-- IRC client plugin for KOReader
-- Implements a simple IRC client using LuaSocket.
-- Provides a submenu with Server list & Username, and a basic chat view.

local DataStorage = require("datastorage")
local Dispatcher = require("dispatcher")
local InfoMessage = require("ui/widget/infomessage")
local InputDialog = require("ui/widget/inputdialog")
local LuaSettings = require("luasettings")
local MultiInputDialog = require("ui/widget/multiinputdialog")
local ConfirmBox = require("ui/widget/confirmbox")
local UIManager = require("ui/uimanager")
local WidgetContainer = require("ui/widget/container/widgetcontainer")
local TextViewer = require("ui/widget/textviewer")
local NetworkMgr = require("ui/network/manager")
local socket = require("socket")
local socketutil = require("socketutil")
local _ = require("gettext")
local T = require("ffi/util").template
local lfs = require("libs/libkoreader-lfs")

-- Chat view based on TextViewer for scrollable text & menu buttons
local IrcChatView = TextViewer:extend{
    title = _("IRC Chat"),
    text = "",
    add_default_buttons = true,
    monospace_font = true,
    text_type = "code",
    keep_running = true, -- keep connection alive when UI is closed
    _connected = false,
    _closing = false,
    _receive_task = nil,
    _sock = nil,
    _server = nil, -- {name, host, port}
    _channel = nil, -- optional starting channel
    _nick = nil,
    -- Multi-target buffers
    _buffers = nil,          -- map target => text
    _ordered_targets = nil,  -- ordered list of targets for UI
    _current_target = nil,   -- active target ("*" for server console)
    _server_label = nil,
    _unread = nil,          -- map target => count of unseen messages
    -- History persistence
    _history_dir = nil,
    _history_server_dir = nil,
    _history_preload_lines = 500,
    _ui_open = false,
}

function IrcChatView:init(reinit)
    -- Mark UI as open so append/refresh paths repaint immediately
    self._ui_open = true
    -- Build buttons: first our Send row, then TextViewer's default row
    -- Disable TextViewer's automatic default buttons to avoid duplication
    self.add_default_buttons = false
    local send_row = {
        {
            text = _("Send"),
            callback = function()
                self:promptSendMessage()
            end,
        },
    }
    local default_row = {
        {
            text = _("Find"),
            id = "find",
            callback = function()
                if self._find_next then
                    self:findCallback()
                else
                    self:findDialog()
                end
            end,
            hold_callback = function()
                if self._find_next then
                    self:findDialog()
                else
                    if self.default_hold_callback then
                        self.default_hold_callback()
                    end
                end
            end,
        },
        {
            text = "⇱",
            id = "top",
            callback = function()
                if self.scroll_text_w then self.scroll_text_w:scrollToTop() end
            end,
            hold_callback = self.default_hold_callback,
            allow_hold_when_disabled = true,
        },
        {
            text = "⇲",
            id = "bottom",
            callback = function()
                if self.scroll_text_w then self.scroll_text_w:scrollToBottom() end
            end,
            hold_callback = self.default_hold_callback,
            allow_hold_when_disabled = true,
        },
        {
            text = _("Close"),
            callback = function()
                self:onClose()
            end,
            hold_callback = self.default_hold_callback,
        },
    }
    self.buttons_table = { send_row, default_row }
    -- Buffers & title
    if not reinit then
        self._buffers = {}
        self._ordered_targets = {}
        self._current_target = nil
        self._unread = {}
    end
    if not self._server_label then
        self._server_label = self._server and (self._server.name or (self._server.host .. ":" .. tostring(self._server.port or 6667))) or "IRC"
    end
    if not reinit then
        -- Init history before selecting initial buffer
        self:initHistory()
        -- default to server console target
        self:switchTarget("*")
    end
    -- Restore last active target if available
    local last = self:loadLastTarget()
    if last and last ~= "" then
        self:switchTarget(last)
    end
    self:updateTitle()
    TextViewer.init(self, reinit)
    -- Ensure current buffer content is shown immediately after (re)init
    local tgt = self._current_target or "*"
    self:preloadHistory(tgt)
    if self.scroll_text_w and self.scroll_text_w.text_widget then
        self.scroll_text_w.text_widget:setText(self._buffers[tgt] or "")
        self.scroll_text_w:scrollToBottom()
    end
    -- Start connection after UI init so we can show logs
    UIManager:nextTick(function() self:startConnection() end)
end

