summaryrefslogtreecommitdiff
path: root/src/Erebos/State.hs
blob: 79f17b72e8d7a2b030e78eafb8e182e1be62d31e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
module Erebos.State (
    LocalState(..),
    SharedState, SharedType(..),
    SharedTypeID, mkSharedTypeID,

    MonadHead(..),
    updateLocalHead_,

    loadLocalStateHead,

    updateSharedState, updateSharedState_,
    lookupSharedValue, makeSharedStateUpdate,

    localIdentity,
    headLocalIdentity,

    mergeSharedIdentity,
    updateSharedIdentity,
    interactiveIdentityUpdate,
) where

import Control.Monad.Except
import Control.Monad.Reader

import Data.ByteString (ByteString)
import Data.ByteString.Char8 qualified as BC
import Data.Foldable
import Data.Maybe
import Data.Text qualified as T
import Data.Text.IO qualified as T
import Data.Typeable
import Data.UUID (UUID)
import Data.UUID qualified as U

import System.IO

import Erebos.Identity
import Erebos.Object
import Erebos.PubKey
import Erebos.Storable
import Erebos.Storage.Head
import Erebos.Storage.Merge

data LocalState = LocalState
    { lsIdentity :: Stored (Signed ExtendedIdentityData)
    , lsShared :: [Stored SharedState]
    , lsOther :: [ ( ByteString, RecItem ) ]
    }

data SharedState = SharedState
    { ssPrev :: [Stored SharedState]
    , ssType :: Maybe SharedTypeID
    , ssValue :: [Ref]
    }

newtype SharedTypeID = SharedTypeID UUID
    deriving (Eq, Ord, StorableUUID)

mkSharedTypeID :: String -> SharedTypeID
mkSharedTypeID = maybe (error "Invalid shared type ID") SharedTypeID . U.fromString

class Mergeable a => SharedType a where
    sharedTypeID :: proxy a -> SharedTypeID

instance Storable LocalState where
    store' LocalState {..} = storeRec $ do
        storeRef "id" lsIdentity
        mapM_ (storeRef "shared") lsShared
        storeRecItems lsOther

    load' = loadRec $ do
        lsIdentity <- loadRef "id"
        lsShared <- loadRefs "shared"
        lsOther <- filter ((`notElem` [ BC.pack "id", BC.pack "shared" ]) . fst) <$> loadRecItems
        return LocalState {..}

instance HeadType LocalState where
    headTypeID _ = mkHeadTypeID "1d7491a9-7bcb-4eaa-8f13-c8c4c4087e4e"

instance Storable SharedState where
    store' st = storeRec $ do
        mapM_ (storeRef "PREV") $ ssPrev st
        storeMbUUID "type" $ ssType st
        mapM_ (storeRawRef "value") $ ssValue st

    load' = loadRec $ SharedState
        <$> loadRefs "PREV"
        <*> loadMbUUID "type"
        <*> loadRawRefs "value"

instance SharedType (Maybe ComposedIdentity) where
    sharedTypeID _ = mkSharedTypeID "0c6c1fe0-f2d7-4891-926b-c332449f7871"


class (MonadIO m, MonadStorage m) => MonadHead a m where
    updateLocalHead :: (Stored a -> m (Stored a, b)) -> m b
    getLocalHead :: m (Stored a)
    getLocalHead = updateLocalHead $ \x -> return (x, x)

updateLocalHead_ :: MonadHead a m => (Stored a -> m (Stored a)) -> m ()
updateLocalHead_ f = updateLocalHead (fmap (,()) . f)

instance (HeadType a, MonadIO m) => MonadHead a (ReaderT (Head a) m) where
    updateLocalHead f = do
        h <- ask
        snd <$> updateHead h f


loadLocalStateHead :: MonadIO m => Storage -> m (Head LocalState)
loadLocalStateHead st = loadHeads st >>= \case
    (h:_) -> return h
    [] -> liftIO $ do
        putStr "Name: "
        hFlush stdout
        name <- T.getLine

        putStr "Device: "
        hFlush stdout
        devName <- T.getLine

        owner <- if
            | T.null name -> return Nothing
            | otherwise -> Just <$> createIdentity st (Just name) Nothing

