)
    if strategy == SYNC_STRATEGY.PROMPT then
        return _("Prompt")
    elseif strategy == SYNC_STRATEGY.SILENT then
        return _("Auto")
    else
        return _("Disable")
    end
end

function Bookhoard:toggleAutoSync()
    if not self.settings.auto_sync
        and Device:hasSeamlessWifiToggle()
        and G_reader_settings:readSetting("wifi_enable_action") ~= "turn_on" then
        UIManager:show(InfoMessage:new{
            text = _("Set 'Action when Wi-Fi is off' to 'turn on' in Network settings to enable auto sync."),
        })
        return
    end
    self.settings.auto_sync = not self.settings.auto_sync
    self:registerEvents()
    G_reader_settings:saveSetting(self.settings_key, self.settings)

    if self.settings.auto_sync and self.ui.doc_settings then
        self:getProgress(true, true)
    end
end

function Bookhoard:startRegistration()
    if not self.settings.server_url or self.settings.server_url == "" then
        UIManager:show(InfoMessage:new{
            text = _("Please set your server URL first."),
            timeout = 3,
        })
        return
    end

    if NetworkMgr:willRerunWhenOnline(function() self:startRegistration() end) then
        return
    end

    local device_name = Device.model or "KOReader Device"
    local device_identifier = Device:info() or device_name

    UIManager:show(InfoMessage:new{
        text = _("Registering device…"),
        timeout = 1,
    })

    UIManager:scheduleIn(0.5, function()
        local api = BookhoardAPI:new({ server_url = self.settings.server_url })
        local ok, result = api:registerDevice(device_name, device_identifier)

        if not ok then
            UIManager:show(InfoMessage:new{
                text = T(_("Registration failed: %1"),
                    result and result.error or _("unknown error")),
            })
            return
        end

        self.registration_id = result.registration_id

        self.waiting_dialog = InfoMessage:new{
            text = T(_("Device registered on server.\n\nOpen your Bookhoard web UI and go to:\n%1/devices\n\nApprove this device in the \"Pending Device Registrations\" section.\n\nWaiting for approval…"), self.settings.server_url),
        }
        UIManager:show(self.waiting_dialog)

        self:startRegistrationPoll()
    end)
end

function Bookhoard:startRegistrationPoll()
    if self.registration_poll_scheduled then return end
    self.registration_poll_scheduled = true

    local function poll()
        self.registration_poll_scheduled = false

        if not self.registration_id then return end

        local api = BookhoardAPI:new({ server_url = self.settings.server_url })
        local ok, result = api:checkRegistrationStatus(self.registration_id)

        if not ok then
            if result and result.status == 410 then
                self.registration_id = nil
                UIManager:show(InfoMessage:new{
                    text = _("Registration expired. Please try again."),
                })
                return
            end
            self.registration_poll_scheduled = true
            UIManager:scheduleIn(3, poll)
            return
        end

        if result.status == "approved" then
            self.registration_id = nil
            self.settings.auth_token = result.auth_token
            self.settings.device_id = result.device_id and tostring(result.device_id) or nil
            self.settings.sync_endpoints = result.sync_endpoints
            G_reader_settings:saveSetting(self.settings_key, self.settings)
            self:registerEvents()
            self:setupOPDS()
            if self.waiting_dialog then
                UIManager:close(self.waiting_dialog)
                self.waiting_dialog = nil
            end
            UIManager:show(InfoMessage:new{
                text = _("Device registered successfully!"),
                timeout = 3,
            })
        elseif result.status == "pending" then
            self.registration_poll_scheduled = true
            UIManager:scheduleIn(3, poll)
        else
            self.registration_id = nil
            UIManager:show(InfoMessage:new{
                text = T(_("Registration %1"), result.status or _("failed")),
            })
        end
    end

