# Copyright 2017 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.

"""Recipe for building Rust toolchain."""

from recipe_engine.config import Enum, ReturnSchema, Single
from recipe_engine.recipe_api import Property

import re
from itertools import product


DEPS = [
  'infra/git',
  'infra/gitiles',
  'infra/jiri',
  'recipe_engine/cipd',
  'recipe_engine/context',
  'recipe_engine/json',
  'recipe_engine/path',
  'recipe_engine/platform',
  'recipe_engine/properties',
  'recipe_engine/python',
  'recipe_engine/raw_io',
  'recipe_engine/file',
  'recipe_engine/step',
  'recipe_engine/url',
]

TARGETS = [
  ('aarch64', 'arm64'),
  ('x86_64', 'x64'),
]

RUST_FUCHSIA_GIT = 'https://fuchsia.googlesource.com/third_party/rust'

PROPERTIES = {
  'url': Property(kind=str, help='Git repository URL', default=RUST_FUCHSIA_GIT),
  'ref': Property(kind=str, help='Git reference', default='refs/heads/master'),
  'revision': Property(kind=str, help='Revision', default=None),
}

BUILD_CONFIG = '''
[llvm]
optimize = true
static-libstdcpp = true
ninja = true
targets = "X86;AArch64"

[build]
target = ["x86_64-fuchsia", "aarch64-fuchsia"]
docs = false
extended = true
cargo-native-static = true

[install]
prefix = "{prefix}"
sysconfdir = "etc"

[rust]
optimize = true
channel = "nightly"
lld = true

[target.x86_64-fuchsia]
cc = "{cc}"
cxx = "{cxx}"
ar = "{ar}"
linker = "{linker}"

[target.aarch64-fuchsia]
cc = "{cc}"
cxx = "{cxx}"
ar = "{ar}"
linker = "{linker}"

[dist]
'''

CARGO_CONFIG = '''
[target.x86_64-fuchsia]
ar = "{ar}"
rustflags = [
  "-C", "link-arg=--sysroot={x86_64_sysroot}",
  "-C", "link-arg=-L{x86_64_sysroot}/lib",
  "-C", "link-arg=-L{x86_64_lib}",
  "-C", "link-arg=-L{clang_resource_dir}/x86_64-fuchsia/lib",
]

[target.aarch64-fuchsia]
ar = "{ar}"
rustflags = [
  "-C", "link-arg=--sysroot={aarch64_sysroot}",
  "-C", "link-arg=-L{aarch64_sysroot}/lib",
  "-C", "link-arg=-L{aarch64_lib}",
  "-C", "link-arg=-L{clang_resource_dir}/aarch64-fuchsia/lib",
]
'''


def RunSteps(api, url, ref, revision):
  api.gitiles.ensure_gitiles()
  api.jiri.ensure_jiri()

  if not revision:
    revision = api.gitiles.refs(url).get(ref, None)
  cipd_pkg_name = 'fuchsia/rust/${platform}'
  pins = api.cipd.search(cipd_pkg_name, 'git_revision:' + revision)
  if len(pins) > 0:
    api.step('Package is up-to-date', cmd=None)
    return

  with api.step.nest('ensure_packages'):
    with api.context(infra_steps=True):
      pkgs = api.cipd.EnsureFile()
      pkgs.add_package('infra/cmake/${platform}', 'version:3.9.2')
      pkgs.add_package('infra/ninja/${platform}', 'version:1.8.2')
      pkgs.add_package('infra/swig/${platform}', 'version:3.0.12')
      pkgs.add_package('fuchsia/clang/${platform}', 'goma')
      cipd_dir = api.path['start_dir'].join('cipd')
      api.cipd.ensure(cipd_dir, pkgs)

  with api.step.nest('ensure_sdk'):
    with api.context(infra_steps=True):
      pkgs = api.cipd.EnsureFile()
      pkgs.add_package('fuchsia/sdk/${platform}', 'latest')
      sdk_dir = api.path['start_dir'].join('sdk')
      api.cipd.ensure(sdk_dir, pkgs)

  with api.context(infra_steps=True):
    rust_dir = api.path['start_dir'].join('rust')
    api.git.checkout(url, rust_dir, ref=revision, recursive=True)

  # get clang resource dir path (for libunwind)
  step_result = api.step(
    'clang resource dir',
    [cipd_dir.join('bin', 'clang'), '-print-resource-dir'],
    stdout=api.raw_io.output(name='resource-dir', add_output_log=True),
    step_test_data=lambda: api.raw_io.test_api.stream_output(
        str(cipd_dir.join('lib', 'clang', '8.0.0'))))
  clang_resource_dir = step_result.stdout.strip()

