# beacon_chain
# Copyright (c) 2021 Status Research & Development GmbH
# Licensed and distributed under either of
#   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
#   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.

{.push raises: [Defect].}

import
  stew/[assign2, results],
  serialization,
  eth/db/kvstore,
  ./spec/datatypes/[base, altair, merge],
  ./spec/[eth2_ssz_serialization, eth2_merkleization]

type
  # https://github.com/ethereum/consensus-specs/blob/v1.1.5/specs/phase0/beacon-chain.md#beaconstate
  # Memory-representation-equivalent to a phase0 BeaconState for in-place SSZ reading and writing
  Phase0BeaconStateNoImmutableValidators* = object
    # Versioning
    genesis_time*: uint64
    genesis_validators_root*: Eth2Digest
    slot*: Slot
    fork*: Fork

    # History
    latest_block_header*: BeaconBlockHeader ##\
    ## `latest_block_header.state_root == ZERO_HASH` temporarily

    block_roots*: HashArray[Limit SLOTS_PER_HISTORICAL_ROOT, Eth2Digest] ##\
    ## Needed to process attestations, older to newer

    state_roots*: HashArray[Limit SLOTS_PER_HISTORICAL_ROOT, Eth2Digest]
    historical_roots*: HashList[Eth2Digest, Limit HISTORICAL_ROOTS_LIMIT]

    # Eth1
    eth1_data*: Eth1Data
    eth1_data_votes*:
      HashList[Eth1Data, Limit(EPOCHS_PER_ETH1_VOTING_PERIOD * SLOTS_PER_EPOCH)]
    eth1_deposit_index*: uint64

    # Registry
    validators*: HashList[ValidatorStatus, Limit VALIDATOR_REGISTRY_LIMIT]
    balances*: HashList[uint64, Limit VALIDATOR_REGISTRY_LIMIT]

    # Randomness
    randao_mixes*: HashArray[Limit EPOCHS_PER_HISTORICAL_VECTOR, Eth2Digest]

    # Slashings
    slashings*: HashArray[Limit EPOCHS_PER_SLASHINGS_VECTOR, uint64] ##\
    ## Per-epoch sums of slashed effective balances

    # Attestations
    previous_epoch_attestations*:
      HashList[PendingAttestation, Limit(MAX_ATTESTATIONS * SLOTS_PER_EPOCH)]
    current_epoch_attestations*:
      HashList[PendingAttestation, Limit(MAX_ATTESTATIONS * SLOTS_PER_EPOCH)]

    # Finality
    justification_bits*: uint8 ##\
    ## Bit set for every recent justified epoch
    ## Model a Bitvector[4] as a one-byte uint, which should remain consistent
    ## with ssz/hashing.

    previous_justified_checkpoint*: Checkpoint ##\
    ## Previous epoch snapshot

    current_justified_checkpoint*: Checkpoint
    finalized_checkpoint*: Checkpoint

  # https://github.com/ethereum/consensus-specs/blob/v1.1.5/specs/altair/beacon-chain.md#beaconstate
  # Memory-representation-equivalent to an Altair BeaconState for in-place SSZ
  # reading and writing
  AltairBeaconStateNoImmutableValidators* = object
    # Versioning
    genesis_time*: uint64
    genesis_validators_root*: Eth2Digest
    slot*: Slot
    fork*: Fork

    # History
    latest_block_header*: BeaconBlockHeader ##\
    ## `latest_block_header.state_root == ZERO_HASH` temporarily

    block_roots*: HashArray[Limit SLOTS_PER_HISTORICAL_ROOT, Eth2Digest] ##\
    ## Needed to process attestations, older to newer

    state_roots*: HashArray[Limit SLOTS_PER_HISTORICAL_ROOT, Eth2Digest]
    historical_roots*: HashList[Eth2Digest, Limit HISTORICAL_ROOTS_LIMIT]

    # Eth1
    eth1_data*: Eth1Data
    eth1_data_votes*:
      HashList[Eth1Data, Limit(EPOCHS_PER_ETH1_VOTING_PERIOD * SLOTS_PER_EPOCH)]
    eth1_deposit_index*: uint64

