local InputContainer = require("ui/widget/container/inputcontainer")
local LoginDialog = require("ui/widget/logindialog")
local InfoMessage = require("ui/widget/infomessage")
local NetworkMgr = require("ui/networkmgr")
local DataStorage = require("datastorage")
local DocSettings = require("docsettings")
local UIManager = require("ui/uimanager")
local Screen = require("device").screen
local Event = require("ui/event")
local DEBUG = require("dbg")
local T = require("ffi/util").template
local _ = require("gettext")
local slt2 = require('slt2')
local MyClipping = require("clip")

local EvernoteExporter = InputContainer:new{
    name = "evernote",
    login_title = _("Login to Evernote"),
    notebook_name = _("Koreader Notes"),
    evernote_domain = nil,
    notemarks = _("Note: "),
    clipping_dir = DataStorage:getDataDir() .. "/clipboard",

    evernote_token,
    notebook_guid,
}

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

    local settings = G_reader_settings:readSetting("evernote") or {}
    self.evernote_domain = settings.domain
    self.evernote_username = settings.username or ""
    self.evernote_token = settings.token
    self.notebook_guid = settings.notebook
    self.html_export = settings.html_export or false

    self.parser = MyClipping:new{
        my_clippings = "/mnt/us/documents/My Clippings.txt",
        history_dir = "./history",
    }
    self.template = slt2.loadfile(self.path.."/note.tpl")
    self.config = DocSettings:open(self.path)
end

function EvernoteExporter:addToMainMenu(tab_item_table)
    table.insert(tab_item_table.plugins, {
        text = _("Evernote"),
        sub_item_table = {
            {
                text_func = function()
                    local domain = nil
                    if self.evernote_domain == "sandbox" then
                        domain = "Sandbox"
                    elseif self.evernote_domain == "yinxiang" then
                        domain = "Yinxiang"
                    else
                        domain = "Evernote"
                    end
                    return self.evernote_token and (_("Logout") .. " " .. domain)
                            or _("Login")
                end,
                callback_func = function()
                    return self.evernote_token and function() self:logout() end
                            or nil
                end,
                sub_item_table_func = function()
                    return not self.evernote_token and {
                        {
                            text = "Evernote",
                            callback = function()
                                self.evernote_domain = nil
                                self:login()
                            end
                        },
                        {
                            text = "印象笔记",
                            callback = function()
                                self.evernote_domain = "yinxiang"
                                self:login()
                            end
                        }
                    } or nil
                end,
            },
            {
                text = _("Export all notes in this book"),
                enabled_func = function()
                    return self.evernote_token ~= nil or self.html_export ~= false
                end,
                callback = function()
                    UIManager:scheduleIn(0.5, function()
                        self:exportCurrentNotes(self.view)
                    end)

                    UIManager:show(InfoMessage:new{
                        text = _("Exporting may take several seconds..."),
                        timeout = 1,
                    })
                end
            },
            {
                text = _("Export all notes in your library"),
                enabled_func = function()
                    return self.evernote_token ~= nil or self.html_export ~= false
                end,
                callback = function()
                    UIManager:scheduleIn(0.5, function()
                        self:exportAllNotes()
                    end)

                    UIManager:show(InfoMessage:new{
                        text = _("Exporting may take several minutes..."),
                        timeout = 1,
                    })
                end
            },
            {
                text = _("Export to local HTML files"),
                checked_func = function() return self.html_export end,
                callback = function()
                    self.html_export = not self.html_export
                end
            },
        }
    })
end

function EvernoteExporter:login()
    if NetworkMgr:getWifiStatus() == false then
        NetworkMgr:promptWifiOn()
    end
    self.login_dialog = LoginDialog:new{
        title = self.login_title,
        username = self.evernote_username or "",
        buttons = {
            {
                {
                    text = _("Cancel"),
                    enabled = true,
                    callback = function()
                        self:closeDialog()
                    end,
                },
                {
                    text = _("Login"),
                    enabled = true,
                    callback = function()
                        local username, password = self:getCredential()
                        self:closeDialog()
                        UIManager:scheduleIn(0.5, function()
                            self:doLogin(username, password)
                        end)

