#!/usr/bin/env bash
# Infraestrutura do laboratorio. Compativel com curl -fsSL URL | bash.
# Configuracao por variaveis de ambiente; nao le perguntas de stdin.
set -Eeuo pipefail
export AWS_PAGER="" AWS_CLI_AUTO_PROMPT=off

main() {
  local mode="${1:---apply}"
  case "$mode" in --plan|--apply) ;; *) echo 'Use --plan ou --apply' >&2; return 2;; esac
  for tool in aws python3 curl; do
    command -v "$tool" >/dev/null || { echo "Falta instalar: $tool" >&2; return 2; }
  done
  REGION="${REGION:-us-east-1}"
  LAB_NAME="${LAB_NAME:-ssor-vpn}"
  INSTANCE_TYPE="${INSTANCE_TYPE:-t3.micro}"
  LOCAL_CIDR="${LOCAL_CIDR:-172.17.0.0/24}"
  VPN_CIDR="${VPN_CIDR:-10.8.0.0/24}"
  local create_key=false key_file='' run_id
  run_id="$(date -u +%Y%m%dT%H%M%SZ)-$$"
  if [[ -z "${KEY_NAME:-}" ]]; then
    KEY_NAME="$LAB_NAME-$run_id"
    create_key=true
  fi
  [[ "$LAB_NAME" =~ ^[a-zA-Z][a-zA-Z0-9-]{0,39}$ ]] || { echo 'LAB_NAME invalido' >&2; return 2; }

  # Validar as redes local e VPN.
  python3 - "$LOCAL_CIDR" "$VPN_CIDR" <<'PY'
import ipaddress, sys
local, vpn = [ipaddress.IPv4Network(x, strict=True) for x in sys.argv[1:]]
vpc = ipaddress.IPv4Network('10.20.0.0/16')
private = [ipaddress.ip_network(x) for x in ['10.0.0.0/8','172.16.0.0/12','192.168.0.0/16']]
for net in [local, vpn]:
    if not any(net.subnet_of(x) for x in private):
        raise SystemExit('Redes local e VPN devem usar faixas privadas RFC1918.')
if local.overlaps(vpn) or local.overlaps(vpc) or vpn.overlaps(vpc):
    raise SystemExit('As redes local, VPN e VPC nao podem se sobrepor.')
PY
  aw() { aws --region "$REGION" "$@"; }
  local account existing ami root_device az
  account=$(aw sts get-caller-identity --query Account --output text)
  if [[ "$create_key" == false ]]; then
    aw ec2 describe-key-pairs --key-names "$KEY_NAME" >/dev/null
  fi
  existing=$(aw ec2 describe-vpcs --filters "Name=tag:Lab,Values=$LAB_NAME" --query 'Vpcs[].VpcId' --output text)
  if [[ -n "$existing" && "$existing" != None ]]; then
    echo "Ja existe uma VPC deste laboratorio: $existing. Revise-a antes de executar novamente." >&2
    return 2
  fi
  # Imagem oficial Canonical Ubuntu 24.04 LTS amd64, sem Marketplace.
  ami=$(aw ec2 describe-images --owners 099720109477 --filters \
    'Name=name,Values=ubuntu/images/hvm-ssd-gp3/ubuntu-noble-24.04-amd64-server-*' \
    'Name=state,Values=available' 'Name=architecture,Values=x86_64' \
    'Name=root-device-type,Values=ebs' 'Name=virtualization-type,Values=hvm' \
    --query 'sort_by(Images,&CreationDate)[-1].ImageId' --output text)
  [[ -n "$ami" && "$ami" != None ]] || { echo 'AMI Ubuntu nao encontrada.' >&2; return 2; }
  root_device=$(aw ec2 describe-images --image-ids "$ami" --query 'Images[0].RootDeviceName' --output text)
  az=$(aw ec2 describe-instance-type-offerings --location-type availability-zone \
    --filters "Name=instance-type,Values=$INSTANCE_TYPE" \
    --query 'sort_by(InstanceTypeOfferings,&Location)[0].Location' --output text)
  [[ -n "$az" && "$az" != None ]] || { echo 'Tipo de instancia indisponivel na regiao.' >&2; return 2; }
  cat <<EOF
Conta: $account | Regiao: $REGION | Zona: $az | Lab: $LAB_NAME
Ubuntu 24.04: $ami | Duas EC2: $INSTANCE_TYPE | Chave: $KEY_NAME
VPC: 10.20.0.0/16
Gateway publico: 10.20.1.10 | Servidor privado: 10.20.2.10
SSH publico permitido de: 0.0.0.0/0
Criar chave SSH automaticamente: $create_key
VPC 10.20.0.0/16: todos os protocolos liberados entre as maquinas.
