terraform {
  required_providers {
    coder = {
      source = "coder/coder"
    }
    azurerm = {
      source = "hashicorp/azurerm"
    }
    cloudinit = {
      source = "hashicorp/cloudinit"
    }
  }
}

# See https://registry.coder.com/modules/coder/azure-region
module "azure_region" {
  source = "registry.coder.com/coder/azure-region/coder"

  # This ensures that the latest non-breaking version of the module gets downloaded, you can also pin the module version to prevent breaking changes in production.
  version = "~> 1.0"

  default = "eastus"
}

data "coder_parameter" "instance_type" {
  name         = "instance_type"
  display_name = "Instance type"
  description  = "What instance type should your workspace use?"
  default      = "Standard_B4ms"
  icon         = "/icon/azure.png"
  mutable      = false
  option {
    name  = "Standard_B1ms (1 vCPU, 2 GiB RAM)"
    value = "Standard_B1ms"
  }
  option {
    name  = "Standard_B2ms (2 vCPU, 8 GiB RAM)"
    value = "Standard_B2ms"
  }
  option {
    name  = "Standard_B4ms (4 vCPU, 16 GiB RAM)"
    value = "Standard_B4ms"
  }
  option {
    name  = "Standard_B8ms (8 vCPU, 32 GiB RAM)"
    value = "Standard_B8ms"
  }
  option {
    name  = "Standard_B12ms (12 vCPU, 48 GiB RAM)"
    value = "Standard_B12ms"
  }
  option {
    name  = "Standard_B16ms (16 vCPU, 64 GiB RAM)"
    value = "Standard_B16ms"
  }
  option {
    name  = "Standard_D2as_v5 (2 vCPU, 8 GiB RAM)"
    value = "Standard_D2as_v5"
  }
  option {
    name  = "Standard_D4as_v5 (4 vCPU, 16 GiB RAM)"
    value = "Standard_D4as_v5"
  }
  option {
    name  = "Standard_D8as_v5 (8 vCPU, 32 GiB RAM)"
    value = "Standard_D8as_v5"
  }
  option {
    name  = "Standard_D16as_v5 (16 vCPU, 64 GiB RAM)"
    value = "Standard_D16as_v5"
  }
  option {
    name  = "Standard_D32as_v5 (32 vCPU, 128 GiB RAM)"
    value = "Standard_D32as_v5"
  }
}

data "coder_parameter" "home_size" {
  name         = "home_size"
  display_name = "Home volume size"
  description  = "How large would you like your home volume to be (in GB)?"
  default      = 20
  type         = "number"
  icon         = "/icon/azure.png"
  mutable      = false
  validation {
    min = 1
    max = 1024
  }
}

provider "azurerm" {
  features {}
}

data "coder_workspace" "me" {}
data "coder_workspace_owner" "me" {}

resource "coder_agent" "main" {
  arch = "amd64"
  os   = "linux"
  auth = "azure-instance-identity"

  metadata {
    key          = "cpu"
    display_name = "CPU Usage"
    interval     = 5
    timeout      = 5
    script       = <<-EOT
      #!/bin/bash
      set -e
      top -bn1 | grep "Cpu(s)" | awk '{print $2 + $4 "%"}'
    EOT
  }
  metadata {
    key          = "memory"
    display_name = "Memory Usage"
    interval     = 5
    timeout      = 5
    script       = <<-EOT
      #!/bin/bash
      set -e
      free -m | awk 'NR==2{printf "%.2f%%\t", $3*100/$2 }'
    EOT
  }
  metadata {
    key          = "disk"
    display_name = "Disk Usage"
    interval     = 600 # every 10 minutes
    timeout      = 30  # df can take a while on large filesystems
    script       = <<-EOT
      #!/bin/bash
      set -e
      df /home/coder | awk '$NF=="/"{printf "%s", $5}'
    EOT
  }
}

# See https://registry.coder.com/modules/coder/code-server
module "code-server" {
  count  = data.coder_workspace.me.start_count
  source = "registry.coder.com/coder/code-server/coder"

