package query

import (
	"bytes"
	"cmp"
	"encoding/base64"
	"fmt"
	"slices"
	"strconv"
	"strings"
	"text/tabwriter"

	"github.com/nspcc-dev/neo-go/cli/cmdargs"
	"github.com/nspcc-dev/neo-go/cli/flags"
	"github.com/nspcc-dev/neo-go/cli/options"
	"github.com/nspcc-dev/neo-go/pkg/core/state"
	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
	"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/neorpc/result"
	"github.com/nspcc-dev/neo-go/pkg/rpcclient/invoker"
	"github.com/nspcc-dev/neo-go/pkg/rpcclient/neo"
	"github.com/nspcc-dev/neo-go/pkg/util"
	"github.com/nspcc-dev/neo-go/pkg/vm"
	"github.com/nspcc-dev/neo-go/pkg/vm/vmstate"
	"github.com/urfave/cli/v2"
)

// NewCommands returns 'query' command.
func NewCommands() []*cli.Command {
	queryTxFlags := append([]cli.Flag{
		&cli.BoolFlag{
			Name:    "verbose",
			Aliases: []string{"v"},
			Usage:   "Output full tx info and execution logs",
		},
	}, options.RPC...)
	return []*cli.Command{{
		Name:  "query",
		Usage: "Query data from RPC node",
		Subcommands: []*cli.Command{
			{
				Name:      "candidates",
				Usage:     "Get candidates and votes",
				UsageText: "neo-go query candidates -r endpoint [-s timeout]",
				Action:    queryCandidates,
				Flags:     options.RPC,
			},
			{
				Name:      "committee",
				Usage:     "Get committee list",
				UsageText: "neo-go query committee -r endpoint [-s timeout]",
				Action:    queryCommittee,
				Flags:     options.RPC,
			},
			{
				Name:      "height",
				Usage:     "Get node height",
				UsageText: "neo-go query height -r endpoint [-s timeout]",
				Action:    queryHeight,
				Flags:     options.RPC,
			},
			{
				Name:      "tx",
				Usage:     "Query transaction status",
				UsageText: "neo-go query tx -r endpoint [-s timeout] [-v] <hash>",
				Action:    queryTx,
				Flags:     queryTxFlags,
			},
			{
				Name:      "voter",
				Usage:     "Print NEO holder account state",
				UsageText: "neo-go query voter -r endpoint [-s timeout] <address>",
				Action:    queryVoter,
				Flags:     options.RPC,
			},
		},
	}}
}

func queryTx(ctx *cli.Context) error {
	args := ctx.Args().Slice()
	if len(args) == 0 {
		return cli.Exit("transaction hash is missing", 1)
	} else if len(args) > 1 {
		return cli.Exit("only one transaction hash is accepted", 1)
	}

	txHash, err := util.Uint256DecodeStringLE(strings.TrimPrefix(args[0], "0x"))
	if err != nil {
		return cli.Exit(fmt.Sprintf("invalid tx hash: %s", args[0]), 1)
	}

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

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

	txOut, err := c.GetRawTransactionVerbose(txHash)
	if err != nil {
		return cli.Exit(err, 1)
	}

	var res *result.ApplicationLog
	if !txOut.Blockhash.Equals(util.Uint256{}) {
		res, err = c.GetApplicationLog(txHash, nil)
		if err != nil {
			return cli.Exit(err, 1)
		}
	}

	err = DumpApplicationLog(ctx, res, &txOut.Transaction, &txOut.TransactionMetadata, ctx.Bool("verbose"))
	if err != nil {
		return cli.Exit(err, 1)
	}
	return nil
}

func DumpApplicationLog(
	ctx *cli.Context,
	res *result.ApplicationLog,
	tx *transaction.Transaction,
	txMeta *result.TransactionMetadata,
	verbose bool) error {
	var buf []byte

	buf = fmt.Appendf(buf, "Hash:\t%s\n", tx.Hash().StringLE())
	buf = fmt.Appendf(buf, "OnChain:\t%t\n", res != nil)
	if res == nil {
		buf = fmt.Appendf(buf, "ValidUntil:\t%s\n", strconv.FormatUint(uint64(tx.ValidUntilBlock), 10))
	} else {
		if txMeta != nil {
			buf = fmt.Appendf(buf, "BlockHash:\t%s\n", txMeta.Blockhash.StringLE())
		}
		if len(res.Executions) != 1 {
			buf = fmt.Appendf(buf, "Success:\tunknown (no execution data)\n")
		} else {
			buf = fmt.Appendf(buf, "Success:\t%t\n", res.Executions[0].VMState == vmstate.Halt)
		}
	}
	if verbose {
		for _, sig := range tx.Signers {
			buf = fmt.Appendf(buf, "Signer:\t%s (%s)\n", address.Uint160ToString(sig.Account), sig.Scopes)
		}
		buf = fmt.Appendf(buf, "SystemFee:\t%s GAS\n", fixedn.Fixed8(tx.SystemFee).String())
		buf = fmt.Appendf(buf, "NetworkFee:\t%s GAS\n", fixedn.Fixed8(tx.NetworkFee).String())
		buf = fmt.Appendf(buf, "Script:\t%s\n", base64.StdEncoding.EncodeToString(tx.Script))
		v := vm.New()
		v.Load(tx.Script)
		opts := bytes.NewBuffer(nil)
		v.PrintOps(opts)
		buf = append(buf, opts.Bytes()...)
		if res != nil {
			for _, e := range res.Executions {
				if e.VMState != vmstate.Halt {
					buf = fmt.Appendf(buf, "Exception:\t%s\n", e.FaultException)
				}
			}
		}
	}
	tw := tabwriter.NewWriter(ctx.App.Writer, 0, 4, 4, '\t', 0)
	_, err := tw.Write(buf)
	if err != nil {
		return err
	}
	return tw.Flush()
}