VPN: UDP/1194 aberto; rotas AWS, permissoes e encaminhamento IPv4 preparados.
Rede local: $LOCAL_CIDR | Tunel: $VPN_CIDR | OpenVPN roteado sem NAT entre sites.
Serao criados recursos que consomem o saldo do laboratorio: EC2, EBS e IPv4 publico.
Aloca um Elastic IP fixo para o gateway. Nao cria NAT Gateway, IAM ou certificados VPN.
EOF
  if [[ "$mode" == --plan ]]; then
    echo 'Plano somente: nenhuma alteracao. Use --apply para criar.'
    return
  fi

  # Diario salvo no terminal que executar o script. Nao contem chaves privadas.
  umask 077
  local state_dir="${LAB_STATE_DIR:-$PWD/aws-lab-state}"
  mkdir -p "$state_dir"
  state_dir=$(cd "$state_dir" && pwd -P)
  STATE_FILE="$state_dir/${LAB_NAME}-$run_id.txt"
  printf 'Account=%s\nRegion=%s\nLab=%s\n' "$account" "$REGION" "$LAB_NAME" > "$STATE_FILE"
  trap 'echo "Falha na linha $LINENO. Recursos parciais podem existir; consulte $STATE_FILE e a tag Lab=$LAB_NAME. Nao houve rollback automatico." >&2' ERR
  record() { printf '%s=%s\n' "$1" "$2" | tee -a "$STATE_FILE"; }
  tags() { printf 'ResourceType=%s,Tags=[{Key=Lab,Value=%s},{Key=Name,Value=%s-%s}]' "$1" "$LAB_NAME" "$LAB_NAME" "$2"; }
  record LocalCidr "$LOCAL_CIDR"
  record VpnCidr "$VPN_CIDR"
  record KeyName "$KEY_NAME"
  record KeyCreatedByScript "$create_key"
  if [[ "$create_key" == true ]]; then
    key_file="$state_dir/$KEY_NAME.pem"
    # noclobber impede sobrescrever uma chave preexistente; conteudo nunca vai para stdout.
    # RSA/PEM sao os padroes; omitir flags novas permite usar a CLI antiga do Learner Lab.
    (set -o noclobber; aw ec2 create-key-pair --key-name "$KEY_NAME" \
      --tag-specifications "$(tags key-pair ssh)" --query KeyMaterial --output text > "$key_file")
    chmod 600 "$key_file"
    [[ -s "$key_file" ]] || { echo 'Arquivo da chave vazio.' >&2; return 1; }
    record PrivateKeyFile "$key_file"
  fi
  local vpc igw public_subnet private_subnet public_rt private_rt gateway_sg services_sg gateway server
  vpc=$(aw ec2 create-vpc --cidr-block 10.20.0.0/16 --tag-specifications "$(tags vpc vpc)" --query Vpc.VpcId --output text)
  record VpcId "$vpc"
  aw ec2 wait vpc-available --vpc-ids "$vpc"
  aw ec2 modify-vpc-attribute --vpc-id "$vpc" --enable-dns-support '{"Value":true}'
  aw ec2 modify-vpc-attribute --vpc-id "$vpc" --enable-dns-hostnames '{"Value":true}'
  igw=$(aw ec2 create-internet-gateway --tag-specifications "$(tags internet-gateway igw)" --query InternetGateway.InternetGatewayId --output text)
  record InternetGatewayId "$igw"
  aw ec2 attach-internet-gateway --internet-gateway-id "$igw" --vpc-id "$vpc"
  public_subnet=$(aw ec2 create-subnet --vpc-id "$vpc" --cidr-block 10.20.1.0/24 --availability-zone "$az" --tag-specifications "$(tags subnet publica)" --query Subnet.SubnetId --output text)
  record PublicSubnetId "$public_subnet"
  private_subnet=$(aw ec2 create-subnet --vpc-id "$vpc" --cidr-block 10.20.2.0/24 --availability-zone "$az" --tag-specifications "$(tags subnet privada)" --query Subnet.SubnetId --output text)
  record PrivateSubnetId "$private_subnet"
  public_rt=$(aw ec2 create-route-table --vpc-id "$vpc" --tag-specifications "$(tags route-table publica)" --query RouteTable.RouteTableId --output text)
