package polycat

import (
	"context"
	"math/big"

	"git.lehouerou.net/laurent/evm"
	"git.lehouerou.net/laurent/evm/polycat/contracts"
	"github.com/ethereum/go-ethereum/accounts/abi/bind"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/pkg/errors"
	"github.com/shopspring/decimal"
)

const RewardLockerAddress = "0xE0e44d4E7e61f2f4f990f5F4e2408D2187315C94"

type RewardLockerService struct {
	client   evm.Client
	contract *contracts.RewardLocker
}

func NewRewardLockerService(c evm.Client) (*RewardLockerService, error) {
	contract, err := contracts.NewRewardLocker(common.HexToAddress(RewardLockerAddress), c)
	if err != nil {
		return nil, errors.Wrap(err, "init contract")
	}
	return &RewardLockerService{
		contract: contract,
		client:   c,
	}, nil
}

func (s *RewardLockerService) ClaimAll(ctx context.Context, token common.Address, opts ...evm.ExecutionOption) (evm.Transaction, error) {
	schedcount, err := s.contract.NumVestingSchedules(&bind.CallOpts{}, s.client.PublicAddress(), token)
	if err != nil {
		return nil, errors.Wrap(err, "getting schedule count")
	}
	return s.client.Execute(ctx, func(ctx context.Context, options *evm.TransactOpts) (*types.Transaction, error) {
		return s.contract.VestSchedulesInRange(options.TransactOpts, token, big.NewInt(0), decimal.NewFromBigInt(schedcount, 0).Sub(decimal.NewFromInt(1)).BigInt())
	}, opts...)
}

func (s *RewardLockerService) GetClaimableReward(ctx context.Context, token common.Address) (decimal.Decimal, error) {
	scheds, err := s.contract.GetVestingSchedules(&bind.CallOpts{}, s.client.PublicAddress(), token)
	if err != nil {
		return decimal.Zero, errors.Wrap(err, "getting vesting schedules")
	}
	var tot decimal.Decimal
	block, err := s.client.CurrentBlockNumber(ctx)
	if err != nil {
		return decimal.Zero, errors.Wrap(err, "getting current block")
	}
	for _, sched := range scheds {
		tot = tot.Add(GetVestingQuantity(sched, block))
	}
	return tot, nil
}

func GetVestingQuantity(sched contracts.IRewardLockerVestingSchedule, block uint64) decimal.Decimal {
	if block >= sched.EndBlock {
		return decimal.NewFromBigInt(sched.Quantity, -18).Sub(decimal.NewFromBigInt(sched.VestedQuantity, -18))
	}
	if block <= sched.StartBlock {
		return decimal.Zero
	}

	lockduration := sched.EndBlock - sched.StartBlock
	passedDuration := block - sched.StartBlock
	return decimal.NewFromBigInt(sched.Quantity, -18).Mul(decimal.NewFromInt(int64(passedDuration))).Div(decimal.NewFromInt(int64(lockduration))).Sub(decimal.NewFromBigInt(sched.VestedQuantity, -18))
}

func (s *RewardLockerService) GetLockedReward(token common.Address) (decimal.Decimal, error) {
	scheds, err := s.contract.GetVestingSchedules(&bind.CallOpts{}, s.client.PublicAddress(), token)
	if err != nil {
		return decimal.Zero, errors.Wrap(err, "getting vesting schedules")
	}
	var tot decimal.Decimal
	for _, sched := range scheds {
		tot = tot.Add(decimal.NewFromBigInt(sched.Quantity, -18).Sub(decimal.NewFromBigInt(sched.VestedQuantity, -18)))
	}
	return tot, nil
}