AWSTemplateFormatVersion: "2010-09-09"
Description: |
  This template is for building and maintaining a Minecraft server.
  Everything is within the free usage limit.
  This server is not made for a large group of people to play on, as the specs themselves are low. 

Mappings:
  ServerSettings:
    port:
      v4: 59132
  EC2:
    ap-northeast-1:
      Ubuntu2004AMI: ami-09b18720cb71042df
    ap-northeast-3:
      Ubuntu2004AMI: ami-09d2f3a31110c6ad4

Parameters:
  VPCId:
    Type: AWS::EC2::VPC::Id
  MinecraftVersion:
    Type: String
    Default: 1.19.30.04
  ServerName:
    Type: String
    Default: ydak Minecraft
  GameMode:
    Type: String
    Default: survival
    AllowedValues:
      - survival
      - creative
      - adventure
  Difficulty:
    Type: String
    Default: easy
    AllowedValues:
      - peaceful
      - easy
      - normal
      - hard
  AllowCheats:
    Type: String
    Default: false
    AllowedValues:
      - true
      - false
  Seed:
    Type: String
    Default: ''
    AllowedPattern: "[-0-9]*"
  DefaultPermission:
    Type: String
    Default: member
    AllowedValues:
      - visitor
      - member
      - operator

Resources:

  InstanceSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: for minecraft
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: !FindInMap [ ServerSettings, port, v4 ]
          ToPort: !FindInMap [ ServerSettings, port, v4 ]
          CidrIp: 0.0.0.0/0
        - IpProtocol: udp
          FromPort: !FindInMap [ ServerSettings, port, v4 ]
          ToPort: !FindInMap [ ServerSettings, port, v4 ]
          CidrIp: 0.0.0.0/0

  KeyMinecraft:
    Type: AWS::EC2::KeyPair
    Properties:
      KeyName: minecraft

  EC2IAMRole:
    Type: AWS::IAM::Role
    Properties:
      RoleName: minecraft-SSM-role
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - ec2.amazonaws.com
            Action:
              - sts:AssumeRole
      Path: /
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/AmazonSSMManagedInstanceCore

  EC2InstanceProfile:
    Type: AWS::IAM::InstanceProfile
    Properties:
      Path: /
      Roles:
        - Ref: EC2IAMRole
      InstanceProfileName: minecraft-EC2InstanceProfile

  EC2Instance:
    Type: AWS::EC2::Instance
    Properties:
      InstanceType: t2.micro
      SecurityGroups:
        - !Ref InstanceSecurityGroup
      KeyName: !Ref KeyMinecraft
      ImageId: !FindInMap [ EC2, !Ref AWS::Region, Ubuntu2004AMI ]
      IamInstanceProfile: !Ref EC2InstanceProfile
      Tags:
        - Key: Name
          Value: minecraft
      UserData:
        Fn::Base64: !Sub
          - |
            #!/usr/bin/env bash
            set -eu
            
            mkdir /var/minecraft && cd /var/minecraft/
            
            wget -O bedrock-server.zip https://minecraft.azureedge.net/bin-linux/bedrock-server-${minecraft_version}.zip
            
            sudo apt install -y unzip && unzip bedrock-server.zip
            
            sed -i -e 's/^\(server-name=\)Dedicated Server/\1${server_name}/g' server.properties
            sed -i -e 's/^\(gamemode=\)survival/\1${game_mode}/g' server.properties
            sed -i -e 's/^\(difficulty=\)easy/\1${difficulty}/g' server.properties
            sed -i -e 's/^\(server-port=\)19132/\1${ip4_port}/g' server.properties
            sed -i -e 's/^\(allow-cheats=\)false/\1${allow_cheats}/g' server.properties
            sed -i -e 's/^\(level-seed=\)/\1${seed}/g' server.properties
            sed -i -e 's/^\(default-player-permission-level=\)member/\1${permission}/g' server.properties
            
            screen -UAmdS minecraft ./bedrock_server

          - {
              minecraft_version: !Ref MinecraftVersion,
              server_name: !Ref ServerName,
              game_mode: !Ref GameMode,
              difficulty: !Ref Difficulty,
              ip4_port: !FindInMap [ ServerSettings, port, v4 ],
              allow_cheats: !Ref AllowCheats,
              seed: !Ref Seed,
              permission: !Ref DefaultPermission,
            }