package app

import (
	"encoding/json"
	"github.com/cosmos/ethermint/x/evm"
	"os"

	bam "github.com/cosmos/cosmos-sdk/baseapp"
	"github.com/cosmos/cosmos-sdk/codec"
	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"
	distrclient "github.com/cosmos/cosmos-sdk/x/distribution/client"
	"github.com/cosmos/cosmos-sdk/x/genaccounts"
	"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"
	"github.com/cosmos/cosmos-sdk/x/slashing"
	"github.com/cosmos/cosmos-sdk/x/staking"
	"github.com/cosmos/cosmos-sdk/x/supply"

	"github.com/cosmos/ethermint/crypto"
	evmtypes "github.com/cosmos/ethermint/x/evm/types"

	abci "github.com/tendermint/tendermint/abci/types"
	dbm "github.com/tendermint/tendermint/libs/db"
	tmlog "github.com/tendermint/tendermint/libs/log"
	tmtypes "github.com/tendermint/tendermint/types"
)

const appName = "Ethermint"

var (
	// 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")

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

// MakeCodec generates the necessary codecs for Amino
func MakeCodec() *codec.Codec {
	var cdc = codec.New()

	// TODO: Move this codec to module (Issue #12 https://github.com/ChainSafe/ethermint/issues/12)
	crypto.RegisterCodec(cdc)

	ModuleBasics.RegisterCodec(cdc)
	sdk.RegisterCodec(cdc)
	codec.RegisterCrypto(cdc)
	return cdc
}

// 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
	keyMain     *sdk.KVStoreKey
	keyAccount  *sdk.KVStoreKey
	keySupply   *sdk.KVStoreKey
	keyStaking  *sdk.KVStoreKey
	tkeyStaking *sdk.TransientStoreKey
	keySlashing *sdk.KVStoreKey
	keyMint     *sdk.KVStoreKey
	keyDistr    *sdk.KVStoreKey
	tkeyDistr   *sdk.TransientStoreKey
	keyGov      *sdk.KVStoreKey
	keyParams   *sdk.KVStoreKey
	tkeyParams  *sdk.TransientStoreKey
	evmStoreKey *sdk.KVStoreKey
	evmCodeKey  *sdk.KVStoreKey

	// 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
	evmKeeper      evm.Keeper

	// the module manager
	mm *module.Manager
}

// 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 tmlog.Logger, db dbm.DB, loadLatest bool,
	invCheckPeriod uint, baseAppOptions ...func(*bam.BaseApp)) *EthermintApp {
	cdc := MakeCodec()

	baseApp := bam.NewBaseApp(appName, logger, db, evmtypes.TxDecoder(cdc), baseAppOptions...)
	baseApp.SetAppVersion(version.Version)

	var app = &EthermintApp{
		BaseApp:        baseApp,
		cdc:            cdc,
		invCheckPeriod: invCheckPeriod,
		keyMain:        sdk.NewKVStoreKey(bam.MainStoreKey),
		keyAccount:     sdk.NewKVStoreKey(auth.StoreKey),
		keyStaking:     sdk.NewKVStoreKey(staking.StoreKey),
		keySupply:      sdk.NewKVStoreKey(supply.StoreKey),
		tkeyStaking:    sdk.NewTransientStoreKey(staking.TStoreKey),
		keyMint:        sdk.NewKVStoreKey(mint.StoreKey),
		keyDistr:       sdk.NewKVStoreKey(distr.StoreKey),
		tkeyDistr:      sdk.NewTransientStoreKey(distr.TStoreKey),
		keySlashing:    sdk.NewKVStoreKey(slashing.StoreKey),
		keyGov:         sdk.NewKVStoreKey(gov.StoreKey),
		keyParams:      sdk.NewKVStoreKey(params.StoreKey),
		tkeyParams:     sdk.NewTransientStoreKey(params.TStoreKey),
		evmStoreKey:    sdk.NewKVStoreKey(evmtypes.EvmStoreKey),
		evmCodeKey:     sdk.NewKVStoreKey(evmtypes.EvmCodeKey),
	}

	// init params keeper and subspaces
	app.paramsKeeper = params.NewKeeper(app.cdc, app.keyParams, app.tkeyParams, params.DefaultCodespace)
	authSubspace := app.paramsKeeper.Subspace(auth.DefaultParamspace)
	bankSubspace := app.paramsKeeper.Subspace(bank.DefaultParamspace)
	stakingSubspace := app.paramsKeeper.Subspace(staking.DefaultParamspace)
	mintSubspace := app.paramsKeeper.Subspace(mint.DefaultParamspace)
	distrSubspace := app.paramsKeeper.Subspace(distr.DefaultParamspace)
	slashingSubspace := app.paramsKeeper.Subspace(slashing.DefaultParamspace)
	govSubspace := app.paramsKeeper.Subspace(gov.DefaultParamspace)
	crisisSubspace := app.paramsKeeper.Subspace(crisis.DefaultParamspace)

