// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"context"
	"fmt"
	"path/filepath"
	"strings"
	"time"

	"github.com/fatih/color"
	"github.com/minio/cli"
	"github.com/minio/minio-go/v7"
	"github.com/minio/pkg/console"
)

var lhSetFlags = []cli.Flag{
	cli.BoolFlag{
		Name:  "recursive, r",
		Usage: "apply legal hold recursively",
	},
	cli.StringFlag{
		Name:  "version-id, vid",
		Usage: "apply legal hold to a specific object version",
	},
	cli.StringFlag{
		Name:  "rewind",
		Usage: "apply legal hold on an object version at specified time",
	},
	cli.BoolFlag{
		Name:  "versions",
		Usage: "apply legal hold on multiple versions of an object",
	},
}

var legalHoldSetCmd = cli.Command{
	Name:         "set",
	Usage:        "set legal hold for object(s)",
	Action:       mainLegalHoldSet,
	OnUsageError: onUsageError,
	Before:       setGlobalsFromContext,
	Flags:        append(lhSetFlags, globalFlags...),
	CustomHelpTemplate: `NAME:
  {{.HelpName}} - {{.Usage}}

USAGE:
  {{.HelpName}} [FLAGS] TARGET

FLAGS:
  {{range .VisibleFlags}}{{.}}
  {{end}}

EXAMPLES:
   1. Enable legal hold on a specific object
      $ {{.HelpName}} myminio/mybucket/prefix/obj.csv

   2. Enable legal hold on a specific object version
      $ {{.HelpName}} myminio/mybucket/prefix/obj.csv --version-id "HiMFUTOowG6ylfNi4LKxD3ieHbgfgrvC"

   3. Enable object legal hold recursively for all objects at a prefix
      $ {{.HelpName}} myminio/mybucket/prefix --recursive

   4. Enable object legal hold recursively for all objects versions older than one year
      $ {{.HelpName}} myminio/mybucket/prefix --recursive --rewind 365d --versions
`,
}

// setLegalHold - Set legalhold for all objects within a given prefix.
func setLegalHold(ctx context.Context, urlStr, versionID string, timeRef time.Time, withOlderVersions, recursive bool, lhold minio.LegalHoldStatus) error {
	clnt, err := newClient(urlStr)
	if err != nil {
		fatalIf(err.Trace(), "Unable to parse the provided url.")
	}

	prefixPath := clnt.GetURL().Path
	prefixPath = filepath.ToSlash(prefixPath)
	if !strings.HasSuffix(prefixPath, "/") {
		prefixPath = prefixPath[:strings.LastIndex(prefixPath, "/")+1]
	}
	prefixPath = strings.TrimPrefix(prefixPath, "./")

	if !recursive && !withOlderVersions {
		err = clnt.PutObjectLegalHold(ctx, versionID, lhold)
		if err != nil {
			errorIf(err.Trace(urlStr), "Failed to set legal hold on `"+urlStr+"` successfully")
		} else {
			contentURL := filepath.ToSlash(clnt.GetURL().Path)
			key := strings.TrimPrefix(contentURL, prefixPath)

			printMsg(legalHoldCmdMessage{
				LegalHold: lhold,
				Status:    "success",
				URLPath:   clnt.GetURL().String(),
				Key:       key,
				VersionID: versionID,
			})
		}
		return nil
	}

	alias, _, _ := mustExpandAlias(urlStr)
	var cErr error
	objectsFound := false
	lstOptions := ListOptions{Recursive: recursive, ShowDir: DirNone}
	if !timeRef.IsZero() {
		lstOptions.WithOlderVersions = withOlderVersions
		lstOptions.TimeRef = timeRef
	}
	for content := range clnt.List(ctx, lstOptions) {
		if content.Err != nil {
			errorIf(content.Err.Trace(clnt.GetURL().String()), "Unable to list folder.")
			cErr = exitStatus(globalErrorExitStatus) // Set the exit status.
			continue
		}

		if !recursive && alias+getKey(content) != getStandardizedURL(urlStr) {
			break
		}

		objectsFound = true

		newClnt, perr := newClientFromAlias(alias, content.URL.String())
		if perr != nil {
			errorIf(content.Err.Trace(clnt.GetURL().String()), "Invalid URL")
			continue
		}

		probeErr := newClnt.PutObjectLegalHold(ctx, content.VersionID, lhold)
		if probeErr != nil {
			errorIf(probeErr.Trace(content.URL.Path), "Failed to set legal hold on `"+content.URL.Path+"` successfully")
		} else {
			if !globalJSON {
				contentURL := filepath.ToSlash(content.URL.Path)
				key := strings.TrimPrefix(contentURL, prefixPath)

				printMsg(legalHoldCmdMessage{
					LegalHold: lhold,
					Status:    "success",
					URLPath:   content.URL.String(),
					Key:       key,
					VersionID: content.VersionID,
				})
			}
		}
	}

	if cErr == nil && !globalJSON {
		if !objectsFound {
			console.Print(console.Colorize("LegalHoldMessageFailure",
				fmt.Sprintf("No objects/versions found while setting legal hold on `%s`. \n", urlStr)))
		}
	}
	return cErr
}

// Validate command line arguments.
func parseLegalHoldArgs(cliCtx *cli.Context) (targetURL, versionID string, timeRef time.Time, recursive, withVersions bool) {
	args := cliCtx.Args()
	if len(args) != 1 {
		cli.ShowCommandHelpAndExit(cliCtx, cliCtx.Command.Name, 1)
	}

	targetURL = args[0]
	if targetURL == "" {
		fatalIf(errInvalidArgument(), "You cannot pass an empty target url.")
	}

	versionID = cliCtx.String("version-id")
	recursive = cliCtx.Bool("recursive")
	withVersions = cliCtx.Bool("versions")
	rewind := cliCtx.String("rewind")

	if versionID != "" && (recursive || withVersions || rewind != "") {
		fatalIf(errInvalidArgument(), "You cannot pass --version-id with any of --versions, --recursive and --rewind flags.")
	}

	timeRef = parseRewindFlag(rewind)
	return
}

// main for legalhold set command.
func mainLegalHoldSet(cliCtx *cli.Context) error {
	console.SetColor("LegalHoldSuccess", color.New(color.FgGreen, color.Bold))
	console.SetColor("LegalHoldFailure", color.New(color.FgRed, color.Bold))
	console.SetColor("LegalHoldPartialFailure", color.New(color.FgRed, color.Bold))
	console.SetColor("LegalHoldMessageFailure", color.New(color.FgYellow))

	targetURL, versionID, timeRef, recursive, withVersions := parseLegalHoldArgs(cliCtx)
	if timeRef.IsZero() && withVersions {
		timeRef = time.Now().UTC()
	}

	ctx, cancelLegalHold := context.WithCancel(globalContext)
	defer cancelLegalHold()

	enabled, err := isBucketLockEnabled(ctx, targetURL)
	if err != nil {
		fatalIf(err, "Unable to set legalhold on `%s`", targetURL)
	}
	if !enabled {
		fatalIf(errDummy().Trace(), "Bucket lock needs to be enabled in order to use this feature.")
	}

	return setLegalHold(ctx, targetURL, versionID, timeRef, withVersions, recursive, minio.LegalHoldEnabled)
}