-- History helpers
function IrcChatView:sanitizePathPart(part)
    part = part or ""
    part = part:gsub("[^%w%._%-#@]+", "_")
    if part == "" then part = "_" end
    return part
end

function IrcChatView:getServerId()
    -- Stable ID independent of display name
    local host = self._server and (self._server.host or "") or ""
    local port = self._server and tostring(self._server.port or 6667) or "6667"
    local id = string.format("%s_%s", host, port)
    return self:sanitizePathPart(id)
end

function IrcChatView:getLegacyServerId()
    -- Old scheme: name_host_port (used briefly); try loading history from there, if present
    local name = self._server and (self._server.name or "") or ""
    local host = self._server and (self._server.host or "") or ""
    local port = self._server and tostring(self._server.port or 6667) or "6667"
    local id = string.format("%s_%s_%s", name, host, port)
    return self:sanitizePathPart(id)
end

function IrcChatView:initHistory()
    self._history_dir = DataStorage:getDataDir() .. "/irc_logs"
    lfs.mkdir(self._history_dir)
    self._history_server_dir = self._history_dir .. "/" .. self:getServerId()
    lfs.mkdir(self._history_server_dir)
    -- Legacy path support
    self._history_server_dir_legacy = self._history_dir .. "/" .. self:getLegacyServerId()
end

function IrcChatView:getLogPath(target)
    target = target or "*"
    local fname = target == "*" and "console" or self:sanitizePathPart(target)
    return string.format("%s/%s.log", self._history_server_dir, fname)
end

function IrcChatView:getLegacyLogPath(target)
    target = target or "*"
    local fname = target == "*" and "console" or self:sanitizePathPart(target)
    return string.format("%s/%s.log", self._history_server_dir_legacy, fname)
end

function IrcChatView:writeHistory(target, line)
    local path = self:getLogPath(target)
    local f = io.open(path, "a")
    if f then
        f:write(line, "\n")
        f:close()
    end
end

function IrcChatView:saveLastTarget(target)
    local path = string.format("%s/.last", self._history_server_dir)
    local f = io.open(path, "w")
    if f then
        f:write(target or "")
        f:close()
    end
end

function IrcChatView:loadLastTarget()
    local path = string.format("%s/.last", self._history_server_dir)
    local f = io.open(path, "r")
    if not f then return nil end
    local s = f:read("*l")
    f:close()
    return s
end

function IrcChatView:readLastLines(path, max_lines)
    local f = io.open(path, "r")
    if not f then return nil end
    local buf = {}
    local count = 0
    for l in f:lines() do
        table.insert(buf, l)
        count = count + 1
        if count > max_lines then
            table.remove(buf, 1)
            count = count - 1
        end
    end
    f:close()
    if #buf == 0 then return nil end
    return table.concat(buf, "\n")
end

function IrcChatView:preloadHistory(target)
    target = target or self._current_target or "*"
    if self._buffers[target] and #self._buffers[target] > 0 then return end
    local path = self:getLogPath(target)
    local content = self:readLastLines(path, self._history_preload_lines)
    if (not content or #content == 0) and self._history_server_dir_legacy then
        -- Fallback to legacy path if it exists
        local lpath = self:getLegacyLogPath(target)
        content = self:readLastLines(lpath, self._history_preload_lines)
    end
    if content and #content > 0 then
        self._buffers[target] = content
        if target == (self._current_target or "*") and self.scroll_text_w and self.scroll_text_w.text_widget then
            self.scroll_text_w.text_widget:setText(content)
        end
    end
end

function IrcChatView:updateTitle()
    local tgt = self._current_target
    local new_title
    if tgt and tgt ~= "*" then
        new_title = tgt
    else
        new_title = self._server_label
    end
    self.title = new_title
    if self.titlebar and self.titlebar.setTitle then
        self.titlebar:setTitle(new_title)
    end
end

function IrcChatView:ensureBuffer(target)
    target = target or "*"
    if not self._buffers[target] then
        self._buffers[target] = ""
        table.insert(self._ordered_targets, target)
    end
    if self._unread[target] == nil then
        self._unread[target] = 0
    end
    if target:sub(1,1) == "#" then
        self._members = self._members or {}
        if not self._members[target] then
            self._members[target] = {}
        end
    end
end

function IrcChatView:switchTarget(target)
    if not target then return end
    self:ensureBuffer(target)
    -- Preload history (if any) when switching to a buffer
    self:preloadHistory(target)
    self._current_target = target
    self:updateTitle()
    if self.scroll_text_w and self.scroll_text_w.text_widget then
        self.scroll_text_w.text_widget:setText(self._buffers[target] or "")
        self.scroll_text_w:scrollToBottom()
    end
    -- reset unread counter when focusing this target
    self._unread[target] = 0
    -- persist last active target for this server
    self:saveLastTarget(target)
end

