From cfca7a6af77a674ed5a3f68b1bc1a2d9db8e2524 Mon Sep 17 00:00:00 2001
From: rymnc <43716372+rymnc@users.noreply.github.com>
Date: Wed, 14 Dec 2022 18:47:30 +0530
Subject: [PATCH] feat(rln-relay): group manager api

---
 .../protocol/waku_rln_relay/group_manager.nim |   6 +
 .../group_manager/group_manager_base.nim      |  66 ++++++++++
 .../waku_rln_relay/group_manager/on_chain.nim |   3 +
 .../group_manager/on_chain/group_manager.nim  | 118 ++++++++++++++++++
 .../waku_rln_relay/group_manager/static.nim   |   3 +
 .../group_manager/static/group_manager.nim    |  97 ++++++++++++++
 6 files changed, 293 insertions(+)
 create mode 100644 waku/v2/protocol/waku_rln_relay/group_manager.nim
 create mode 100644 waku/v2/protocol/waku_rln_relay/group_manager/group_manager_base.nim
 create mode 100644 waku/v2/protocol/waku_rln_relay/group_manager/on_chain.nim
 create mode 100644 waku/v2/protocol/waku_rln_relay/group_manager/on_chain/group_manager.nim
 create mode 100644 waku/v2/protocol/waku_rln_relay/group_manager/static.nim
 create mode 100644 waku/v2/protocol/waku_rln_relay/group_manager/static/group_manager.nim

diff --git a/waku/v2/protocol/waku_rln_relay/group_manager.nim b/waku/v2/protocol/waku_rln_relay/group_manager.nim
new file mode 100644
index 0000000000..1e1a17b488
--- /dev/null
+++ b/waku/v2/protocol/waku_rln_relay/group_manager.nim
@@ -0,0 +1,6 @@
+import 
+    group_manager/[static, on_chain]
+
+export
+    static,
+    on_chain
\ No newline at end of file
diff --git a/waku/v2/protocol/waku_rln_relay/group_manager/group_manager_base.nim b/waku/v2/protocol/waku_rln_relay/group_manager/group_manager_base.nim
new file mode 100644
index 0000000000..432e6eac6f
--- /dev/null
+++ b/waku/v2/protocol/waku_rln_relay/group_manager/group_manager_base.nim
@@ -0,0 +1,66 @@
+# This module contains the GroupManagerBase interface
+# The GroupManager is responsible for managing the group state
+# It should be used to register new members, and withdraw existing members
+# It should also be used to sync the group state with the rest of the group members
+
+type OnRegisterCallback* = proc (registrations: seq[(IDCommitment, MembershipIndex)]) {.async, gcsafe.}
+type OnWithdrawCallback* = proc (withdrawals: seq[(IDCommitment, MembershipIndex)]) {.async, gcsafe.}
+
+type 
+    GroupManagerBase*[Config] = ref object of RootObj
+        idCredentials*: Option[IdentityCredentials]
+        onRegisterCb: Option[OnRegisterCallback]
+        onWithdrawCb: Option[OnWithdrawCallback]
+        config*: Config
+        rlnInstance: ptr RLN
+        initialized*: bool
+
+# This method is used to initialize the group manager
+# Any initialization logic should be implemented here
+method init*(g: GroupManagerBase): Result[void] {.async,base.} =
+    return err("init method for " & $g.kind & " is not implemented yet")
+
+# This method is used to start the group sync process
+# It should be used to sync the group state with the rest of the group members
+method startGroupSync*(g: GroupManagerBase): Result[void] {.async,base.} =
+    return err("startGroupSync method for " & $g.kind & " is not implemented yet")
+
+# This method is used to register a new identity commitment into the merkle tree
+# The user may or may not have the identity secret to this commitment
+# It should be used when detecting new members in the group, and syncing the group state
+method register*(g: GroupManagerBase, idCommitment: IDCommitment): Result[void] {.async,base.} = 
+    return err("register method for " & $g.kind & " is not implemented yet")
+
+# This method is used to register a new identity commitment into the merkle tree
+# The user should have the identity secret to this commitment
+# It should be used when the user wants to join the group
+method register*(g: GroupManagerBase, credentials: IdentityCredentials): Result[void] {.async,base.} = 