        identity <- createIdentity st (if T.null devName then Nothing else Just devName) owner

        shared <- wrappedStore st $ SharedState
            { ssPrev = []
            , ssType = Just $ sharedTypeID @(Maybe ComposedIdentity) Proxy
            , ssValue = [storedRef $ idExtData $ fromMaybe identity owner]
            }
        storeHead st $ LocalState
            { lsIdentity = idExtData identity
            , lsShared = [ shared ]
            , lsOther = []
            }

localIdentity :: LocalState -> UnifiedIdentity
localIdentity ls = maybe (error "failed to verify local identity")
    (updateOwners $ maybe [] idExtDataF $ lookupSharedValue $ lsShared ls)
    (validateExtendedIdentity $ lsIdentity ls)

headLocalIdentity :: Head LocalState -> UnifiedIdentity
headLocalIdentity = localIdentity . headObject


updateSharedState_ :: forall a m. (SharedType a, MonadHead LocalState m) => (a -> m a) -> Stored LocalState -> m (Stored LocalState)
updateSharedState_ f = fmap fst <$> updateSharedState (fmap (,()) . f)

updateSharedState :: forall a b m. (SharedType a, MonadHead LocalState m) => (a -> m (a, b)) -> Stored LocalState -> m (Stored LocalState, b)
updateSharedState f = \ls -> do
    let shared = lsShared $ fromStored ls
        val = lookupSharedValue shared
    st <- getStorage
    (val', x) <- f val
    (,x) <$> if toComponents val' == toComponents val
                then return ls
                else do shared' <- makeSharedStateUpdate st val' shared
                        wrappedStore st (fromStored ls) { lsShared = [shared'] }

lookupSharedValue :: forall a. SharedType a => [Stored SharedState] -> a
lookupSharedValue = mergeSorted . filterAncestors . map wrappedLoad . concatMap (ssValue . fromStored) . filterAncestors . helper
    where helper (x:xs) | Just sid <- ssType (fromStored x), sid == sharedTypeID @a Proxy = x : helper xs
                        | otherwise = helper $ ssPrev (fromStored x) ++ xs
          helper [] = []

makeSharedStateUpdate :: forall a m. MonadIO m => SharedType a => Storage -> a -> [Stored SharedState] -> m (Stored SharedState)
makeSharedStateUpdate st val prev = liftIO $ wrappedStore st SharedState
    { ssPrev = prev
    , ssType = Just $ sharedTypeID @a Proxy
    , ssValue = storedRef <$> toComponents val
    }


mergeSharedIdentity :: (MonadHead LocalState m, MonadError String m) => m UnifiedIdentity
mergeSharedIdentity = updateLocalHead $ updateSharedState $ \case
    Just cidentity -> do
        identity <- mergeIdentity cidentity
        return (Just $ toComposedIdentity identity, identity)
    Nothing -> throwError "no existing shared identity"

updateSharedIdentity :: (MonadHead LocalState m, MonadError String m) => m ()
updateSharedIdentity = updateLocalHead_ $ updateSharedState_ $ \case
    Just identity -> do
        Just . toComposedIdentity <$> interactiveIdentityUpdate identity
    Nothing -> throwError "no existing shared identity"

interactiveIdentityUpdate :: (Foldable f, MonadStorage m, MonadIO m, MonadError String m) => Identity f -> m UnifiedIdentity
interactiveIdentityUpdate identity = do
    let public = idKeyIdentity identity

    name <- liftIO $ do
        T.putStr $ T.concat $ concat
            [ [ T.pack "Name" ]
            , case idName identity of
                   Just name -> [T.pack " [", name, T.pack "]"]
                   Nothing -> []
            , [ T.pack ": " ]
            ]
        hFlush stdout
        T.getLine

    if  | T.null name -> mergeIdentity identity
        | otherwise -> do
            secret <- loadKey public
            maybe (throwError "created invalid identity") return . validateIdentity =<<
                mstore =<< sign secret =<< mstore (emptyIdentityData public)
                { iddPrev = toList $ idDataF identity
                , iddName = Just name
                }