package wallet

import (
	"errors"
	"fmt"
	"math/big"
	"strings"

	"github.com/nspcc-dev/neo-go/cli/flags"
	"github.com/nspcc-dev/neo-go/cli/options"
	"github.com/nspcc-dev/neo-go/cli/paramcontext"
	smartcontractcli "github.com/nspcc-dev/neo-go/cli/smartcontract"
	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
	"github.com/nspcc-dev/neo-go/pkg/encoding/fixedn"
	"github.com/nspcc-dev/neo-go/pkg/rpc/client"
	"github.com/nspcc-dev/neo-go/pkg/util"
	"github.com/nspcc-dev/neo-go/pkg/wallet"
	"github.com/urfave/cli"
)

var (
	tokenFlag = cli.StringFlag{
		Name:  "token",
		Usage: "Token to use (hash or name (for NEO/GAS or imported tokens))",
	}
	gasFlag = flags.Fixed8Flag{
		Name:  "gas",
		Usage: "Amount of GAS to attach to a tx",
	}
)

func newNEP17Commands() []cli.Command {
	balanceFlags := []cli.Flag{
		walletPathFlag,
		tokenFlag,
		cli.StringFlag{
			Name:  "address, a",
			Usage: "Address to use",
		},
	}
	balanceFlags = append(balanceFlags, options.RPC...)
	importFlags := []cli.Flag{
		walletPathFlag,
		cli.StringFlag{
			Name:  "token",
			Usage: "Token contract hash in LE",
		},
	}
	importFlags = append(importFlags, options.RPC...)
	transferFlags := []cli.Flag{
		walletPathFlag,
		outFlag,
		fromAddrFlag,
		toAddrFlag,
		tokenFlag,
		gasFlag,
		cli.StringFlag{
			Name:  "amount",
			Usage: "Amount of asset to send",
		},
	}
	transferFlags = append(transferFlags, options.RPC...)
	multiTransferFlags := []cli.Flag{
		walletPathFlag,
		outFlag,
		fromAddrFlag,
		gasFlag,
	}
	multiTransferFlags = append(multiTransferFlags, options.RPC...)
	return []cli.Command{
		{
			Name:      "balance",
			Usage:     "get address balance",
			UsageText: "balance --wallet <path> --rpc-endpoint <node> [--timeout <time>] [--address <address>] [--token <hash-or-name>]",
			Action:    getNEP17Balance,
			Flags:     balanceFlags,
		},
		{
			Name:      "import",
			Usage:     "import NEP17 token to a wallet",
			UsageText: "import --wallet <path> --rpc-endpoint <node> --timeout <time> --token <hash>",
			Action:    importNEP17Token,
			Flags:     importFlags,
		},
		{
			Name:      "info",
			Usage:     "print imported NEP17 token info",
			UsageText: "print --wallet <path> [--token <hash-or-name>]",
			Action:    printNEP17Info,
			Flags: []cli.Flag{
				walletPathFlag,
				cli.StringFlag{
					Name:  "token",
					Usage: "Token name or hash",
				},
			},
		},
		{
			Name:      "remove",
			Usage:     "remove NEP17 token from the wallet",
			UsageText: "remove --wallet <path> --token <hash-or-name>",
			Action:    removeNEP17Token,
			Flags: []cli.Flag{
				walletPathFlag,
				cli.StringFlag{
					Name:  "token",
					Usage: "Token name or hash",
				},
				forceFlag,
			},
		},
		{
			Name:      "transfer",
			Usage:     "transfer NEP17 tokens",
			UsageText: "transfer --wallet <path> --rpc-endpoint <node> --timeout <time> --from <addr> --to <addr> --token <hash> --amount string [data]",
			Action:    transferNEP17,
			Flags:     transferFlags,
			Description: `Transfers specified NEP17 token amount with optional 'data' parameter attached to the transfer.
   See 'contract testinvokefunction' documentation for the details about 'data'
   parameter. If no 'data' is given then default nil value will be used`,
		},
		{
			Name:  "multitransfer",
			Usage: "transfer NEP17 tokens to multiple recipients",
			UsageText: `multitransfer --wallet <path> --rpc-endpoint <node> --timeout <time> --from <addr>` +
				` <token1>:<addr1>:<amount1> [<token2>:<addr2>:<amount2> [...]]`,
			Action: multiTransferNEP17,
			Flags:  multiTransferFlags,
		},
	}
}

