/*
 * Minio Client (C) 2014, 2015 Minio, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package cmd

import (
	"bufio"
	"encoding/json"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"syscall"

	"github.com/cheggaaa/pb"
	"github.com/fatih/color"
	"github.com/minio/cli"
	"github.com/minio/mc/pkg/console"
	"github.com/minio/minio/pkg/probe"
)

// cp command flags.
var (
	cpFlags = []cli.Flag{
		cli.BoolFlag{
			Name:  "help, h",
			Usage: "Help of cp.",
		},
		cli.BoolFlag{
			Name:  "recursive, r",
			Usage: "Copy recursively.",
		},
	}
)

// Copy command.
var cpCmd = cli.Command{
	Name:   "cp",
	Usage:  "Copy one or more objects to a target.",
	Action: mainCopy,
	Flags:  append(cpFlags, globalFlags...),
	CustomHelpTemplate: `NAME:
   mc {{.Name}} - {{.Usage}}

USAGE:
   mc {{.Name}} [FLAGS] SOURCE [SOURCE...] TARGET

FLAGS:
  {{range .Flags}}{{.}}
  {{end}}
EXAMPLES:
   1. Copy a list of objects from local file system to Amazon S3 cloud storage.
      $ mc {{.Name}} Music/*.ogg s3/jukebox/

   2. Copy a folder recursively from Minio cloud storage to Amazon S3 cloud storage.
      $ mc {{.Name}} --recursive play/mybucket/burningman2011/ s3/mybucket/

   3. Copy multiple local folders recursively to Minio cloud storage.
      $ mc {{.Name}} --recursive backup/2014/ backup/2015/ play/archive/

   4. Copy a bucket recursively from aliased Amazon S3 cloud storage to local filesystem on Windows.
      $ mc {{.Name}} --recursive s3\documents\2014\ C:\Backups\2014

   5. Copy an object with name containing unicode characters to Amazon S3 cloud storage.
      $ mc {{.Name}} 本語 s3/andoria/

   6. Copy a local folder with space separated characters to Amazon S3 cloud storage.
      $ mc {{.Name}} --recursive 'workdir/documents/May 2014/' s3/miniocloud
`,
}

// copyMessage container for file copy messages
type copyMessage struct {
	Status string `json:"status"`
	Source string `json:"source"`
	Target string `json:"target"`
}

// String colorized copy message
func (c copyMessage) String() string {
	return console.Colorize("Copy", fmt.Sprintf("‘%s’ -> ‘%s’", c.Source, c.Target))
}

// JSON jsonified copy message
func (c copyMessage) JSON() string {
	c.Status = "success"
	copyMessageBytes, e := json.Marshal(c)
	fatalIf(probe.NewError(e), "Failed to marshal copy message.")

	return string(copyMessageBytes)
}

// copyStatMessage container for copy accounting message
type copyStatMessage struct {
	Total       int64
	Transferred int64
	Speed       float64
}

const (
	// 5GiB.
	fiveGB = 5 * 1024 * 1024 * 1024
)

// copyStatMessage copy accounting message
func (c copyStatMessage) String() string {
	speedBox := pb.Format(int64(c.Speed)).To(pb.U_BYTES).String()
	if speedBox == "" {
		speedBox = "0 MB"
	} else {
		speedBox = speedBox + "/s"
	}
	message := fmt.Sprintf("Total: %s, Transferred: %s, Speed: %s", pb.Format(c.Total).To(pb.U_BYTES),
		pb.Format(c.Transferred).To(pb.U_BYTES), speedBox)
	return message
}

// doCopy - Copy a singe file from source to destination
func doCopy(cpURLs URLs, progressReader *progressBar, accountingReader *accounter) URLs {
	if cpURLs.Error != nil {
		cpURLs.Error = cpURLs.Error.Trace()
		return cpURLs
	}

	if !globalQuiet && !globalJSON {
		progressReader = progressReader.SetCaption(cpURLs.SourceContent.URL.String() + ": ")
	}

	sourceAlias := cpURLs.SourceAlias
	sourceURL := cpURLs.SourceContent.URL
	targetAlias := cpURLs.TargetAlias
	targetURL := cpURLs.TargetContent.URL
	length := cpURLs.SourceContent.Size