function IrcChatView:appendLine(line, target)
    if not line or line == "" then return end
    target = target or self._current_target or "*"
    self:ensureBuffer(target)
    local prefix = os.date("[%H:%M]") .. " "
    local buf = self._buffers[target]
    buf = (buf and #buf > 0) and (buf .. "\n" .. prefix .. line) or (prefix .. line)
    self._buffers[target] = buf
    -- Persist to history
    self:writeHistory(target, prefix .. line)
    if target == (self._current_target or "*") then
        if self._ui_open then
            -- Reuse the same refresh path as the channel switcher
            self:refreshView(target)
        end
    else
        -- increment unread counter for background target
        self._unread[target] = (self._unread[target] or 0) + 1
    end
end

function IrcChatView:startConnection()
    if self._connected or self._closing then return end
    local host = self._server.host
    local port = tonumber(self._server.port) or 6667
    self:appendLine(T(_("Connecting to %1:%2…"), host, tostring(port)))

    local sock, err = socket.tcp()
    if not sock then
        self:appendLine(T(_("Socket error: %1"), tostring(err)))
        return
    end

    -- Do a blocking connect with a short timeout, then switch to non-blocking (and TLS if needed).
    sock:settimeout(10, 't')
    local ok, cerr = sock:connect(host, port)
    if not ok then
        self:appendLine(T(_("Connect failed: %1"), tostring(cerr)))
        pcall(function() sock:close() end)
        return
    end
    local use_tls = (tonumber(port) == 6697) or (self._server.tls == true)
    if use_tls then
        local okreq, ssl = pcall(require, "ssl")
        if not okreq or not ssl then
            self:appendLine(_("TLS requested but LuaSec is unavailable."))
            sock:settimeout(0, 'b')
            self._sock = sock
        else
            local params = {
                mode = "client",
                protocol = "tlsv1_2",
                verify = "none",
                options = "all",
                -- SNI support
                server = host,
            }
            local ssock, werr = ssl.wrap(sock, params)
            if not ssock then
                self:appendLine(T(_("TLS wrap failed: %1"), tostring(werr)))
                sock:settimeout(0, 'b')
                self._sock = sock
            else
                ssock:settimeout(10, 't')
                local hok, herr = ssock:dohandshake()
                if not hok then
                    self:appendLine(T(_("TLS handshake failed: %1"), tostring(herr)))
                    pcall(function() ssock:close() end)
                    return
                end
                ssock:settimeout(0, 'b')
                self._sock = ssock
            end
        end
    else
        sock:settimeout(0, 'b')
        self._sock = sock
    end

    -- Authenticate if configured, then send NICK/USER; Join will be sent after welcome (001)
    self._connected = true
    self._registered = false
    self._pending_join = self._channel
    self:appendLine(T(_("Logging in as %1…"), self._nick))
    -- PASS MUST be sent before NICK/USER if needed (e.g., ZNC)
    local auth_user = self._server.auth_user
    local auth_pass = self._server.auth_pass
    if auth_user and auth_pass then
        self:sendRaw(string.format("PASS %s:%s\r\n", auth_user, auth_pass))
    elseif auth_pass and #auth_pass > 0 then
        -- plain server password
        self:sendRaw(string.format("PASS %s\r\n", auth_pass))
    end
    self:sendRaw(string.format("NICK %s\r\n", self._nick))
    self:sendRaw(string.format("USER %s 0 * :%s\r\n", self._nick, self._nick))

    -- Schedule receive loop
    self._receive_task = function() self:receiveLoop() end
    UIManager:scheduleIn(0.2, self._receive_task)
end

function IrcChatView:sendRaw(line)
    if not self._sock then return end
    -- Best effort write
    pcall(function()
        self._sock:send(line)
    end)
end

