----------------------------------------------------------------------------
--- Notification library
--
-- @author koniu <gkusnierz@gmail.com>
-- @copyright 2008 koniu
-- @release @AWESOME_VERSION@
-- @module naughty
----------------------------------------------------------------------------

-- Package environment
local pairs = pairs
local table = table
local type = type
local string = string
local tostring = tostring
local pcall = pcall
local capi = { screen = screen,
               awesome = awesome }
local timer = require("gears.timer")
local button = require("awful.button")
local util = require("awful.util")
local bt = require("beautiful")
local wibox = require("wibox")
local surface = require("gears.surface")
local cairo = require("lgi").cairo

local schar = string.char
local sbyte = string.byte
local tcat = table.concat
local tins = table.insert

local naughty = {}

--[[--
Naughty configuration - a table containing common popup settings.

@table naughty.config
@field padding Space between popups and edge of the workarea.
   Default: `4`
@field spacing Spacing between popups.
   Default: `1`
@field icon_dirs List of directories that will be checked by `getIcon()`.
   Default: `{ "/usr/share/pixmaps/", }`
@field icon_formats List of formats that will be checked by `getIcon()`.
   Default: `{ "png", "gif" }`
@field notify_callback Callback used to modify or reject notifications.
   Default: `nil`
    naughty.config.notify_callback = function(args)
        args.text = 'prefix: ' .. args.text
        return args
    end

@field presets Notification Presets - a table containing presets for
   different purposes.  Preset is a table of any parameters available to
   `notify()`, overriding default values (`naughty.config.defaults`) You have
   to pass a reference of a preset in your notify() call to use the preset The
   presets `"low"`, `"normal"` and `"critical"` are used for notifications
   over DBUS.

@field presets.low The preset for notifications with low urgency level.
@field presets.normal The default preset for every notification without a
   preset that will also be used for normal urgency level.
@field presets.critical The preset for notifications with a critical urgency
   level.

@field defaults Default values for the params to `notify()`.
   These can optionally be overridden by specifying a preset.

@field mapping DBUS notification to preset mapping.
   The first element is an object containing the filter If the rules in the
   filter matches the associated preset will be applied The rules object can
   contain: urgency, category, appname The second element is the preset

@field mapping.1 low urgency
@field mapping.2 normal urgency
@field mapping.3 critical urgency
--]]
--
naughty.config = {
    padding = 4,
    spacing = 1,
    icon_dirs = { "/usr/share/pixmaps/", },
    icon_formats = { "png", "gif" },
    notify_callback = nil,
}

naughty.config.presets = {
    low = {
        timeout = 5
    },
    normal = {},
    critical = {
        bg = "#ff0000",
        fg = "#ffffff",
        timeout = 0,
    }
}

naughty.config.defaults = {
    timeout = 5,
    text = "",
    screen = 1,
    ontop = true,
    margin = "5",
    border_width = "1",
    position = "top_right"
}

naughty.notificationClosedReason = {
    silent = -1,
    expired = 1,
    dismissedByUser = 2,
    dismissedByCommand = 3,
    undefined = 4
}

-- Counter for the notifications
-- Required for later access via DBUS
local counter = 1

-- True if notifying is suspended
local suspended = false

--- Index of notifications per screen and position.
-- See config table for valid 'position' values.
-- Each element is a table consisting of:
--
-- @field box Wibox object containing the popup
-- @field height Popup height
-- @field width Popup width
-- @field die Function to be executed on timeout
-- @field id Unique notification id based on a counter
-- @table notifications
naughty.notifications = { suspended = { } }
for s = 1, capi.screen.count() do
    naughty.notifications[s] = {
        top_left = {},
        top_middle = {},
        top_right = {},
        bottom_left = {},
        bottom_middle = {},
        bottom_right = {},
    }
end

--- Suspend notifications
function naughty.suspend()
    suspended = true
end

--- Resume notifications
function naughty.resume()
    suspended = false
    for i, v in pairs(naughty.notifications.suspended) do
        v.box.visible = true
        if v.timer then v.timer:start() end
    end
    naughty.notifications.suspended = { }
end

