package app

import (
	"io"
	"os"

	bam "github.com/cosmos/cosmos-sdk/baseapp"
	"github.com/cosmos/cosmos-sdk/codec"
	"github.com/cosmos/cosmos-sdk/simapp"
	sdk "github.com/cosmos/cosmos-sdk/types"
	"github.com/cosmos/cosmos-sdk/types/module"
	"github.com/cosmos/cosmos-sdk/version"
	"github.com/cosmos/cosmos-sdk/x/auth"
	"github.com/cosmos/cosmos-sdk/x/bank"
	"github.com/cosmos/cosmos-sdk/x/crisis"
	distr "github.com/cosmos/cosmos-sdk/x/distribution"
	"github.com/cosmos/cosmos-sdk/x/evidence"
	"github.com/cosmos/cosmos-sdk/x/genutil"
	"github.com/cosmos/cosmos-sdk/x/gov"
	"github.com/cosmos/cosmos-sdk/x/mint"
	"github.com/cosmos/cosmos-sdk/x/params"
	paramsclient "github.com/cosmos/cosmos-sdk/x/params/client"
	paramproposal "github.com/cosmos/cosmos-sdk/x/params/types/proposal"
	"github.com/cosmos/cosmos-sdk/x/slashing"
	"github.com/cosmos/cosmos-sdk/x/staking"
	"github.com/cosmos/cosmos-sdk/x/supply"
	ethermintcodec "github.com/cosmos/ethermint/codec"

	"github.com/cosmos/ethermint/app/ante"
	eminttypes "github.com/cosmos/ethermint/types"
	"github.com/cosmos/ethermint/x/evm"
	"github.com/cosmos/ethermint/x/faucet"

	abci "github.com/tendermint/tendermint/abci/types"
	"github.com/tendermint/tendermint/libs/log"
	tmos "github.com/tendermint/tendermint/libs/os"
	dbm "github.com/tendermint/tm-db"
)

const appName = "Ethermint"

var (
	// DefaultCLIHome sets the default home directories for the application CLI
	DefaultCLIHome = os.ExpandEnv("$HOME/.emintcli")

	// DefaultNodeHome sets the folder where the applcation data and configuration will be stored
	DefaultNodeHome = os.ExpandEnv("$HOME/.emintd")

	// ModuleBasics defines the module BasicManager is in charge of setting up basic,
	// non-dependant module elements, such as codec registration
	// and genesis verification.
	ModuleBasics = module.NewBasicManager(
		auth.AppModuleBasic{},
		supply.AppModuleBasic{},
		genutil.AppModuleBasic{},
		bank.AppModuleBasic{},
		staking.AppModuleBasic{},
		mint.AppModuleBasic{},
		distr.AppModuleBasic{},
		gov.NewAppModuleBasic(
			paramsclient.ProposalHandler, distr.ProposalHandler,
		),
		params.AppModuleBasic{},
		crisis.AppModuleBasic{},
		slashing.AppModuleBasic{},
		evidence.AppModuleBasic{},
		evm.AppModuleBasic{},
		faucet.AppModuleBasic{},
	)

	// module account permissions
	maccPerms = map[string][]string{
		auth.FeeCollectorName:     nil,
		distr.ModuleName:          nil,
		mint.ModuleName:           {supply.Minter},
		staking.BondedPoolName:    {supply.Burner, supply.Staking},
		staking.NotBondedPoolName: {supply.Burner, supply.Staking},
		gov.ModuleName:            {supply.Burner},
		faucet.ModuleName:         {supply.Minter},
	}

	// module accounts that are allowed to receive tokens
	allowedReceivingModAcc = map[string]bool{
		distr.ModuleName: true,
	}
)

var _ simapp.App = (*EthermintApp)(nil)

// EthermintApp implements an extended ABCI application. It is an application
// that may process transactions through Ethereum's EVM running atop of
// Tendermint consensus.
type EthermintApp struct {
	*bam.BaseApp
	cdc *codec.Codec

	invCheckPeriod uint

	// keys to access the substores
	keys  map[string]*sdk.KVStoreKey
	tkeys map[string]*sdk.TransientStoreKey

	// subspaces
	subspaces map[string]params.Subspace

	// keepers
	AccountKeeper  auth.AccountKeeper
	BankKeeper     bank.Keeper
	SupplyKeeper   supply.Keeper
	StakingKeeper  staking.Keeper
	SlashingKeeper slashing.Keeper
	MintKeeper     mint.Keeper
	DistrKeeper    distr.Keeper
	GovKeeper      gov.Keeper
	CrisisKeeper   crisis.Keeper
	ParamsKeeper   params.Keeper
	EvidenceKeeper evidence.Keeper
	EvmKeeper      evm.Keeper
	FaucetKeeper   faucet.Keeper

