package config

import (
	"fmt"
	"io/ioutil"
	"time"

	"github.com/BurntSushi/toml"
	ethCommon "github.com/ethereum/go-ethereum/common"
	"github.com/hermeznetwork/hermez-node/common"
	"github.com/hermeznetwork/tracerr"
	"gopkg.in/go-playground/validator.v9"
)

// Duration is a wrapper type that parses time duration from text.
type Duration struct {
	time.Duration `validate:"required"`
}

// UnmarshalText unmarshalls time duration from text.
func (d *Duration) UnmarshalText(data []byte) error {
	duration, err := time.ParseDuration(string(data))
	if err != nil {
		return tracerr.Wrap(err)
	}
	d.Duration = duration
	return nil
}

// ServerProof is the server proof configuration data.
type ServerProof struct {
	// URL is the server proof API URL
	URL string `validate:"required"`
}

// Coordinator is the coordinator specific configuration.
type Coordinator struct {
	// ForgerAddress is the address under which this coordinator is forging
	ForgerAddress ethCommon.Address `validate:"required"`
	// ConfirmBlocks is the number of confirmation blocks to wait for sent
	// ethereum transactions before forgetting about them
	ConfirmBlocks int64 `validate:"required"`
	// L1BatchTimeoutPerc is the portion of the range before the L1Batch
	// timeout that will trigger a schedule to forge an L1Batch
	L1BatchTimeoutPerc float64 `validate:"required"`
	// ProofServerPollInterval is the waiting interval between polling the
	// ProofServer while waiting for a particular status
	ProofServerPollInterval Duration `validate:"required"`
	// SyncRetryInterval is the waiting interval between calls to the main
	// handler of a synced block after an error
	SyncRetryInterval Duration `validate:"required"`
	// L2DB is the DB that holds the pool of L2Txs
	L2DB struct {
		// SafetyPeriod is the number of batches after which
		// non-pending L2Txs are deleted from the pool
		SafetyPeriod common.BatchNum `validate:"required"`
		// MaxTxs is the number of L2Txs that once reached triggers
		// deletion of old L2Txs
		MaxTxs uint32 `validate:"required"`
		// TTL is the Time To Live for L2Txs in the pool.  Once MaxTxs
		// L2Txs is reached, L2Txs older than TTL will be deleted.
		TTL Duration `validate:"required"`
		// PurgeBatchDelay is the delay between batches to purge outdated transactions
		PurgeBatchDelay int64 `validate:"required"`
		// InvalidateBatchDelay is the delay between batches to mark invalid transactions
		InvalidateBatchDelay int64 `validate:"required"`
		// PurgeBlockDelay is the delay between blocks to purge outdated transactions
		PurgeBlockDelay int64 `validate:"required"`
		// InvalidateBlockDelay is the delay between blocks to mark invalid transactions
		InvalidateBlockDelay int64 `validate:"required"`
	} `validate:"required"`
	TxSelector struct {
		// Path where the TxSelector StateDB is stored
		Path string `validate:"required"`
	} `validate:"required"`
	BatchBuilder struct {
		// Path where the BatchBuilder StateDB is stored
		Path string `validate:"required"`
	} `validate:"required"`
	ServerProofs []ServerProof `validate:"required"`
	Circuit      struct {
		// VerifierIdx uint8  `validate:"required"`
		// MaxTx is the maximum number of txs supported by the circuit
		MaxTx int64 `validate:"required"`
		// NLevels is the maximum number of merkle tree levels
		// supported by the circuit
		NLevels int64 `validate:"required"`
	} `validate:"required"`
	EthClient struct {
		// CallGasLimit is the default gas limit set for ethereum
		// calls, except for methods  where a particular gas limit is
		// harcoded because it's known to be a big value
		CallGasLimit uint64 `validate:"required"`
		// GasPriceDiv is the gas price division
		GasPriceDiv uint64 `validate:"required"`
		// CheckLoopInterval is the waiting interval between receipt
		// checks of ethereum transactions in the TxManager
		CheckLoopInterval Duration `validate:"required"`
		// Attempts is the number of attempts to do an eth client RPC
		// call before giving up
		Attempts int `validate:"required"`
		// AttemptsDelay is delay between attempts do do an eth client
		// RPC call
		AttemptsDelay Duration `validate:"required"`
		// Keystore is the ethereum keystore where private keys are kept
		Keystore struct {
			// Path to the keystore
			Path string `validate:"required"`
			// Password used to decrypt the keys in the keystore
			Password string `validate:"required"`
		} `validate:"required"`
	} `validate:"required"`
	API struct {
		// Coordinator enables the coordinator API endpoints
		Coordinator bool
	} `validate:"required"`
	Debug struct {
		// BatchPath if set, specifies the path where batchInfo is stored
		// in JSON in every step/update of the pipeline
		BatchPath string
		// LightScrypt if set, uses light parameters for the ethereum
		// keystore encryption algorithm.
		LightScrypt bool
	}
}

