#
# Copyright 2024, The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from abc import ABC
import argparse
import functools
import json
import logging
import os
import pathlib
import subprocess

from build_context import BuildContext
import test_mapping_module_retriever


class OptimizedBuildTarget(ABC):
  """A representation of an optimized build target.

  This class will determine what targets to build given a given build_cotext and
  will have a packaging function to generate any necessary output zips for the
  build.
  """

  _SOONG_UI_BASH_PATH = 'build/soong/soong_ui.bash'
  _PREBUILT_SOONG_ZIP_PATH = 'prebuilts/build-tools/linux-x86/bin/soong_zip'

  def __init__(
      self,
      target: str,
      build_context: BuildContext,
      args: argparse.Namespace,
  ):
    self.target = target
    self.build_context = build_context
    self.args = args

  def get_build_targets(self) -> set[str]:
    features = self.build_context.enabled_build_features
    if self.get_enabled_flag() in features:
      self.modules_to_build = self.get_build_targets_impl()
      return self.modules_to_build

    self.modules_to_build = {self.target}
    return {self.target}

  def get_package_outputs_commands(self) -> list[list[str]]:
    features = self.build_context.enabled_build_features
    if self.get_enabled_flag() in features:
      return self.get_package_outputs_commands_impl()

    return []

  def get_package_outputs_commands_impl(self) -> list[list[str]]:
    raise NotImplementedError(
        'get_package_outputs_commands_impl not implemented in'
        f' {type(self).__name__}'
    )

  def get_enabled_flag(self):
    raise NotImplementedError(
        f'get_enabled_flag not implemented in {type(self).__name__}'
    )

  def get_build_targets_impl(self) -> set[str]:
    raise NotImplementedError(
        f'get_build_targets_impl not implemented in {type(self).__name__}'
    )

  def _generate_zip_options_for_items(
      self,
      prefix: str = '',
      relative_root: str = '',
      list_files: list[str] | None = None,
      files: list[str] | None = None,
      directories: list[str] | None = None,
  ) -> list[str]:
    if not list_files and not files and not directories:
      raise RuntimeError(
          f'No items specified to be added to zip! Prefix: {prefix}, Relative'
          f' root: {relative_root}'
      )
    command_segment = []
    # These are all soong_zip options so consult soong_zip --help for specifics.
    if prefix:
      command_segment.append('-P')
      command_segment.append(prefix)
    if relative_root:
      command_segment.append('-C')
      command_segment.append(relative_root)
    if list_files:
      for list_file in list_files:
        command_segment.append('-l')
        command_segment.append(list_file)
    if files:
      for file in files:
        command_segment.append('-f')
        command_segment.append(file)
    if directories:
      for directory in directories:
        command_segment.append('-D')
        command_segment.append(directory)

    return command_segment

  def _query_soong_vars(
      self, src_top: pathlib.Path, soong_vars: list[str]
  ) -> dict[str, str]:
    process_result = subprocess.run(
        args=[
            f'{src_top / self._SOONG_UI_BASH_PATH}',
            '--dumpvars-mode',
            f'--abs-vars={" ".join(soong_vars)}',
        ],
        env=os.environ,
        check=False,
        capture_output=True,
        text=True,
    )
    if not process_result.returncode == 0:
      logging.error('soong dumpvars command failed! stderr:')
      logging.error(process_result.stderr)
      raise RuntimeError('Soong dumpvars failed! See log for stderr.')

    if not process_result.stdout:
      raise RuntimeError(
          'Necessary soong variables ' + soong_vars + ' not found.'
      )

    try:
      return {
          line.split('=')[0]: line.split('=')[1].strip("'")
          for line in process_result.stdout.strip().split('\n')
      }
    except IndexError as e:
      raise RuntimeError(
          'Error parsing soong dumpvars output! See output here:'
          f' {process_result.stdout}',
          e,
      )

  def _base_zip_command(
      self, src_top: pathlib.Path, dist_dir: pathlib.Path, name: str
  ) -> list[str]:
    return [
        f'{src_top / self._PREBUILT_SOONG_ZIP_PATH }',
        '-d',
        '-o',
        f'{dist_dir / name}',
    ]


class NullOptimizer(OptimizedBuildTarget):
  """No-op target optimizer.

  This will simply build the same target it was given and do nothing for the
  packaging step.
  """

  def __init__(self, target):
    self.target = target

  def get_build_targets(self):
    return {self.target}

  def get_package_outputs_commands(self):
    return []


class ChangeInfo:

  def __init__(self, change_info_file_path):
    try:
      with open(change_info_file_path) as change_info_file:
        change_info_contents = json.load(change_info_file)
    except json.decoder.JSONDecodeError:
      logging.error(f'Failed to load CHANGE_INFO: {change_info_file_path}')
      raise

    self._change_info_contents = change_info_contents

  def find_changed_files(self) -> set[str]:
    changed_files = set()

    for change in self._change_info_contents['changes']:
      project_path = change.get('projectPath') + '/'

      for revision in change.get('revisions'):
        for file_info in revision.get('fileInfos'):
          changed_files.add(project_path + file_info.get('path'))

    return changed_files


class GeneralTestsOptimizer(OptimizedBuildTarget):
  """general-tests optimizer

  This optimizer reads in the list of changed files from the file located in
  env[CHANGE_INFO] and uses this list alongside the normal TEST MAPPING logic to
  determine what test mapping modules will run for the given changes. It then
  builds those modules and packages them in the same way general-tests.zip is
  normally built.
  """