	// the module manager
	mm *module.Manager

	// simulation manager
	sm *module.SimulationManager
}

// NewEthermintApp returns a reference to a new initialized Ethermint
// application.
//
// TODO: Ethermint needs to support being bootstrapped as an application running
// in a sovereign zone and as an application running with a shared security model.
// For now, it will support only running as a sovereign application.
func NewEthermintApp(
	logger log.Logger, db dbm.DB, traceStore io.Writer, loadLatest bool,
	invCheckPeriod uint, baseAppOptions ...func(*bam.BaseApp),
) *EthermintApp {

	cdc := ethermintcodec.MakeCodec(ModuleBasics)
	appCodec := ethermintcodec.NewAppCodec(cdc)

	// use custom Ethermint transaction decoder
	bApp := bam.NewBaseApp(appName, logger, db, evm.TxDecoder(cdc), baseAppOptions...)
	bApp.SetCommitMultiStoreTracer(traceStore)
	bApp.SetAppVersion(version.Version)

	keys := sdk.NewKVStoreKeys(
		bam.MainStoreKey, auth.StoreKey, bank.StoreKey, staking.StoreKey,
		supply.StoreKey, mint.StoreKey, distr.StoreKey, slashing.StoreKey,
		gov.StoreKey, params.StoreKey, evidence.StoreKey, evm.CodeKey, evm.StoreKey,
		faucet.StoreKey,
	)
	blockKey := sdk.NewKVStoreKey(evm.BlockKey)

	tkeys := sdk.NewTransientStoreKeys(params.TStoreKey)

	app := &EthermintApp{
		BaseApp:        bApp,
		cdc:            cdc,
		invCheckPeriod: invCheckPeriod,
		keys:           keys,
		tkeys:          tkeys,
		subspaces:      make(map[string]params.Subspace),
	}

	// init params keeper and subspaces
	app.ParamsKeeper = params.NewKeeper(appCodec, keys[params.StoreKey], tkeys[params.TStoreKey])
	app.subspaces[auth.ModuleName] = app.ParamsKeeper.Subspace(auth.DefaultParamspace)
	app.subspaces[bank.ModuleName] = app.ParamsKeeper.Subspace(bank.DefaultParamspace)
	app.subspaces[staking.ModuleName] = app.ParamsKeeper.Subspace(staking.DefaultParamspace)
	app.subspaces[mint.ModuleName] = app.ParamsKeeper.Subspace(mint.DefaultParamspace)
	app.subspaces[distr.ModuleName] = app.ParamsKeeper.Subspace(distr.DefaultParamspace)
	app.subspaces[slashing.ModuleName] = app.ParamsKeeper.Subspace(slashing.DefaultParamspace)
	app.subspaces[gov.ModuleName] = app.ParamsKeeper.Subspace(gov.DefaultParamspace).WithKeyTable(gov.ParamKeyTable())
	app.subspaces[crisis.ModuleName] = app.ParamsKeeper.Subspace(crisis.DefaultParamspace)
	app.subspaces[evidence.ModuleName] = app.ParamsKeeper.Subspace(evidence.DefaultParamspace)

	// use custom Ethermint account for contracts
	app.AccountKeeper = auth.NewAccountKeeper(
		appCodec, keys[auth.StoreKey], app.subspaces[auth.ModuleName], eminttypes.ProtoAccount,
	)
	app.BankKeeper = bank.NewBaseKeeper(
		appCodec, keys[bank.StoreKey], app.AccountKeeper, app.subspaces[bank.ModuleName], app.BlacklistedAccAddrs(),
	)
	app.SupplyKeeper = supply.NewKeeper(
		appCodec, keys[supply.StoreKey], app.AccountKeeper, app.BankKeeper, maccPerms,
	)
	stakingKeeper := staking.NewKeeper(
		appCodec, keys[staking.StoreKey], app.BankKeeper, app.SupplyKeeper, app.subspaces[staking.ModuleName],
	)
	app.MintKeeper = mint.NewKeeper(
		appCodec, keys[mint.StoreKey], app.subspaces[mint.ModuleName], &stakingKeeper,
		app.SupplyKeeper, auth.FeeCollectorName,
	)
	app.DistrKeeper = distr.NewKeeper(
		appCodec, keys[distr.StoreKey], app.subspaces[distr.ModuleName], app.BankKeeper, &stakingKeeper,
		app.SupplyKeeper, auth.FeeCollectorName, app.ModuleAccountAddrs(),
	)
	app.SlashingKeeper = slashing.NewKeeper(
		appCodec, keys[slashing.StoreKey], &stakingKeeper, app.subspaces[slashing.ModuleName],
	)
	app.CrisisKeeper = crisis.NewKeeper(
		app.subspaces[crisis.ModuleName], invCheckPeriod, app.SupplyKeeper, auth.FeeCollectorName,
	)
	app.EvmKeeper = evm.NewKeeper(
		app.cdc, blockKey, keys[evm.CodeKey], keys[evm.StoreKey], app.AccountKeeper,
		app.BankKeeper,
	)
	// TODO: use protobuf
	app.FaucetKeeper = faucet.NewKeeper(
		app.cdc, keys[faucet.StoreKey], app.SupplyKeeper,
	)

