package main

import (
	"errors"
	"fmt"
	"os"
	"strconv"
	"time"

	"github.com/golang/protobuf/jsonpb"
	"github.com/golang/protobuf/proto"
	"github.com/lightninglabs/loop"
	"github.com/lightninglabs/loop/looprpc"
	"github.com/lightninglabs/loop/swap"

	"github.com/btcsuite/btcutil"

	"github.com/urfave/cli"
	"google.golang.org/grpc"
)

var (
	// Define route independent max routing fees. We have currently no way
	// to get a reliable estimate of the routing fees. Best we can do is
	// the minimum routing fees, which is not very indicative.
	maxRoutingFeeBase = btcutil.Amount(10)

	maxRoutingFeeRate = int64(50000)
)

func printRespJSON(resp proto.Message) {
	jsonMarshaler := &jsonpb.Marshaler{
		EmitDefaults: true,
		Indent:       "    ",
	}

	jsonStr, err := jsonMarshaler.MarshalToString(resp)
	if err != nil {
		fmt.Println("unable to decode response: ", err)
		return
	}

	fmt.Println(jsonStr)
}

func fatal(err error) {
	fmt.Fprintf(os.Stderr, "[loop] %v\n", err)
	os.Exit(1)
}

func main() {
	app := cli.NewApp()

	app.Version = loop.Version()
	app.Name = "loop"
	app.Usage = "control plane for your loopd"
	app.Flags = []cli.Flag{
		cli.StringFlag{
			Name:  "rpcserver",
			Value: "localhost:11010",
			Usage: "loopd daemon address host:port",
		},
	}
	app.Commands = []cli.Command{
		loopOutCommand, termsCommand, monitorCommand, quoteCommand,
	}

	err := app.Run(os.Args)
	if err != nil {
		fatal(err)
	}
}

func getClient(ctx *cli.Context) (looprpc.SwapClientClient, func(), error) {
	rpcServer := ctx.GlobalString("rpcserver")
	conn, err := getClientConn(rpcServer)
	if err != nil {
		return nil, nil, err
	}
	cleanup := func() { conn.Close() }

	loopClient := looprpc.NewSwapClientClient(conn)
	return loopClient, cleanup, nil
}

func getMaxRoutingFee(amt btcutil.Amount) btcutil.Amount {
	return swap.CalcFee(amt, maxRoutingFeeBase, maxRoutingFeeRate)
}

type limits struct {
	maxSwapRoutingFee   btcutil.Amount
	maxPrepayRoutingFee btcutil.Amount
	maxMinerFee         btcutil.Amount
	maxSwapFee          btcutil.Amount
	maxPrepayAmt        btcutil.Amount
}

func getLimits(amt btcutil.Amount, quote *looprpc.QuoteResponse) *limits {
	return &limits{
		maxSwapRoutingFee: getMaxRoutingFee(btcutil.Amount(amt)),
		maxPrepayRoutingFee: getMaxRoutingFee(btcutil.Amount(
			quote.PrepayAmt,
		)),

		// Apply a multiplier to the estimated miner fee, to not get
		// the swap canceled because fees increased in the mean time.
		maxMinerFee: btcutil.Amount(quote.MinerFee) * 3,

		maxSwapFee:   btcutil.Amount(quote.SwapFee),
		maxPrepayAmt: btcutil.Amount(quote.PrepayAmt),
	}
}

func displayLimits(amt btcutil.Amount, l *limits) error {
	totalSuccessMax := l.maxSwapRoutingFee + l.maxPrepayRoutingFee +
		l.maxMinerFee + l.maxSwapFee

	fmt.Printf("Max swap fees for %d loop out: %d\n",
		btcutil.Amount(amt), totalSuccessMax,
	)

	fmt.Printf("CONTINUE SWAP? (y/n), expand fee detail (x): ")

	var answer string
	fmt.Scanln(&answer)

	switch answer {
	case "y":
		return nil
	case "x":
		fmt.Println()
		fmt.Printf("Max on-chain fee:                 %d\n", l.maxMinerFee)
		fmt.Printf("Max off-chain swap routing fee:   %d\n",
			l.maxSwapRoutingFee)
		fmt.Printf("Max off-chain prepay routing fee: %d\n",
			l.maxPrepayRoutingFee)
		fmt.Printf("Max swap fee:                     %d\n", l.maxSwapFee)
		fmt.Printf("Max no show penalty:              %d\n",
			l.maxPrepayAmt)

		fmt.Printf("CONTINUE SWAP? (y/n): ")
		fmt.Scanln(&answer)
		if answer == "y" {
			return nil
		}
	}

	return errors.New("swap canceled")
}

func parseAmt(text string) (btcutil.Amount, error) {
	amtInt64, err := strconv.ParseInt(text, 10, 64)
	if err != nil {
		return 0, fmt.Errorf("invalid amt value")
	}
	return btcutil.Amount(amtInt64), nil
}

func logSwap(swap *looprpc.SwapStatus) {
	fmt.Printf("%v %v %v %v - %v\n",
		time.Unix(0, swap.LastUpdateTime).Format(time.RFC3339),
		swap.Type, swap.State, btcutil.Amount(swap.Amt),
		swap.HtlcAddress,
	)
}

func getClientConn(address string) (*grpc.ClientConn, error) {
	opts := []grpc.DialOption{
		grpc.WithInsecure(),
	}

	conn, err := grpc.Dial(address, opts...)
	if err != nil {
		return nil, fmt.Errorf("unable to connect to RPC server: %v", err)
	}

	return conn, nil
}