function IrcChatView:sendMessage(msg)
    if not msg or msg == "" then return end
    if msg:sub(1,1) == "/" then
        -- Simple slash commands: /join, /part, /me, /msg
        local parts = {}
        for w in msg:gmatch("%S+") do table.insert(parts, w) end
        local cmd = parts[1]:sub(2):lower()
        if cmd == "join" and parts[2] then
            local ch = parts[2]
            self:sendRaw(string.format("JOIN %s\r\n", ch))
            self:appendLine(T(_("Joining %1"), ch), ch)
            self:ensureBuffer(ch)
            self:switchTarget(ch)
        elseif cmd == "part" then
            local ch = parts[2] or self._current_target
            if ch then
                self:sendRaw(string.format("PART %s\r\n", ch))
                self:appendLine(T(_("Leaving %1"), ch), ch)
            end
        elseif cmd == "me" and parts[2] then
            if self._current_target and self._current_target ~= "*" then
                local action = msg:match("/me%s+(.+)$") or ""
                self:sendRaw(string.format("PRIVMSG %s :\u{0001}ACTION %s\u{0001}\r\n", self._current_target, action))
                self:appendLine(T(_("* %1 %2"), self._nick, action), self._current_target)
            end
        elseif cmd == "msg" and parts[2] and parts[3] then
            local target = parts[2]
            local text = msg:match("/msg%s+%S+%s+(.+)$") or ""
            self:sendRaw(string.format("PRIVMSG %s :%s\r\n", target, text))
            self:appendLine(T(_("→ [%1] %2"), target, text), target)
        else
            self:appendLine(_("Unknown command."))
        end
        return
    end
    if self._current_target and self._current_target ~= "*" then
        self:sendRaw(string.format("PRIVMSG %s :%s\r\n", self._current_target, msg))
        self:appendLine(T(_("<%1> %2"), self._nick, msg), self._current_target)
    else
        self:appendLine(_("No channel joined. Use /join #channel"))
    end
end

function IrcChatView:promptSendMessage()
    local dialog
    dialog = InputDialog:new{
        title = _("Send message"),
        input = "",
        -- Keep single-line input semantics on Enter, but expand the box
        use_available_height = true,    -- expand input to available height
        condensed = true,               -- reduce extra padding to maximize text area
        buttons = {
            {
                {
                    text = _("Send"),
                    is_default = true,
                    is_enter_default = true,
                    callback = function()
                        local txt = dialog:getInputText()
                        -- Update buffer/UI before closing dialog to ensure immediate repaint
                        self:sendMessage(txt)
                        UIManager:close(dialog)
                        -- And schedule a focused refresh after the dialog is gone
                        if UIManager and self._ui_open then
                            UIManager:nextTick(function()
                                self:refreshView(self._current_target or "*")
                            end)
                        end
                    end,
                },
                {
                    text = _("Cancel"),
                    callback = function()
                        UIManager:close(dialog)
                    end,
                },
            }
        }
    }
    UIManager:show(dialog)
    dialog:onShowKeyboard(true)
end

function IrcChatView:refreshView(target)
    target = target or self._current_target or "*"
    if not self._ui_open then return end
    self:preloadHistory(target)
    if self.scroll_text_w and self.scroll_text_w.text_widget then
        local s = self._buffers[target] or ""
        self.text = s
        self.scroll_text_w.text_widget:setText(s)
        self.scroll_text_w:scrollToBottom()
        if self.scroll_text_w.updateScrollBar then
            self.scroll_text_w:updateScrollBar(true)
        end
    end
    if UIManager and self.frame and self.frame.dimen then
        UIManager:setDirty(self, function() return "ui", self.frame.dimen end)
    end
end

function IrcChatView:receiveLoop()
    if self._closing then return end
    if not self._sock then return end
    -- Non-blocking receive lines; iterate until no more data
    for i = 1, 50 do -- cap per tick
        local line, err, partial = self._sock:receive("*l")
        if line then
            self:handleLine(line)
        elseif err == "timeout" then
            break
        elseif err == "closed" then
            self:appendLine(_("Disconnected."))
            self._closing = true
            pcall(function() self._sock:close() end)
            self._sock = nil
            break
        else
            if partial and #partial > 0 then
                self:handleLine(partial)
            end
            break
        end
    end
    if not self._closing then
        UIManager:scheduleIn(0.3, self._receive_task)
    end
end

function IrcChatView:handleLine(line)
    -- Handle PING/PONG and display messages
    -- Raw IRC line: ":prefix COMMAND params :trailing" or "PING :token"
    if line:match("^PING%s*:") then
        local token = line:match("^PING%s*:(.+)$") or ""
        self:sendRaw("PONG :" .. token .. "\r\n")
        return
    end

