// 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"
	"path/filepath"
	"time"

	"github.com/ethereum/go-ethereum/cmd/utils"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
	"github.com/ethereum/go-ethereum/console/prompt"
	"github.com/ethereum/go-ethereum/core/rawdb"
	"github.com/ethereum/go-ethereum/ethdb"
	"github.com/ethereum/go-ethereum/log"
	"gopkg.in/urfave/cli.v1"
)

var (
	removedbCommand = cli.Command{
		Action:    utils.MigrateFlags(removeDB),
		Name:      "removedb",
		Usage:     "Remove blockchain and state databases",
		ArgsUsage: "",
		Flags: []cli.Flag{
			utils.DataDirFlag,
		},
		Category: "DATABASE COMMANDS",
		Description: `
Remove blockchain and state databases`,
	}
	dbCommand = cli.Command{
		Name:      "db",
		Usage:     "Low level database operations",
		ArgsUsage: "",
		Category:  "DATABASE COMMANDS",
		Subcommands: []cli.Command{
			dbInspectCmd,
			dbStatCmd,
			dbCompactCmd,
			dbGetCmd,
			dbDeleteCmd,
			dbPutCmd,
		},
	}
	dbInspectCmd = cli.Command{
		Action:    utils.MigrateFlags(inspect),
		Name:      "inspect",
		ArgsUsage: "<prefix> <start>",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.SyncModeFlag,
			utils.MainnetFlag,
			utils.RopstenFlag,
			utils.RinkebyFlag,
			utils.GoerliFlag,
			utils.YoloV3Flag,
		},
		Usage:       "Inspect the storage size for each type of data in the database",
		Description: `This commands iterates the entire database. If the optional 'prefix' and 'start' arguments are provided, then the iteration is limited to the given subset of data.`,
	}
	dbStatCmd = cli.Command{
		Action: utils.MigrateFlags(dbStats),
		Name:   "stats",
		Usage:  "Print leveldb statistics",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.SyncModeFlag,
			utils.MainnetFlag,
			utils.RopstenFlag,
			utils.RinkebyFlag,
			utils.GoerliFlag,
			utils.YoloV3Flag,
		},
	}
	dbCompactCmd = cli.Command{
		Action: utils.MigrateFlags(dbCompact),
		Name:   "compact",
		Usage:  "Compact leveldb database. WARNING: May take a very long time",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.SyncModeFlag,
			utils.MainnetFlag,
			utils.RopstenFlag,
			utils.RinkebyFlag,
			utils.GoerliFlag,
			utils.YoloV3Flag,
			utils.CacheFlag,
			utils.CacheDatabaseFlag,
		},
		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:    utils.MigrateFlags(dbGet),
		Name:      "get",
		Usage:     "Show the value of a database key",
		ArgsUsage: "<hex-encoded key>",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.SyncModeFlag,
			utils.MainnetFlag,
			utils.RopstenFlag,
			utils.RinkebyFlag,
			utils.GoerliFlag,
			utils.YoloV3Flag,
		},
		Description: "This command looks up the specified database key from the database.",
	}
	dbDeleteCmd = cli.Command{
		Action:    utils.MigrateFlags(dbDelete),
		Name:      "delete",
		Usage:     "Delete a database key (WARNING: may corrupt your database)",
		ArgsUsage: "<hex-encoded key>",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.SyncModeFlag,
			utils.MainnetFlag,
			utils.RopstenFlag,
			utils.RinkebyFlag,
			utils.GoerliFlag,
			utils.YoloV3Flag,
		},
		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:    utils.MigrateFlags(dbPut),
		Name:      "put",
		Usage:     "Set the value of a database key (WARNING: may corrupt your database)",
		ArgsUsage: "<hex-encoded key> <hex-encoded value>",
		Flags: []cli.Flag{
			utils.DataDirFlag,
			utils.SyncModeFlag,
			utils.MainnetFlag,
			utils.RopstenFlag,
			utils.RinkebyFlag,
			utils.GoerliFlag,
			utils.YoloV3Flag,
		},
		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, config := makeConfigNode(ctx)

	// Remove the full node state database
	path := stack.ResolvePath("chaindata")
	if common.FileExist(path) {
		confirmAndRemoveDB(path, "full node state database")
	} else {
		log.Info("Full node state database missing", "path", path)
	}
	// Remove the full node ancient database
	path = config.Eth.DatabaseFreezer
	switch {
	case path == "":
		path = filepath.Join(stack.ResolvePath("chaindata"), "ancient")
	case !filepath.IsAbs(path):
		path = config.Node.ResolvePath(path)
	}
	if common.FileExist(path) {
		confirmAndRemoveDB(path, "full node ancient database")
	} else {
		log.Info("Full node ancient database missing", "path", path)
	}
	// Remove the light node database
	path = stack.ResolvePath("lightchaindata")
	if common.FileExist(path) {
		confirmAndRemoveDB(path, "light node database")
	} else {
		log.Info("Light node database missing", "path", path)
	}
	return nil
}

// confirmAndRemoveDB prompts the user for a last confirmation and removes the
// folder if accepted.
func confirmAndRemoveDB(database string, kind string) {
	confirm, err := prompt.Stdin.PromptConfirm(fmt.Sprintf("Remove %s (%s)?", kind, database))
	switch {
	case err != nil:
		utils.Fatalf("%v", err)
	case !confirm:
		log.Info("Database deletion skipped", "path", database)
	default:
		start := time.Now()
		filepath.Walk(database, func(path string, info os.FileInfo, err error) error {
			// If we're at the top level folder, recurse into
			if path == database {
				return nil
			}
			// Delete all the files, but not subfolders
			if !info.IsDir() {
				os.Remove(path)
				return nil
			}
			return filepath.SkipDir
		})
		log.Info("Database successfully deleted", "path", database, "elapsed", common.PrettyDuration(time.Since(start)))
	}
}

func inspect(ctx *cli.Context) error {
	var (
		prefix []byte
		start  []byte
	)
	if ctx.NArg() > 2 {
		return fmt.Errorf("Max 2 arguments: %v", ctx.Command.ArgsUsage)
	}
	if ctx.NArg() >= 1 {
		if d, err := hexutil.Decode(ctx.Args().Get(0)); err != nil {
			return fmt.Errorf("failed to hex-decode 'prefix': %v", err)
		} else {
			prefix = d
		}
	}
	if ctx.NArg() >= 2 {
		if d, err := hexutil.Decode(ctx.Args().Get(1)); err != nil {
			return fmt.Errorf("failed to hex-decode 'start': %v", err)
		} else {
			start = d
		}
	}
	stack, _ := makeConfigNode(ctx)
	defer stack.Close()

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

	return rawdb.InspectDatabase(db, prefix, 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 := hexutil.Decode(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", "error", err)
		return err
	}
	fmt.Printf("key %#x: %#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 := hexutil.Decode(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", "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 = hexutil.Decode(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: %#x\n", data)
	}
	return db.Put(key, value)
}