  # build rust
  staging_dir = api.path.mkdtemp('rust')
  build_dir = staging_dir.join('build')
  api.file.ensure_directory('build', build_dir)
  pkg_dir = staging_dir.join('rust')
  api.file.ensure_directory('create pkg_dir', pkg_dir)

  config_file = build_dir.join('config.toml')
  api.file.write_text('write config.toml',
      config_file,
      BUILD_CONFIG.format(
          prefix=pkg_dir,
          linker=cipd_dir.join('bin', 'ld.lld'),
          cc=cipd_dir.join('bin', 'clang'),
          cxx=cipd_dir.join('bin', 'clang++'),
          ar=cipd_dir.join('bin', 'llvm-ar'),
      )
  )

  cargo_dir = staging_dir.join('.cargo')
  api.file.ensure_directory('.cargo', cargo_dir)
  api.file.write_text('write config',
      cargo_dir.join('config'),
      CARGO_CONFIG.format(
          ar=cipd_dir.join('bin', 'llvm-ar'),
          x86_64_sysroot=sdk_dir.join('arch', 'x64', 'sysroot'),
          aarch64_sysroot=sdk_dir.join('arch', 'arm64', 'sysroot'),
          x86_64_lib=sdk_dir.join('arch', 'x64', 'lib'),
          aarch64_lib=sdk_dir.join('arch', 'arm64', 'lib'),
          clang_resource_dir=clang_resource_dir,
      ),
  )

  env = {}
  for tc_arch, gn_arch in TARGETS:
    env['CFLAGS_%s-fuchsia' % tc_arch] = (
      '--target=%s-fuchsia --sysroot=%s -I%s' % (
        tc_arch,
        sdk_dir.join('arch', gn_arch, 'sysroot'),
        sdk_dir.join('pkg', 'fdio', 'include'),
      )
    )
    env['LDFLAGS_%s-fuchsia' % tc_arch] = (
      '--target=%s-fuchsia --sysroot=%s -L%s' % (
        tc_arch,
        sdk_dir.join('arch', gn_arch, 'sysroot'),
        sdk_dir.join('arch', gn_arch, 'lib'),
      )
    )
  env['CARGO_HOME'] = cargo_dir
  env['CFG_VERSION'] = revision
  env_prefixes = {'PATH': [cipd_dir, cipd_dir.join('bin')]}
  with api.context(cwd=build_dir, env=env, env_prefixes=env_prefixes):
    api.python(
      'rust install',
      rust_dir.join('x.py'),
      args=['install', '--config', config_file])

  # package rust
  step_result = api.step('rust version',
      [pkg_dir.join('bin', 'rustc'), '--version'],
      stdout=api.raw_io.output(),
      step_test_data=lambda:
      api.raw_io.test_api.stream_output('rustc 1.19.0-nightly (75b056812 2017-05-15)'))
  m = re.search(r'rustc ([0-9a-z.-]+)', step_result.stdout)
  assert m, 'Cannot determine Rust version'
  version = m.group(1)

  pkg_def = api.cipd.PackageDefinition(
      package_name=cipd_pkg_name,
      package_root=pkg_dir,
      install_mode='copy')
  pkg_def.add_dir(pkg_dir)
  pkg_def.add_version_file('.versions/rust.cipd_version')

  cipd_pkg_file = api.path['cleanup'].join('rust.cipd')

  api.cipd.build_from_pkg(
      pkg_def=pkg_def,
      output_package=cipd_pkg_file,
  )
  step_result = api.cipd.register(
      package_name=cipd_pkg_name,
      package_path=cipd_pkg_file,
      refs=['latest'],
      tags={
        'version': version,
        'git_repository': RUST_FUCHSIA_GIT,
        'git_revision': revision,
      },
  )

def GenTests(api):
  revision = '75b05681239cb309a23fcb4f8864f177e5aa62da'
  for platform in ('linux', 'mac'):
    yield (api.test(platform) +
           api.platform.name(platform) +
           api.gitiles.refs('refs', ('refs/heads/master', revision)))
    yield (api.test(platform + '_new') +
           api.platform.name(platform) +
           api.gitiles.refs('refs', ('refs/heads/master', revision)) +
           api.step_data('cipd search fuchsia/rust/${platform} ' +
                         'git_revision:'+ revision,
                         api.json.output({'result': []})))