+    return err("register method for " & $g.kind & " is not implemented yet")
+
+# This method is used to register a batch of new identity commitments into the merkle tree
+# The user may or may not have the identity secret to these commitments
+# It should be used when detecting a batch of new members in the group, and syncing the group state
+method registerBatch*(g: GroupManagerBase, idCommitments: seq[IDCommitment]): Result[void] {.async,base.} = 
+    return err("registerBatch method for " & $g.kind & " is not implemented yet")
+
+# This method is used to set a callback that will be called when a new identity commitment is registered
+# The callback may be called multiple times, and should be used to for any post processing
+method onRegister*(g: GroupManagerBase, cb: OnRegisterCallback): Result[void] {.base.} = 
+    g.onRegisterCb = some(cb)
+    return ok()
+
+# This method is used to withdraw/remove an identity commitment from the merkle tree
+# The user should have the identity secret hash to this commitment, by either deriving it, or owning it
+method withdraw*(g: GroupManagerBase, identitySecretHash: IdentitySecretHash): Result[void] {.async,base.} = 
+    return err("withdraw method for " & $g.kind & " is not implemented yet")
+
+# This method is used to withdraw/remove a batch of identity commitments from the merkle tree
+# The user should have the identity secret hash to these commitments, by either deriving them, or owning them
+method withdrawBatch*(g: GroupManagerBase, identitySecretHashes: seq[IdentitySecretHash]): Result[void] {.async,base.} =
+    return err("withdrawBatch method for " & $g.kind & " is not implemented yet")
+
+# This method is used to set a callback that will be called when an identity commitment is withdrawn
+# The callback may be called multiple times, and should be used to for any post processing
+method onWithdraw*(g: GroupManagerBase, cb: OnRegisterCallback): Result[void] {.base.} =
+    g.onWithdrawCb = some(cb)
+    return ok()
diff --git a/waku/v2/protocol/waku_rln_relay/group_manager/on_chain.nim b/waku/v2/protocol/waku_rln_relay/group_manager/on_chain.nim
new file mode 100644
index 0000000000..e6a900f973
--- /dev/null
+++ b/waku/v2/protocol/waku_rln_relay/group_manager/on_chain.nim
@@ -0,0 +1,3 @@
+import on_chain/group_manager
+
+export group_manager
\ No newline at end of file
diff --git a/waku/v2/protocol/waku_rln_relay/group_manager/on_chain/group_manager.nim b/waku/v2/protocol/waku_rln_relay/group_manager/on_chain/group_manager.nim
new file mode 100644
index 0000000000..1036ba7ed2
--- /dev/null
+++ b/waku/v2/protocol/waku_rln_relay/group_manager/on_chain/group_manager.nim
@@ -0,0 +1,118 @@
+import 
+    ../group_manager_base
+
+type
+    RlnContractWithSender = Sender[RlnContract]
+    OnchainGroupManagerConfig* = object
+        ethClientUrl*: string
+        ethPrivateKey*: Option[string]
+        ethContractAddress*: string
+        ethRpc: Option[web3]
+        rlnContract: Option[RlnContractWithSender]
+        membershipFee: Option[Uint256]
+
+    OnchainGroupManager* = ref object of GroupManagerBase[OnchainGroupManagerConfig]
+
+template initializedGuard*(g: OnchainGroupManager): untyped =
+    if not g.initialized:
+        return err("OnchainGroupManager is not initialized")
+
+method init*(g: OnchainGroupManager): Result[void] {.async.} =
+    var web3: Web3
+    var contract: RlnContractWithSender
+    # check if the Ethereum client is reachable
+    try:
+        web3 = some(await newWeb3(ethClientAddress))
+    except:
+        return err("could not connect to the Ethereum client")
+
+    contract = some(web3.contractSender(RlnContract, g.config.ethContractAddress))
+
+    # check if the contract exists by calling a static method
+    var membershipFee: uint64
+    try:
