# Copyright 2016 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import("//build/config/dcheck_always_on.gni")

# Used to produce a Service Manifest for a Service.
#
# Service manifests may be subsequently aggregated into one or more catalog
# manifests (see //services/catalog/public/tools/catalog.gni). A catalog
# manifest provides the Service Manager at runtime with a static service layout
# configuration to dictate which services are supported by the runtime
# environment as well as how individual services may be launched and
# interconnected.
#
# Note that this target may be used to produce partial manifests, and partial
# manifests may be aggregated by using one service_manifest target as the
# |source_manifest| of another (see below.)
#
# Parameters:
#
#   source (optional**)
#       The manifest template for this service. Must be the name of a valid JSON
#       file.
#
#   source_manifest (optional**)
#       The manifest template for this service. Must be the name of another
#       service_manifest target.
#
#       ** NOTE: Either |source| OR |source_manifest| MUST be specified.
#
#   name (optional)
#       The name of the service whose manifest is to be generated. A script
#       validates that the value of this parameter matches the name set in the
#       source manifest and raises an error if it does not match.
#
#   overlays (optional)
#       A list of other manifest targets whose outputs should be overlayed onto
#       the source manifest before emitting the final output. Overlays are
#       applied in-order as the last step of output generation, after any
#       |packaged_services| manifests are embedded.
#
#   packaged_services (optional)
#       A list of other manifest targets whose outputs should be packaged
#       within this output manifest, specifically within a toplevel "services"
#       list.
#
# Outputs:
#
#   An instantiation of this template produces a meta manifest from the source
#   template and the output manifests of all its |overlay| and
#   |packaged_services|dependencies. The output file is always
#   "$target_gen_dir/${target_name}.json".
#
template("service_manifest") {
  assert(
      defined(invoker.source) || defined(invoker.source_manifest),
      "\"source\" or \"source_manifest\" must be defined for the $target_name target")
  assert(
      !defined(invoker.source) || !defined(invoker.source_manifest),
      "Only one of \"source\" or \"source_manifest\" must be defined for the $target_name target")

  action(target_name) {
    script =
        "//services/service_manager/public/tools/manifest/manifest_collator.py"

    deps = []
    if (defined(invoker.deps)) {
      deps += invoker.deps
    }

    if (defined(invoker.source)) {
      source = invoker.source
    } else {
      source_target_dir =
          get_label_info(invoker.source_manifest, "target_gen_dir")
      source_target_name = get_label_info(invoker.source_manifest, "name")
      source = "$source_target_dir/${source_target_name}.json"
      deps += [ invoker.source_manifest ]
    }
    inputs = [
      source,
    ]

    output = "$target_gen_dir/${target_name}.json"
    outputs = [
      output,
    ]

    rebase_parent = rebase_path(source, root_build_dir)
    rebase_output = rebase_path(output, root_build_dir)

    args = [
      "--parent=$rebase_parent",
      "--output=$rebase_output",
    ]

    if (defined(invoker.name)) {
      args += [
        "--name",
        invoker.name,
      ]
    }

    if (is_debug || dcheck_always_on) {
      args += [ "--pretty" ]
    }

    if (defined(invoker.overlays) && invoker.overlays != []) {
      args += [ "--overlays" ]
      foreach(manifest_target, invoker.overlays) {
        manifest_target_dir = get_label_info(manifest_target, "target_gen_dir")
        manifest_target_name = get_label_info(manifest_target, "name")
        manifest_filename = "$manifest_target_dir/${manifest_target_name}.json"

        inputs += [ manifest_filename ]
        deps += [ manifest_target ]
        args += [ rebase_path(manifest_filename, root_build_dir) ]

        # Ensure that each entry does in fact reference a manifest rule.
        label_no_toolchain =
            get_label_info(manifest_target, "label_no_toolchain")
        toolchain = get_label_info(manifest_target, "toolchain")
        deps += [ "${label_no_toolchain}__is_service_manifest(${toolchain})" ]
      }
    }

    if (defined(invoker.packaged_services)) {
      args += [ "--packaged-services" ]
      foreach(manifest_target, invoker.packaged_services) {
        manifest_target_dir = get_label_info(manifest_target, "target_gen_dir")
        manifest_target_name = get_label_info(manifest_target, "name")
        manifest_filename = "$manifest_target_dir/${manifest_target_name}.json"

        inputs += [ manifest_filename ]
        deps += [ manifest_target ]
        args += [ rebase_path(manifest_filename, root_build_dir) ]

        # Ensure that each entry does in fact reference a manifest rule.
        label_no_toolchain =
            get_label_info(manifest_target, "label_no_toolchain")
        toolchain = get_label_info(manifest_target, "toolchain")
        deps += [ "${label_no_toolchain}__is_service_manifest(${toolchain})" ]
      }
    }
  }

  group("${target_name}__is_service_manifest") {
  }
}