# |source| this file
#
# Utilities for working with EC2 instances
#

zone=
region=

cloud_SetZone() {
  zone="$1"
  # AWS region is zone with the last character removed
  region="${zone:0:$((${#zone} - 1))}"
}

# Set the default zone
cloud_SetZone "us-east-1b"

# sshPrivateKey should be globally defined whenever this function is called.
#
# TODO: Remove usage of the sshPrivateKey global
__cloud_SshPrivateKeyCheck() {
  # shellcheck disable=SC2154
  if [[ -z $sshPrivateKey ]]; then
    echo Error: sshPrivateKey not defined
    exit 1
  fi
  if [[ ! -r $sshPrivateKey ]]; then
    echo "Error: file is not readable: $sshPrivateKey"
    exit 1
  fi
}

#
# __cloud_FindInstances
#
# Find instances with name matching the specified pattern.
#
# For each matching instance, an entry in the `instances` array will be added with the
# following information about the instance:
#   "name:public IP:private IP"
#
# filter   - The instances to filter on
#
# examples:
#   $ __cloud_FindInstances "exact-machine-name"
#   $ __cloud_FindInstances "all-machines-with-a-common-machine-prefix*"
#
__cloud_FindInstances() {
  declare filter="$1"

  instances=()
  declare name publicIp privateIp
  while read -r name publicIp privateIp; do
    printf "%-30s | publicIp=%-16s privateIp=%s\n" "$name" "$publicIp" "$privateIp"
    instances+=("$name:$publicIp:$privateIp")
  done < <(aws ec2 describe-instances \
             --region "$region" \
             --filters \
               "Name=tag:name,Values=$filter" \
               "Name=instance-state-name,Values=pending,running" \
             --query "Reservations[].Instances[].[InstanceId,PublicIpAddress,PrivateIpAddress]" \
             --output text
    )
}

#
# cloud_FindInstances [namePrefix]
#
# Find instances with names matching the specified prefix
#
# For each matching instance, an entry in the `instances` array will be added with the
# following information about the instance:
#   "name:public IP:private IP"
#
# namePrefix - The instance name prefix to look for
#
# examples:
#   $ cloud_FindInstances all-machines-with-a-common-machine-prefix
#
cloud_FindInstances() {
  declare namePrefix="$1"
  __cloud_FindInstances "$namePrefix*"
}

#
# cloud_FindInstance [name]
#
# Find an instance with a name matching the exact pattern.
#
# For each matching instance, an entry in the `instances` array will be added with the
# following information about the instance:
#   "name:public IP:private IP"
#
# name - The instance name to look for
#
# examples:
#   $ cloud_FindInstance exact-machine-name
#
cloud_FindInstance() {
  declare name="$1"
  __cloud_FindInstances "$name"
}


#
# cloud_CreateInstances [networkName] [namePrefix] [numNodes] [imageName]
#                       [machineType] [bootDiskSize] [startupScript] [address]
#
# Creates one more identical instances.
#
# networkName   - unique name of this testnet
# namePrefix    - unique string to prefix all the instance names with
# numNodes      - number of instances to create
# imageName     - Disk image for the instances
# machineType   - GCE machine type
# bootDiskSize  - Optional size of the boot disk in GB
# startupScript - Optional startup script to execute when the instance boots
# address       - Optional name of the GCE static IP address to attach to the
#                 instance.  Requires that |numNodes| = 1 and that addressName
#                 has been provisioned in the GCE region that is hosting |zone|
#
# Tip: use cloud_FindInstances to locate the instances once this function
#      returns
cloud_CreateInstances() {
  declare networkName="$1"
  declare namePrefix="$2"
  declare numNodes="$3"
  declare imageName="$4"
  declare machineType="$5"
  declare optionalBootDiskSize="$6"
  declare optionalStartupScript="$7"
  declare optionalAddress="$8"

  __cloud_SshPrivateKeyCheck
  (
    set -x
    aws ec2 delete-key-pair --region "$region" --key-name "$networkName"
    aws ec2 import-key-pair --region "$region" --key-name "$networkName" \
      --public-key-material file://"${sshPrivateKey}".pub
  )

  declare -a args
  args=(
    --key-name "$networkName"
    --count "$numNodes"
    --region "$region"
    --placement "AvailabilityZone=$zone"
    --security-groups testnet
    --image-id "$imageName"
    --instance-type "$machineType"
    --tag-specifications "ResourceType=instance,Tags=[{Key=name,Value=$namePrefix}]"
  )
  if [[ -n $optionalBootDiskSize ]]; then
    args+=(
      --block-device-mapping "[{\"DeviceName\": \"/dev/sda1\", \"Ebs\": { \"VolumeSize\": $optionalBootDiskSize }}]"
    )
  fi
  if [[ -n $optionalStartupScript ]]; then
    args+=(
      --user-data "file://$optionalStartupScript"
    )
  fi

  if [[ -n $optionalAddress ]]; then
    [[ $numNodes = 1 ]] || {
      echo "Error: address may not be supplied when provisioning multiple nodes: $optionalAddress"
      exit 1
    }
  fi

  (
    set -x
    aws ec2 run-instances "${args[@]}"
  )

  if [[ -n $optionalAddress ]]; then
    cloud_FindInstance "$namePrefix"
    if [[ ${#instances[@]} -ne 1 ]]; then
      echo "Failed to find newly created instance: $namePrefix"
    fi

    declare instanceId
    IFS=: read -r instanceId _ < <(echo "${instances[0]}")
    (
      set -x
      # TODO: Poll that the instance has moved to the 'running' state instead of
      #       blindly sleeping for 30 seconds...
      sleep 30
      aws ec2 associate-address \
        --instance-id "$instanceId" \
        --region "$region" \
        --allocation-id "$optionalAddress"
    )
  fi
}

#
# cloud_DeleteInstances
#
# Deletes all the instances listed in the `instances` array
#
cloud_DeleteInstances() {
  if [[ ${#instances[0]} -eq 0 ]]; then
    echo No instances to delete
    return
  fi
  declare names=("${instances[@]/:*/}")
  (
    set -x
    aws ec2 terminate-instances --region "$region" --instance-ids "${names[@]}"
  )
}


#
# cloud_FetchFile [instanceName] [publicIp] [remoteFile] [localFile]
#
# Fetch a file from the given instance.  This function uses a cloud-specific
# mechanism to fetch the file
#
cloud_FetchFile() {
  # shellcheck disable=SC2034 # instanceName is unused
  declare instanceName="$1"
  declare publicIp="$2"
  declare remoteFile="$3"
  declare localFile="$4"

  __cloud_SshPrivateKeyCheck
  (
    set -x
    scp \
      -o "StrictHostKeyChecking=no" \
      -o "UserKnownHostsFile=/dev/null" \
      -o "User=solana" \
      -o "IdentityFile=$sshPrivateKey" \
      -o "LogLevel=ERROR" \
      -F /dev/null \
      "solana@$publicIp:$remoteFile" "$localFile"
  )
}