    local prefix, command, rest = line:match("^:([^%s]+)%s+(%S+)%s+(.+)$")
    if command then
        command = command:upper()
        if command == "PRIVMSG" then
            local target, msg = rest:match("^(%S+)%s+:(.+)$")
            if target and msg then
                local nick = prefix:match("^([^!]+)!") or prefix
                if target:sub(1,1) == "#" then
                    self:appendLine(string.format("<%s> %s", nick, msg), target)
                    -- track speaker as member
                    self:ensureBuffer(target)
                    self._members = self._members or {}
                    self._members[target] = self._members[target] or {}
                    self._members[target][nick] = true
                else
                    -- PM to us
                    self:appendLine(string.format("[%s -> you] %s", nick, msg), nick)
                end
                return
            end
        elseif command == "NOTICE" then
            local target, msg = rest:match("^(%S+)%s+:(.+)$")
            if msg then
                local nick = prefix and (prefix:match("^([^!]+)!") or prefix) or "*"
                local tgt = (target and target:sub(1,1) == "#") and target or nil
                self:appendLine(string.format("-%s- %s", nick, msg), tgt)
                return
            end
        elseif command == "JOIN" then
            local nick = prefix:match("^([^!]+)!") or prefix
            local ch = rest:match("^:(.+)$") or rest
            if ch and ch ~= "" then
                self:appendLine(string.format("* %s joined %s", nick, ch), ch)
                if nick == self._nick then
                    self:ensureBuffer(ch)
                    -- Auto-switch to first joined channel if we're still on console
                    if self._current_target == "*" then
                        self:switchTarget(ch)
                    end
                end
                self:ensureBuffer(ch)
                self._members = self._members or {}
                self._members[ch] = self._members[ch] or {}
                self._members[ch][nick] = true
            end
            return
        elseif command == "PART" then
            local nick = prefix:match("^([^!]+)!") or prefix
            local ch, msg = rest:match("^(%S+)%s*:?(.*)$")
            if ch then
                self:appendLine(string.format("* %s left %s %s", nick, ch, msg or ""), ch)
                if self._members and self._members[ch] then
                    self._members[ch][nick] = nil
                end
            end
            return
        elseif command == "QUIT" then
            local nick = prefix:match("^([^!]+)!") or prefix
            local msg = rest:match("^:(.+)$") or ""
            local shown = false
            if self._members then
                for ch, set in pairs(self._members) do
                    if set[nick] then
                        self:appendLine(string.format("* %s quit %s", nick, msg), ch)
                        set[nick] = nil
                        shown = true
                    end
                end
            end
            -- If not shown anywhere, drop it to avoid cross-channel noise
            return
        elseif command == "353" then -- RPL_NAMREPLY
            local nickmode, chan, names = rest:match("^(%S+)%s+=%s+(%S+)%s+:(.+)$")
            if names then
                self:ensureBuffer(chan)
                self._members = self._members or {}
                self._members[chan] = self._members[chan] or {}
                for name in names:gmatch("%S+") do
                    local clean = name:gsub("^[~&@%+%%]", "")
                    self._members[chan][clean] = true
                end
                self:appendLine(T(_("Users: %1"), names), chan)
            end
            return
        elseif command == "001" then -- welcome (registered)
            local target_nick, msg = rest:match("^(%S+)%s+:(.+)$")
            if target_nick then
                self._nick = target_nick
            else
                msg = rest
            end
            self._registered = true
            self:appendLine(msg)
            if self._pending_join and #self._pending_join > 0 then
                self:sendRaw(string.format("JOIN %s\r\n", self._pending_join))
            end
            return
        elseif command == "NICK" then -- self or others changed nick
            local newnick = rest:match("^:(.+)$") or rest
            local oldnick = prefix:match("^([^!]+)!") or prefix
            if oldnick == self._nick and newnick and #newnick > 0 then
                self._nick = newnick
                self:appendLine(T(_("You are now known as %1"), newnick))
            end
            if self._members and newnick and #newnick > 0 then
                for ch, set in pairs(self._members) do
                    if set[oldnick] then
                        set[oldnick] = nil
                        set[newnick] = true
                    end
                end
            end
            return
        elseif command == "376" or command == "422" then
            -- End of MOTD / No MOTD: safe to join if not yet joined
            if not self._registered then self._registered = true end
            if self._pending_join and #self._pending_join > 0 then
                self:sendRaw(string.format("JOIN %s\r\n", self._pending_join))
            end
            return
        elseif command == "433" then -- ERR_NICKNAMEINUSE
            self:appendLine(_("Nickname in use. Try changing Username in menu."))
            return
        end
    end
    -- Fallback: show raw line trimmed
    self:appendLine((line:gsub("\r", "")))
end

function IrcChatView:onClose()
    -- If keep_running, only close the UI; keep socket and receive loop alive in background
    if self.keep_running then
        self._ui_open = false
        TextViewer.onClose(self)
        return
    end
    if self._closing then return end
    self._closing = true
    if self._receive_task then
        UIManager:unschedule(self._receive_task)
        self._receive_task = nil
    end
    if self._sock then
        pcall(function()
            if self._current_target and self._current_target:sub(1,1) == "#" then
                self:sendRaw(string.format("PART %s\r\n", self._current_target))
            end
            self:sendRaw("QUIT :bye\r\n")
            self._sock:close()
        end)
        self._sock = nil
    end
    TextViewer.onClose(self)
end

