local Event = require("ui/event")
local util = require("ffi/util")
local DEBUG = require("dbg")

local function yes() return true end
local function no() return false end

local Device = {
    screen_saver_mode = false,
    charging_mode = false,
    survive_screen_saver = false,
    is_cover_closed = false,
    model = nil,
    powerd = nil,
    screen = nil,
    input = nil,
    -- For Kobo, wait at least 15 seconds before calling suspend script. Otherwise, suspend might
    -- fail and the battery will be drained while we are in screensaver mode
    suspend_wait_timeout = 15,

    -- hardware feature tests: (these are functions!)
    hasKeyboard = no,
    hasKeys = no,
    hasDPad = no,
    isTouchDevice = no,
    hasFrontlight = no,
    needsTouchScreenProbe = no,

    -- use these only as a last resort. We should abstract the functionality
    -- and have device dependent implementations in the corresponting
    -- device/<devicetype>/device.lua file
    -- (these are functions!)
    isKindle = no,
    isKobo = no,
    isPocketBook = no,
    isAndroid = no,
    isSDL = no,

    -- some devices have part of their screen covered by the bezel
    viewport = nil,
    -- enforce portrait orientation on display, no matter how configured at
    -- startup
    isAlwaysPortrait = no,
    -- needs full screen refresh when resumed from screensaver?
    needsScreenRefreshAfterResume = yes,
}

function Device:new(o)
    o = o or {}
    setmetatable(o, self)
    self.__index = self
    return o
end

function Device:init()
    if not self.screen then
        error("screen/framebuffer must be implemented")
    end

    local is_eink = G_reader_settings:readSetting("eink")
    self.screen.eink = (is_eink == nil) or is_eink

    DEBUG("initializing for device", self.model)
    DEBUG("framebuffer resolution:", self.screen:getSize())

    if not self.input then
        self.input = require("device/input"):new{device = self}
    end
    if not self.powerd then
        self.powerd = require("device/generic/powerd"):new{device = self}
    end

    if self.viewport then
        DEBUG("setting a viewport:", self.viewport)
        self.screen:setViewport(self.viewport)
        self.input:registerEventAdjustHook(
            self.input.adjustTouchTranslate,
            {x = 0 - self.viewport.x, y = 0 - self.viewport.y})
    end
end

function Device:getPowerDevice()
    return self.powerd
end

-- ONLY used for Kindle devices
function Device:intoScreenSaver()
    local UIManager = require("ui/uimanager")
    if self.charging_mode == false and self.screen_saver_mode == false then
        self.screen:saveCurrentBB()
        self.screen_saver_mode = true
        -- On FW >= 5.7.2, we sigstop awesome, but we need it to show stuff...
        if os.getenv("AWESOME_STOPPED") == "yes" then
            os.execute("killall -cont awesome")
        end
    end
    UIManager:broadcastEvent(Event:new("FlushSettings"))
end

-- ONLY used for Kindle devices
function Device:outofScreenSaver()
    if self.screen_saver_mode == true and self.charging_mode == false then
        -- On FW >= 5.7.2, put awesome to sleep again...
        if os.getenv("AWESOME_STOPPED") == "yes" then
            os.execute("killall -stop awesome")
        end
        -- wait for native system update screen before we recover saved
        -- Blitbuffer.
        util.usleep(1500000)
        self.screen:restoreFromSavedBB()
        self:resume()
        if self:needsScreenRefreshAfterResume() then
            self.screen:refreshFull()
        end
        self.powerd:refreshCapacity()
    end
    self.screen_saver_mode = false
end

function Device:rescheduleSuspend()
    local UIManager = require("ui/uimanager")
    UIManager:unschedule(self.suspend)
    UIManager:scheduleIn(self.suspend_wait_timeout, self.suspend)
end