func getNEP17Balance(ctx *cli.Context) error {
	var accounts []*wallet.Account

	wall, err := openWallet(ctx.String("wallet"))
	if err != nil {
		return cli.NewExitError(fmt.Errorf("bad wallet: %w", err), 1)
	}
	defer wall.Close()

	addr := ctx.String("address")
	if addr != "" {
		addrHash, err := address.StringToUint160(addr)
		if err != nil {
			return cli.NewExitError(fmt.Errorf("invalid address: %w", err), 1)
		}
		acc := wall.GetAccount(addrHash)
		if acc == nil {
			return cli.NewExitError(fmt.Errorf("can't find account for the address: %s", addr), 1)
		}
		accounts = append(accounts, acc)
	} else {
		if len(wall.Accounts) == 0 {
			return cli.NewExitError(errors.New("no accounts in the wallet"), 1)
		}
		accounts = wall.Accounts
	}

	gctx, cancel := options.GetTimeoutContext(ctx)
	defer cancel()

	c, err := options.GetRPCClient(gctx, ctx)
	if err != nil {
		return cli.NewExitError(err, 1)
	}

	name := ctx.String("token")

	for k, acc := range accounts {
		addrHash, err := address.StringToUint160(acc.Address)
		if err != nil {
			return cli.NewExitError(fmt.Errorf("invalid account address: %w", err), 1)
		}
		balances, err := c.GetNEP17Balances(addrHash)
		if err != nil {
			return cli.NewExitError(err, 1)
		}

		if k != 0 {
			fmt.Fprintln(ctx.App.Writer)
		}
		fmt.Fprintf(ctx.App.Writer, "Account %s\n", acc.Address)

		for i := range balances.Balances {
			var tokenName, tokenSymbol string
			tokenDecimals := 0
			asset := balances.Balances[i].Asset
			token, err := getMatchingToken(ctx, wall, asset.StringLE())
			if err != nil {
				token, err = c.NEP17TokenInfo(asset)
			}
			if err == nil {
				if name != "" && !(token.Name == name || token.Symbol == name || token.Address() == name || token.Hash.StringLE() == name) {
					continue
				}
				tokenName = token.Name
				tokenSymbol = token.Symbol
				tokenDecimals = int(token.Decimals)
			} else {
				if name != "" {
					continue
				}
				tokenSymbol = "UNKNOWN"
			}
			fmt.Fprintf(ctx.App.Writer, "%s: %s (%s)\n", tokenSymbol, tokenName, asset.StringLE())
			amount := balances.Balances[i].Amount
			if tokenDecimals != 0 {
				b, ok := new(big.Int).SetString(amount, 10)
				if ok {
					amount = fixedn.ToString(b, tokenDecimals)
				}
			}
			fmt.Fprintf(ctx.App.Writer, "\tAmount : %s\n", amount)
			fmt.Fprintf(ctx.App.Writer, "\tUpdated: %d\n", balances.Balances[i].LastUpdated)
		}
	}
	return nil
}

func getMatchingToken(ctx *cli.Context, w *wallet.Wallet, name string) (*wallet.Token, error) {
	return getMatchingTokenAux(ctx, func(i int) *wallet.Token {
		return w.Extra.Tokens[i]
	}, len(w.Extra.Tokens), name)
}

func getMatchingTokenRPC(ctx *cli.Context, c *client.Client, addr util.Uint160, name string) (*wallet.Token, error) {
	bs, err := c.GetNEP17Balances(addr)
	if err != nil {
		return nil, err
	}
	get := func(i int) *wallet.Token {
		t, _ := c.NEP17TokenInfo(bs.Balances[i].Asset)
		return t
	}
	return getMatchingTokenAux(ctx, get, len(bs.Balances), name)
}

func getMatchingTokenAux(ctx *cli.Context, get func(i int) *wallet.Token, n int, name string) (*wallet.Token, error) {
	var token *wallet.Token
	var count int
	for i := 0; i < n; i++ {
		t := get(i)
		if t != nil && (t.Hash.StringLE() == name || t.Address() == name || t.Symbol == name || t.Name == name) {
			if count == 1 {
				printTokenInfo(ctx, token)
				printTokenInfo(ctx, t)
				return nil, errors.New("multiple matching tokens found")
			}
			count++
			token = t
		}
	}
	if count == 0 {
		return nil, errors.New("token was not found")
	}
	return token, nil
}

