package simulation

import (
	"encoding/json"
	"fmt"
	"math/rand"
	"time"

	"cosmossdk.io/math"
	"cosmossdk.io/x/slashing/types"

	"github.com/cosmos/cosmos-sdk/types/module"
	"github.com/cosmos/cosmos-sdk/types/simulation"
)

// Simulation parameter constants
const (
	SignedBlocksWindow      = "signed_blocks_window"
	MinSignedPerWindow      = "min_signed_per_window"
	DowntimeJailDuration    = "downtime_jail_duration"
	SlashFractionDoubleSign = "slash_fraction_double_sign"
	SlashFractionDowntime   = "slash_fraction_downtime"
)

// GenSignedBlocksWindow randomized SignedBlocksWindow
func GenSignedBlocksWindow(r *rand.Rand) int64 {
	return int64(simulation.RandIntBetween(r, 10, 1000))
}

// GenMinSignedPerWindow randomized MinSignedPerWindow
func GenMinSignedPerWindow(r *rand.Rand) math.LegacyDec {
	return math.LegacyNewDecWithPrec(int64(r.Intn(10)), 1)
}

// GenDowntimeJailDuration randomized DowntimeJailDuration
func GenDowntimeJailDuration(r *rand.Rand) time.Duration {
	return time.Duration(simulation.RandIntBetween(r, 60, 60*60*24)) * time.Second
}

// GenSlashFractionDoubleSign randomized SlashFractionDoubleSign
func GenSlashFractionDoubleSign(r *rand.Rand) math.LegacyDec {
	return math.LegacyNewDec(1).Quo(math.LegacyNewDec(int64(r.Intn(50) + 1)))
}

// GenSlashFractionDowntime randomized SlashFractionDowntime
func GenSlashFractionDowntime(r *rand.Rand) math.LegacyDec {
	return math.LegacyNewDec(1).Quo(math.LegacyNewDec(int64(r.Intn(200) + 1)))
}

// RandomizedGenState generates a random GenesisState for slashing
func RandomizedGenState(simState *module.SimulationState) {
	var signedBlocksWindow int64
	simState.AppParams.GetOrGenerate(SignedBlocksWindow, &signedBlocksWindow, simState.Rand, func(r *rand.Rand) { signedBlocksWindow = GenSignedBlocksWindow(r) })

	var minSignedPerWindow math.LegacyDec
	simState.AppParams.GetOrGenerate(MinSignedPerWindow, &minSignedPerWindow, simState.Rand, func(r *rand.Rand) { minSignedPerWindow = GenMinSignedPerWindow(r) })

	var downtimeJailDuration time.Duration
	simState.AppParams.GetOrGenerate(DowntimeJailDuration, &downtimeJailDuration, simState.Rand, func(r *rand.Rand) { downtimeJailDuration = GenDowntimeJailDuration(r) })

	var slashFractionDoubleSign math.LegacyDec
	simState.AppParams.GetOrGenerate(SlashFractionDoubleSign, &slashFractionDoubleSign, simState.Rand, func(r *rand.Rand) { slashFractionDoubleSign = GenSlashFractionDoubleSign(r) })

	var slashFractionDowntime math.LegacyDec
	simState.AppParams.GetOrGenerate(SlashFractionDowntime, &slashFractionDowntime, simState.Rand, func(r *rand.Rand) { slashFractionDowntime = GenSlashFractionDowntime(r) })

	params := types.NewParams(
		signedBlocksWindow, minSignedPerWindow, downtimeJailDuration,
		slashFractionDoubleSign, slashFractionDowntime,
	)

	slashingGenesis := types.NewGenesisState(params, []types.SigningInfo{}, []types.ValidatorMissedBlocks{})

	bz, err := json.MarshalIndent(&slashingGenesis, "", " ")
	if err != nil {
		panic(err)
	}
	fmt.Printf("Selected randomly generated slashing parameters:\n%s\n", bz)
	simState.GenState[types.ModuleName] = simState.Cdc.MustMarshalJSON(slashingGenesis)
}