package multisig

import (
	"fmt"

	"github.com/minio/blake2b-simd"
	"golang.org/x/xerrors"

	"github.com/filecoin-project/go-address"
	"github.com/filecoin-project/go-state-types/abi"

	multisig2 "github.com/filecoin-project/specs-actors/v2/actors/builtin/multisig"

	"github.com/filecoin-project/lotus/chain/actors"
	"github.com/filecoin-project/lotus/chain/types"
)

func Message(version actors.Version, from address.Address) MessageBuilder {
	switch version {
	case actors.Version0:
		return message0{from}
	case actors.Version2:
		return message2{message0{from}}
	default:
		panic(fmt.Sprintf("unsupported actors version: %d", version))
	}
}

type MessageBuilder interface {
	// Create a new multisig with the specified parameters.
	Create(signers []address.Address, threshold uint64,
		vestingStart, vestingDuration abi.ChainEpoch,
		initialAmount abi.TokenAmount) (*types.Message, error)

	// Propose a transaction to the given multisig.
	Propose(msig, target address.Address, amt abi.TokenAmount,
		method abi.MethodNum, params []byte) (*types.Message, error)

	// Approve a multisig transaction. The "hash" is optional.
	Approve(msig address.Address, txID uint64, hash *ProposalHashData) (*types.Message, error)

	// Cancel a multisig transaction. The "hash" is optional.
	Cancel(msig address.Address, txID uint64, hash *ProposalHashData) (*types.Message, error)
}

// this type is the same between v0 and v2
type ProposalHashData = multisig2.ProposalHashData

func txnParams(id uint64, data *ProposalHashData) ([]byte, error) {
	params := multisig2.TxnIDParams{ID: multisig2.TxnID(id)}
	if data != nil {
		if data.Requester.Protocol() != address.ID {
			return nil, xerrors.Errorf("proposer address must be an ID address, was %s", data.Requester)
		}
		if data.Value.Sign() == -1 {
			return nil, xerrors.Errorf("proposal value must be non-negative, was %s", data.Value)
		}
		if data.To == address.Undef {
			return nil, xerrors.Errorf("proposed destination address must be set")
		}
		pser, err := data.Serialize()
		if err != nil {
			return nil, err
		}
		hash := blake2b.Sum256(pser)
		params.ProposalHash = hash[:]
	}

	return actors.SerializeParams(&params)
}