+        membershipFee = await contract.MEMBERSHIP_DEPOSIT()
+    except:
+        return err("could not get the membership deposit")
+
+    if g.config.ethPrivateKey.isSome():
+        let pk = g.config.ethPrivateKey.get()
+        web3.privateKey = pk
+
+    g.config.ethRpc = some(web3)
+    g.config.rlnContract = some(contract)
+    g.config.membershipFee = some(membershipFee)
+    
+    g.initialized = true
+    return ok()
+
+method startGroupSync*(g: OnchainGroupManager): Result[void] {.async.} =
+    initializedGuard(g)
+
+    if g.config.ethPrivateKey.isSome():
+        # TODO: use register() after generating credentials
+        debug "registering commitment on contract"
+        await g.register(g.config.idCredentials)
+
+    # TODO: set up the contract event listener and block listener
+
+    
+method register*(g: OnchainGroupManager, idCommitment: IDCommitment): Result[void] {.async.} =
+    initializedGuard(g)
+
+    let memberInserted = g.rlnInstance.insertMember(idCommitment)
+    if not memberInserted:
+        return err("Failed to insert member into the merkle tree")
+
+    if g.onRegisterCb.isSome():
+        await g.onRegisterCb.get()(@[idCommitment])
+
+    return ok()
+
+method register*(g: OnchainGroupManager, identityCredentials: IdentityCredentials): Result[void] {.async.} =
+    initializedGuard(g)
+
+    # TODO: interact with the contract
+    let ethRpc = g.config.ethRpc.get()
+    let rlnContract = g.config.rlnContract.get()
+    let membershipFee = g.config.membershipFee.get()
+
+    let gasPrice = int(await ethRpc.provider.eth_gasPrice()) * 2
+    let idCommitment = identityCredentials.idCommitment.toUInt256()
+    
+    var txHash: TxHash
+    try: # send the registration transaction and check if any error occurs
+        txHash = await rlnContract.register(pk).send(value = membershipFee, gasPrice = gasPrice)
+    except ValueError as e:
+        return err("registration transaction failed: " & e.msg)
+
+    let tsReceipt = await ethRpc.getMinedTransactionReceipt(txHash)
+
+    # the receipt topic holds the hash of signature of the raised events
+    # TODO: make this robust. search within the event list for the event
+    let firstTopic = tsReceipt.logs[0].topics[0]
+    # the hash of the signature of MemberRegistered(uint256,uint256) event is equal to the following hex value
+    if firstTopic[0..65] != "0x5a92c2530f207992057b9c3e544108ffce3beda4a63719f316967c49bf6159d2":
+        return err("invalid event signature hash")
+
+    # the arguments of the raised event i.e., MemberRegistered are encoded inside the data field
+    # data = pk encoded as 256 bits || index encoded as 256 bits
+    let arguments = tsReceipt.logs[0].data
+    debug "tx log data", arguments=arguments
+    let
+        argumentsBytes = arguments.hexToSeqByte()
+        # In TX log data, uints are encoded in big endian
+        eventIndex =  UInt256.fromBytesBE(argumentsBytes[32..^1])
+
+    # don't handle member insertion into the tree here, it will be handled by the event listener
+    return ok()
+
+method withdraw*(g: OnchainGroupManager, idCommitment: IDCommitment): Result[void] {.async.} =
+    initializedGuard(g)
+
+    # TODO: after slashing is enabled on the contract
+
+method withdrawBatch*(g: OnchainGroupManager, idCommitments: seq[IDCommitment]): Result[void] {.async.} =
+    initializedGuard(g)
+
+    # TODO: after slashing is enabled on the contract
\ No newline at end of file
diff --git a/waku/v2/protocol/waku_rln_relay/group_manager/static.nim b/waku/v2/protocol/waku_rln_relay/group_manager/static.nim
new file mode 100644
index 0000000000..64a0f8ec3a
--- /dev/null
+++ b/waku/v2/protocol/waku_rln_relay/group_manager/static.nim
@@ -0,0 +1,3 @@
+import static/group_manager
+
+export group_manager
\ No newline at end of file
