# Copyright 2020 The Fuchsia 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/dist/fini_manifest.gni")
import("//build/dist/verify_manifest_elf_binaries.gni")
import("//build/images/args.gni")
import("//build/packages/package_metadata.gni")
import("//src/sys/pkg/bin/package-tool/package-tool.gni")
import("//tools/cmc/build/cmc.gni")
import("//tools/configc/build/config.gni")

# Defines a Fuchsia package.
# See: https://fuchsia.dev/fuchsia-src/development/components/build
#
# Fuchsia packages are a collection of any number of files (or resources), each
# with a unique path that is relative to the package's root.
# Package targets collect resources via their dependencies. These dependencies
# are typically either:
#
#   * `fuchsia_component()` targets, which provide their component manifest and
#     other files that the component needs (such as an executable)
#   * other `fuchsia_package()` targets, declared as `subpackages`
#
# Packages can be defined as a collection of pairs each representing a file in
# the package. Each pair consists of the path in the package that is assigned
# to the file, and a path relative to the build system's output directory where
# the contents of the file will be sourced from.
# This mapping is generated at build time, and is known as the package
# manifest.
#
# To view the package manifest, For instance assume you have defined
# a package at `path/to/project:my_package` and built it:
# ```
# $ fx build path/to/project:my_package
# ```
# You can then find the path to the generated manifest:
# ```
# $ fx gn outputs out/default path/to/project:my_package_manifest
# ```
#
# The package name is defined by the target name.
# Some rules apply to package names.
# See: https://fuchsia.dev/fuchsia-src/concepts/packages/package_url#package-name
#
# It's recommended for a package to depend on one or more `fuchsia_component()`
# targets, and zero or more `subpackages` and/or `renameable_subpackages`.
#
# Examples:
# ```
# fuchsia_package("my-package") {
#   deps = [
#     ":main_component",
#   ]
#   subpackages = [
#     ":second_package",
#   ]
# }
# ```
#
# ```
# fuchsia_package("my-package") {
#   deps = [
#     ":main_component",
#   ]
#   renameable_subpackages = [
#     {
#       package = ":second_package"
#     },
#     {
#       name = "renamed-subpackage"
#       package = ":third_package"
#     }
#   ]
# }
# ```
#
# ```
# fuchsia_package("my-package") {
#   deps = [
#     ":first_component",
#     ":second_component",
#   ]
# }
# ```
#
# Parameters
#
#   package_name (optional)
#     The name of the package.
#     Type: string
#     Default: target_name
#
#   disable_elf_binaries_checks (optional)
#     Set to true to disable ELF binaries verification checks. Useful
#     if your package includes non-Fuchsia ELF binaries, or if some
#     of them are unstripped.
#     Type: boolean
#     Default: false
#
#   validate_structured_config (optional)
#     If true, check that component manifests which declare config schemas have been
#     packaged with the resources needed to resolve them at runtime. Only useful for
#     those packages which fully generate their configuration during the build. If a
#     component has configuration provided by assembly tooling, that happens after the
#     package is built and this should be set to false to prevent spurious errors.
#     Type: boolean
#     Default: true
#
#   is_system_package (optional)
#     Used internally to implement fuchsia_system_package(), do not use!
#     If this is true, this is a fuchsia_system_package(), and it is allowed
#     to be included in //build/input:system_image.
#     Type: boolean
#
#   is_driver_package (optional)
#     Used internally to implement fuchsia_driver_package(), do not use!
#     If defined, this is a fuchsia_driver_package(). The only behavior
#     difference is a fuchsia_driver_package can be added as a dependency
#     to the boot image, and its contents will appear in the boot image.
#     This flag will be removed eventually as fuchsia_driver_packages
#     are included in the build in the correct way.
#     Type: boolean
#
#   repository (optional)
#     The repository host name part of the package URL. Defaults to "fuchsia.com".
#     See https://fuchsia.dev/fuchsia-src/concepts/packages/package_url#repository
#     for more details.
#     Type: string
#     Default: fuchsia.com
#
#   subpackages (optional)
#     A list of `fuchsia_package` targets. Each target is converted into the
#     equivalent of a `renameable_targets` entry with its `package` property set
#     to the target, and no `name` override. All included `package` entries will
#     be added as `deps` of the generated meta file, and do not need to be
#     listed as additional `deps` of the `fuchsia_package` target.
#     Subpackage names must be unique (relative to the containing package), but
#     both `renameable_subpackages` and `subpackages` may be included,
#     additively.
#     Type: list of targets
#
#   renameable_subpackages (optional)
#     A list of subpackages defined by scoped variables `package` and an
#     optional `name`. If `name` is omitted, the subpackage target's package
#     name is used by default. The generated package will include a
#     `subpackages` meta file that declares dependencies on the listed packages,
#     using the current package hash of each package. All included `package`
#     entries will be added as `deps` of the generated meta file, and do not
#     need to be listed as additional `deps` of the `fuchsia_package` target.
#     Subpackage names must be unique (relative to the containing package), but
#     both `renameable_subpackages` and `subpackages` may be included,
#     additively.
#     Type: list of scopes
#
#   shell_commands (optional)
#     An explicit list of dependencies included as part of the fuchsia package invocation that are
#     shell command dependencies to include in the shell command distribution manifest and it's
#     subsequent metadata walk
#
#   is_shell_package (optional)
#     Used internally to implement fuchsia_shell_package(). Use with caution, as this flag marks
#     all the package's binaries as shell commands and includes them in the shell_commands package
#     during the generation of the legacy_assembly_input_bundle
#
#   data_deps
#   deps
#   testonly
#   visibility
template("fuchsia_package") {
  if (current_toolchain == target_toolchain) {
    package_name = target_name
    if (defined(invoker.package_name)) {
      package_name = invoker.package_name
    }