func importNEP17Token(ctx *cli.Context) error {
	wall, err := openWallet(ctx.String("wallet"))
	if err != nil {
		return cli.NewExitError(err, 1)
	}
	defer wall.Close()

	tokenHash, err := flags.ParseAddress(ctx.String("token"))
	if err != nil {
		return cli.NewExitError(fmt.Errorf("invalid token contract hash: %w", err), 1)
	}

	for _, t := range wall.Extra.Tokens {
		if t.Hash.Equals(tokenHash) {
			printTokenInfo(ctx, t)
			return cli.NewExitError("token already exists", 1)
		}
	}

	gctx, cancel := options.GetTimeoutContext(ctx)
	defer cancel()

	c, err := options.GetRPCClient(gctx, ctx)
	if err != nil {
		return cli.NewExitError(err, 1)
	}

	tok, err := c.NEP17TokenInfo(tokenHash)
	if err != nil {
		return cli.NewExitError(fmt.Errorf("can't receive token info: %w", err), 1)
	}

	wall.AddToken(tok)
	if err := wall.Save(); err != nil {
		return cli.NewExitError(err, 1)
	}
	printTokenInfo(ctx, tok)
	return nil
}

func printTokenInfo(ctx *cli.Context, tok *wallet.Token) {
	w := ctx.App.Writer
	fmt.Fprintf(w, "Name:\t%s\n", tok.Name)
	fmt.Fprintf(w, "Symbol:\t%s\n", tok.Symbol)
	fmt.Fprintf(w, "Hash:\t%s\n", tok.Hash.StringLE())
	fmt.Fprintf(w, "Decimals: %d\n", tok.Decimals)
	fmt.Fprintf(w, "Address: %s\n", tok.Address())
}

func printNEP17Info(ctx *cli.Context) error {
	wall, err := openWallet(ctx.String("wallet"))
	if err != nil {
		return cli.NewExitError(err, 1)
	}
	defer wall.Close()

	if name := ctx.String("token"); name != "" {
		token, err := getMatchingToken(ctx, wall, name)
		if err != nil {
			return cli.NewExitError(err, 1)
		}
		printTokenInfo(ctx, token)
		return nil
	}

	for i, t := range wall.Extra.Tokens {
		if i > 0 {
			fmt.Fprintln(ctx.App.Writer)
		}
		printTokenInfo(ctx, t)
	}
	return nil
}

func removeNEP17Token(ctx *cli.Context) error {
	wall, err := openWallet(ctx.String("wallet"))
	if err != nil {
		return cli.NewExitError(err, 1)
	}
	defer wall.Close()

	token, err := getMatchingToken(ctx, wall, ctx.String("token"))
	if err != nil {
		return cli.NewExitError(err, 1)
	}
	if !ctx.Bool("force") {
		if ok := askForConsent(ctx.App.Writer); !ok {
			return nil
		}
	}
	if err := wall.RemoveToken(token.Hash); err != nil {
		return cli.NewExitError(fmt.Errorf("can't remove token: %w", err), 1)
	} else if err := wall.Save(); err != nil {
		return cli.NewExitError(fmt.Errorf("error while saving wallet: %w", err), 1)
	}
	return nil
}

func multiTransferNEP17(ctx *cli.Context) error {
	wall, err := openWallet(ctx.String("wallet"))
	if err != nil {
		return cli.NewExitError(err, 1)
	}
	defer wall.Close()

	fromFlag := ctx.Generic("from").(*flags.Address)
	from, err := getDefaultAddress(fromFlag, wall)
	if err != nil {
		return cli.NewExitError(err, 1)
	}
	acc, err := getDecryptedAccount(ctx, wall, from)
	if err != nil {
		return cli.NewExitError(err, 1)
	}

	gctx, cancel := options.GetTimeoutContext(ctx)
	defer cancel()

	c, err := options.GetRPCClient(gctx, ctx)
	if err != nil {
		return cli.NewExitError(err, 1)
	}