  # This ensures that the latest non-breaking version of the module gets downloaded, you can also pin the module version to prevent breaking changes in production.
  version = "~> 1.0"

  agent_id   = coder_agent.main.id
  agent_name = "main"
  order      = 1
}

# See https://registry.coder.com/modules/coder/jetbrains
module "jetbrains" {
  count      = data.coder_workspace.me.start_count
  source     = "registry.coder.com/modules/coder/jetbrains/coder"
  version    = "~> 1.0"
  agent_id   = coder_agent.main.id
  agent_name = "main"
  folder     = "/home/coder"
}

locals {
  prefix = "coder-${data.coder_workspace_owner.me.name}-${data.coder_workspace.me.name}"
}

data "cloudinit_config" "user_data" {
  gzip          = false
  base64_encode = true

  boundary = "//"

  part {
    filename     = "cloud-config.yaml"
    content_type = "text/cloud-config"

    content = templatefile("${path.module}/cloud-init/cloud-config.yaml.tftpl", {
      username    = "coder" # Ensure this user/group does not exist in your VM image
      init_script = base64encode(coder_agent.main.init_script)
      hostname    = lower(data.coder_workspace.me.name)
    })
  }
}

resource "azurerm_resource_group" "main" {
  name     = "${local.prefix}-resources"
  location = module.azure_region.value

  tags = {
    Coder_Provisioned = "true"
  }
}

// Uncomment here and in the azurerm_network_interface resource to obtain a public IP
#resource "azurerm_public_ip" "main" {
#  name                = "publicip"
#  resource_group_name = azurerm_resource_group.main.name
#  location            = azurerm_resource_group.main.location
#  allocation_method   = "Static"
#
#  tags = {
#    Coder_Provisioned = "true"
#  }
#}

resource "azurerm_virtual_network" "main" {
  name                = "network"
  address_space       = ["10.0.0.0/24"]
  location            = azurerm_resource_group.main.location
  resource_group_name = azurerm_resource_group.main.name

  tags = {
    Coder_Provisioned = "true"
  }
}

resource "azurerm_subnet" "internal" {
  name                 = "internal"
  resource_group_name  = azurerm_resource_group.main.name
  virtual_network_name = azurerm_virtual_network.main.name
  address_prefixes     = ["10.0.0.0/29"]
}

resource "azurerm_network_interface" "main" {
  name                = "nic"
  resource_group_name = azurerm_resource_group.main.name
  location            = azurerm_resource_group.main.location

  ip_configuration {
    name                          = "internal"
    subnet_id                     = azurerm_subnet.internal.id
    private_ip_address_allocation = "Dynamic"
    // Uncomment for public IP address as well as azurerm_public_ip resource above
    //public_ip_address_id = azurerm_public_ip.main.id
  }

  tags = {
    Coder_Provisioned = "true"
  }
}

resource "azurerm_managed_disk" "home" {
  create_option        = "Empty"
  location             = azurerm_resource_group.main.location
  name                 = "home"
  resource_group_name  = azurerm_resource_group.main.name
  storage_account_type = "StandardSSD_LRS"
  disk_size_gb         = data.coder_parameter.home_size.value
}

// azurerm requires an SSH key (or password) for an admin user or it won't start a VM.  However,
// cloud-init overwrites this anyway, so we'll just use a dummy SSH key.
resource "tls_private_key" "dummy" {
  algorithm = "RSA"
  rsa_bits  = 4096
}

resource "azurerm_linux_virtual_machine" "main" {
  count               = data.coder_workspace.me.start_count
  name                = "vm"
  resource_group_name = azurerm_resource_group.main.name
  location            = azurerm_resource_group.main.location
  size                = data.coder_parameter.instance_type.value
  // cloud-init overwrites this, so the value here doesn't matter
  admin_username = "adminuser"
  admin_ssh_key {
    public_key = tls_private_key.dummy.public_key_openssh
    username   = "adminuser"
  }

  network_interface_ids = [
    azurerm_network_interface.main.id,
  ]
  computer_name = lower(data.coder_workspace.me.name)
  os_disk {
    caching              = "ReadWrite"
    storage_account_type = "Standard_LRS"
  }
  source_image_reference {
    publisher = "Canonical"
    offer     = "0001-com-ubuntu-server-focal"
    sku       = "20_04-lts-gen2"
    version   = "latest"
  }
  user_data = data.cloudinit_config.user_data.rendered

  tags = {
    Coder_Provisioned = "true"
  }
}

resource "azurerm_virtual_machine_data_disk_attachment" "home" {
  count              = data.coder_workspace.me.transition == "start" ? 1 : 0
  managed_disk_id    = azurerm_managed_disk.home.id
  virtual_machine_id = azurerm_linux_virtual_machine.main[0].id
  lun                = "10"
  caching            = "ReadWrite"
}

resource "coder_metadata" "workspace_info" {
  count       = data.coder_workspace.me.start_count
  resource_id = azurerm_linux_virtual_machine.main[0].id

  item {
    key   = "type"
    value = azurerm_linux_virtual_machine.main[0].size
  }
}

resource "coder_metadata" "home_info" {
  resource_id = azurerm_managed_disk.home.id

  item {
    key   = "size"
    value = "${data.coder_parameter.home_size.value} GiB"
  }
}