	var progress io.Reader
	if globalQuiet || globalJSON {
		sourcePath := filepath.ToSlash(filepath.Join(sourceAlias, sourceURL.Path))
		targetPath := filepath.ToSlash(filepath.Join(targetAlias, targetURL.Path))
		printMsg(copyMessage{
			Source: sourcePath,
			Target: targetPath,
		})
		// Proxy reader to accounting reader only during quiet mode.
		if globalQuiet || globalJSON {
			progress = accountingReader
		}
	} else {
		// Set up progress reader.
		progress = progressReader.ProgressBar
	}
	// If source size is <= 5GB and operation is across same server type try to use Copy.
	if length <= fiveGB && (sourceURL.Type == targetURL.Type) {
		// FS -> FS Copy includes alias in path.
		if sourceURL.Type == fileSystem {
			sourcePath := filepath.ToSlash(filepath.Join(sourceAlias, sourceURL.Path))
			err := copySourceStreamFromAlias(targetAlias, targetURL.String(), sourcePath, length, progress)
			if err != nil {
				cpURLs.Error = err.Trace(sourceURL.String())
				return cpURLs
			}
		} else if sourceURL.Type == objectStorage {
			// If source/target are object storage their aliases must be the same.
			if sourceAlias == targetAlias {
				// Do not include alias inside path for ObjStore -> ObjStore.
				err := copySourceStreamFromAlias(targetAlias, targetURL.String(), sourceURL.Path, length, progress)
				if err != nil {
					cpURLs.Error = err.Trace(sourceURL.String())
					return cpURLs
				}
			} else {
				reader, err := getSourceStreamFromAlias(sourceAlias, sourceURL.String())
				if err != nil {
					cpURLs.Error = err.Trace(sourceURL.String())
					return cpURLs
				}
				_, err = putTargetStreamFromAlias(targetAlias, targetURL.String(), reader, length, progress)
				if err != nil {
					cpURLs.Error = err.Trace(targetURL.String())
					return cpURLs
				}
			}
		}
	} else {
		// Standard GET/PUT for size > 5GB.
		reader, err := getSourceStreamFromAlias(sourceAlias, sourceURL.String())
		if err != nil {
			cpURLs.Error = err.Trace(sourceURL.String())
			return cpURLs
		}
		_, err = putTargetStreamFromAlias(targetAlias, targetURL.String(), reader, length, progress)
		if err != nil {
			cpURLs.Error = err.Trace(targetURL.String())
			return cpURLs
		}
	}
	cpURLs.Error = nil // just for safety
	return cpURLs
}

// doCopyFake - Perform a fake copy to update the progress bar appropriately.
func doCopyFake(cpURLs URLs, progressReader *progressBar) URLs {
	if !globalQuiet && !globalJSON {
		progressReader.ProgressBar.Add64(cpURLs.SourceContent.Size)
	}
	return cpURLs
}

// doPrepareCopyURLs scans the source URL and prepares a list of objects for copying.
func doPrepareCopyURLs(session *sessionV7, trapCh <-chan bool) {
	// Separate source and target. 'cp' can take only one target,
	// but any number of sources.
	sourceURLs := session.Header.CommandArgs[:len(session.Header.CommandArgs)-1]
	targetURL := session.Header.CommandArgs[len(session.Header.CommandArgs)-1] // Last one is target

	var totalBytes int64
	var totalObjects int

	// Access recursive flag inside the session header.
	isRecursive := session.Header.CommandBoolFlags["recursive"]

	// Create a session data file to store the processed URLs.
	dataFP := session.NewDataWriter()

	var scanBar scanBarFunc
	if !globalQuiet && !globalJSON { // set up progress bar
		scanBar = scanBarFactory()
	}

	URLsCh := prepareCopyURLs(sourceURLs, targetURL, isRecursive)
	done := false
	for !done {
		select {
		case cpURLs, ok := <-URLsCh:
			if !ok { // Done with URL preparation
				done = true
				break
			}
			if cpURLs.Error != nil {
				// Print in new line and adjust to top so that we don't print over the ongoing scan bar
				if !globalQuiet && !globalJSON {
					console.Eraseline()
				}
				if strings.Contains(cpURLs.Error.ToGoError().Error(), " is a folder.") {
					errorIf(cpURLs.Error.Trace(), "Folder cannot be copied. Please use ‘...’ suffix.")
				} else {
					errorIf(cpURLs.Error.Trace(), "Unable to prepare URL for copying.")
				}
				break
			}

			jsonData, e := json.Marshal(cpURLs)
			if e != nil {
				session.Delete()
				fatalIf(probe.NewError(e), "Unable to prepare URL for copying. Error in JSON marshaling.")
			}
			fmt.Fprintln(dataFP, string(jsonData))
			if !globalQuiet && !globalJSON {
				scanBar(cpURLs.SourceContent.URL.String())
			}

			totalBytes += cpURLs.SourceContent.Size
			totalObjects++
		case <-trapCh:
			// Print in new line and adjust to top so that we don't print over the ongoing scan bar
			if !globalQuiet && !globalJSON {
				console.Eraseline()
			}
			session.Delete() // If we are interrupted during the URL scanning, we drop the session.
			os.Exit(0)
		}
	}
	session.Header.TotalBytes = totalBytes
	session.Header.TotalObjects = totalObjects
	session.Save()
}

func doCopySession(session *sessionV7) {
	trapCh := signalTrap(os.Interrupt, syscall.SIGTERM)

	if !session.HasData() {
		doPrepareCopyURLs(session, trapCh)
	}

	// Enable accounting reader by default.
	accntReader := newAccounter(session.Header.TotalBytes)