    UIManager:scheduleIn(3, poll)
end

function Bookhoard:setupOPDS()
    if not self.settings.server_url or not self.settings.device_id
        or not self.settings.auth_token then
        return false
    end

    local opds_base_url = self.settings.server_url
        .. "/opds/devices/" .. self.settings.device_id .. "/catalog"
    local opds_url = opds_base_url .. "?token=" .. self.settings.auth_token

    local opds_settings_file = DataStorage:getSettingsDir() .. "/opds.lua"
    local opds_settings = LuaSettings:open(opds_settings_file)
    local servers = opds_settings:readSetting("servers", {})

    local found = false
    for i, server in ipairs(servers) do
        if server.url and (
            server.url == opds_url
            or server.url == opds_base_url
            or server.url:sub(1, #opds_base_url + 1) == opds_base_url .. "?"
        ) then
            servers[i] = {
                title = "Bookhoard",
                url = opds_url,
            }
            found = true
            break
        end
    end

    if not found then
        table.insert(servers, {
            title = "Bookhoard",
            url = opds_url,
        })
    end

    opds_settings:saveSetting("servers", servers)
    opds_settings:flush()

    if self.ui.opds then
        self.ui.opds.servers = servers
    end

    return true
end

function Bookhoard:getLastPercent()
    if self.ui.document.info.has_pages then
        return Math.roundPercent(self.ui.paging:getLastPercent())
    else
        return Math.roundPercent(self.ui.rolling:getLastPercent())
    end
end

function Bookhoard:getLastProgress()
    if self.ui.document.info.has_pages then
        return self.ui.paging:getLastProgress()
    else
        return self.ui.rolling:getLastProgress()
    end
end

function Bookhoard:getFileSHA256()
    local cached = self.ui.doc_settings:readSetting("bookhoard_sha256")
    if cached then return cached end

    local file = io.open(self.ui.document.file, "rb")
    if not file then return nil end
    local data = file:read("*a")
    file:close()

    local hash = sha256hex(data)
    if hash then
        self.ui.doc_settings:saveSetting("bookhoard_sha256", hash)
    end
    return hash
end

function Bookhoard:getBookhoardUUID()
    if not self.ui.doc_settings then return nil end
    return self.ui.doc_settings:readSetting("bookhoard_uuid")
end

function Bookhoard:collectBookData()
    local props = self.ui.doc_props
    local file_path = self.ui.document.file

    local title = props.display_title or ""
    local authors = {}
    if props.authors then
        authors = { props.authors }
    end

    local file_sha256 = self:getFileSHA256()
    local book_uuid = self:getBookhoardUUID()

    local percentage = self:getLastPercent()
    local progress = self:getLastProgress()
    local page = self.ui:getCurrentPage()
    local total_pages = self.ui.document:getPageCount()

    local book_data = {
        uuid = book_uuid,
        sha256 = file_sha256,
        title = title,
        authors = authors,
        percentage = percentage,
        epubcfi = progress,
        page = page,
        total_pages = total_pages,
        file_path = file_path,
        device_info = {
            koreader_version = require("version"):getCurrentRevision(),
            device_model = Device.model,
        },
    }

    return book_data
end

function Bookhoard:collectAnnotations()
    local bookmarks = {}
    local highlights = {}
    local notes = {}

    if not self.ui.bookmark then
        return bookmarks, highlights, notes
    end

    local all_bookmarks = self.ui.bookmark.bookmarks
    if not all_bookmarks then
        return bookmarks, highlights, notes
    end

    local file_sha256 = self:getFileSHA256()
    local total_pages = self.ui.document:getPageCount()

    for _, bm in ipairs(all_bookmarks) do
        local page_num = bm.page
        if type(page_num) == "string" and self.ui.document.info.has_pages == false then
            page_num = self.ui.document:getPageFromXPointer(page_num)
        end
        page_num = tonumber(page_num) or 0

        local percentage = total_pages > 0 and (page_num / total_pages) or 0
        local chapter = bm.chapter or ""

        local entry = {
            chapter = chapter,
            datetime = bm.datetime or "",
            notes = bm.notes or "",
            pos0 = bm.pos0 or "",
            pos1 = bm.pos1 or "",
            page = tostring(bm.page or ""),
            text = bm.text or "",
            percentage = Math.roundPercent(percentage),
            book_sha256 = file_sha256,
        }