diff --git a/waku/v2/protocol/waku_rln_relay/group_manager/static/group_manager.nim b/waku/v2/protocol/waku_rln_relay/group_manager/static/group_manager.nim
new file mode 100644
index 0000000000..070add17c0
--- /dev/null
+++ b/waku/v2/protocol/waku_rln_relay/group_manager/static/group_manager.nim
@@ -0,0 +1,97 @@
+import 
+    ../group_manager_base
+
+type
+    StaticGroupManagerConfig* = object
+        rawGroupKeys*: seq[string]
+        groupKeys*: Option[seq[IdentityCredentials]]
+        groupSize*: uint
+        membershipIndex*: MembershipIndex
+
+    StaticGroupManager* = ref object of GroupManagerBase[StaticGroupManagerConfig]
+
+template initializedGuard*(g: StaticGroupManager): untyped =
+    if not g.initialized:
+        return err("StaticGroupManager is not initialized")
+
+method init*(g: StaticGroupManager): Result[void] =
+    let
+        rawGroupKeys = g.config.rawGroupKeys
+        groupSize = g.config.groupSize
+        membershipIndex = g.config.membershipIndex
+    
+    if membershipIndex < MembershipIndex(0) or membershipIndex >= MembershipIndex(groupSize):
+        return err("Invalid membership index. Must be within 0 and " & $(groupSize - 1) & "but was " & $membershipIndex)
+
+    let parsedGroupKeys = rawGroupKeys.map(parseGroupKey)
+    if parsedGroupKeys.anyIt(it.isErr):
+        return err("Invalid group key: " & $parsedGroupKeys.findIt(it.isErr).getErr())
+
+    g.config.groupKeys = some(parsedGroupKeys.mapIt(it.get()))
+    g.idCredentials = g.config.groupKeys[membershipIndex]
+
+    # Seed the received commitments into the merkle tree
+    let membersInserted = g.rlnInstance.insertMembers(g.config.groupKeys.mapIt(it.idCommitment))
+    if not membersInserted:
+        return err("Failed to insert members into the merkle tree")
+
+    g.initialized = true
+    return ok()
+
+method startGroupSync*(g: StaticGroupManager): Result[void] {.async.} =
+    initializedGuard(g)
+    # No-op
+    return ok()
+    
+method register*(g: StaticGroupManager, idCommitment: IDCommitment): Result[void] {.async.} =
+    initializedGuard(g)
+
+    let memberInserted = g.rlnInstance.insertMember(idCommitment)
+    if not memberInserted:
+        return err("Failed to insert member into the merkle tree")
+
+    if g.onRegisterCb.isSome():
+        await g.onRegisterCb.get()(@[idCommitment])
+
+    return ok()
+
+
+method registerBatch*(g: StaticGroupManager, idCommitments: seq[IDCommitment]): Result[void] {.async.} =
+    initializedGuard(g)
+
+    let membersInserted = g.rlnInstance.insertMembers(idCommitments)
+    if not membersInserted:
+        return err("Failed to insert members into the merkle tree")
+
+    if g.onRegisterCb.isSome():
+        await g.onRegisterCb.get()(idCommitments)
+    
+    return ok()
+
+method withdraw*(g: StaticGroupManager, idSecretHash: IdentitySecretHash): Result[void] {.async.} =
+    initializedGuard(g)
+
+    let groupKeys = g.config.groupKeys.get()
+    let idCommitment = groupKeys.findIt(it.idSecretHash == idSecretHash).get().idCommitment
+    let memberRemoved = g.rlnInstance.removeMember(idCommitment)
+    if not memberRemoved:
+        return err("Failed to remove member from the merkle tree")
+
+    if g.onWithdrawCb.isSome():
+        await g.onWithdrawCb.get()(@[idCommitment])
+
+    return ok()
+
+method withdrawBatch*(g: StaticGroupManager, idSecretHashes: seq[IdentitySecretHash]): Result[void] {.async.} =
+    initializedGuard(g)
+
+    let groupKeys = g.config.groupKeys.get()
+    let identityCommitments = idSecretHashes.map(groupKeys.findIt(it.idSecretHash == idSecretHash).get().idCommitment)
+    let membersRemoved = g.rlnInstance.removeMembers(idCommitments)
+    if not membersRemoved:
+        return err("Failed to remove members from the merkle tree")
+
+    if g.onWithdrawCb.isSome():
+        await g.onWithdrawCb.get()(idCommitments)
+
+    return ok()
\ No newline at end of file