#!/bin/bash

# Usage:
# bash s3BackUp.sh YOUR_BACKUP_DIRECTORY BACKUP_NAME YOUR_BUCKET MAIL_FROM MAIL_TO (OPTIONAL: S3_FOLDER PROFILE)
# bash s3BackUp.sh /var/www/webdisk/example.com/ example my_bucket info@example.com soporte@example.com backup default

# Arguments:
readonly BACKUP_PATH_NO_REMOVE=$1
readonly BACKUP_NAME=$2
readonly S3_BUCKET_NAME=$3
readonly MAIL_FROM=${4}
readonly MAIL_TO=${5}
readonly S3_FOLDER=${6-backup}
readonly PROFILE=${7-default}

# Default:
readonly PREFIX=backup_
readonly DATE=`date +%d-%m-%Y`
readonly BACKUP_FILE_NAME=${PREFIX}${BACKUP_NAME}_${DATE}.tgz
readonly BACKUP_PATH_FILE=${HOME}/${BACKUP_FILE_NAME}
readonly S3_BUCKET_BACKUP=s3://${S3_BUCKET_NAME}/${S3_FOLDER}/
readonly S3_OUTPUT_BACKUP=${S3_FOLDER}/${BACKUP_FILE_NAME}
readonly TEMP_PARTS=${HOME}/temp-parts
readonly TEMP_EXTRACT=${HOME}/temp-extract

#####
function finish() {
    rm -r ${TEMP_PARTS} 2> /dev/null
    rm -r ${TEMP_EXTRACT} 2> /dev/null
    rm ${BACKUP_PATH_FILE} 2> /dev/null
}
trap finish EXIT
#####
function s3-send-mail() {
    local from=$1
    local to=$2
    local subject=$3
    local text=$4
    aws ses send-email \
    --from $from \
    --destination "ToAddresses=${to}" \
    --message "Subject={Data=${subject},Charset=utf8},Body={Text={Data=${text},Charset=utf8},Html={Data=${text},Charset=utf8}}"
}
#####
function s3-multipart-upload() {
    sudo apt-get install -y -qq jq
    local filePath=$1 # file to upload
    local bucket=$2 # name of S3 bucket
    local s3Folder=$3 # destination of the file in S3
    local dirParts=$4 # local folder where you create the parts of the file to send
    local profile=${5-default} # configuration profile of aws-cli

    #Set to 90 MBs as default, 100 MBs is the limit for AWS files
    mbSplitSize=90
    ((partSize = $mbSplitSize * 1000000))

    # Get main file size
    echo "Preparing $filePath for multipart upload"
    fileSize=`wc -c $filePath | awk '{print $1}'`
    ((parts = ($fileSize+$partSize-1) / partSize))

    # Get main file hash
    mainMd5Hash=`openssl md5 -binary $filePath | base64`

    # Make directory to store temporary parts
    echo "Splitting $filePath into $parts temporary parts"
    rm -r ${dirParts}
    mkdir -p ${dirParts}
    cd ${dirParts}
    split -b $partSize $filePath

    # Create mutlipart upload
    echo "Initiating multipart upload for $filePath"
    uploadId=`aws s3api create-multipart-upload --bucket $bucket --key $s3Folder --metadata md5=$mainMd5Hash --profile $profile | jq -r '.UploadId'`

    # Generate fileparts.json file that will be used at the end of the multipart upload
    jsonData="{\"Parts\":["
    for file in *
      do
        ((index++))
        echo "Uploading part $index of $parts..."
        hashData=`openssl md5 -binary $file | base64`
        eTag=`aws s3api upload-part --bucket $bucket --key $s3Folder --part-number $index --body $file --upload-id $uploadId --profile $profile | jq -r '.ETag'`
        jsonData+="{\"ETag\":$eTag,\"PartNumber\":$index}"

        if (( $index == $parts ))
          then
            jsonData+="]}"
          else
            jsonData+=","
        fi
    done
    jq -n $jsonData > fileparts.json

    # Complete multipart upload, check ETag to verify success
    mainEtag=`aws s3api complete-multipart-upload --multipart-upload file://fileparts.json --bucket $bucket --key $s3Folder --upload-id $uploadId --profile $profile | jq -r '.ETag'`
    if [[ $mainEtag != "" ]];
      then
        echo "Successfully uploaded: $filePath to S3 bucket: $bucket"
      else
        echo "Something went wrong! $filePath was not uploaded to S3 bucket: $bucket"
        # SEND FAULT REPORT
        s3-send-mail MAIL_FROM MAIL_TO "ALERT BACKUP FAULT - ${BACKUP_NAME}" "Verify the sending of file parts to the AWS S3 service"
        exit 1
    fi

    # Clean up files
    rm -r ${TEMP_PARTS}
    cd ..
}
#####
function main() {
    # Release file in local and remote destination
    rm ${BACKUP_PATH_FILE} 2> /dev/null

    # CREATE BACKUP ARCHIVE
    tar czvf ${BACKUP_PATH_FILE} ${BACKUP_PATH_NO_REMOVE}

    # VERIFY BACKING ARCHIVE
    rm -r ${TEMP_EXTRACT}
    mkdir -p ${TEMP_EXTRACT}

    tar xzf ${BACKUP_PATH_FILE} --directory ${TEMP_EXTRACT} > /dev/null
    if [ $? != 0 ]; then
      echo  "File is corrupted ... $1"
      # SEND FAULT REPORT
      s3-send-mail MAIL_FROM MAIL_TO "ALERT BACKUP FAULT - ${BACKUP_NAME}" "Check backup compression"
      exit 1
    fi

    rm -r ${TEMP_EXTRACT}

    # SEND NEW BACKUP TO S3
    s3-multipart-upload ${BACKUP_PATH_FILE} ${S3_BUCKET_NAME} ${S3_OUTPUT_BACKUP} ${TEMP_PARTS} ${PROFILE}

    # DELETE OLD BACKUP IN S3
    aws s3 ls ${S3_BUCKET_BACKUP} | while read -r line;
      do
          strCreateDate=`echo $line|awk {'print $1" "$2'}`
          if date -d "${strCreateDate}" >/dev/null 2>&1
          then
              createDate=`date --date "$strCreateDate" +%s`
              olderThan=`date --date "7 days ago" +%s`
              if [[ $createDate -lt $olderThan ]]
              then
                  filePath=`echo $line|awk {'print $4'}`

                  if [[ $filePath != "" ]]
                  then
                      aws s3 rm ${S3_BUCKET_BACKUP}$filePath
                  fi
              fi
          fi
      done;
}
#####

main