  record PublicRouteTableId "$public_rt"
  aw ec2 associate-route-table --route-table-id "$public_rt" --subnet-id "$public_subnet" >/dev/null
  aw ec2 create-route --route-table-id "$public_rt" --destination-cidr-block 0.0.0.0/0 --gateway-id "$igw" >/dev/null
  private_rt=$(aw ec2 create-route-table --vpc-id "$vpc" --tag-specifications "$(tags route-table privada)" --query RouteTable.RouteTableId --output text)
  record PrivateRouteTableId "$private_rt"
  aw ec2 associate-route-table --route-table-id "$private_rt" --subnet-id "$private_subnet" >/dev/null
  gateway_sg=$(aw ec2 create-security-group --vpc-id "$vpc" --group-name "$LAB_NAME-gateway" --description 'Gateway OpenVPN do laboratorio' --tag-specifications "$(tags security-group gateway)" --query GroupId --output text)
  record GatewaySecurityGroupId "$gateway_sg"
  services_sg=$(aw ec2 create-security-group --vpc-id "$vpc" --group-name "$LAB_NAME-servicos" --description 'Servicos privados do laboratorio' --tag-specifications "$(tags security-group servicos)" --query GroupId --output text)
  record ServicesSecurityGroupId "$services_sg"
  allow() { aw ec2 authorize-security-group-ingress --group-id "$1" --protocol "$2" --port "$3" --cidr "$4" >/dev/null; }
  allow "$gateway_sg" tcp 22 0.0.0.0/0
  allow "$gateway_sg" udp 1194 0.0.0.0/0
  # Comunicacao interna irrestrita na VPC; saida padrao dos grupos ja permite tudo.
  local internal_sg internal_cidr
  for internal_sg in "$gateway_sg" "$services_sg"; do
    for internal_cidr in 10.20.0.0/16 "$LOCAL_CIDR" "$VPN_CIDR"; do
      aw ec2 authorize-security-group-ingress --group-id "$internal_sg" --ip-permissions \
        "[{\"IpProtocol\":\"-1\",\"IpRanges\":[{\"CidrIp\":\"$internal_cidr\",\"Description\":\"Redes privadas do laboratorio\"}]}]" >/dev/null
    done
  done
  # Encaminhamento persistente, sem depender de download de pacotes.
  local gateway_user_data='#cloud-config
write_files:
  - path: /etc/sysctl.d/90-vpn-lab.conf
    permissions: "0644"
    content: |
      net.ipv4.ip_forward=1
runcmd:
  - [sysctl, --system]
'
  local disk="[{\"DeviceName\":\"$root_device\",\"Ebs\":{\"VolumeSize\":8,\"VolumeType\":\"gp3\",\"DeleteOnTermination\":true,\"Encrypted\":true}}]"
  gateway=$(aw ec2 run-instances --image-id "$ami" --instance-type "$INSTANCE_TYPE" --count 1 \
    --key-name "$KEY_NAME" --subnet-id "$public_subnet" --private-ip-address 10.20.1.10 \
    --security-group-ids "$gateway_sg" --no-associate-public-ip-address \
    --metadata-options HttpTokens=required,HttpEndpoint=enabled \
    --block-device-mappings "$disk" --user-data "$gateway_user_data" \
    --tag-specifications "$(tags instance gateway)" "$(tags volume gateway)" \
    --client-token "$vpc-gateway" --query 'Instances[0].InstanceId' --output text)
  record GatewayInstanceId "$gateway"
  aw ec2 wait instance-running --instance-ids "$gateway"
  aw ec2 modify-instance-attribute --instance-id "$gateway" --no-source-dest-check
  local return_rt return_cidr
  for return_rt in "$public_rt" "$private_rt"; do
    for return_cidr in "$LOCAL_CIDR" "$VPN_CIDR"; do
      aw ec2 create-route --route-table-id "$return_rt" --destination-cidr-block "$return_cidr" \
