use super::{process_registry_updates, process_slashings, EpochProcessingSummary, Error};
use crate::per_epoch_processing::{
    effective_balance_updates::process_effective_balance_updates,
    historical_roots_update::process_historical_roots_update,
    resets::{process_eth1_data_reset, process_randao_mixes_reset, process_slashings_reset},
    validator_statuses::ValidatorStatuses,
};
pub use inactivity_updates::process_inactivity_updates;
pub use justification_and_finalization::process_justification_and_finalization;
pub use participation_flag_updates::process_participation_flag_updates;
pub use rewards_and_penalties::process_rewards_and_penalties;
pub use sync_committee_updates::process_sync_committee_updates;
use types::{BeaconState, ChainSpec, EthSpec, RelativeEpoch};

pub mod inactivity_updates;
pub mod justification_and_finalization;
pub mod participation_flag_updates;
pub mod rewards_and_penalties;
pub mod sync_committee_updates;

pub fn process_epoch<T: EthSpec>(
    state: &mut BeaconState<T>,
    spec: &ChainSpec,
) -> Result<EpochProcessingSummary, Error> {
    // Ensure the committee caches are built.
    state.build_committee_cache(RelativeEpoch::Previous, spec)?;
    state.build_committee_cache(RelativeEpoch::Current, spec)?;
    state.build_committee_cache(RelativeEpoch::Next, spec)?;

    // Justification and finalization.
    process_justification_and_finalization(state, spec)?;

    process_inactivity_updates(state, spec)?;

    // Rewards and Penalties.
    process_rewards_and_penalties(state, spec)?;

    // Registry Updates.
    process_registry_updates(state, spec)?;

    // Slashings.
    process_slashings(
        state,
        state.get_total_active_balance(spec)?,
        spec.proportional_slashing_multiplier_altair,
        spec,
    )?;

    // Reset eth1 data votes.
    process_eth1_data_reset(state)?;

    // Update effective balances with hysteresis (lag).
    process_effective_balance_updates(state, spec)?;

    // Reset slashings
    process_slashings_reset(state)?;

    // Set randao mix
    process_randao_mixes_reset(state)?;

    // Set historical root accumulator
    process_historical_roots_update(state)?;

    // Rotate current/previous epoch participation
    process_participation_flag_updates(state)?;

    process_sync_committee_updates(state, spec)?;

    // Rotate the epoch caches to suit the epoch transition.
    state.advance_caches()?;

    // FIXME(altair): this is an incorrect dummy value, we should think harder
    // about how we want to unify validator statuses between phase0 & altair.
    // We should benchmark the new state transition and work out whether Altair could
    // be accelerated by some similar cache.
    let validator_statuses = ValidatorStatuses::new(state, spec)?;

    Ok(EpochProcessingSummary {
        total_balances: validator_statuses.total_balances,
        statuses: validator_statuses.statuses,
    })
}