	// create evidence keeper with router
	evidenceKeeper := evidence.NewKeeper(
		appCodec, keys[evidence.StoreKey], app.subspaces[evidence.ModuleName], &app.StakingKeeper, app.SlashingKeeper,
	)
	evidenceRouter := evidence.NewRouter()
	// TODO: Register evidence routes.
	evidenceKeeper.SetRouter(evidenceRouter)
	app.EvidenceKeeper = *evidenceKeeper

	// register the proposal types
	govRouter := gov.NewRouter()
	govRouter.AddRoute(gov.RouterKey, gov.ProposalHandler).
		AddRoute(paramproposal.RouterKey, params.NewParamChangeProposalHandler(app.ParamsKeeper)).
		AddRoute(distr.RouterKey, distr.NewCommunityPoolSpendProposalHandler(app.DistrKeeper))
	app.GovKeeper = gov.NewKeeper(
		appCodec, keys[gov.StoreKey], app.subspaces[gov.ModuleName], app.SupplyKeeper,
		&stakingKeeper, govRouter,
	)

	// register the staking hooks
	// NOTE: stakingKeeper above is passed by reference, so that it will contain these hooks
	app.StakingKeeper = *stakingKeeper.SetHooks(
		staking.NewMultiStakingHooks(app.DistrKeeper.Hooks(), app.SlashingKeeper.Hooks()),
	)

	// NOTE: Any module instantiated in the module manager that is later modified
	// must be passed by reference here.
	app.mm = module.NewManager(
		genutil.NewAppModule(app.AccountKeeper, app.StakingKeeper, app.BaseApp.DeliverTx),
		auth.NewAppModule(app.AccountKeeper, app.SupplyKeeper),
		bank.NewAppModule(app.BankKeeper, app.AccountKeeper),
		crisis.NewAppModule(&app.CrisisKeeper),
		supply.NewAppModule(app.SupplyKeeper, app.BankKeeper, app.AccountKeeper),
		gov.NewAppModule(app.GovKeeper, app.AccountKeeper, app.BankKeeper, app.SupplyKeeper),
		mint.NewAppModule(app.MintKeeper, app.SupplyKeeper),
		slashing.NewAppModule(app.SlashingKeeper, app.AccountKeeper, app.BankKeeper, app.StakingKeeper),
		distr.NewAppModule(app.DistrKeeper, app.AccountKeeper, app.BankKeeper, app.SupplyKeeper, app.StakingKeeper),
		staking.NewAppModule(app.StakingKeeper, app.AccountKeeper, app.BankKeeper, app.SupplyKeeper),
		evidence.NewAppModule(app.EvidenceKeeper),
		evm.NewAppModule(app.EvmKeeper, app.AccountKeeper),
		faucet.NewAppModule(app.FaucetKeeper),
	)

	// During begin block slashing happens after distr.BeginBlocker so that
	// there is nothing left over in the validator fee pool, so as to keep the
	// CanWithdrawInvariant invariant.
	app.mm.SetOrderBeginBlockers(
		evm.ModuleName, mint.ModuleName, distr.ModuleName, slashing.ModuleName,
		evidence.ModuleName,
	)
	app.mm.SetOrderEndBlockers(
		evm.ModuleName, crisis.ModuleName, gov.ModuleName, staking.ModuleName,
	)

	// NOTE: The genutils module must occur after staking so that pools are
	// properly initialized with tokens from genesis accounts.
	app.mm.SetOrderInitGenesis(
		auth.ModuleName, distr.ModuleName, staking.ModuleName, bank.ModuleName,
		slashing.ModuleName, gov.ModuleName, mint.ModuleName, supply.ModuleName,
		crisis.ModuleName, genutil.ModuleName, evidence.ModuleName, evm.ModuleName,
		faucet.ModuleName,
	)

	app.mm.RegisterInvariants(&app.CrisisKeeper)
	app.mm.RegisterRoutes(app.Router(), app.QueryRouter())

