locals {
  db_private_ip    = "10.0.1.10"
  caddy_private_ip = "10.0.1.5"
  app_base_ip      = 20 # App-Nodes: 10.0.1.20, .21, ...

  database_url = "mysql://${var.db_user}:${var.db_password}@${local.db_private_ip}:3306/${var.db_name}?serverVersion=11.4.0-MariaDB&charset=utf8mb4"

  # Caddy-Upstreams = private IPs der App-Nodes (:80)
  app_upstreams = join(" ", [for i in range(var.app_count) : "10.0.1.${local.app_base_ip + i}:80"])
  ask_upstream  = "10.0.1.${local.app_base_ip}" # app-1 für die On-Demand-TLS-Abfrage
}

resource "hcloud_ssh_key" "admin" {
  name       = "vcard4-admin"
  public_key = var.ssh_public_key
}

# --- Privates Netz ---
resource "hcloud_network" "net" {
  name     = "vcard4-net"
  ip_range = "10.0.0.0/16"
}

resource "hcloud_network_subnet" "subnet" {
  network_id   = hcloud_network.net.id
  type         = "cloud"
  network_zone = var.network_zone
  ip_range     = "10.0.1.0/24"
}

# --- Firewalls ---
resource "hcloud_firewall" "app" {
  name = "vcard4-app-fw"
  rule {
    direction  = "in"
    protocol   = "tcp"
    port       = "22"
    source_ips = [var.admin_cidr]
  }
  rule {
    direction  = "in"
    protocol   = "tcp"
    port       = "80"
    source_ips = ["10.0.0.0/16"] # nur aus dem privaten Netz (Load Balancer)
  }
}

resource "hcloud_firewall" "db" {
  name = "vcard4-db-fw"
  rule {
    direction  = "in"
    protocol   = "tcp"
    port       = "22"
    source_ips = [var.admin_cidr]
  }
  rule {
    direction  = "in"
    protocol   = "tcp"
    port       = "3306"
    source_ips = ["10.0.0.0/16"] # nur App-Nodes
  }
}

# --- DB-Node ---
resource "hcloud_server" "db" {
  name         = "vcard4-db"
  server_type  = var.db_server_type
  image        = "ubuntu-24.04"
  location     = var.location
  ssh_keys     = [hcloud_ssh_key.admin.id]
  firewall_ids = [hcloud_firewall.db.id]

  user_data = templatefile("${path.module}/cloud-init-db.yaml.tftpl", {
    db_name          = var.db_name
    db_user          = var.db_user
    db_password      = var.db_password
    db_root_password = var.db_root_password
  })

  network {
    network_id = hcloud_network.net.id
    ip         = local.db_private_ip
  }

  depends_on = [hcloud_network_subnet.subnet]
}

# --- App-Nodes (zustandslos) ---
resource "hcloud_server" "app" {
  count        = var.app_count
  name         = "vcard4-app-${count.index + 1}"
  server_type  = var.app_server_type
  image        = "ubuntu-24.04"
  location     = var.location
  ssh_keys     = [hcloud_ssh_key.admin.id]
  firewall_ids = [hcloud_firewall.app.id]

  user_data = templatefile("${path.module}/cloud-init-app.yaml.tftpl", {
    repo_url          = var.repo_url
    repo_branch       = var.repo_branch
    run_migrations    = count.index == 0 # Migrationen nur auf dem ersten Node
    app_secret        = var.app_secret
    database_url      = local.database_url
    domain            = var.domain
    cors_allow_origin = "^https?://(www\\.)?${replace(var.domain, ".", "\\.")}$"
    jwt_passphrase  = var.jwt_passphrase
    jwt_private_key = var.jwt_private_key
    jwt_public_key  = var.jwt_public_key
    s3_endpoint     = var.s3_endpoint
    s3_region       = var.s3_region
    s3_bucket       = var.s3_bucket
    s3_key          = var.s3_key
    s3_secret       = var.s3_secret
  })

  network {
    network_id = hcloud_network.net.id
    ip         = "10.0.1.${local.app_base_ip + count.index}"
  }

  # cloud-init zählt nur beim Erstboot; Code-Updates laufen über den Rollout
  # (terraform_data.app_deploy) → Server nicht wegen user_data-Änderung ersetzen.
  lifecycle {
    ignore_changes = [user_data]
  }

  depends_on = [hcloud_network_subnet.subnet, hcloud_server.db]
}

# --- Caddy-Edge (TLS-Terminierung + Reverse-Proxy/Load-Balancing) ---
resource "hcloud_firewall" "caddy" {
  name = "vcard4-caddy-fw"
  rule {
    direction  = "in"
    protocol   = "tcp"
    port       = "22"
    source_ips = [var.admin_cidr]
  }
  rule {
    direction  = "in"
    protocol   = "tcp"
    port       = "80"
    source_ips = ["0.0.0.0/0", "::/0"]
  }
  rule {
    direction  = "in"
    protocol   = "tcp"
    port       = "443"
    source_ips = ["0.0.0.0/0", "::/0"]
  }
  rule {
    direction  = "in"
    protocol   = "udp"
    port       = "443"
    source_ips = ["0.0.0.0/0", "::/0"]
  }
}

resource "hcloud_server" "caddy" {
  name         = "vcard4-caddy"
  server_type  = var.app_server_type
  image        = "ubuntu-24.04"
  location     = var.location
  ssh_keys     = [hcloud_ssh_key.admin.id]
  firewall_ids = [hcloud_firewall.caddy.id]

  user_data = templatefile("${path.module}/cloud-init-caddy.yaml.tftpl", {
    acme_email    = var.acme_email
    domain        = var.domain
    app_upstreams = local.app_upstreams
    ask_upstream  = local.ask_upstream
  })

  network {
    network_id = hcloud_network.net.id
    ip         = local.caddy_private_ip
  }

  depends_on = [hcloud_network_subnet.subnet, hcloud_server.app]
}