-- | Make ARM systems bootable using Debian's flash-kernel package.

module Propellor.Property.FlashKernel where

import Propellor.Base
import qualified Propellor.Property.File as File
import qualified Propellor.Property.Apt as Apt
import Propellor.Property.Mount
import Propellor.Types.Bootloader
import Propellor.Types.Info

-- | A machine name, such as "Cubietech Cubietruck" or "Olimex A10-OLinuXino-LIME"
-- flash-kernel supports many different machines,
-- see its file /usr/share/flash-kernel/db/all.db for a list.
type Machine = String

-- | Uses flash-kernel to make a machine bootable.
-- Before using this, an appropriate kernel needs to already be installed, 
-- and on many machines, u-boot needs to be installed too.
installed :: Machine -> Property (HasInfo + DebianLike)
installed machine = setInfoProperty go (toInfo [FlashKernelInstalled])
        go = "/etc/flash-kernel/machine" `File.hasContent` [machine]
                `onChange` flashKernel
                `requires` File.dirExists "/etc/flash-kernel"
                `requires` Apt.installed ["flash-kernel"]

-- | Runs flash-kernel with whatever machine `installed` configured.
flashKernel :: Property DebianLike
flashKernel = tightenTargets $
        cmdProperty "flash-kernel" [] `assume` MadeChange

-- | Runs flash-kernel in the system mounted at a particular directory.
flashKernelMounted :: FilePath -> Property Linux
flashKernelMounted mnt = combineProperties desc $ props
        -- remove mounts that are done below to make sure the right thing
        -- gets mounted
        & cleanupmounts
        & bindMount "/dev" (inmnt "/dev")
        & mounted "proc" "proc" (inmnt "/proc") mempty
        & mounted "sysfs" "sys" (inmnt "/sys") mempty
        -- update the initramfs so it gets the uuid of the root partition
        & inchroot "update-initramfs" ["-u"]
                `assume` MadeChange
        & inchroot "flash-kernel" []
                `assume` MadeChange
        & cleanupmounts
        desc = "flash-kernel run"

        -- cannot use </> since the filepath is absolute
        inmnt f = mnt ++ f

        inchroot cmd ps = cmdProperty "chroot" ([mnt, cmd] ++ ps)

        cleanupmounts :: Property Linux
        cleanupmounts = property desc $ liftIO $ do
                cleanup "/sys"
                cleanup "/proc"
                cleanup "/dev"
                return NoChange
                cleanup m =
                        let mp = inmnt m
                        in whenM (isMounted mp) $
                                umountLazy mp