	// Prepare URL scanner from session data file.
	urlScanner := bufio.NewScanner(session.NewDataReader())
	// isCopied returns true if an object has been already copied
	// or not. This is useful when we resume from a session.
	isCopied := isLastFactory(session.Header.LastCopied)

	// Enable progress bar reader only during default mode.
	var progressReader *progressBar
	if !globalQuiet && !globalJSON { // set up progress bar
		progressReader = newProgressBar(session.Header.TotalBytes)
	}

	// Wait on status of doCopy() operation.
	var statusCh = make(chan URLs)

	// Add a wait group.
	var wg = new(sync.WaitGroup)
	wg.Add(1)

	// Go routine to monitor signal traps if any.
	go func() {
		defer wg.Done()
		for {
			select {
			case <-trapCh:
				// Receive interrupt notification.
				if !globalQuiet && !globalJSON {
					console.Eraseline()
				}
				session.CloseAndDie()
			case cpURLs, ok := <-statusCh:
				// Status channel is closed, we should return.
				if !ok {
					return
				}
				if cpURLs.Error == nil {
					session.Header.LastCopied = cpURLs.SourceContent.URL.String()
					session.Save()
				} else {
					// Print in new line and adjust to top so that we
					// don't print over the ongoing progress bar.
					if !globalQuiet && !globalJSON {
						console.Eraseline()
					}
					errorIf(cpURLs.Error.Trace(cpURLs.SourceContent.URL.String()),
						fmt.Sprintf("Failed to copy ‘%s’.", cpURLs.SourceContent.URL.String()))
					// For all non critical errors we can continue for the
					// remaining files.
					switch cpURLs.Error.ToGoError().(type) {
					// Handle this specifically for filesystem related errors.
					case BrokenSymlink, TooManyLevelsSymlink, PathNotFound, PathInsufficientPermission:
						continue
					// Handle these specifically for object storage related errors.
					case BucketNameEmpty, ObjectMissing, ObjectAlreadyExists, BucketDoesNotExist, BucketInvalid, ObjectOnGlacier:
						continue
					}
					// For critical errors we should exit. Session
					// can be resumed after the user figures out
					// the  problem.
					session.CloseAndDie()
				}
			}
		}
	}()

	// Loop through all urls.
	for urlScanner.Scan() {
		var cpURLs URLs
		// Unmarshal copyURLs from each line.
		json.Unmarshal([]byte(urlScanner.Text()), &cpURLs)

		// Verify if previously copied, notify progress bar.
		if isCopied(cpURLs.SourceContent.URL.String()) {
			statusCh <- doCopyFake(cpURLs, progressReader)
		} else {
			statusCh <- doCopy(cpURLs, progressReader, accntReader)
		}
	}

	// Close the goroutine.
	close(statusCh)

	// Wait for the goroutines to finish.
	wg.Wait()

	if !globalQuiet && !globalJSON {
		if progressReader.ProgressBar.Get() > 0 {
			progressReader.ProgressBar.Finish()
		}
	} else {
		accntStat := accntReader.Stat()
		cpStatMessage := copyStatMessage{
			Total:       accntStat.Total,
			Transferred: accntStat.Transferred,
			Speed:       accntStat.Speed,
		}
		console.Println(console.Colorize("Copy", cpStatMessage.String()))
	}
}

// mainCopy is the entry point for cp command.
func mainCopy(ctx *cli.Context) {
	// Set global flags from context.
	setGlobalsFromContext(ctx)

	// check 'copy' cli arguments.
	checkCopySyntax(ctx)

	// Additional command speific theme customization.
	console.SetColor("Copy", color.New(color.FgGreen, color.Bold))

	session := newSessionV7()
	session.Header.CommandType = "cp"
	session.Header.CommandBoolFlags["recursive"] = ctx.Bool("recursive")

	var e error
	if session.Header.RootPath, e = os.Getwd(); e != nil {
		session.Delete()
		fatalIf(probe.NewError(e), "Unable to get current working folder.")
	}

	// extract URLs.
	session.Header.CommandArgs = ctx.Args()
	doCopySession(session)
	session.Delete()
}