{- git-annex repo sizes
 -
 - Copyright 2024 Joey Hess <id@joeyh.name>
 -
 - Licensed under the GNU AGPL version 3 or higher.
 -}

module Annex.RepoSize where

import Annex.Common
import Annex.Branch (UnmergedBranches(..))
import Types.RepoSize
import Logs.Location
import Logs.UUID
import Git.Types (Sha)

import qualified Data.Map.Strict as M

{- Sum up the sizes of all keys in all repositories, from the information
 - in the git-annex branch, but not the journal. Retuns the sha of the
 - branch commit that was used.
 -
 - The map includes the UUIDs of all known repositories, including
 - repositories that are empty.
 -
 - Note that private repositories, which do not get recorded in
 - the git-annex branch, will have 0 size. journalledRepoSizes
 - takes care of getting repo sizes for those.
 -}
calcBranchRepoSizes :: Annex (M.Map UUID RepoSize, Sha)
calcBranchRepoSizes = do
	knownuuids <- M.keys <$> uuidDescMap
	let startmap = M.fromList $ map (\u -> (u, RepoSize 0)) knownuuids
	overLocationLogs True startmap accumsizes >>= \case
		UnmergedBranches v -> return v
		NoUnmergedBranches v -> return v
  where
	accumsizes k locs m = return $
		foldl' (flip $ M.alter $ addKeyRepoSize k) m locs

{- Given the RepoSizes calculated from the git-annex branch, updates it with
 - data from journalled location logs.
  -}
journalledRepoSizes :: M.Map UUID RepoSize -> Sha -> Annex (M.Map UUID RepoSize)
journalledRepoSizes startmap branchsha =
	overLocationLogsJournal startmap branchsha accumsizes
  where
	accumsizes k (newlocs, removedlocs) m = return $
		let m' = foldl' (flip $ M.alter $ addKeyRepoSize k) m newlocs
		in foldl' (flip $ M.alter $ removeKeyRepoSize k) m' removedlocs

addKeyRepoSize :: Key -> Maybe RepoSize -> Maybe RepoSize
addKeyRepoSize k mrs = case mrs of
	Just (RepoSize sz) -> Just $ RepoSize $ sz + ksz
	Nothing -> Just $ RepoSize ksz
  where
	ksz = fromMaybe 0 $ fromKey keySize k

removeKeyRepoSize :: Key -> Maybe RepoSize -> Maybe RepoSize
removeKeyRepoSize k mrs = case mrs of
	Just (RepoSize sz) -> Just $ RepoSize $ sz - ksz
	Nothing -> Nothing
  where
	ksz = fromMaybe 0 $ fromKey keySize k