// Copyright 2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License"). You may not
// use this file except in compliance with the License. A copy of the
// License is located at
//
// http://aws.amazon.com/apache2.0/
//
// or in the "license" file accompanying this file. This file 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 processor contains the methods for update ssm agent.
// It also provides methods for sendReply and updateInstanceInfo
package processor

import (
	"fmt"
	"os"
	"path"
	"regexp"
	"strings"
	"time"

	"github.com/aws/amazon-ssm-agent/agent/appconfig"
	"github.com/aws/amazon-ssm-agent/agent/context"
	"github.com/aws/amazon-ssm-agent/agent/contracts"
	"github.com/aws/amazon-ssm-agent/agent/fileutil"
	"github.com/aws/amazon-ssm-agent/agent/jsonutil"
	"github.com/aws/amazon-ssm-agent/agent/log"
	"github.com/aws/amazon-ssm-agent/agent/s3util"
	"github.com/aws/amazon-ssm-agent/agent/updateutil"
	"github.com/aws/amazon-ssm-agent/agent/updateutil/updateconstants"
	"github.com/aws/amazon-ssm-agent/agent/updateutil/updatemanifest"
	"github.com/aws/amazon-ssm-agent/common/identity"
	"github.com/twinj/uuid"
)

// UpdateState represents the state of update process
type UpdateState string

const (
	// NotStarted represents the state value not started for agent update
	NotStarted UpdateState = "NotStarted"

	// Initialized represents the state value initialized for agent update
	Initialized UpdateState = "Initialized"

	// Staged represents the state value staged for agent update
	Staged UpdateState = "Staged"

	// Installed represents the state value installed for agent update
	Installed UpdateState = "Installed"

	// Rollback represents the state value rollback for agent update
	Rollback UpdateState = "Rollback"

	// RolledBack represents the state value rolledBack for agent update
	RolledBack UpdateState = "RolledBack"

	// Completed represents the state value completed for agent update
	Completed UpdateState = "Completed"

	// TestExecution represents state value denoting test execution on customer's instance
	TestExecution UpdateState = "TestExecution"
)

const (
	// maxAllowedUpdateDuration represents the maximum allowed agent update time in seconds
	maxAllowedUpdateDuration = 180
)

// ContextMgr reprents context management logics
type ContextMgr interface {
	uploadOutput(log log.T, updateDetail *UpdateDetail, orchestrationDir string) error
}

type contextManager struct {
	context context.T
}

// UpdateDetail Book keeping detail for Agent Update
type UpdateDetail struct {
	State               UpdateState
	Result              contracts.ResultStatus
	StandardOut         string
	StandardError       string
	OutputS3KeyPrefix   string
	OutputS3BucketName  string
	StdoutFileName      string
	StderrFileName      string
	SourceVersion       string
	SourceLocation      string
	SourceHash          string
	TargetVersion       string
	TargetResolver      updateconstants.TargetVersionResolver
	TargetLocation      string
	TargetHash          string
	PackageName         string
	StartDateTime       time.Time
	EndDateTime         time.Time
	MessageID           string
	UpdateRoot          string
	RequiresUninstall   bool
	ManifestURL         string
	Manifest            updatemanifest.T
	SelfUpdate          bool
	AllowDowngrade      bool
	UpstreamServiceName string
}

// HasMessageID represents if update is triggered by run command
func (update *UpdateDetail) HasMessageID() bool {
	return len(update.MessageID) > 0
}

// AppendInfo appends messages to UpdateDetail StandardOut
func (update *UpdateDetail) AppendInfo(log log.T, format string, params ...interface{}) {
	message := fmt.Sprintf(format, params...)
	log.Infof(message)
	if update.StandardOut != "" {
		update.StandardOut = fmt.Sprintf("%v\n%v", update.StandardOut, message)
	} else {
		update.StandardOut = message
	}
}

// AppendError appends messages to UpdateDetail StandardError and StandardOut
func (update *UpdateDetail) AppendError(log log.T, format string, params ...interface{}) {
	message := fmt.Sprintf(format, params...)
	log.Errorf(message)
	if update.StandardOut != "" {
		update.StandardOut = fmt.Sprintf("%v\n%v", update.StandardOut, message)
	} else {
		update.StandardOut = message
	}
	if update.StandardError != "" {
		update.StandardError = fmt.Sprintf("%v\n%v", update.StandardError, message)
	} else {
		update.StandardError = message
	}
}

// processMessageID splits the messageID and returns the commandID part of it.
func processMessageID(messageID string) string {
	// MdsMessageID is in the format of : aws.ssm.CommandId.InstanceId
	// E.g (aws.ssm.2b196342-d7d4-436e-8f09-3883a1116ac3.i-57c0a7be)
	mdsMessageIDSplit := strings.Split(messageID, ".")
	return mdsMessageIDSplit[len(mdsMessageIDSplit)-2]
}