function IrcChatView:disconnect()
    -- Terminate receive loop and close socket
    if self._receive_task then
        UIManager:unschedule(self._receive_task)
        self._receive_task = nil
    end
    if self._sock then
        pcall(function()
            self:sendRaw("QUIT :bye\r\n")
            self._sock:close()
        end)
        self._sock = nil
    end
    self._connected = false
    self._closing = true
    self:appendLine(_("Disconnected."))
end

-- Extend the hamburger menu to add a list of joined channels/targets.
function IrcChatView:showChannelSwitcher()
    local Menu = require("ui/widget/menu")
    local items = {}
    local targets = self._ordered_targets or {}
    for i, tgt in ipairs(targets) do
        local label = (tgt == "*" and _("Server console")) or tgt
        table.insert(items, {
            text_func = function()
                local n = self._unread[tgt] or 0
                if n > 0 then
                    return string.format("%s (%d)", label, n)
                else
                    return label
                end
            end,
            checked_func = function() return self._current_target == tgt end,
            callback = function(item)
                self:switchTarget(tgt)
                UIManager:close(self._switcher_menu)
            end,
        })
    end
    self._switcher_menu = Menu:new{
        title = _("Switch channel"),
        item_table = items,
        covers_fullscreen = true,
        is_borderless = true,
        is_popout = false,
        close_callback = function()
            UIManager:close(self._switcher_menu)
            self._switcher_menu = nil
        end,
    }
    UIManager:show(self._switcher_menu)
end

function IrcChatView:onShowMenu()
    local ButtonDialog = require("ui/widget/buttondialog")
    local SpinWidget = require("ui/widget/spinwidget")
    local buttons = {}

    table.insert(buttons, {
        {
            text = _("Switch channel"),
            enabled_func = function() return self._ordered_targets and #self._ordered_targets > 0 end,
            callback = function()
                self:showChannelSwitcher()
            end,
        }
    })

    -- Disconnect action
    table.insert(buttons, {
        {
            text = _("Disconnect"),
            enabled_func = function() return self._sock ~= nil end,
            callback = function()
                self:disconnect()
            end,
        }
    })

    -- Font size
    table.insert(buttons, {
        {
            text_func = function()
                return T(_("Font size: %1"), self.text_font_size)
            end,
            align = "left",
            callback = function()
                local widget = SpinWidget:new{
                    title_text = _("Font size"),
                    value = self.text_font_size,
                    value_min = 12,
                    value_max = 30,
                    default_value = self.monospace_font and 16 or 20,
                    keep_shown_on_apply = true,
                    callback = function(spin)
                        self.text_font_size = spin.value
                        self:reinit()
                    end,
                }
                UIManager:show(widget)
            end,
        }
    })

    -- Monospace toggle
    table.insert(buttons, {
        {
            text = _("Monospace font"),
            checked_func = function()
                return self.monospace_font
            end,
            align = "left",
            callback = function()
                self.monospace_font = not self.monospace_font
                self:reinit()
            end,
        }
    })

    -- Justify toggle
    table.insert(buttons, {
        {
            text = _("Justify"),
            checked_func = function()
                return self.justified
            end,
            align = "left",
            callback = function()
                self.justified = not self.justified
                self:reinit()
            end,
        }
    })

    local dialog = ButtonDialog:new{
        shrink_unneeded_width = true,
        buttons = buttons,
        anchor = function()
            return self.titlebar.left_button.image.dimen
        end,
    }
    UIManager:show(dialog)
end

-- Main plugin
local IRC = WidgetContainer:extend{
    name = "irc",
    fullname = _("IRC client"),
    is_doc_only = false,
    settings_file = DataStorage:getSettingsDir() .. "/irc_client.lua",
    settings = nil,
    servers = nil, -- array of { name, host, port, channels = {"#chan"} }
    username = nil,
}

function IRC:onDispatcherRegisterActions()
    Dispatcher:registerAction("irc_open", {category="none", event="OpenIRC", title=self.fullname, general=true})
end

function IRC:init()
    self:onDispatcherRegisterActions()
    self:loadSettings()
    self.ui.menu:registerToMainMenu(self)
end

function IRC:loadSettings()
    if self.settings then return end
    self.settings = LuaSettings:open(self.settings_file)
    self.username = self.settings:readSetting("username") or os.getenv("USER") or "koreader"
    self.servers = self.settings:readSetting("servers") or {}
end

