package simulation

import (
	"math/rand"

	"cosmossdk.io/x/protocolpool/keeper"
	"cosmossdk.io/x/protocolpool/types"

	"github.com/cosmos/cosmos-sdk/client"
	"github.com/cosmos/cosmos-sdk/codec"
	sdk "github.com/cosmos/cosmos-sdk/types"
	simtypes "github.com/cosmos/cosmos-sdk/types/simulation"
	"github.com/cosmos/cosmos-sdk/x/simulation"
)

// Simulation operation weights constants
const (
	OpWeightMsgFundCommunityPool = "op_weight_msg_fund_community_pool"

	DefaultWeightMsgFundCommunityPool int = 50
)

// WeightedOperations returns all the operations from the module with their respective weights
func WeightedOperations(
	appParams simtypes.AppParams,
	cdc codec.JSONCodec,
	txConfig client.TxConfig,
	ak types.AccountKeeper,
	bk types.BankKeeper,
	k keeper.Keeper,
) simulation.WeightedOperations {
	var weightMsgFundCommunityPool int
	appParams.GetOrGenerate(OpWeightMsgFundCommunityPool, &weightMsgFundCommunityPool, nil, func(_ *rand.Rand) {
		weightMsgFundCommunityPool = DefaultWeightMsgFundCommunityPool
	})

	return simulation.WeightedOperations{
		simulation.NewWeightedOperation(
			weightMsgFundCommunityPool,
			SimulateMsgFundCommunityPool(txConfig, ak, bk, k),
		),
	}
}

// SimulateMsgFundCommunityPool simulates MsgFundCommunityPool execution where
// a random account sends a random amount of its funds to the community pool.
func SimulateMsgFundCommunityPool(txConfig client.TxConfig, ak types.AccountKeeper, bk types.BankKeeper, k keeper.Keeper) simtypes.Operation {
	return func(
		r *rand.Rand, app simtypes.AppEntrypoint, ctx sdk.Context, accs []simtypes.Account, chainID string,
	) (simtypes.OperationMsg, []simtypes.FutureOperation, error) {
		funder, _ := simtypes.RandomAcc(r, accs)

		account := ak.GetAccount(ctx, funder.Address)
		spendable := bk.SpendableCoins(ctx, account.GetAddress())

		fundAmount := simtypes.RandSubsetCoins(r, spendable)
		if fundAmount.Empty() {
			return simtypes.NoOpMsg(types.ModuleName, sdk.MsgTypeURL(&types.MsgFundCommunityPool{}), "fund amount is empty"), nil, nil
		}

		var (
			fees sdk.Coins
			err  error
		)

		coins, hasNeg := spendable.SafeSub(fundAmount...)
		if !hasNeg {
			fees, err = simtypes.RandomFees(r, coins)
			if err != nil {
				return simtypes.NoOpMsg(types.ModuleName, sdk.MsgTypeURL(&types.MsgFundCommunityPool{}), "unable to generate fees"), nil, err
			}
		}

		funderAddr, err := ak.AddressCodec().BytesToString(funder.Address)
		if err != nil {
			return simtypes.NoOpMsg(types.ModuleName, sdk.MsgTypeURL(&types.MsgFundCommunityPool{}), "unable to get funder address"), nil, err
		}
		msg := types.NewMsgFundCommunityPool(fundAmount, funderAddr)

		txCtx := simulation.OperationInput{
			R:             r,
			App:           app,
			TxGen:         txConfig,
			Cdc:           nil,
			Msg:           msg,
			Context:       ctx,
			SimAccount:    funder,
			AccountKeeper: ak,
			ModuleName:    types.ModuleName,
		}

		return simulation.GenAndDeliverTx(txCtx, fees)
	}
}