--- Toggle notification state
function naughty.toggle()
    if suspended then
        naughty.resume()
    else
        naughty.suspend()
    end
end

--- Evaluate desired position of the notification by index - internal
--
-- @param screen Screen to use
-- @param position top_right | top_left | bottom_right | bottom_left
--             | top_middle | bottom_middle
-- @param idx Index of the notification
-- @param[opt] width Popup width.
-- @param height Popup height
-- @return Absolute position and index in { x = X, y = Y, idx = I } table
local function get_offset(screen, position, idx, width, height)
    local ws = capi.screen[screen].workarea
    local v = {}
    local idx = idx or #naughty.notifications[screen][position] + 1
    local width = width or naughty.notifications[screen][position][idx].width

    -- calculate x
    if position:match("left") then
        v.x = ws.x + naughty.config.padding
    elseif position:match("middle") then
        v.x = (ws.width / 2) - (width / 2)
    else
        v.x = ws.x + ws.width - (width + naughty.config.padding)
    end

    -- calculate existing popups' height
    local existing = 0
    for i = 1, idx-1, 1 do
        existing = existing + naughty.notifications[screen][position][i].height + naughty.config.spacing
    end

    -- calculate y
    if position:match("top") then
        v.y = ws.y + naughty.config.padding + existing
    else
        v.y = ws.y + ws.height - (naughty.config.padding + height + existing)
    end

    -- if positioned outside workarea, destroy oldest popup and recalculate
    if v.y + height > ws.y + ws.height or v.y < ws.y then
        idx = idx - 1
        naughty.destroy(naughty.notifications[screen][position][1])
        v = get_offset(screen, position, idx, width, height)
    end
    if not v.idx then v.idx = idx end

    return v
end

--- Re-arrange notifications according to their position and index - internal
--
-- @return None
local function arrange(screen)
    for p,pos in pairs(naughty.notifications[screen]) do
        for i,notification in pairs(naughty.notifications[screen][p]) do
            local offset = get_offset(screen, p, i, notification.width, notification.height)
            notification.box:geometry({ x = offset.x, y = offset.y })
            notification.idx = offset.idx
        end
    end
end

--- Destroy notification by notification object
--
-- @param notification Notification object to be destroyed
-- @param reason One of the reasons from notificationClosedReason
-- @return True if the popup was successfully destroyed, nil otherwise
function naughty.destroy(notification, reason)
    if notification and notification.box.visible then
        if suspended then
            for k, v in pairs(naughty.notifications.suspended) do
                if v.box == notification.box then
                    table.remove(naughty.notifications.suspended, k)
                    break
                end
            end
        end
        local scr = notification.screen
        table.remove(naughty.notifications[scr][notification.position], notification.idx)
        if notification.timer then
            notification.timer:stop()
        end
        notification.box.visible = false
        arrange(scr)
        if notification.destroy_cb and reason ~= naughty.notificationClosedReason.silent then
            notification.destroy_cb(reason or naughty.notificationClosedReason.undefined)
        end
        return true
    end
end

--- Get notification by ID
--
-- @param id ID of the notification
-- @return notification object if it was found, nil otherwise
function naughty.getById(id)
    -- iterate the notifications to get the notfications with the correct ID
    for s = 1, capi.screen.count() do
        for p,pos in pairs(naughty.notifications[s]) do
            for i,notification in pairs(naughty.notifications[s][p]) do
                if notification.id == id then
                    return notification
                 end
            end
        end
    end
end

--- Install expiration timer for notification object.
-- @tparam notification notification Notification object.
-- @tparam number timeout Time in seconds to be set as expiration timeout.
local function set_timeout(notification, timeout)
    local die = function (reason)
        naughty.destroy(notification, reason)
    end
    if timeout > 0 then
        local timer_die = timer { timeout = timeout }
        timer_die:connect_signal("timeout", function() die(naughty.notificationClosedReason.expired) end)
        if not suspended then
            timer_die:start()
        end
        notification.timer = timer_die
    end
    notification.die = die
end

