import abi "github.com/filecoin-project/specs-actors/actors/abi"
import sector_index "github.com/filecoin-project/specs/systems/filecoin_mining/sector_index"

type UInt64 UInt

// TODO: move this to somewhere the blockchain can import
// candidates:
// - filproofs - may have to learn about Sectors (and if we move Seal stuff, Deals)
// - "blockchain/builtins" or something like that - a component in the blockchain that handles storage verification
type PoStSubmission struct {
    PostProof   abi.PoStProof
    ChainEpoch  abi.ChainEpoch
}

type PoStGenerator struct {
    SectorStore sector_index.SectorStore

    GeneratePoStCandidates(
        challengeSeed   abi.PoStRandomness
        candidateCount  UInt
        sectors         [abi.SectorID]
    ) [abi.PoStCandidate]

    CreateElectionPoStProof(
        randomness  abi.PoStRandomness
        witness     [abi.PoStCandidate]
    ) [abi.PoStProof]

    CreateSurprisePoStProof(
        randomness  abi.PoStRandomness
        witness     [abi.PoStCandidate]
    ) [abi.PoStProof]

    // FIXME: Verification shouldn't require a PoStGenerator. Move this.
    VerifyPoStProof(
        Proof          abi.PoStProof
        challengeSeed  abi.PoStRandomness
    ) bool
}

package poster

import (
	abi "github.com/filecoin-project/specs-actors/actors/abi"
	filproofs "github.com/filecoin-project/specs/libraries/filcrypto/filproofs"
	util "github.com/filecoin-project/specs/util"
)

type Serialization = util.Serialization

// See "Proof-of-Spacetime Parameters" Section
// TODO: Unify with orient model.
const POST_CHALLENGE_DEADLINE = uint(480)

func (pg *PoStGenerator_I) GeneratePoStCandidates(challengeSeed abi.PoStRandomness, candidateCount int, sectors []abi.SectorID) []abi.PoStCandidate {
	// Question: Should we pass metadata into FilProofs so it can interact with SectorStore directly?
	// Like this:
	// PoStReponse := SectorStorageSubsystem.GeneratePoSt(sectorSize, challenge, faults, sectorsMetatada);

	// Question: Or should we resolve + manifest trees here and pass them in?
	// Like this:
	// trees := sectorsMetadata.map(func(md) { SectorStorage.GetMerkleTree(md.MerkleTreePath) });
	// Done this way, we redundantly pass the tree paths in the metadata. At first thought, the other way
	// seems cleaner.
	// PoStReponse := SectorStorageSubsystem.GeneratePoSt(sectorSize, challenge, faults, sectorsMetadata, trees);

	// For now, dodge this by passing the whole SectorStore. Once we decide how we want to represent this, we can narrow the call.

	return filproofs.GenerateElectionPoStCandidates(challengeSeed, sectors, candidateCount, pg.SectorStore())
}

func (pg *PoStGenerator_I) CreateElectionPoStProof(randomness abi.PoStRandomness, postCandidates []abi.PoStCandidate) []abi.PoStProof {
	var privateProofs []abi.PrivatePoStCandidateProof

	for _, candidate := range postCandidates {
		privateProofs = append(privateProofs, candidate.PrivateProof)
	}

	return filproofs.CreateElectionPoStProof(privateProofs, randomness)
}

func (pg *PoStGenerator_I) CreateSurprisePoStProof(randomness abi.PoStRandomness, postCandidates []abi.PoStCandidate) []abi.PoStProof {
	var privateProofs []abi.PrivatePoStCandidateProof

	for _, candidate := range postCandidates {
		privateProofs = append(privateProofs, candidate.PrivateProof)
	}

	return filproofs.CreateSurprisePoStProof(privateProofs, randomness)
}