// Copyright 2020 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.

package main

import (
	"fmt"
	"os"
	"time"

	"github.com/XinFinOrg/XDPoSChain/cmd/utils"
	"github.com/XinFinOrg/XDPoSChain/common"
	"github.com/XinFinOrg/XDPoSChain/common/hexutil"
	"github.com/XinFinOrg/XDPoSChain/console"
	"github.com/XinFinOrg/XDPoSChain/ethdb"
	"github.com/XinFinOrg/XDPoSChain/log"
	"github.com/urfave/cli/v2"
)

var (
	removedbCommand = &cli.Command{
		Action:    removeDB,
		Name:      "removedb",
		Usage:     "Remove blockchain and state databases",
		ArgsUsage: " ",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.XDCXDataDirFlag,
			utils.LightModeFlag,
		},
		Description: `
Remove blockchain and state databases`,
	}
	dbCommand = &cli.Command{
		Name:      "db",
		Usage:     "Low level database operations",
		ArgsUsage: "",
		Subcommands: []*cli.Command{
			dbStatCmd,
			dbCompactCmd,
			dbGetCmd,
			dbDeleteCmd,
			dbPutCmd,
		},
	}
	dbStatCmd = &cli.Command{
		Action: dbStats,
		Name:   "stats",
		Usage:  "Print leveldb statistics",
	}
	dbCompactCmd = &cli.Command{
		Action: dbCompact,
		Name:   "compact",
		Usage:  "Compact leveldb database. WARNING: May take a very long time",
		Description: `This command performs a database compaction.
WARNING: This operation may take a very long time to finish, and may cause database
corruption if it is aborted during execution'!`,
	}
	dbGetCmd = &cli.Command{
		Action:      dbGet,
		Name:        "get",
		Usage:       "Show the value of a database key",
		ArgsUsage:   "<hex-encoded key>",
		Description: "This command looks up the specified database key from the database.",
	}
	dbDeleteCmd = &cli.Command{
		Action:    dbDelete,
		Name:      "delete",
		Usage:     "Delete a database key (WARNING: may corrupt your database)",
		ArgsUsage: "<hex-encoded key>",
		Description: `This command deletes the specified database key from the database.
WARNING: This is a low-level operation which may cause database corruption!`,
	}
	dbPutCmd = &cli.Command{
		Action:    dbPut,
		Name:      "put",
		Usage:     "Set the value of a database key (WARNING: may corrupt your database)",
		ArgsUsage: "<hex-encoded key> <hex-encoded value>",
		Description: `This command sets a given database key to the given value.
WARNING: This is a low-level operation which may cause database corruption!`,
	}
)

func removeDB(ctx *cli.Context) error {
	stack, _ := makeConfigNode(ctx)
	for _, name := range []string{"chaindata", "lightchaindata"} {
		// Ensure the database exists in the first place
		logger := log.New("database", name)

		dbdir := stack.ResolvePath(name)
		if !common.FileExist(dbdir) {
			logger.Info("Database doesn't exist, skipping", "path", dbdir)
			continue
		}
		confirmAndRemoveDB(dbdir, name)
	}
	return nil
}

// confirmAndRemoveDB prompts the user for a last confirmation and removes the
// folder if accepted.
func confirmAndRemoveDB(database string, kind string) {
	confirm, err := console.Stdin.PromptConfirm(fmt.Sprintf("Remove %s (%s)?", kind, database))
	switch {
	case err != nil:
		utils.Fatalf("%v", err)
	case !confirm:
		log.Warn("Database deletion aborted", "path", database)
	default:
		start := time.Now()
		os.RemoveAll(database)
		log.Info("Database successfully deleted", "path", database, "elapsed", common.PrettyDuration(time.Since(start)))
	}
}

func showLeveldbStats(db ethdb.Stater) {
	if stats, err := db.Stat("leveldb.stats"); err != nil {
		log.Warn("Failed to read database stats", "error", err)
	} else {
		fmt.Println(stats)
	}
	if ioStats, err := db.Stat("leveldb.iostats"); err != nil {
		log.Warn("Failed to read database iostats", "error", err)
	} else {
		fmt.Println(ioStats)
	}
}

func dbStats(ctx *cli.Context) error {
	stack, _ := makeConfigNode(ctx)
	defer stack.Close()

	db := utils.MakeChainDatabase(ctx, stack, true)
	defer db.Close()

	showLeveldbStats(db)
	return nil
}

func dbCompact(ctx *cli.Context) error {
	stack, _ := makeConfigNode(ctx)
	defer stack.Close()

	db := utils.MakeChainDatabase(ctx, stack, false)
	defer db.Close()

	log.Info("Stats before compaction")
	showLeveldbStats(db)

	log.Info("Triggering compaction")
	if err := db.Compact(nil, nil); err != nil {
		log.Info("Compact err", "error", err)
		return err
	}

	log.Info("Stats after compaction")
	showLeveldbStats(db)
	return nil
}

// dbGet shows the value of a given database key
func dbGet(ctx *cli.Context) error {
	if ctx.NArg() != 1 {
		return fmt.Errorf("required arguments: %v", ctx.Command.ArgsUsage)
	}
	stack, _ := makeConfigNode(ctx)
	defer stack.Close()

	db := utils.MakeChainDatabase(ctx, stack, true)
	defer db.Close()

	key, err := common.ParseHexOrString(ctx.Args().Get(0))
	if err != nil {
		log.Info("Could not decode the key", "error", err)
		return err
	}

	data, err := db.Get(key)
	if err != nil {
		log.Info("Get operation failed", "key", fmt.Sprintf("%#x", key), "error", err)
		return err
	}
	fmt.Printf("key %#x:\n\t%#x\n", key, data)
	return nil
}

// dbDelete deletes a key from the database
func dbDelete(ctx *cli.Context) error {
	if ctx.NArg() != 1 {
		return fmt.Errorf("required arguments: %v", ctx.Command.ArgsUsage)
	}
	stack, _ := makeConfigNode(ctx)
	defer stack.Close()

	db := utils.MakeChainDatabase(ctx, stack, false)
	defer db.Close()

	key, err := common.ParseHexOrString(ctx.Args().Get(0))
	if err != nil {
		log.Info("Could not decode the key", "error", err)
		return err
	}
	data, err := db.Get(key)
	if err == nil {
		fmt.Printf("Previous value: %#x\n", data)
	}
	if err = db.Delete(key); err != nil {
		log.Info("Delete operation returned an error", "key", fmt.Sprintf("%#x", key), "error", err)
		return err
	}
	return nil
}

// dbPut overwrite a value in the database
func dbPut(ctx *cli.Context) error {
	if ctx.NArg() != 2 {
		return fmt.Errorf("required arguments: %v", ctx.Command.ArgsUsage)
	}
	stack, _ := makeConfigNode(ctx)
	defer stack.Close()

	db := utils.MakeChainDatabase(ctx, stack, false)
	defer db.Close()

	var (
		key   []byte
		value []byte
		data  []byte
		err   error
	)
	key, err = common.ParseHexOrString(ctx.Args().Get(0))
	if err != nil {
		log.Info("Could not decode the key", "error", err)
		return err
	}
	value, err = hexutil.Decode(ctx.Args().Get(1))
	if err != nil {
		log.Info("Could not decode the value", "error", err)
		return err
	}
	data, err = db.Get(key)
	if err == nil {
		fmt.Printf("Previous value:\n%#x\n", data)
	}
	return db.Put(key, value)
}