--- Set new notification timeout.
-- @tparam notification notification Notification object, which timer is to be reset.
-- @tparam number new_timeout Time in seconds after which notification disappears.
-- @return None.
function naughty.reset_timeout(notification, new_timeout)
    if notification.timer then notification.timer:stop() end

    local timeout = timeout or notification.timeout
    set_timeout(notification, timeout)
    notification.timeout = timeout

    notification.timer:start()
end

--- Escape and set title and text for notification object.
-- @tparam notification notification Notification object.
-- @tparam string title Title of notification.
-- @tparam string text Main text of notification.
-- @return None.
local function set_text(notification, title, text)
    local escape_pattern = "[<>&]"
    local escape_subs = { ['<'] = "&lt;", ['>'] = "&gt;", ['&'] = "&amp;" }

    local textbox = notification.textbox

    local function setMarkup(pattern, replacements)
        textbox:set_markup(string.format('<b>%s</b>%s', title, text:gsub(pattern, replacements)))
    end
    local function setText()
        textbox:set_text(string.format('%s %s', title, text))
    end

    -- Since the title cannot contain markup, it must be escaped first so that
    -- it is not interpreted by Pango later.
    title = title:gsub(escape_pattern, escape_subs)
    -- Try to set the text while only interpreting <br>.
    -- (Setting a textbox' .text to an invalid pattern throws a lua error)
    if not pcall(setMarkup, "<br.->", "\n") then
        -- That failed, escape everything which might cause an error from pango
        if not pcall(setMarkup, escape_pattern, escape_subs) then
            -- Ok, just ignore all pango markup. If this fails, we got some invalid utf8
            if not pcall(setText) then
                textbox:set_markup("<i>&lt;Invalid markup or UTF8, cannot display message&gt;</i>")
            end
        end
    end
end

--- Replace title and text of an existing notification.
-- @tparam notification notification Notification object, which contents are to be replaced.
-- @tparam string new_title New title of notification. If not specified, old title remains unchanged.
-- @tparam string new_text New text of notification. If not specified, old text remains unchanged.
-- @return None.
function naughty.replace_text(notification, new_title, new_text)
    local title = new_title

    if title then title = title .. "\n" else title = "" end

    set_text(notification, title, new_text)
end

--- Create a notification.
--
-- @tab args The argument table containing any of the arguments below.
-- @string args.text Text of the notification.
--   Default: ''
-- @string args.title Title of the notification.
--   Default: nil
-- @int args.timeout Time in seconds after which popup expires.
--   Set 0 for no timeout.
--   Default: 5
-- @int args.hover_timeout Delay in seconds after which hovered popup disappears.
--   Default: nil
-- @int args.screen Target screen for the notification.
--   Default: 1
-- @string args.position Corner of the workarea displaying the popups.
--   Values: `"top_right"` (default), `"top_left"`, `"bottom_left"`,
--           `"bottom_right"`, `"top_middle"`, `"bottom_middle"`.
-- @bool args.ontop Boolean forcing popups to display on top.
--   Default: true
-- @int args.height Popup height.
--   Default: nil (auto)
-- @int args.width Popup width.
--   Default: nil (auto)
-- @string args.font Notification font.
--   Default: beautiful.font or awesome.font
-- @string args.icon Path to icon.
--   Default: nil
-- @int args.icon_size Desired icon size in px.
--   Default: nil
-- @string args.fg Foreground color.
--   Default: `beautiful.fg_focus` or `'#ffffff'`
-- @string args.bg Background color.
--   Default: `beautiful.bg_focus` or `'#535d6c'`
-- @int args.border_width Border width.
--   Default: 1
-- @string args.border_color Border color.
--   Default: `beautiful.border_focus` or `'#535d6c'`
-- @tparam func args.run Function to run on left click. Default: nil
-- @tparam func args.destroy Function to run when notification is destroyed. Default: nil.
-- @tparam table args.preset Table with any of the above parameters.
--                          Note: Any parameters specified directly in args
--                          will override ones defined in the preset.
-- @tparam int args.replaces_id Replace the notification with the given ID.
-- @tparam func args.callback Function that will be called with all arguments.
--                            The notification will only be displayed if the
--                            function returns true.
--                            Note: this function is only relevant to
--                            notifications sent via dbus.
-- @tparam table args.actions Mapping that maps a string to a callback when this
--                            action is selected.
-- @usage naughty.notify({ title = "Achtung!", text = "You're idling", timeout = 0 })
-- @return The notification object
function naughty.notify(args)
    if naughty.config.notify_callback then
        args = naughty.config.notify_callback(args)
        if not args then return end
    end