        local has_text = bm.text and bm.text ~= ""
        local has_notes = bm.notes and bm.notes ~= ""

        if has_text and has_notes then
            entry.type = "note"
            table.insert(notes, entry)
        elseif has_text then
            entry.type = "highlight"
            if bm.color then
                entry.color = bm.color
            end
            table.insert(highlights, entry)
        else
            entry.type = "bookmark"
            table.insert(bookmarks, entry)
        end
    end

    return bookmarks, highlights, notes
end

function Bookhoard:syncToProgress(progress, percentage)
    logger.dbg("Bookhoard: sync to progress", progress, percentage)
    if self.ui.document.info.has_pages then
        self.ui:handleEvent(Event:new("GotoPage", tonumber(progress)))
    else
        self.ui:handleEvent(Event:new("GotoXPointer", progress))
    end
end

function Bookhoard:updateProgress(ensure_networking, interactive)
    if not self:isConfigured() then
        if interactive then
            UIManager:show(InfoMessage:new{
                text = _("Please configure and register your device first."),
                timeout = 3,
            })
        end
        return
    end

    if not self.settings.sync_progress then return end

    local now = UIManager:getElapsedTimeSinceBoot()
    if not interactive and now - self.push_timestamp <= API_CALL_DEBOUNCE_DELAY then
        return
    end

    if ensure_networking
        and NetworkMgr:willRerunWhenOnline(function() self:updateProgress(ensure_networking, interactive) end) then
        return
    end

    UIManager:scheduleIn(0.5, function()
        self:_doUpdateProgress(interactive)
    end)

    self.push_timestamp = now
end

function Bookhoard:_doUpdateProgress(interactive)
    local book_data = self:collectBookData()
    if not book_data then return end

    if self.settings.sync_bookmarks or self.settings.sync_highlights or self.settings.sync_notes then
        local bm, hl, nt = self:collectAnnotations()
        book_data.bookmarks = self.settings.sync_bookmarks and bm or {}
        book_data.highlights = self.settings.sync_highlights and hl or {}
        book_data.notes = self.settings.sync_notes and nt or {}
    else
        book_data.bookmarks = {}
        book_data.highlights = {}
        book_data.notes = {}
    end

    local api = self:getAPI()
    local ok, result = api:syncProgress(book_data, self.settings.sync_mode)

    UIManager:nextTick(function()
        if ok then
            logger.dbg("Bookhoard: progress pushed successfully")
            if result and result.device_updated and result.device_updated.uuid then
                self.ui.doc_settings:saveSetting("bookhoard_uuid", result.device_updated.uuid)
                self.ui.doc_settings:flush()
            end
            if interactive then
                UIManager:show(InfoMessage:new{
                    text = _("Progress has been pushed."),
                    timeout = 3,
                })
            end
        else
            logger.warn("Bookhoard: failed to push progress")
            if interactive then
                UIManager:show(InfoMessage:new{
                    text = _("Failed to push progress. Check your network connection."),
                    timeout = 3,
                })
            end
        end
    end)
end

function Bookhoard:getProgress(ensure_networking, interactive)
    if not self:isConfigured() then
        if interactive then
            UIManager:show(InfoMessage:new{
                text = _("Please configure and register your device first."),
                timeout = 3,
            })
        end
        return
    end

    if not self.settings.sync_progress then return end

    local now = UIManager:getElapsedTimeSinceBoot()
    if not interactive and now - self.pull_timestamp <= API_CALL_DEBOUNCE_DELAY then
        return
    end

    if ensure_networking
        and NetworkMgr:willRerunWhenOnline(function() self:getProgress(ensure_networking, interactive) end) then
        return
    end

    local book_uuid = self:getBookhoardUUID()
    if not book_uuid then
        if interactive then
            UIManager:show(InfoMessage:new{
                text = _("No Bookhoard UUID for this document. Push progress first."),
                timeout = 3,
            })
        end
        return
    end