    # Registry
    validators*: HashList[ValidatorStatus, Limit VALIDATOR_REGISTRY_LIMIT]
    balances*: HashList[uint64, Limit VALIDATOR_REGISTRY_LIMIT]

    # Randomness
    randao_mixes*: HashArray[Limit EPOCHS_PER_HISTORICAL_VECTOR, Eth2Digest]

    # Slashings
    slashings*: HashArray[Limit EPOCHS_PER_SLASHINGS_VECTOR, uint64] ##\
    ## Per-epoch sums of slashed effective balances

    # Participation
    previous_epoch_participation*:
      HashList[ParticipationFlags, Limit VALIDATOR_REGISTRY_LIMIT]
    current_epoch_participation*:
      HashList[ParticipationFlags, Limit VALIDATOR_REGISTRY_LIMIT]

    # Finality
    justification_bits*: uint8 ##\
    ## Bit set for every recent justified epoch
    ## Model a Bitvector[4] as a one-byte uint, which should remain consistent
    ## with ssz/hashing.

    previous_justified_checkpoint*: Checkpoint ##\
    ## Previous epoch snapshot

    current_justified_checkpoint*: Checkpoint
    finalized_checkpoint*: Checkpoint

    # Inactivity
    inactivity_scores*: HashList[uint64, Limit VALIDATOR_REGISTRY_LIMIT]  # [New in Altair]

    # Light client sync committees
    current_sync_committee*: SyncCommittee     # [New in Altair]
    next_sync_committee*: SyncCommittee        # [New in Altair]

  # https://github.com/ethereum/consensus-specs/blob/v1.1.3/specs/merge/beacon-chain.md#beaconstate
  # Memory-representation-equivalent to a Merge BeaconState for in-place SSZ
  # reading and writing
  MergeBeaconStateNoImmutableValidators* = object
    # Versioning
    genesis_time*: uint64
    genesis_validators_root*: Eth2Digest
    slot*: Slot
    fork*: Fork

    # History
    latest_block_header*: BeaconBlockHeader ##\
    ## `latest_block_header.state_root == ZERO_HASH` temporarily

    block_roots*: HashArray[Limit SLOTS_PER_HISTORICAL_ROOT, Eth2Digest] ##\
    ## Needed to process attestations, older to newer

    state_roots*: HashArray[Limit SLOTS_PER_HISTORICAL_ROOT, Eth2Digest]
    historical_roots*: HashList[Eth2Digest, Limit HISTORICAL_ROOTS_LIMIT]

    # Eth1
    eth1_data*: Eth1Data
    eth1_data_votes*:
      HashList[Eth1Data, Limit(EPOCHS_PER_ETH1_VOTING_PERIOD * SLOTS_PER_EPOCH)]
    eth1_deposit_index*: uint64

    # Registry
    validators*: HashList[ValidatorStatus, Limit VALIDATOR_REGISTRY_LIMIT]
    balances*: HashList[uint64, Limit VALIDATOR_REGISTRY_LIMIT]

    # Randomness
    randao_mixes*: HashArray[Limit EPOCHS_PER_HISTORICAL_VECTOR, Eth2Digest]

    # Slashings
    slashings*: HashArray[Limit EPOCHS_PER_SLASHINGS_VECTOR, uint64] ##\
    ## Per-epoch sums of slashed effective balances

    # Participation
    previous_epoch_participation*:
      HashList[ParticipationFlags, Limit VALIDATOR_REGISTRY_LIMIT]
    current_epoch_participation*:
      HashList[ParticipationFlags, Limit VALIDATOR_REGISTRY_LIMIT]

    # Finality
    justification_bits*: uint8 ##\
    ## Bit set for every recent justified epoch
    ## Model a Bitvector[4] as a one-byte uint, which should remain consistent
    ## with ssz/hashing.

    previous_justified_checkpoint*: Checkpoint ##\
    ## Previous epoch snapshot

    current_justified_checkpoint*: Checkpoint
    finalized_checkpoint*: Checkpoint

    # Inactivity
    inactivity_scores*: HashList[uint64, Limit VALIDATOR_REGISTRY_LIMIT]

    # Sync
    current_sync_committee*: SyncCommittee
    next_sync_committee*: SyncCommittee

    # Execution
    latest_execution_payload_header*: ExecutionPayloadHeader  # [New in Merge]