	// create the simulation manager and define the order of the modules for deterministic simulations
	//
	// NOTE: this is not required apps that don't use the simulator for fuzz testing
	// transactions
	app.sm = module.NewSimulationManager(
		auth.NewAppModule(app.AccountKeeper, app.SupplyKeeper),
		bank.NewAppModule(app.BankKeeper, app.AccountKeeper),
		supply.NewAppModule(app.SupplyKeeper, app.BankKeeper, app.AccountKeeper),
		gov.NewAppModule(app.GovKeeper, app.AccountKeeper, app.BankKeeper, app.SupplyKeeper),
		mint.NewAppModule(app.MintKeeper, app.SupplyKeeper),
		staking.NewAppModule(app.StakingKeeper, app.AccountKeeper, app.BankKeeper, app.SupplyKeeper),
		distr.NewAppModule(app.DistrKeeper, app.AccountKeeper, app.BankKeeper, app.SupplyKeeper, app.StakingKeeper),
		slashing.NewAppModule(app.SlashingKeeper, app.AccountKeeper, app.BankKeeper, app.StakingKeeper),
		params.NewAppModule(), // NOTE: only used for simulation to generate randomized param change proposals
	)

	app.sm.RegisterStoreDecoders()

	// initialize stores
	app.MountKVStores(keys)
	app.MountTransientStores(tkeys)

	// Mount block hash mapping key as DB (no need for historical queries)
	// TODO: why does this need to be always StoreTypeDB?
	app.MountStore(blockKey, sdk.StoreTypeDB)

	// initialize BaseApp
	app.SetInitChainer(app.InitChainer)
	app.SetBeginBlocker(app.BeginBlocker)
	app.SetAnteHandler(ante.NewAnteHandler(app.AccountKeeper, app.BankKeeper, app.SupplyKeeper))
	app.SetEndBlocker(app.EndBlocker)

	if loadLatest {
		err := app.LoadLatestVersion(app.keys[bam.MainStoreKey])
		if err != nil {
			tmos.Exit(err.Error())
		}
	}

	return app
}

// Name returns the name of the App
func (app *EthermintApp) Name() string { return app.BaseApp.Name() }

// BeginBlocker updates every begin block
func (app *EthermintApp) BeginBlocker(ctx sdk.Context, req abci.RequestBeginBlock) abci.ResponseBeginBlock {
	return app.mm.BeginBlock(ctx, req)
}

// EndBlocker updates every end block
func (app *EthermintApp) EndBlocker(ctx sdk.Context, req abci.RequestEndBlock) abci.ResponseEndBlock {
	return app.mm.EndBlock(ctx, req)
}

// InitChainer updates at chain initialization
func (app *EthermintApp) InitChainer(ctx sdk.Context, req abci.RequestInitChain) abci.ResponseInitChain {
	var genesisState simapp.GenesisState
	app.cdc.MustUnmarshalJSON(req.AppStateBytes, &genesisState)
	return app.mm.InitGenesis(ctx, app.cdc, genesisState)
}

// LoadHeight loads state at a particular height
func (app *EthermintApp) LoadHeight(height int64) error {
	return app.LoadVersion(height, app.keys[bam.MainStoreKey])
}

// ModuleAccountAddrs returns all the app's module account addresses.
func (app *EthermintApp) ModuleAccountAddrs() map[string]bool {
	modAccAddrs := make(map[string]bool)
	for acc := range maccPerms {
		modAccAddrs[supply.NewModuleAddress(acc).String()] = true
	}

	return modAccAddrs
}

// BlacklistedAccAddrs returns all the app's module account addresses black listed for receiving tokens.
func (app *EthermintApp) BlacklistedAccAddrs() map[string]bool {
	blacklistedAddrs := make(map[string]bool)
	for acc := range maccPerms {
		blacklistedAddrs[supply.NewModuleAddress(acc).String()] = !allowedReceivingModAcc[acc]
	}

	return blacklistedAddrs
}

// SimulationManager implements the SimulationApp interface
func (app *EthermintApp) SimulationManager() *module.SimulationManager {
	return app.sm
}

// GetKey returns the KVStoreKey for the provided store key.
//
// NOTE: This is solely to be used for testing purposes.
func (app *EthermintApp) GetKey(storeKey string) *sdk.KVStoreKey {
	return app.keys[storeKey]
}

// Codec returns Ethermint's codec.
//
// NOTE: This is solely to be used for testing purposes as it may be desirable
// for modules to register their own custom testing types.
func (app *EthermintApp) Codec() *codec.Codec {
	return app.cdc
}

// GetMaccPerms returns a copy of the module account permissions
func GetMaccPerms() map[string][]string {
	dupMaccPerms := make(map[string][]string)
	for k, v := range maccPerms {
		dupMaccPerms[k] = v
	}
	return dupMaccPerms
}