func queryCandidates(ctx *cli.Context) error {
	var err error

	if err := cmdargs.EnsureNone(ctx); err != nil {
		return err
	}

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

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

	vals, err := c.GetCandidates()
	if err != nil {
		return cli.Exit(err, 1)
	}
	comm, err := c.GetCommittee()
	if err != nil {
		return cli.Exit(err, 1)
	}

	slices.SortFunc(vals, func(a, b result.Candidate) int {
		if a.Active && !b.Active {
			return 1
		}
		if !a.Active && b.Active {
			return -1
		}
		return cmp.Or(
			cmp.Compare(a.Votes, b.Votes),
			a.PublicKey.Cmp(&b.PublicKey),
		)
	})
	var res []byte
	res = fmt.Appendf(res, "Key\tVotes\tCommittee\tConsensus\n")
	for _, val := range vals {
		res = fmt.Appendf(res, "%s\t%d\t%t\t%t\n", val.PublicKey.StringCompressed(), val.Votes, comm.Contains(&val.PublicKey), val.Active)
	}
	tw := tabwriter.NewWriter(ctx.App.Writer, 0, 2, 2, ' ', 0)
	_, err = tw.Write(res)
	if err != nil {
		return err
	}
	return tw.Flush()
}

func queryCommittee(ctx *cli.Context) error {
	var err error

	if err := cmdargs.EnsureNone(ctx); err != nil {
		return err
	}

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

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

	comm, err := c.GetCommittee()
	if err != nil {
		return cli.Exit(err, 1)
	}

	for _, k := range comm {
		fmt.Fprintln(ctx.App.Writer, k.StringCompressed())
	}
	return nil
}

func queryHeight(ctx *cli.Context) error {
	var err error

	if err := cmdargs.EnsureNone(ctx); err != nil {
		return err
	}

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

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

	blockCount, err := c.GetBlockCount()
	if err != nil {
		return cli.Exit(err, 1)
	}
	blockHeight := blockCount - 1 // GetBlockCount returns block count (including 0), not the highest block index.

	fmt.Fprintf(ctx.App.Writer, "Latest block: %d\n", blockHeight)

	stateHeight, err := c.GetStateHeight()
	if err == nil { // We can be talking to a node without getstateheight request support.
		fmt.Fprintf(ctx.App.Writer, "Validated state: %d\n", stateHeight.Validated)
	}

	return nil
}

func queryVoter(ctx *cli.Context) error {
	args := ctx.Args().Slice()
	if len(args) == 0 {
		return cli.Exit("no address specified", 1)
	} else if len(args) > 1 {
		return cli.Exit("this command only accepts one address", 1)
	}

	addr, err := flags.ParseAddress(args[0])
	if err != nil {
		return cli.Exit(fmt.Sprintf("wrong address: %s", args[0]), 1)
	}

	gctx, cancel := options.GetTimeoutContext(ctx)
	defer cancel()
	c, exitErr := options.GetRPCClient(gctx, ctx)
	if exitErr != nil {
		return exitErr
	}

	neoToken := neo.NewReader(invoker.New(c, nil))

	st, err := neoToken.GetAccountState(addr)
	if err != nil {
		return cli.Exit(err, 1)
	}
	if st == nil {
		st = new(state.NEOBalance)
	}
	dec, err := neoToken.Decimals()
	if err != nil {
		return cli.Exit(fmt.Errorf("failed to get decimals: %w", err), 1)
	}
	voted := "null"
	if st.VoteTo != nil {
		voted = fmt.Sprintf("%s (%s)", st.VoteTo.StringCompressed(), address.Uint160ToString(st.VoteTo.GetScriptHash()))
	}
	fmt.Fprintf(ctx.App.Writer, "\tVoted: %s\n", voted)
	fmt.Fprintf(ctx.App.Writer, "\tAmount : %s\n", fixedn.ToString(&st.Balance, int(dec)))
	fmt.Fprintf(ctx.App.Writer, "\tBlock: %d\n", st.BalanceHeight)
	return nil
}