package rpc

import (
	"fmt"
	"net"
	"strings"
	"time"

	"github.com/ethereum/go-ethereum/rpc"
	"github.com/harmony-one/harmony/hmy"
	nodeconfig "github.com/harmony-one/harmony/internal/configs/node"
	"github.com/harmony-one/harmony/internal/utils"
	v1 "github.com/harmony-one/harmony/rpc/v1"
	v2 "github.com/harmony-one/harmony/rpc/v2"
)

// Version enum
const (
	V1 Version = iota
	V2
)

const (
	// APIVersion used for DApp's, bumped after RPC refactor (7/2020)
	APIVersion = "1.1"
	// CallTimeout is the timeout given to all contract calls
	CallTimeout = 5 * time.Second
	// LogTag is the tag found in the log for all RPC logs
	LogTag = "[RPC]"
	// HTTPPortOffset ..
	HTTPPortOffset = 500
	// WSPortOffset ..
	WSPortOffset = 800

	netV1Namespace = "net"
	netV2Namespace = "netv2"
)

var (
	// HTTPModules ..
	HTTPModules = []string{"hmy", "hmyv2", netV1Namespace, netV2Namespace, "explorer"}
	// WSModules ..
	WSModules = []string{"hmy", "hmyv2", netV1Namespace, netV2Namespace, "web3"}

	httpListener     net.Listener
	httpHandler      *rpc.Server
	wsListener       net.Listener
	wsHandler        *rpc.Server
	httpEndpoint     = ""
	wsEndpoint       = ""
	httpVirtualHosts = []string{"*"}
	httpTimeouts     = rpc.DefaultHTTPTimeouts
	httpOrigins      = []string{"*"}
	wsOrigins        = []string{"*"}
)

// Version of the RPC
type Version int

// Namespace of the RPC version
func (n Version) Namespace() string {
	return HTTPModules[n]
}

// StartServers starts the http & ws servers
func StartServers(hmy *hmy.Harmony, apis []rpc.API, config nodeconfig.RPCServerConfig) error {
	apis = append(apis, getAPIs(hmy, config.DebugEnabled)...)

	if config.HTTPEnabled {
		httpEndpoint = fmt.Sprintf("%v:%v", config.HTTPIp, config.HTTPPort)
		if err := startHTTP(apis); err != nil {
			return err
		}
	}

	if config.WSEnabled {
		wsEndpoint = fmt.Sprintf("%v:%v", config.WSIp, config.WSPort)
		if err := startWS(apis); err != nil {
			return err
		}
	}

	return nil
}

// StopServers stops the http & ws servers
func StopServers() error {
	if httpListener != nil {
		if err := httpListener.Close(); err != nil {
			return err
		}
		httpListener = nil
		utils.Logger().Info().
			Str("url", fmt.Sprintf("http://%s", httpEndpoint)).
			Msg("HTTP endpoint closed")
	}
	if httpHandler != nil {
		httpHandler.Stop()
		httpHandler = nil
	}
	if wsListener != nil {
		if err := wsListener.Close(); err != nil {
			return err
		}
		wsListener = nil
		utils.Logger().Info().
			Str("url", fmt.Sprintf("http://%s", wsEndpoint)).
			Msg("WS endpoint closed")
	}
	if wsHandler != nil {
		wsHandler.Stop()
		wsHandler = nil
	}
	return nil
}

// getAPIs returns all the API methods for the RPC interface
func getAPIs(hmy *hmy.Harmony, debugEnable bool) []rpc.API {
	publicAPIs := []rpc.API{
		// Public methods
		NewPublicHarmonyAPI(hmy, V1),
		NewPublicHarmonyAPI(hmy, V2),
		NewPublicBlockchainAPI(hmy, V1),
		NewPublicBlockchainAPI(hmy, V2),
		NewPublicContractAPI(hmy, V1),
		NewPublicContractAPI(hmy, V2),
		NewPublicTransactionAPI(hmy, V1),
		NewPublicTransactionAPI(hmy, V2),
		NewPublicPoolAPI(hmy, V1),
		NewPublicPoolAPI(hmy, V2),
		NewPublicStakingAPI(hmy, V1),
		NewPublicStakingAPI(hmy, V2),
		// Legacy methods (subject to removal)
		v1.NewPublicLegacyAPI(hmy),
		v2.NewPublicLegacyAPI(hmy),
	}

	privateAPIs := []rpc.API{
		NewPrivateDebugAPI(hmy, V1),
		NewPrivateDebugAPI(hmy, V2),
	}

	if debugEnable {
		return append(publicAPIs, privateAPIs...)
	}
	return publicAPIs
}

func startHTTP(apis []rpc.API) (err error) {
	httpListener, httpHandler, err = rpc.StartHTTPEndpoint(
		httpEndpoint, apis, HTTPModules, httpOrigins, httpVirtualHosts, httpTimeouts,
	)
	if err != nil {
		return err
	}

	utils.Logger().Info().
		Str("url", fmt.Sprintf("http://%s", httpEndpoint)).
		Str("cors", strings.Join(httpOrigins, ",")).
		Str("vhosts", strings.Join(httpVirtualHosts, ",")).
		Msg("HTTP endpoint opened")
	return nil
}

func startWS(apis []rpc.API) (err error) {
	wsListener, wsHandler, err = rpc.StartWSEndpoint(wsEndpoint, apis, WSModules, wsOrigins, true)
	if err != nil {
		return err
	}

	utils.Logger().Info().
		Str("url", fmt.Sprintf("ws://%s", wsListener.Addr())).
		Msg("WebSocket endpoint opened")
	return nil
}