function IRC:onFlushSettings()
    if not self.settings then return end
    self.settings:saveSetting("username", self.username)
    self.settings:saveSetting("servers", self.servers)
    self.settings:flush()
end

function IRC:addToMainMenu(menu_items)
    menu_items.irc_client = {
        text = self.fullname,
        sorting_hint = "more_tools",
        sub_item_table_func = function()
            return self:getRootMenuItems()
        end,
    }
end

function IRC:getRootMenuItems()
    local items = {
        {
            text = _("Server list"),
            keep_menu_open = true,
            sub_item_table_func = function()
                return self:getServerListItems()
            end,
        },
        {
            text_func = function()
                return T(_("Default username: %1"), self.username)
            end,
            callback = function()
                self:promptUsername()
            end,
        },
    }
    return items
end

function IRC:getServerDisplay(server)
    local label = server.name and #server.name > 0 and server.name or (server.host or "?")
    local port = server.port and tostring(server.port) or "6667"
    return string.format("%s (%s:%s)", label, server.host or "?", port)
end

function IRC:getServerListItems()
    local items = {}
    for idx, server in ipairs(self.servers) do
        table.insert(items, {
            text = self:getServerDisplay(server),
            sub_item_table = self:getServerActions(server, idx),
        })
    end
    table.insert(items, { separator = true })
    table.insert(items, {
        text = _("Add server…"),
        callback = function()
            self:promptAddServer()
        end,
    })
    return items
end

function IRC:getServerActions(server, index)
    local function isConnected()
        return self._bg_view and self._bg_view._sock and self._bg_view._server
            and self._bg_view._server.host == server.host
            and tostring(self._bg_view._server.port or 6667) == tostring(server.port or 6667)
    end
    local actions = {
        {
            text_func = function()
                return isConnected() and _("Open") or _("Connect")
            end,
            callback = function()
                self:connectToServer(server)
            end,
        },
        {
            text = _("Disconnect"),
            enabled_func = function() return isConnected() end,
            callback = function()
                if self._bg_view and self._bg_view.disconnect then
                    self._bg_view:disconnect()
                end
            end,
        },
        {
            text = _("Edit"),
            callback = function()
                self:promptEditServer(server, index)
            end,
        },
        {
            text = _("Delete"),
            callback = function()
                UIManager:show(ConfirmBox:new{
                    text = T(_("Delete %1?"), self:getServerDisplay(server)),
                    ok_text = _("Delete"),
                    ok_callback = function()
                        table.remove(self.servers, index)
                        self:onFlushSettings()
                        UIManager:show(InfoMessage:new{ text = _("Server removed."), timeout = 2 })
                    end,
                })
            end,
        },
    }
    return actions
end

function IRC:promptUsername()
    local dialog
    dialog = InputDialog:new{
        title = _("Username"),
        input = self.username or "",
        buttons = {
            {
                {
                    text = _("Save"),
                    is_default = true,
                    callback = function()
                        self.username = dialog:getInputText()
                        self:onFlushSettings()
                        UIManager:close(dialog)
                    end,
                },
                {
                    text = _("Cancel"),
                    callback = function()
                        UIManager:close(dialog)
                    end,
                },
            }
        }
    }
    UIManager:show(dialog)
    dialog:onShowKeyboard(true)
end

function IRC:promptAddServer()
    local fields = {
        { text = "", hint = _("Display name (optional)") },
        { text = self.username or "koreader", hint = _("Nick (per-server)") },
        { text = "irc.libera.chat", hint = _("Host") },
        { text = "6667", hint = _("Port") },
        { text = "#koreader", hint = _("Channels (comma-separated)") },
        { text = "", hint = _("Auth user (optional, e.g., user or user/network)") },
        { text = "", hint = _("Auth password (optional)"), text_type = "password" },
    }
    local dialog
    dialog = MultiInputDialog:new{
        title = _("Add server"),
        fields = fields,
        buttons = {
            {
                {
                    text = _("Add"),
                    is_default = true,
                    callback = function()
                        local name, nick, host, port_str, chans, auth_user, auth_pass = unpack(dialog:getFields())
                        local port = tonumber(port_str) or 6667
                        local channels = {}
                        if chans and #chans > 0 then
                            for ch in chans:gmatch("[^,%s]+") do table.insert(channels, ch) end
                        end
                        if not host or host == "" then
                            UIManager:show(InfoMessage:new{ text = _("Host is required."), timeout = 2 })
                            return
                        end
                        table.insert(self.servers, {
                            name = name,
                            nick = (nick ~= "" and nick or nil),
                            host = host,
                            port = port,
                            channels = channels,
                            auth_user = (auth_user ~= "" and auth_user or nil),
                            auth_pass = (auth_pass ~= "" and auth_pass or nil),
                        })
                        self:onFlushSettings()
                        UIManager:close(dialog)
                        UIManager:show(InfoMessage:new{ text = _("Server added."), timeout = 2 })
                    end,
                },
                {
                    text = _("Cancel"),
                    callback = function() UIManager:close(dialog) end,
                },
            }
        }
    }
    UIManager:show(dialog)
    dialog:onShowKeyboard(true)
end