// GetCommandID verifies the regex of messageID and returns the commandID by calling processMessageID
func getCommandID(messageID string) (string, error) {
	//messageID format: E.g (aws.ssm.2b196342-d7d4-436e-8f09-3883a1116ac3.i-57c0a7be)
	if match, err := regexp.MatchString("aws\\.ssm\\..+\\.+", messageID); !match {
		return messageID, fmt.Errorf("invalid messageID format: %v | %v", messageID, err)
	}

	return processMessageID(messageID), nil
}

// getV12DocOrchDir returns the orchestration path for v1.2 document plugins
func getV12DocOrchDir(identity identity.IAgentIdentity, log log.T, update *UpdateDetail) string {
	shortInstanceId, err := identity.ShortInstanceID()

	if err != nil {
		log.Errorf("Cannot get instance id: %v", err)
	}

	var commandID string
	if update.HasMessageID() {
		commandID, _ = getCommandID(update.MessageID)
	}

	return fileutil.BuildPath(
		appconfig.DefaultDataStorePath,
		shortInstanceId,
		appconfig.DefaultDocumentRootDirName,
		"orchestration",
		commandID,
		updateconstants.DefaultOutputFolder)
}

// getV22DocOrchDir returns the orchestration path for v2.2 document plugins
func getV22DocOrchDir(identity identity.IAgentIdentity, log log.T, update *UpdateDetail) string {
	return fileutil.BuildPath(getV12DocOrchDir(identity, log, update), updateconstants.DefaultOutputFolder)
}

// isV22DocUpdate returns true if the v2.2 document plugin folder exists
func isV22DocUpdate(identity identity.IAgentIdentity, log log.T, update *UpdateDetail) bool {
	return fileutil.Exists(getV22DocOrchDir(identity, log, update))
}

// getOrchestrationDir returns the orchestration directory
func getOrchestrationDir(identity identity.IAgentIdentity, log log.T, update *UpdateDetail) string {
	if isV22DocUpdate(identity, log, update) {
		log.Debugf("Assuming v2.2 document is being executed")
		return getV22DocOrchDir(identity, log, update)
	}

	log.Debugf("Assuming v1.2 document is being executed")
	return getV12DocOrchDir(identity, log, update)
}

// uploadOutput uploads the stdout and stderr file to S3
func (c *contextManager) uploadOutput(log log.T, updateDetail *UpdateDetail, orchestrationDirectory string) (err error) {

	// upload outputs (if any) to s3
	uploadOutputsToS3 := func() {
		// delete temp outputDir once we're done
		defer func() {
			if err := fileutil.DeleteDirectory(updateutil.UpdateOutputDirectory(updateDetail.UpdateRoot)); err != nil {
				log.Error("error deleting directory", err)
			}
		}()

		// get stdout file path
		stdoutPath := updateutil.UpdateStdOutPath(orchestrationDirectory, updateDetail.StdoutFileName)
		s3Key := path.Join(updateDetail.OutputS3KeyPrefix, updateDetail.StdoutFileName)
		log.Debugf("Uploading %v to s3://%v/%v", stdoutPath, updateDetail.OutputS3BucketName, s3Key)
		if s3, err := s3util.NewAmazonS3Util(c.context, updateDetail.OutputS3BucketName); err == nil {
			if err := s3.S3Upload(log, updateDetail.OutputS3BucketName, s3Key, stdoutPath); err != nil {
				log.Errorf("failed uploading %v to s3://%v/%v \n err:%v",
					stdoutPath,
					updateDetail.OutputS3BucketName,
					s3Key,
					err)
			}
		} else {
			log.Errorf("s3 client initialization failed, not uploading %v to s3. err: %v", stdoutPath, err)
		}

		// get stderr file path
		stderrPath := updateutil.UpdateStdErrPath(orchestrationDirectory, updateDetail.StderrFileName)
		s3Key = path.Join(updateDetail.OutputS3KeyPrefix, updateDetail.StderrFileName)
		log.Debugf("Uploading %v to s3://%v/%v", stderrPath, updateDetail.OutputS3BucketName, s3Key)
		if s3, err := s3util.NewAmazonS3Util(c.context, updateDetail.OutputS3BucketName); err == nil {
			if err := s3.S3Upload(log, updateDetail.OutputS3BucketName, s3Key, stderrPath); err != nil {
				log.Errorf("failed uploading %v to s3://%v/%v \n err:%v", stderrPath, updateDetail.StderrFileName, s3Key, err)
			}
		} else {
			log.Errorf("s3 client initialization failed, not uploading %v to s3. err: %v", stderrPath, err)
		}
	}

	uploadOutputsToS3()

	return nil
}

// persistPayload saves the MGS reply payload in the MGS replies directory.
func persistPayload(log log.T, updateDetail *UpdateDetail, identity identity.IAgentIdentity, agentResult contracts.DocumentResult) (err error) {
	content, err := jsonutil.Marshal(struct {
		AgentResult contracts.DocumentResult
		ReplyId     string
		RetryNumber int
	}{
		AgentResult: agentResult,
		ReplyId:     uuid.NewV4().String(),
		RetryNumber: 0,
	})

	if err != nil {
		log.Errorf("encountered error with message %v while marshalling %v to string", updateDetail.MessageID, err)
	} else {
		persistTime := time.Now().UTC()
		fileName := fmt.Sprintf("%v_%v_update", persistTime.Format("2006-01-02T15-04-05.000000"), updateDetail.MessageID)
		instanceId, _ := identity.ShortInstanceID()
		writePath := path.Join(appconfig.DefaultDataStorePath, instanceId, appconfig.RepliesMGSRootDirName, fileName)
		s, err := fileutil.WriteIntoFileWithPermissions(writePath, jsonutil.Indent(content), os.FileMode(appconfig.ReadWriteAccess))
		if s && err == nil {
			log.Debugf("Successfully persisted update response for %v", fileName)
		} else {
			return err
		}
	}
	return err
}