// Node is the hermez node configuration.
type Node struct {
	PriceUpdater struct {
		// Interval between price updater calls
		Interval Duration `valudate:"required"`
		// URL of the token prices provider
		URL string `valudate:"required"`
		// Type of the API of the token prices provider
		Type string `valudate:"required"`
	} `validate:"required"`
	StateDB struct {
		// Path where the synchronizer StateDB is stored
		Path string `validate:"required"`
		// Keep is the number of checkpoints to keep
		Keep int `validate:"required"`
	} `validate:"required"`
	PostgreSQL struct {
		// Port of the PostgreSQL server
		Port int `validate:"required"`
		// Host of the PostgreSQL server
		Host string `validate:"required"`
		// User of the PostgreSQL server
		User string `validate:"required"`
		// Password of the PostgreSQL server
		Password string `validate:"required"`
		// Name of the PostgreSQL server database
		Name string `validate:"required"`
	} `validate:"required"`
	Web3 struct {
		// URL is the URL of the web3 ethereum-node RPC server
		URL string `validate:"required"`
	} `validate:"required"`
	Synchronizer struct {
		// SyncLoopInterval is the interval between attempts to
		// synchronize a new block from an ethereum node
		SyncLoopInterval Duration `validate:"required"`
		// StatsRefreshPeriod is the interval between updates of the
		// synchronizer state Eth parameters (`Eth.LastBlock` and
		// `Eth.LastBatch`)
		StatsRefreshPeriod Duration `validate:"required"`
	} `validate:"required"`
	SmartContracts struct {
		// Rollup is the address of the Hermez.sol smart contract
		Rollup ethCommon.Address `validate:"required"`
		// Rollup is the address of the HermezAuctionProtocol.sol smart
		// contract
		Auction ethCommon.Address `validate:"required"`
		// WDelayer is the address of the WithdrawalDelayer.sol smart
		// contract
		WDelayer ethCommon.Address `validate:"required"`
		// TokenHEZ is the address of the HEZTokenFull.sol smart
		// contract
		TokenHEZ ethCommon.Address `validate:"required"`
		// TokenHEZName is the name of the HEZ token deployed at
		// TokenHEZ address
		TokenHEZName string `validate:"required"`
	} `validate:"required"`
	API struct {
		// Address where the API will listen if set
		Address string
		// Explorer enables the Explorer API endpoints
		Explorer bool
		// UpdateMetricsInterval is the interval between updates of the
		// API metrics
		UpdateMetricsInterval Duration
		// UpdateMetricsInterval is the interval between updates of the
		// recommended fees
		UpdateRecommendedFeeInterval Duration
	} `validate:"required"`
	Debug struct {
		// APIAddress is the address where the debugAPI will listen if
		// set
		APIAddress string
		// MeddlerLogs enables meddler debug mode, where unused columns and struct
		// fields will be logged
		MeddlerLogs bool
	}
	Coordinator Coordinator `validate:"-"`
}

// Load loads a generic config.
func Load(path string, cfg interface{}) error {
	bs, err := ioutil.ReadFile(path) //nolint:gosec
	if err != nil {
		return tracerr.Wrap(err)
	}
	cfgToml := string(bs)
	if _, err := toml.Decode(cfgToml, cfg); err != nil {
		return tracerr.Wrap(err)
	}
	return nil
}

// LoadCoordinator loads the Coordinator configuration from path.
func LoadCoordinator(path string) (*Node, error) {
	var cfg Node
	if err := Load(path, &cfg); err != nil {
		return nil, tracerr.Wrap(fmt.Errorf("error loading node configuration file: %w", err))
	}
	validate := validator.New()
	if err := validate.Struct(cfg); err != nil {
		return nil, tracerr.Wrap(fmt.Errorf("error validating configuration file: %w", err))
	}
	if err := validate.Struct(cfg.Coordinator); err != nil {
		return nil, tracerr.Wrap(fmt.Errorf("error validating configuration file: %w", err))
	}
	return &cfg, nil
}

// LoadNode loads the Node configuration from path.
func LoadNode(path string) (*Node, error) {
	var cfg Node
	if err := Load(path, &cfg); err != nil {
		return nil, tracerr.Wrap(fmt.Errorf("error loading node configuration file: %w", err))
	}
	validate := validator.New()
	if err := validate.Struct(cfg); err != nil {
		return nil, tracerr.Wrap(fmt.Errorf("error validating configuration file: %w", err))
	}
	return &cfg, nil
}