function IRC:promptEditServer(server, index)
    local fields = {
        { text = server.name or "", hint = _("Display name (optional)") },
        { text = server.nick or self.username or "koreader", hint = _("Nick (per-server)") },
        { text = server.host or "", hint = _("Host") },
        { text = tostring(server.port or 6667), hint = _("Port") },
        { text = table.concat(server.channels or {}, ", "), hint = _("Channels (comma-separated)") },
        { text = server.auth_user or "", hint = _("Auth user (optional, e.g., user or user/network)") },
        { text = server.auth_pass or "", hint = _("Auth password (optional)"), text_type = "password" },
    }
    local dialog
    dialog = MultiInputDialog:new{
        title = _("Edit server"),
        fields = fields,
        buttons = {
            {
                {
                    text = _("Save"),
                    is_default = true,
                    callback = function()
                        local name, nick, host, port_str, chans, auth_user, auth_pass = unpack(dialog:getFields())
                        local port = tonumber(port_str) or 6667
                        local channels = {}
                        if chans and #chans > 0 then
                            for ch in chans:gmatch("[^,%s]+") do table.insert(channels, ch) end
                        end
                        if not host or host == "" then
                            UIManager:show(InfoMessage:new{ text = _("Host is required."), timeout = 2 })
                            return
                        end
                        server.name = name
                        server.nick = (nick ~= "" and nick or nil)
                        server.host = host
                        server.port = port
                        server.channels = channels
                        server.auth_user = (auth_user ~= "" and auth_user or nil)
                        server.auth_pass = (auth_pass ~= "" and auth_pass or nil)
                        self.servers[index] = server
                        self:onFlushSettings()
                        UIManager:close(dialog)
                        UIManager:show(InfoMessage:new{ text = _("Server saved."), timeout = 2 })
                    end,
                },
                {
                    text = _("Cancel"),
                    callback = function() UIManager:close(dialog) end,
                },
            }
        }
    }
    UIManager:show(dialog)
    dialog:onShowKeyboard(true)
end

function IRC:connectToServer(server)
    -- If multiple channels, ask to select one; otherwise connect to the only one or none
    local function open_chat(channel)
        local function do_open()
            local nick = server.nick or self.username or "koreader"
            -- Reuse background session if already running for this host/port
            if self._bg_view and self._bg_view._sock then
                if self._bg_view.reinit then self._bg_view:reinit() end
                self._bg_view._ui_open = true
                UIManager:show(self._bg_view)
                return
            end
            local view = IrcChatView:new{
                _server = {
                    name = server.name,
                    host = server.host,
                    port = server.port,
                    auth_user = server.auth_user,
                    auth_pass = server.auth_pass,
                },
                _channel = channel,
                _nick = nick,
                keep_running = true,
            }
            self._bg_view = view
            UIManager:show(view)
        end
    -- Mark UI open
    self._ui_open = true
        -- Ensure wifi/network is up before proceeding
        if NetworkMgr:willRerunWhenConnected(function() open_chat(channel) end) then
            return
        end
        socketutil:set_timeout(socketutil.DEFAULT_BLOCK_TIMEOUT, socketutil.DEFAULT_TOTAL_TIMEOUT)
        do_open()
    end

    if server.channels and #server.channels > 1 then
        -- Prompt to pick a channel
        local buttons = {}
        for i, ch in ipairs(server.channels) do
            table.insert(buttons, { { text = ch, callback = function() UIManager:close(self._chan_dlg); open_chat(ch) end } })
        end
        self._chan_dlg = require("ui/widget/buttondialog"):new{
            title = _("Select channel"),
            buttons = buttons,
        }
        UIManager:show(self._chan_dlg)
    else
        open_chat(server.channels and server.channels[1] or nil)
    end
end

function IRC:onOpenIRC()
    -- Open root submenu via info message hint
    UIManager:show(InfoMessage:new{ text = _("Use Tools → IRC client"), timeout = 3 })
end

return IRC