resource "azurerm_storage_account" "main" {
  name                     = "${replace(var.prefix, "/[-_]/", "")}${lower(random_string.storage_suffix.result)}"
  resource_group_name      = azurerm_resource_group.main.name
  location                 = azurerm_resource_group.main.location
  account_tier             = "Standard"
  account_replication_type = "LRS"

  static_website { // magic
    index_document = "index.html"
  }
}

resource "azurerm_storage_blob" "main" {
  name                   = "index.html"
  storage_account_name   = azurerm_storage_account.main.name
  storage_container_name = "$web"
  type                   = "Block"
  content_type           = "text/html"
  source                 = "./content/index.html"
}

resource "azurerm_dns_cname_record" "static" {
  name                = "storage-account"
  zone_name           = azurerm_dns_zone.static.name
  resource_group_name = azurerm_resource_group.main.name
  ttl                 = 60
  record              = azurerm_cdn_endpoint.main.host_name
}

resource "azurerm_dns_cname_record" "static_cdnverify" {
  name                = "cdnverify.storage-account"
  zone_name           = azurerm_dns_zone.static.name
  resource_group_name = azurerm_resource_group.main.name
  ttl                 = 60
  record              = "cdnverify.${azurerm_cdn_endpoint.main.host_name}"
}

resource "null_resource" "publish_swa" {
    triggers = {
      script_checksum = sha1(join("", [for f in fileset("content", "*"): filesha1("content/${f}")])) // recreate resource on file checksum change. This will always trigger a new build, so we don't care about the state as much
    }
    provisioner "local-exec" {
        working_dir = "${path.module}"
        interpreter = ["bash", "-c"]
        command = <<EOT
docker run --rm -e INPUT_AZURE_STATIC_WEB_APPS_API_TOKEN=${azurerm_static_site.main.api_key} -e DEPLOYMENT_PROVIDER=DevOps -e GITHUB_WORKSPACE=/working_dir -e INPUT_APP_LOCATION=. -v `pwd`/content:/working_dir mcr.microsoft.com/appsvc/staticappsclient:stable ./bin/staticsites/StaticSitesClient upload --verbose true
EOT
    }
// the block above assumes static content sits in `./content` directory. Using `pwd` with backticks is particularly important as terraform attempts parsing ${pwd} syntax, while we need to pass it into the shell
    depends_on = [
      azurerm_static_site.main
    ]
}

FROM nginx:alpine
WORKDIR /usr/share/nginx/html/
COPY index.html .
COPY ./nginx.conf /etc/nginx/nginx.conf # there's minimal nginx config, check out github
EXPOSE 80 # we only care to expose HTTP endpoint, so no certs are needed for nginx at this stage

resource "null_resource" "build_container" {
    triggers = {
      script_checksum = sha1(join("", [for f in fileset("content", "*"): filesha1("content/${f}")])) // the operation will kick in on change to any of the files in content directory
    }

// normal build-push flow for private registry
    provisioner "local-exec" { command = "docker login -u ${azurerm_container_registry.acr.admin_username} -p ${azurerm_container_registry.acr.admin_password} ${azurerm_container_registry.acr.login_server}" }
    provisioner "local-exec" { command = "docker build ./content/ -t ${azurerm_container_registry.acr.login_server}/static-site:latest" }
    provisioner "local-exec" { command = "docker push ${azurerm_container_registry.acr.login_server}/static-site:latest" }
    provisioner "local-exec" { command = "docker logout ${azurerm_container_registry.acr.login_server}" }
    depends_on = [
      azurerm_container_registry.acr
    ]
}

resource "azurerm_app_service" "main" {
  name                = "${var.prefix}-app-svc"
  location            = azurerm_resource_group.main.location
  resource_group_name = azurerm_resource_group.main.name
  app_service_plan_id = azurerm_app_service_plan.main.id

  app_settings = {
    WEBSITES_ENABLE_APP_SERVICE_STORAGE = false // this is required for Linux app service plans
    DOCKER_REGISTRY_SERVER_URL      = azurerm_container_registry.acr.login_server // the convenience of rolling ACR with terraform is that we literally have all the variables already available
    DOCKER_REGISTRY_SERVER_USERNAME = azurerm_container_registry.acr.admin_username // App Service uses admin account to pull container images from ACR. We have to enable it when defining the resource
    DOCKER_REGISTRY_SERVER_PASSWORD = azurerm_container_registry.acr.admin_password
  }

  site_config {
    linux_fx_version = "DOCKER|${azurerm_container_registry.acr.name}.azurecr.io/static-site:latest"
    always_on        = "true" // this is also required on Linux app service plans
  }

  depends_on = [
    null_resource.build_container
  ]
}