        --instance-id "$gateway" >/dev/null
    done
  done
  # Registrar a alocacao antes da associacao permite recuperar uma falha parcial.
  local eip_allocation eip_association eip_target public_ip
  eip_allocation=$(aw ec2 allocate-address --domain vpc --query AllocationId --output text)
  record ElasticIpAllocationId "$eip_allocation"
  aw ec2 create-tags --resources "$eip_allocation" \
    --tags "Key=Lab,Value=$LAB_NAME" "Key=Name,Value=$LAB_NAME-gateway"
  public_ip=$(aw ec2 describe-addresses --allocation-ids "$eip_allocation" --query 'Addresses[0].PublicIp' --output text)
  record GatewayPublicIp "$public_ip"
  eip_association=$(aw ec2 associate-address --allocation-id "$eip_allocation" \
    --instance-id "$gateway" --no-allow-reassociation --query AssociationId --output text)
  record ElasticIpAssociationId "$eip_association"
  eip_target=$(aw ec2 describe-addresses --allocation-ids "$eip_allocation" --query 'Addresses[0].InstanceId' --output text)
  [[ "$eip_target" == "$gateway" ]] || { echo 'Elastic IP nao associado ao gateway esperado.' >&2; return 1; }
  server=$(aw ec2 run-instances --image-id "$ami" --instance-type "$INSTANCE_TYPE" --count 1 \
    --key-name "$KEY_NAME" --subnet-id "$private_subnet" --private-ip-address 10.20.2.10 \
    --security-group-ids "$services_sg" --no-associate-public-ip-address \
    --metadata-options HttpTokens=required,HttpEndpoint=enabled --block-device-mappings "$disk" \
    --tag-specifications "$(tags instance servicos)" "$(tags volume servicos)" \
    --client-token "$vpc-servicos" --query 'Instances[0].InstanceId' --output text)
  record ServicesInstanceId "$server"
  aw ec2 wait instance-running --instance-ids "$server"
  local private_public_ip
  private_public_ip=$(aw ec2 describe-instances --instance-ids "$server" --query 'Reservations[0].Instances[0].PublicIpAddress' --output text)
  [[ "$private_public_ip" == None || -z "$private_public_ip" ]] || { echo 'Servidor privado recebeu IP publico inesperado.' >&2; return 1; }
  if [[ "$create_key" == true ]]; then
    local ssh_config="$state_dir/${LAB_NAME}-$run_id.ssh-config"
    cat > "$ssh_config" <<EOF
Host lab-gateway
    HostName $public_ip
    User ubuntu
    IdentityFile "$key_file"
    IdentitiesOnly yes
Host lab-servicos
    HostName 10.20.2.10
    User ubuntu
    IdentityFile "$key_file"
    IdentitiesOnly yes
    ProxyCommand ssh -F "$ssh_config" -W %h:%p lab-gateway
EOF
    record SshConfigFile "$ssh_config"
    printf 'Acesso pelo terminal atual:\n  ssh -F %q lab-gateway\n  ssh -F %q lab-servicos\n' "$ssh_config" "$ssh_config"
    echo 'Guarde uma copia privada do arquivo .pem antes de perder acesso a este terminal.'
  fi
  cat <<EOF
Infraestrutura criada. Diario: $STATE_FILE
Gateway: ubuntu@$public_ip | Servidor privado: ubuntu@10.20.2.10
As EC2 estao running; cloud-init e SSH podem levar mais alguns minutos.
Se usou KEY_NAME preexistente, configure a IdentityFile para ambos os hosts (veja README).
OpenVPN, certificados, intranet e coleta de logs ainda precisam ser configurados.
AWS pronta para rede local $LOCAL_CIDR e tunel $VPN_CIDR; use essas faixas no OpenVPN.
No gateway, apos cloud-init: sysctl net.ipv4.ip_forward deve retornar 1.
A sub-rede privada nao possui saida para Internet. Veja README para instalar pacotes.
Elastic IP do gateway: $public_ip (alocacao: $eip_allocation).
O endereco permanece ao parar/iniciar a instancia enquanto a alocacao e associacao forem mantidas.
Ao desmontar o laboratorio, desassocie e libere esse Elastic IP para encerrar sua cobranca.
EOF
}

# Executar somente depois de Bash ter lido a funcao inteira do pipe.
main "$@"