-- ONLY used for Kobo and PocketBook devices
function Device:onPowerEvent(ev)
    if self.screen_saver_mode then
        if ev == "Power" or ev == "Resume" then
            if self.is_cover_closed then
                -- don't let power key press wake up device when the cover is in closed state
                self:rescheduleSuspend()
            else
                DEBUG("Resuming...")
                local UIManager = require("ui/uimanager")
                UIManager:unschedule(self.suspend)
                local network_manager = require("ui/network/manager")
                if network_manager.wifi_was_on and G_reader_settings:nilOrTrue("auto_restore_wifi") then
                    network_manager:restoreWifiAsync()
                end
                self:resume()
                require("ui/screensaver"):close()
                -- restore to previous rotation mode
                self.screen:setRotationMode(self.orig_rotation_mode)
                if self:needsScreenRefreshAfterResume() then
                    UIManager:scheduleIn(1, function() self.screen:refreshFull() end)
                end
                self.screen_saver_mode = false
                self.powerd:refreshCapacity()
                self.powerd:afterResume()
            end
        elseif ev == "Suspend" then
            -- Already in screen saver mode, no need to update UI/state before
            -- suspending the hardware. This usually happens when sleep cover
            -- is closed after the device was sent to suspend state.
            DEBUG("Already in screen saver mode, suspending...")
            self:rescheduleSuspend()
        end
    -- else we we not in screensaver mode
    elseif ev == "Power" or ev == "Suspend" then
        self.powerd:beforeSuspend()
        local network_manager = require("ui/network/manager")
        if network_manager.wifi_was_on then
            network_manager:releaseIP()
            network_manager:turnOffWifi()
        end
        local UIManager = require("ui/uimanager")
        -- flushing settings first in case the screensaver takes too long time
        -- that flushing has no chance to run
        UIManager:broadcastEvent(Event:new("FlushSettings"))
        DEBUG("Suspending...")
        -- always suspend in portrait mode
        self.orig_rotation_mode = self.screen:getRotationMode()
        self.screen:setRotationMode(0)
        require("ui/screensaver"):show()
        self.screen:refreshFull()
        self.screen_saver_mode = true
        UIManager:scheduleIn(self.suspend_wait_timeout, self.suspend)
    end
end

-- Hardware specific method to suspend the device
function Device:suspend() end

-- Hardware specific method to resume the device
function Device:resume() end

-- Hardware specific method to power off the device
function Device:powerOff() end

function Device:usbPlugIn()
    if self.charging_mode == false and self.screen_saver_mode == false then
        self.screen:saveCurrentBB()
        -- On FW >= 5.7.2, we sigstop awesome, but we need it to show stuff...
        if os.getenv("AWESOME_STOPPED") == "yes" then
            os.execute("killall -cont awesome")
        end
    end
    self.charging_mode = true
end

function Device:usbPlugOut()
    if self.charging_mode == true and self.screen_saver_mode == false then
        -- On FW >= 5.7.2, put awesome to sleep again...
        if os.getenv("AWESOME_STOPPED") == "yes" then
            os.execute("killall -stop awesome")
        end
        -- Same as when going out of screensaver, wait for the native system
        util.usleep(1500000)
        self.screen:restoreFromSavedBB()
        self.screen:refreshFull()
        self.powerd:refreshCapacity()
    end

    --@TODO signal filemanager for file changes  13.06 2012 (houqp)
    self.charging_mode = false
end

-- Hardware specific method to initialize network manager module
function Device:initNetworkManager()
end

--[[
prepare for application shutdown
--]]
function Device:exit()
    require("ffi/input"):closeAll()
    self.screen:close()
end

function Device:retrieveNetworkInfo()
    local std_out = io.popen("ifconfig | " ..
                             "sed -n " ..
                             "-e 's/ \\+$//g' " ..
                             "-e 's/ \\+/ /g' " ..
                             "-e 's/inet6\\? addr: \\?\\([^ ]\\+\\) .*$/\\1/p' " ..
                             "-e 's/Link encap:\\(.*\\)/\\1/p'",
                             "r")
    if std_out then
        local result = std_out:read("*all")
        std_out:close()
        return result
    end
end

return Device