	if ctx.NArg() == 0 {
		return cli.NewExitError("empty recipients list", 1)
	}
	var recipients []client.TransferTarget
	cache := make(map[string]*wallet.Token)
	for i := 0; i < ctx.NArg(); i++ {
		arg := ctx.Args().Get(i)
		ss := strings.SplitN(arg, ":", 3)
		if len(ss) != 3 {
			return cli.NewExitError("send format must be '<token>:<addr>:<amount>", 1)
		}
		token, ok := cache[ss[0]]
		if !ok {
			token, err = getMatchingToken(ctx, wall, ss[0])
			if err != nil {
				fmt.Fprintln(ctx.App.ErrWriter, "Can't find matching token in the wallet. Querying RPC-node for balances.")
				token, err = getMatchingTokenRPC(ctx, c, from, ss[0])
				if err != nil {
					return cli.NewExitError(err, 1)
				}
			}
		}
		cache[ss[0]] = token
		addr, err := address.StringToUint160(ss[1])
		if err != nil {
			return cli.NewExitError(fmt.Errorf("invalid address: '%s'", ss[1]), 1)
		}
		amount, err := fixedn.FromString(ss[2], int(token.Decimals))
		if err != nil {
			return cli.NewExitError(fmt.Errorf("invalid amount: %w", err), 1)
		}
		recipients = append(recipients, client.TransferTarget{
			Token:   token.Hash,
			Address: addr,
			Amount:  amount.Int64(),
			Data:    nil,
		})
	}

	return signAndSendTransfer(ctx, c, acc, recipients)
}

func transferNEP17(ctx *cli.Context) error {
	wall, err := openWallet(ctx.String("wallet"))
	if err != nil {
		return cli.NewExitError(err, 1)
	}
	defer wall.Close()

	fromFlag := ctx.Generic("from").(*flags.Address)
	from, err := getDefaultAddress(fromFlag, wall)
	if err != nil {
		return cli.NewExitError(err, 1)
	}
	acc, err := getDecryptedAccount(ctx, wall, from)
	if err != nil {
		return cli.NewExitError(err, 1)
	}

	gctx, cancel := options.GetTimeoutContext(ctx)
	defer cancel()

	c, err := options.GetRPCClient(gctx, ctx)
	if err != nil {
		return cli.NewExitError(err, 1)
	}

	toFlag := ctx.Generic("to").(*flags.Address)
	to := toFlag.Uint160()
	token, err := getMatchingToken(ctx, wall, ctx.String("token"))
	if err != nil {
		fmt.Fprintln(ctx.App.ErrWriter, "Can't find matching token in the wallet. Querying RPC-node for balances.")
		token, err = getMatchingTokenRPC(ctx, c, from, ctx.String("token"))
		if err != nil {
			return cli.NewExitError(fmt.Errorf("failed to get matching token: %w", err), 1)
		}
	}

	amount, err := fixedn.FromString(ctx.String("amount"), int(token.Decimals))
	if err != nil {
		return cli.NewExitError(fmt.Errorf("invalid amount: %w", err), 1)
	}

	data, extErr := smartcontractcli.GetDataFromContext(ctx)
	if extErr != nil {
		return extErr
	}

	return signAndSendTransfer(ctx, c, acc, []client.TransferTarget{{
		Token:   token.Hash,
		Address: to,
		Amount:  amount.Int64(),
		Data:    data,
	}})
}

func signAndSendTransfer(ctx *cli.Context, c *client.Client, acc *wallet.Account, recipients []client.TransferTarget) error {
	gas := flags.Fixed8FromContext(ctx, "gas")

	tx, err := c.CreateNEP17MultiTransferTx(acc, int64(gas), recipients)
	if err != nil {
		return cli.NewExitError(err, 1)
	}

	if outFile := ctx.String("out"); outFile != "" {
		if err := paramcontext.InitAndSave(c.GetNetwork(), tx, acc, outFile); err != nil {
			return cli.NewExitError(err, 1)
		}
	} else {
		_ = acc.SignTx(c.GetNetwork(), tx)
		res, err := c.SendRawTransaction(tx)
		if err != nil {
			return cli.NewExitError(err, 1)
		}
		fmt.Fprintln(ctx.App.Writer, res.StringLE())
		return nil
	}

	fmt.Fprintln(ctx.App.Writer, tx.Hash().StringLE())
	return nil
}

func getDefaultAddress(fromFlag *flags.Address, w *wallet.Wallet) (util.Uint160, error) {
	if fromFlag.IsSet {
		return fromFlag.Uint160(), nil
	}
	addr := w.GetChangeAddress()
	if addr.Equals(util.Uint160{}) {
		return util.Uint160{}, errors.New("can't get default address")
	}
	return addr, nil
}