                        UIManager:show(InfoMessage:new{
                            text = _("Logging in. Please wait..."),
                            timeout = 1,
                        })
                    end,
                },
            },
        },
        width = Screen:getWidth() * 0.8,
        height = Screen:getHeight() * 0.4,
    }

    self.login_dialog:onShowKeyboard()
    UIManager:show(self.login_dialog)
end

function EvernoteExporter:closeDialog()
    self.login_dialog:onClose()
    UIManager:close(self.login_dialog)
end

function EvernoteExporter:getCredential()
    return self.login_dialog:getCredential()
end

function EvernoteExporter:doLogin(username, password)
    local EvernoteOAuth = require("EvernoteOAuth")
    local EvernoteClient = require("EvernoteClient")

    local oauth = EvernoteOAuth:new{
        domain = self.evernote_domain,
        username = username,
        password = password,
    }
    self.evernote_username = username
    local ok, token = pcall(oauth.getToken, oauth)
    -- prompt users to turn on Wifi if network is unreachable
    if not ok and token then
        UIManager:show(InfoMessage:new{
            text = _("An error occurred while logging in:") .. "\n" .. token,
        })
        return
    end

    local client = EvernoteClient:new{
        domain = self.evernote_domain,
        authToken = token,
    }
    local ok, guid = pcall(self.getExportNotebook, self, client)
    if not ok and guid and guid:find("Transport not open") then
        NetworkMgr:promptWifiOn()
        return
    elseif not ok and guid then
        UIManager:show(InfoMessage:new{
            text = _("An error occurred while logging in:") .. "\n" .. guid,
        })
    elseif ok and guid then
        self.evernote_token = token
        self.notebook_guid = guid
        UIManager:show(InfoMessage:new{
            text = _("Logged in to Evernote successfully."),
        })
    end

    self:onSaveSettings()
end

function EvernoteExporter:logout()
    self.evernote_token = nil
    self.notebook_guid = nil
    self.evernote_domain = nil
    self:onSaveSettings()
end

function EvernoteExporter:onSaveSettings()
    local settings = {
        domain = self.evernote_domain,
        username = self.evernote_username,
        token = self.evernote_token,
        notebook = self.notebook_guid,
        html_export = self.html_export,
    }
    G_reader_settings:saveSetting("evernote", settings)
end

function EvernoteExporter:getExportNotebook(client)
    local name = self.notebook_name
    return client:findNotebookByTitle(name) or client:createNotebook(name).guid
end

function EvernoteExporter:exportCurrentNotes(view)
    local clippings = self.parser:parseCurrentDoc(view)
    self:exportClippings(clippings)
end

function EvernoteExporter:updateHistoryClippings(clippings, new_clippings)
    -- update clippings from history clippings
    for title, booknotes in pairs(new_clippings) do
        for chapter_index, chapternotes in ipairs(booknotes) do
            for note_index, note in ipairs(chapternotes) do
                if clippings[title] == nil or clippings[title][chapter_index] == nil
                    or clippings[title][chapter_index][note_index] == nil
                    or clippings[title][chapter_index][note_index].page ~= note.page
                    or clippings[title][chapter_index][note_index].time ~= note.time
                    or clippings[title][chapter_index][note_index].text ~= note.text
                    or clippings[title][chapter_index][note_index].note ~= note.note then
                    DEBUG("found new notes in history", booknotes.title)
                    clippings[title] = booknotes
                end
            end
        end
    end
    return clippings
end

function EvernoteExporter:updateMyClippings(clippings, new_clippings)
    -- only new titles or new notes in My clippings are updated to clippings
    -- since appending is the only way to modify notes in My Clippings
    for title, booknotes in pairs(new_clippings) do
        if clippings[title] == nil or #clippings[title] < #booknotes then
            DEBUG("found new notes in MyClipping", booknotes.title)
            clippings[title] = booknotes
        end
    end
    return clippings
end