    repository = "fuchsia.com"
    if (defined(invoker.repository)) {
      repository = invoker.repository
    }

    shell_commands_manifest_target = "${target_name}.shell_commands_manifest"
    shell_commands_manifest = "$target_out_dir/$shell_commands_manifest_target"

    _files = {
      fini_manifest = "$target_out_dir/${target_name}_manifest"

      # LINT.IfChange
      package_out_dir = "$target_out_dir/$target_name"
      package_manifest = "$package_out_dir/package_manifest.json"

      # LINT.ThenChange(//build/packages/exported_fuchsia_package_archive.gni)
    }

    main_target_deps = []

    # Generate the "meta/package" file
    meta_package_target = "${target_name}_meta_package"
    generate_meta_package(meta_package_target) {
      forward_variables_from(invoker,
                             [
                               "applicable_licenses",
                               "testonly",
                             ])
      visibility = [ ":*" ]
      package_name = package_name
    }

    if (defined(invoker.subpackages) ||
        defined(invoker.renameable_subpackages) ||
        defined(invoker.test_pkg__subpackages) ||
        defined(invoker.test_pkg__renameable_subpackages)) {
      subpackages_list = []

      if (defined(invoker.renameable_subpackages)) {
        subpackages_list = invoker.renameable_subpackages
      }
      if (defined(invoker.test_pkg__renameable_subpackages)) {
        subpackages_list = invoker.test_pkg__renameable_subpackages
      }

      if (defined(invoker.subpackages)) {
        foreach(subpackage, invoker.subpackages) {
          subpackages_list += [
            {
              package = subpackage
            },
          ]
        }
      }
      if (defined(invoker.test_pkg__subpackages)) {
        foreach(subpackage, invoker.test_pkg__subpackages) {
          subpackages_list += [
            {
              package = subpackage
            },
          ]
        }
      }

      # Generate the "meta/fuchsia.pkg/subpackages" file
      meta_subpackages_target = "${target_name}_meta_subpackages"
      generate_meta_subpackages(meta_subpackages_target) {
        forward_variables_from(invoker, [ "testonly" ])
        visibility = [ ":*" ]
        subpackages = subpackages_list
      }
    }

    _is_shell_package =
        (defined(invoker.is_shell_package) && invoker.is_shell_package) ||
        (defined(invoker.shell_commands) && invoker.shell_commands != [])

    if (_is_shell_package) {
      # Collect all distribution entries from deps.
      distribution_manifest(shell_commands_manifest_target) {
        forward_variables_from(invoker, [ "testonly" ])
        visibility = [ ":*" ]

        package_manifest_path = _files.package_manifest

        if (defined(invoker.shell_commands)) {
          deps = invoker.shell_commands
        } else {
          deps = invoker.deps
        }

        outputs = [ shell_commands_manifest ]

        metadata = {
          shell_commands_distribution_manifests = [
            {
              manifest_path = rebase_path(package_manifest_path, root_build_dir)
              package_name = package_name
            },
          ]
          shell_commands_barrier = []
        }
      }
    } else {
      not_needed([
                   "shell_commands_manifest_target",
                   "shell_commands_manifest",
                 ])
    }

    # Generate package .fini manifest
    package_manifest_target = "${target_name}_manifest"
    fini_manifest(package_manifest_target) {
      forward_variables_from(invoker,
                             [
                               "applicable_licenses",
                               "deps",
                               "testonly",
                             ])
      if (!defined(deps)) {
        deps = []
      }

      if (defined(invoker.shell_commands)) {
        deps += invoker.shell_commands
      }

      deps += [ ":$meta_package_target" ]
      visibility = [ ":*" ]
      outputs = [ _files.fini_manifest ]
    }