    -- gather variables together
    local preset = util.table.join(naughty.config.defaults or {},
        args.preset or naughty.config.presets.normal or {})
    local timeout = args.timeout or preset.timeout
    local icon = args.icon or preset.icon
    local icon_size = args.icon_size or preset.icon_size
    local text = args.text or preset.text
    local title = args.title or preset.title
    local screen = args.screen or preset.screen
    local ontop = args.ontop or preset.ontop
    local width = args.width or preset.width
    local height = args.height or preset.height
    local hover_timeout = args.hover_timeout or preset.hover_timeout
    local opacity = args.opacity or preset.opacity
    local margin = args.margin or preset.margin
    local border_width = args.border_width or preset.border_width
    local position = args.position or preset.position
    local actions = args.actions
    local destroy_cb = args.destroy

    -- beautiful
    local beautiful = bt.get()
    local font = args.font or preset.font or beautiful.font or capi.awesome.font
    local fg = args.fg or preset.fg or beautiful.fg_normal or '#ffffff'
    local bg = args.bg or preset.bg or beautiful.bg_normal or '#535d6c'
    local border_color = args.border_color or preset.border_color or beautiful.bg_focus or '#535d6c'
    local notification = { screen = screen, destroy_cb = destroy_cb, timeout = timeout }

    -- replace notification if needed
    if args.replaces_id then
        local obj = naughty.getById(args.replaces_id)
        if obj then
            -- destroy this and ...
            naughty.destroy(obj, naughty.notificationClosedReason.silent)
        end
        -- ... may use its ID
        if args.replaces_id <= counter then
            notification.id = args.replaces_id
        else
            counter = counter + 1
            notification.id = counter
        end
    else
        -- get a brand new ID
        counter = counter + 1
        notification.id = counter
    end

    notification.position = position

    if title then title = title .. "\n" else title = "" end

    -- hook destroy
    set_timeout(notification, timeout)
    local die = notification.die

    local run = function ()
        if args.run then
            args.run(notification)
        else
            die(naughty.notificationClosedReason.dismissedByUser)
        end
    end

    local hover_destroy = function ()
        if hover_timeout == 0 then
            die(naughty.notificationClosedReason.expired)
        else
            if notification.timer then notification.timer:stop() end
            notification.timer = timer { timeout = hover_timeout }
            notification.timer:connect_signal("timeout", function() die(naughty.notificationClosedReason.expired) end)
            notification.timer:start()
        end
    end

    -- create textbox
    local textbox = wibox.widget.textbox()
    local marginbox = wibox.layout.margin()
    marginbox:set_margins(margin)
    marginbox:set_widget(textbox)
    textbox:set_valign("middle")
    textbox:set_font(font)

    notification.textbox = textbox

    set_text(notification, title, text)

    local actionslayout = wibox.layout.fixed.vertical()
    local actions_max_width = 0
    local actions_total_height = 0
    if actions then
        for action, callback in pairs(actions) do
            local actiontextbox = wibox.widget.textbox()
            local actionmarginbox = wibox.layout.margin()
            actionmarginbox:set_margins(margin)
            actionmarginbox:set_widget(actiontextbox)
            actiontextbox:set_valign("middle")
            actiontextbox:set_font(font)
            actiontextbox:set_markup(string.format('<b>%s</b>', action))
            -- calculate the height and width
            local w, h = actiontextbox:fit(-1, -1)
            local height = h + 2 * margin
            local width = w + 2 * margin

            actionmarginbox:buttons(util.table.join(
                button({ }, 1, callback),
                button({ }, 3, callback)
                ))
            actionslayout:add(actionmarginbox)

            actions_total_height = actions_total_height + height
            if actions_max_width < width then
                actions_max_width = width
            end
        end
    end