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

	// add keepers
	app.accountKeeper = auth.NewAccountKeeper(app.cdc, app.keyAccount, authSubspace, auth.ProtoBaseAccount)
	app.bankKeeper = bank.NewBaseKeeper(app.accountKeeper, bankSubspace, bank.DefaultCodespace)
	app.supplyKeeper = supply.NewKeeper(app.cdc, app.keySupply, app.accountKeeper, app.bankKeeper, supply.DefaultCodespace, maccPerms)
	stakingKeeper := staking.NewKeeper(app.cdc, app.keyStaking, app.tkeyStaking,
		app.supplyKeeper, stakingSubspace, staking.DefaultCodespace)
	app.mintKeeper = mint.NewKeeper(app.cdc, app.keyMint, mintSubspace, &stakingKeeper, app.supplyKeeper, auth.FeeCollectorName)
	app.distrKeeper = distr.NewKeeper(app.cdc, app.keyDistr, distrSubspace, &stakingKeeper,
		app.supplyKeeper, distr.DefaultCodespace, auth.FeeCollectorName)
	app.slashingKeeper = slashing.NewKeeper(app.cdc, app.keySlashing, &stakingKeeper,
		slashingSubspace, slashing.DefaultCodespace)
	app.crisisKeeper = crisis.NewKeeper(crisisSubspace, invCheckPeriod, app.supplyKeeper, auth.FeeCollectorName)
	app.evmKeeper = evm.NewKeeper(app.accountKeeper, app.evmStoreKey, app.evmCodeKey, cdc)

	// register the proposal types
	govRouter := gov.NewRouter()
	govRouter.AddRoute(gov.RouterKey, gov.ProposalHandler).
		AddRoute(params.RouterKey, params.NewParamChangeProposalHandler(app.paramsKeeper)).
		AddRoute(distr.RouterKey, distr.NewCommunityPoolSpendProposalHandler(app.distrKeeper))
	app.govKeeper = gov.NewKeeper(app.cdc, app.keyGov, app.paramsKeeper, govSubspace,
		app.supplyKeeper, &stakingKeeper, gov.DefaultCodespace, 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()))

	app.mm = module.NewManager(
		genaccounts.NewAppModule(app.accountKeeper),
		genutil.NewAppModule(app.accountKeeper, app.stakingKeeper, app.BaseApp.DeliverTx),
		auth.NewAppModule(app.accountKeeper),
		bank.NewAppModule(app.bankKeeper, app.accountKeeper),
		crisis.NewAppModule(app.crisisKeeper),
		supply.NewAppModule(app.supplyKeeper, app.accountKeeper),
		distr.NewAppModule(app.distrKeeper, app.supplyKeeper),
		gov.NewAppModule(app.govKeeper, app.supplyKeeper),
		mint.NewAppModule(app.mintKeeper),
		slashing.NewAppModule(app.slashingKeeper, app.stakingKeeper),
		staking.NewAppModule(app.stakingKeeper, app.distrKeeper, app.accountKeeper, app.supplyKeeper),
		evm.NewAppModule(app.evmKeeper),
	)

	// 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(mint.ModuleName, distr.ModuleName, slashing.ModuleName)

	app.mm.SetOrderEndBlockers(gov.ModuleName, staking.ModuleName)

	// genutils must occur after staking so that pools are properly
	// initialized with tokens from genesis accounts.
	app.mm.SetOrderInitGenesis(genaccounts.ModuleName, supply.ModuleName, distr.ModuleName,
		staking.ModuleName, auth.ModuleName, bank.ModuleName, slashing.ModuleName,
		gov.ModuleName, mint.ModuleName, crisis.ModuleName, genutil.ModuleName, evmtypes.ModuleName)

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

	// initialize stores
	app.MountStores(app.keyMain, app.keyAccount, app.keySupply, app.keyStaking,
		app.keyMint, app.keyDistr, app.keySlashing, app.keyGov, app.keyParams,
		app.tkeyParams, app.tkeyStaking, app.tkeyDistr, app.evmStoreKey, app.evmCodeKey)

	// initialize BaseApp
	app.SetInitChainer(app.InitChainer)
	app.SetBeginBlocker(app.BeginBlocker)
	app.SetAnteHandler(auth.NewAnteHandler(app.accountKeeper, app.supplyKeeper, auth.DefaultSigVerificationGasConsumer))
	app.SetEndBlocker(app.EndBlocker)

	if loadLatest {
		err := app.LoadLatestVersion(app.keyMain)
		if err != nil {
			panic(err)
		}
	}
	return app

}

// The genesis state of the blockchain is represented here as a map of raw json
// messages key'd by a identifier string.
type GenesisState map[string]json.RawMessage

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

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

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

// load a particular height
func (app *EthermintApp) LoadHeight(height int64) error {
	return app.LoadVersion(height, app.keyMain)
}

// ExportAppStateAndValidators exports the state of the application for a genesis
// file.
func (app *EthermintApp) ExportAppStateAndValidators(forZeroHeight bool, jailWhiteList []string,
) (appState json.RawMessage, validators []tmtypes.GenesisValidator, err error) {

	// Creates context with current height and checks txs for ctx to be usable by start of next block
	ctx := app.NewContext(true, abci.Header{Height: app.LastBlockHeight()})

	// Export genesis to be used by SDK modules
	genState := app.mm.ExportGenesis(ctx)
	appState, err = codec.MarshalJSONIndent(app.cdc, genState)
	if err != nil {
		return nil, nil, err
	}

	// Write validators to staking module to be used by TM node
	validators = staking.WriteValidators(ctx, app.stakingKeeper)

	return appState, validators, nil
}