    # Verify ELF binaries
    verify_elf = !(defined(invoker.disable_elf_binaries_checks) &&
                   invoker.disable_elf_binaries_checks)
    if (verify_elf) {
      package_manifest_verify_target = "${target_name}.verify"
      verify_manifest_elf_binaries(package_manifest_verify_target) {
        forward_variables_from(invoker,
                               [
                                 "applicable_licenses",
                                 "testonly",
                               ])
        manifest = _files.fini_manifest
        check_unstripped_files = true
        deps = [ ":$package_manifest_target" ]
      }
    }

    _package_build_target = "${target_name}.pkg"
    _validate_structured_config = true
    if (defined(invoker.validate_structured_config)) {
      _validate_structured_config = invoker.validate_structured_config
    }
    if (_validate_structured_config) {
      _validate_config_target = "${target_name}.validate_config"
      validate_packaged_config(_validate_config_target) {
        forward_variables_from(invoker,
                               [
                                 "applicable_licenses",
                                 "testonly",
                               ])
        package_manifest = _files.package_manifest
        deps = [ ":$_package_build_target" ]
      }
      main_target_deps += [ ":$_validate_config_target" ]
    }

    _is_driver_package =
        defined(invoker.is_driver_package) && invoker.is_driver_package
    not_needed([ "_is_driver_package" ])

    _is_system_package = false
    if (defined(invoker.is_system_package)) {
      _is_system_package = invoker.is_system_package
    }

    _package_target_name = target_name

    # Build package (Generates package_manifest.json).
    package_tool_package_build(_package_build_target) {
      forward_variables_from(invoker,
                             [
                               "applicable_licenses",
                               "data_deps",
                               "deps",
                               "testonly",
                               "visibility",
                             ])
      package_out_dir = _files.package_out_dir
      manifest = ":$package_manifest_target"
      if (defined(meta_subpackages_target)) {
        meta_subpackages = ":$meta_subpackages_target"
      }
      metadata = {
        if (defined(invoker.metadata)) {
          forward_variables_from(invoker.metadata, "*")
        }
        if (!_is_system_package && !_is_driver_package) {
          # Installing a Fuchsia package into another one should not also install
          # its content to the root install location, which is why this metadata key
          # is set to an empty list.
          # An exception to this rule is fuchsia_system_package() instances whose
          # content must end up in either the system image (handled by
          # system_image_package_info below) or the boot filesystem (handled through
          # distribution_manifest()).
          # Another exception is fuchsia_driver_package(), whose content
          # has to end up in the boot filesystem if the boot filesystem depends on it.
          distribution_entries_barrier = []
        }

        # Used by system_image_fuchsia_packages_list() to allow embedding
        # the content of this package into the system image, if necessary.
        #
        # The schema is the following:
        #
        #   label: GN label of this target (used for debugging only).
        #   fini_manifest: path to FINI manifest listing this package's content.
        #   system_image_packaged_allowed_in_extra_deps: (optional)
        #     If defined, this is a fuchsia_system_package() instance, and its
        #     value determines whether it is allowed in extra dependency trees
        #     (see fuchsia_system_package() description for details). If undefined,
        #     this is a regular fuchsia_package().
        #
        system_image_package_info = [
          {
            label = get_label_info(":$target_name", "label_with_toolchain")
            fini_manifest = rebase_path(_files.fini_manifest, root_build_dir)
          },
        ]
        system_image_package_barrier = []
        component_id_index_barrier = []

        system_image_extra_package_manifest_barrier = []
        test_component_manifest_barrier = []
        if (!defined(test_components_barrier)) {
          # don't produce entries for non-test packages.
          test_components_barrier = []
        }
        test_component_manifest_program_barrier = []
        expect_includes_barrier = []
      }
      repository = repository
      if (!defined(deps)) {
        deps = []
      }
      if (verify_elf) {
        deps += [ ":$package_manifest_verify_target" ]
      }

      # Ensure that even if the top-level package restricts its visibility,
      # this package_tool_package_build target is visible to the top-level
      # package.
      if (defined(visibility)) {
        visibility += [ ":${_package_target_name}" ]
        if (_validate_structured_config) {
          visibility += [ ":${_validate_config_target}" ]
        }
      } else {
        not_needed([ "_package_target_name" ])
      }

      if (_is_shell_package) {
        deps += [ ":$shell_commands_manifest_target" ]
      }
    }

    group(target_name) {
      forward_variables_from(invoker,
                             [
                               "testonly",
                               "visibility",
                             ])
      public_deps = [ ":$_package_build_target" ]
      deps = main_target_deps
      if (_is_driver_package) {
        metadata = {
          # Allow exclusion of driver packages by assembly
          driver_package_barrier = []
        }
      }
    }
  } else {
    # Fuchsia packages should only be built with target_toolchain. However, it
    # is possible for package targets to be expanded in other toolchains (host,
    # variant, etc.). In these cases, make fuchsia_package expand to nothing.
    group(target_name) {
      forward_variables_from(invoker,
                             [
                               "testonly",
                               "visibility",
                             ])
    }

    # Suppress unused variable warnings.
    not_needed(invoker, "*")
  }
}