    -- create iconbox
    local iconbox = nil
    local iconmargin = nil
    local icon_w, icon_h = 0, 0
    if icon then
        -- Is this really an URI instead of a path?
        if type(icon) == "string" and string.sub(icon, 1, 7) == "file://" then
            icon = string.sub(icon, 8)
        end
        -- try to guess icon if the provided one is non-existent/readable
        if type(icon) == "string" and not util.file_readable(icon) then
            icon = util.geticonpath(icon, naughty.config.icon_formats, naughty.config.icon_dirs, icon_size) or icon
        end

        -- is the icon file readable?
        local success, res = pcall(function() return surface.load_uncached(icon) end)
        if success then
            icon = res
        else
            io.stderr:write(string.format("naughty: Couldn't load image '%s': %s\n", tostring(icon), res))
            icon = nil
        end

        -- if we have an icon, use it
        if icon then
            iconbox = wibox.widget.imagebox()
            iconmargin = wibox.layout.margin(iconbox, margin, margin, margin, margin)
            if icon_size then
                local scaled = cairo.ImageSurface(cairo.Format.ARGB32, icon_size, icon_size)
                local cr = cairo.Context(scaled)
                cr:scale(icon_size / icon:get_height(), icon_size / icon:get_width())
                cr:set_source_surface(icon, 0, 0)
                cr:paint()
                icon = scaled
            end
            iconbox:set_resize(false)
            iconbox:set_image(icon)
            icon_w = icon:get_width()
            icon_h = icon:get_height()
        end
    end

    -- create container wibox
    notification.box = wibox({ fg = fg,
                               bg = bg,
                               border_color = border_color,
                               border_width = border_width,
                               type = "notification" })

    if hover_timeout then notification.box:connect_signal("mouse::enter", hover_destroy) end

    -- calculate the height
    if not height then
        local w, h = textbox:fit(-1, -1)
        if iconbox and icon_h + 2 * margin > h + 2 * margin then
            height = icon_h + 2 * margin
        else
            height = h + 2 * margin
        end
    end

    height = height + actions_total_height

    -- calculate the width
    if not width then
        local w, h = textbox:fit(-1, -1)
        width = w + (iconbox and icon_w + 2 * margin or 0) + 2 * margin
    end

    if width < actions_max_width then
        width = actions_max_width
    end

    -- crop to workarea size if too big
    local workarea = capi.screen[screen].workarea
    if width > workarea.width - 2 * (border_width or 0) - 2 * (naughty.config.padding or 0) then
        width = workarea.width - 2 * (border_width or 0) - 2 * (naughty.config.padding or 0)
    end
    if height > workarea.height - 2 * (border_width or 0) - 2 * (naughty.config.padding or 0) then
        height = workarea.height - 2 * (border_width or 0) - 2 * (naughty.config.padding or 0)
    end

    -- set size in notification object
    notification.height = height + 2 * (border_width or 0)
    notification.width = width + 2 * (border_width or 0)

    -- position the wibox
    local offset = get_offset(screen, notification.position, nil, notification.width, notification.height)
    notification.box.ontop = ontop
    notification.box:geometry({ width = width,
                                height = height,
                                x = offset.x,
                                y = offset.y })
    notification.box.opacity = opacity
    notification.box.visible = true
    notification.idx = offset.idx

    -- populate widgets
    local layout = wibox.layout.fixed.horizontal()
    if iconmargin then
        layout:add(iconmargin)
    end
    layout:add(marginbox)

    local completelayout = wibox.layout.fixed.vertical()
    completelayout:add(layout)
    completelayout:add(actionslayout)
    notification.box:set_widget(completelayout)

    -- Setup the mouse events
    layout:buttons(util.table.join(button({ }, 1, run),
                                   button({ }, 3, function()
                                        die(naughty.notificationClosedReason.dismissedByUser)
                                    end)))

    -- insert the notification to the table
    table.insert(naughty.notifications[screen][notification.position], notification)

    if suspended then
        notification.box.visible = false
        table.insert(naughty.notifications.suspended, notification)
    end

    -- return the notification
    return notification
end

return naughty

-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80