function EvernoteExporter:exportAllNotes()
    local clippings = self.config:readSetting("clippings") or {}
    clippings = self:updateHistoryClippings(clippings, self.parser:parseHistory())
    clippings = self:updateMyClippings(clippings, self.parser:parseMyClippings())
    -- remove blank entries
    for title, booknotes in pairs(clippings) do
        -- chapter number is zero
        if #booknotes == 0 then
            clippings[title] = nil
        end
    end
    --DEBUG("clippings", clippings)
    self:exportClippings(clippings)
    self.config:saveSetting("clippings", clippings)
    self.config:flush()
end

function EvernoteExporter:exportClippings(clippings)
    local client = nil
    local exported_stamp = "html"
    if not self.html_export then
        client = require("EvernoteClient"):new{
            domain = self.evernote_domain,
            authToken = self.evernote_token,
        }
        exported_stamp = self.notebook_guid
    end

    local export_count, error_count = 0, 0
    local export_title, error_title
    for title, booknotes in pairs(clippings) do
        if type(booknotes.exported) ~= "table" then
            booknotes.exported = {}
        end
        -- check if booknotes are exported in this notebook
        -- so that booknotes will still be exported after switching user account
        if booknotes.exported[exported_stamp] ~= true then
            local ok, err
            if self.html_export then
                ok, err = pcall(self.exportBooknotesToHTML, self,
                        title, booknotes)
            else
                ok, err = pcall(self.exportBooknotesToEvernote, self,
                        client, title, booknotes)
            end
            -- error reporting
            if not ok and err and err:find("Transport not open") then
                NetworkMgr:promptWifiOn()
                return
            elseif not ok and err then
                DEBUG("Error occurs when exporting book:", title, err)
                error_count = error_count + 1
                error_title = title
            elseif ok then
                DEBUG("Exported notes in book:", title)
                export_count = export_count + 1
                export_title = title
                booknotes.exported[exported_stamp] = true
            end
        end
    end

    local msg = "Nothing was exported."
    local all_count = export_count + error_count
    if export_count > 0 and error_count == 0 then
        if all_count == 1 then
            msg = _("Exported notes from book:") .. "\n" .. export_title
        else
            msg = T(
                _("Exported notes from book:\n%1\nand %2 others."),
                export_title,
                all_count-1
            )
        end
    elseif error_count > 0 then
        if all_count == 1 then
            msg = _("An error occurred while trying to export notes from book:") .. "\n" .. error_title
        else
            msg = T(
                _("Multiple errors occurred while trying to export notes from book:\n%1\nand %2 others."),
                error_title,
                error_count-1
            )
        end
    end
    UIManager:show(InfoMessage:new{ text = msg })
end

function EvernoteExporter:exportBooknotesToEvernote(client, title, booknotes)
    local content = slt2.render(self.template, {
        booknotes = booknotes,
        notemarks = self.notemarks,
    })
    --DEBUG("content", content)
    local note_guid = client:findNoteByTitle(title, self.notebook_guid)
    local resources = {}
    for _, chapter in ipairs(booknotes) do
        for _, clipping in ipairs(chapter) do
            if clipping.image then
                table.insert(resources, {
                    image = clipping.image
                })
                -- nullify clipping image after passing it to evernote client
                clipping.image = nil
            end
        end
    end
    if not note_guid then
        client:createNote(title, content, resources, {}, self.notebook_guid)
    else
        client:updateNote(note_guid, title, content, resources, {}, self.notebook_guid)
    end
end

function EvernoteExporter:exportBooknotesToHTML(title, booknotes)
    local content = slt2.render(self.template, {
        booknotes = booknotes,
        notemarks = self.notemarks,
    })
    --DEBUG("content", content)
    local html = io.open(self.clipping_dir .. "/" .. title .. ".html", "w")
    if html then
        html:write(content)
        html:close()
    end
end

return EvernoteExporter