    UIManager:scheduleIn(0.5, function()
        self:_doGetProgress(interactive)
    end)

    self.pull_timestamp = now
end

function Bookhoard:_doGetProgress(interactive)
    local book_uuid = self:getBookhoardUUID()
    if not book_uuid then return end

    local api = self:getAPI()
    local ok, result = api:getMetadata(book_uuid)

    UIManager:nextTick(function()
        if not ok or not result then
            if interactive then
                UIManager:show(InfoMessage:new{
                    text = _("Failed to pull progress."),
                    timeout = 3,
                })
            end
            return
        end

        if not result.progress then
            if interactive then
                UIManager:show(InfoMessage:new{
                    text = _("No progress found for this document."),
                    timeout = 3,
                })
            end
            return
        end

        local progress = result.progress
        local percentage = self:getLastPercent()
        local server_percentage = progress.percentage or 0

        if percentage == server_percentage then
            if interactive then
                UIManager:show(InfoMessage:new{
                    text = _("Progress is already synchronized."),
                    timeout = 3,
                })
            end
            return
        end

        local self_older = server_percentage > percentage

        if self_older then
            if self.settings.sync_forward == SYNC_STRATEGY.SILENT then
                self:syncToProgress(progress.epubcfi or progress.page, server_percentage)
                self:_showSyncedMessage()
            elseif self.settings.sync_forward == SYNC_STRATEGY.PROMPT then
                UIManager:show(ConfirmBox:new{
                    text = T(_("Sync to newer location %1%% from server?"),
                        Math.round(server_percentage * 100)),
                    ok_callback = function()
                        self:syncToProgress(progress.epubcfi or progress.page, server_percentage)
                    end,
                })
            end
        else
            if self.settings.sync_backward == SYNC_STRATEGY.SILENT then
                self:syncToProgress(progress.epubcfi or progress.page, server_percentage)
                self:_showSyncedMessage()
            elseif self.settings.sync_backward == SYNC_STRATEGY.PROMPT then
                UIManager:show(ConfirmBox:new{
                    text = T(_("Sync to previous location %1%% from server?"),
                        Math.round(server_percentage * 100)),
                    ok_callback = function()
                        self:syncToProgress(progress.epubcfi or progress.page, server_percentage)
                    end,
                })
            end
        end
    end)
end

function Bookhoard:_showSyncedMessage()
    UIManager:show(InfoMessage:new{
        text = _("Progress has been synchronized."),
        timeout = 3,
    })
end

function Bookhoard:_onCloseDocument()
    self.onResume = nil
    self.onSuspend = nil
    NetworkMgr:goOnlineToRun(function()
        self:updateProgress(false, false)
    end)
end

function Bookhoard:schedulePeriodicPush()
    UIManager:unschedule(self.periodic_push_task)
    UIManager:scheduleIn(PERIODIC_PUSH_DELAY, self.periodic_push_task)
    self.periodic_push_scheduled = true
end

function Bookhoard:_onPageUpdate(page)
    if page == nil then return end

    if self.last_page ~= page then
        self.last_page = page
        self.page_update_counter = self.page_update_counter + 1
        if self.periodic_push_scheduled
            or (self.settings.pages_before_update
                and self.page_update_counter >= self.settings.pages_before_update) then
            self:schedulePeriodicPush()
        end
    end
end

function Bookhoard:_onResume()
    if Device:hasWifiRestore() and NetworkMgr.wifi_was_on
        and G_reader_settings:isTrue("auto_restore_wifi") then
        return
    end
    UIManager:scheduleIn(1, function()
        self:getProgress(true, false)
    end)
end

function Bookhoard:_onSuspend()
    self:updateProgress(true, false)
end

function Bookhoard:_onNetworkConnected()
    UIManager:scheduleIn(0.5, function()
        self:getProgress(false, false)
    end)
end

function Bookhoard:_onNetworkDisconnecting()
    self:updateProgress(false, false)
end

function Bookhoard:onCloseWidget()
    UIManager:unschedule(self.periodic_push_task)
    self.periodic_push_task = nil
end

return Bookhoard