AWSTemplateFormatVersion: '2010-09-09'
Description: Deploy Gerrit network stack

Parameters:
  InternetGatewayIdProp:
    Type: String
    Default: ""
    Description: Internet Gateway id. If empty Internet Gateway will be created
  VPCIdProp:
    Type: String
    Default: ""
    Description: VPC id. If empty VPC will be created
  Subnet1IdProp:
    Type: String
    Default: ""
    Description: Subnet1 id. If empty Network Stack will be created
  Subnet2IdProp:
    Type: String
    Default: ""
    Description: Subnet2 id. If empty Network Stack will be created
  Subnet1CIDR:
    Type: String
    Default: 10.0.0.0/24
    Description: Subnet 1 CIDR.
  Subnet2CIDR:
    Type: String
    Default: 10.0.32.0/24
    Description: Subnet 2 CIDR.
  VPCCIDR:
    Type: String
    Default: 10.0.0.0/16
    Description: VPC CIDR.
  Subnet1AZProp:
    Type: String
    Default: ""
    Description: The Availability Zone of subnet1
  Subnet2AZProp:
    Type: String
    Default: ""
    Description: The Availability Zone of subnet2

Conditions:
  CreateVPC: !Equals [!Ref VPCIdProp, ""]
  CreateNetworkStack: !Equals [!Ref Subnet1IdProp, ""]
  HasSubnet1AZ: !Not
    - !Equals [!Ref Subnet1AZProp, ""]
  HasSubnet2AZ: !Not
    - !Equals [!Ref Subnet2AZProp, ""]
  CreateInternetGateway: !And
     - !Equals [!Ref InternetGatewayIdProp, ""]
     - !Condition CreateNetworkStack
Resources:
  VPC:
    Condition: CreateVPC
    Type: AWS::EC2::VPC
    Properties:
      EnableDnsSupport: true
      EnableDnsHostnames: true
      CidrBlock: !Ref VPCCIDR

  # Public subnets, where containers can have public IP addresses
  PublicSubnetOne:
    Condition: CreateNetworkStack
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone:
        Fn::If:
          - HasSubnet1AZ
          - !Ref 'Subnet1AZProp'
          - Fn::Select:
              - 0
              - Fn::GetAZs: ""
      VpcId: !If [CreateVPC, !Ref 'VPC', !Ref 'VPCIdProp' ]
      CidrBlock: !Ref 'Subnet1CIDR'
      MapPublicIpOnLaunch: true

  PublicSubnetTwo:
    Condition: CreateNetworkStack
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone:
        Fn::If:
          - HasSubnet2AZ
          - !Ref 'Subnet2AZProp'
          - Fn::Select:
              - 1
              - Fn::GetAZs: ""
      VpcId: !If [CreateVPC, !Ref 'VPC', !Ref 'VPCIdProp' ]
      CidrBlock: !Ref 'Subnet2CIDR'
      MapPublicIpOnLaunch: true

  # Setup networking resources for the public subnets. Containers
  # in the public subnets have public IP addresses and the routing table
  # sends network traffic via the internet gateway.
  InternetGateway:
    Condition: CreateInternetGateway
    Type: AWS::EC2::InternetGateway
  GatewayAttachement:
    Condition: CreateNetworkStack
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId: !If [CreateVPC, !Ref 'VPC', !Ref 'VPCIdProp' ]
      InternetGatewayId: !If [CreateInternetGateway, !Ref 'InternetGateway', !Ref 'InternetGatewayIdProp' ]
  PublicRouteTable:
    Condition: CreateNetworkStack
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !If [CreateVPC, !Ref 'VPC', !Ref 'VPCIdProp' ]
  PublicRoute:
    Condition: CreateNetworkStack
    Type: AWS::EC2::Route
    DependsOn: GatewayAttachement
    Properties:
      RouteTableId: !Ref 'PublicRouteTable'
      DestinationCidrBlock: '0.0.0.0/0'
      GatewayId: !If [CreateInternetGateway, !Ref 'InternetGateway', !Ref 'InternetGatewayIdProp' ]
  PublicSubnetOneRouteTableAssociation:
    Condition: CreateNetworkStack
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnetOne
      RouteTableId: !Ref PublicRouteTable
  PublicSubnetTwoRouteTableAssociation:
    Condition: CreateNetworkStack
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnetTwo
      RouteTableId: !Ref PublicRouteTable
Outputs:
  VPCRef:
    Value: !If [CreateVPC, !Ref 'VPC', !Ref 'VPCIdProp' ]
  PublicSubnetOneRef:
    Value: !If [CreateNetworkStack, !Ref 'PublicSubnetOne', !Ref 'Subnet1IdProp' ]
  PublicSubnetOneAZ:
    Value: !If [CreateNetworkStack, !GetAtt PublicSubnetOne.AvailabilityZone, !Ref 'Subnet1AZProp' ]
  PublicOneCIDR:
    Value: !Ref 'Subnet1CIDR'
  PublicSubnetTwoRef:
    Value: !If [CreateNetworkStack, !Ref 'PublicSubnetTwo', !Ref 'Subnet2IdProp' ]
  PublicSubnetTwoAZ:
    Value: !If [CreateNetworkStack, !GetAtt PublicSubnetTwo.AvailabilityZone, !Ref 'Subnet2AZProp' ]
  PublicTwoCIDR:
    Value: !Ref 'Subnet2CIDR'