  # List of modules that are built alongside general-tests as dependencies.
  _REQUIRED_MODULES = frozenset([
      'cts-tradefed',
      'vts-tradefed',
      'compatibility-host-util',
      'general-tests-shared-libs',
  ])

  def get_build_targets_impl(self) -> set[str]:
    change_info_file_path = os.environ.get('CHANGE_INFO')
    if not change_info_file_path:
      logging.info(
          'No CHANGE_INFO env var found, general-tests optimization disabled.'
      )
      return {'general-tests'}

    test_infos = self.build_context.test_infos
    test_mapping_test_groups = set()
    for test_info in test_infos:
      is_test_mapping = test_info.is_test_mapping
      current_test_mapping_test_groups = test_info.test_mapping_test_groups
      uses_general_tests = test_info.build_target_used('general-tests')

      if uses_general_tests and not is_test_mapping:
        logging.info(
            'Test uses general-tests.zip but is not test-mapping, general-tests'
            ' optimization disabled.'
        )
        return {'general-tests'}

      if is_test_mapping:
        test_mapping_test_groups.update(current_test_mapping_test_groups)

    change_info = ChangeInfo(change_info_file_path)
    changed_files = change_info.find_changed_files()

    test_mappings = test_mapping_module_retriever.GetTestMappings(
        changed_files, set()
    )

    modules_to_build = set(self._REQUIRED_MODULES)

    modules_to_build.update(
        test_mapping_module_retriever.FindAffectedModules(
            test_mappings, changed_files, test_mapping_test_groups
        )
    )

    return modules_to_build

  def get_package_outputs_commands_impl(self):
    src_top = pathlib.Path(os.environ.get('TOP', os.getcwd()))
    dist_dir = pathlib.Path(os.environ.get('DIST_DIR'))

    soong_vars = self._query_soong_vars(
        src_top,
        [
            'HOST_OUT_TESTCASES',
            'TARGET_OUT_TESTCASES',
            'PRODUCT_OUT',
            'SOONG_HOST_OUT',
            'HOST_OUT',
        ],
    )
    host_out_testcases = pathlib.Path(soong_vars.get('HOST_OUT_TESTCASES'))
    target_out_testcases = pathlib.Path(soong_vars.get('TARGET_OUT_TESTCASES'))
    product_out = pathlib.Path(soong_vars.get('PRODUCT_OUT'))
    soong_host_out = pathlib.Path(soong_vars.get('SOONG_HOST_OUT'))
    host_out = pathlib.Path(soong_vars.get('HOST_OUT'))

    host_paths = []
    target_paths = []
    host_config_files = []
    target_config_files = []
    for module in self.modules_to_build:
      # The required modules are handled separately, no need to package.
      if module in self._REQUIRED_MODULES:
        continue

      host_path = host_out_testcases / module
      if os.path.exists(host_path):
        host_paths.append(host_path)
        self._collect_config_files(src_top, host_path, host_config_files)

      target_path = target_out_testcases / module
      if os.path.exists(target_path):
        target_paths.append(target_path)
        self._collect_config_files(src_top, target_path, target_config_files)

      if not os.path.exists(host_path) and not os.path.exists(target_path):
        logging.info(f'No host or target build outputs found for {module}.')

    zip_commands = []

    zip_commands.extend(
        self._get_zip_test_configs_zips_commands(
            src_top,
            dist_dir,
            host_out,
            product_out,
            host_config_files,
            target_config_files,
        )
    )

    zip_command = self._base_zip_command(src_top, dist_dir, 'general-tests.zip')

    # Add host testcases.
    if host_paths:
      zip_command.extend(
          self._generate_zip_options_for_items(
              prefix='host',
              relative_root=f'{src_top / soong_host_out}',
              directories=host_paths,
          )
      )

    # Add target testcases.
    if target_paths:
      zip_command.extend(
          self._generate_zip_options_for_items(
              prefix='target',
              relative_root=f'{src_top / product_out}',
              directories=target_paths,
          )
      )

    # TODO(lucafarsi): Push this logic into a general-tests-minimal build command
    # Add necessary tools. These are also hardcoded in general-tests.mk.
    framework_path = soong_host_out / 'framework'

    zip_command.extend(
        self._generate_zip_options_for_items(
            prefix='host/tools',
            relative_root=str(framework_path),
            files=[
                f"{framework_path / 'cts-tradefed.jar'}",
                f"{framework_path / 'compatibility-host-util.jar'}",
                f"{framework_path / 'vts-tradefed.jar'}",
            ],
        )
    )

    zip_commands.append(zip_command)
    return zip_commands

  def _collect_config_files(
      self,
      src_top: pathlib.Path,
      root_dir: pathlib.Path,
      config_files: list[str],
  ):
    for root, dirs, files in os.walk(src_top / root_dir):
      for file in files:
        if file.endswith('.config'):
          config_files.append(root_dir / file)

  def _get_zip_test_configs_zips_commands(
      self,
      src_top: pathlib.Path,
      dist_dir: pathlib.Path,
      host_out: pathlib.Path,
      product_out: pathlib.Path,
      host_config_files: list[str],
      target_config_files: list[str],
  ) -> tuple[list[str], list[str]]:
    """Generate general-tests_configs.zip and general-tests_list.zip.

    general-tests_configs.zip contains all of the .config files that were
    built and general-tests_list.zip contains a text file which lists
    all of the .config files that are in general-tests_configs.zip.

    general-tests_configs.zip is organized as follows:
    /
      host/
        testcases/
          test_1.config
          test_2.config
          ...
      target/
        testcases/
          test_1.config
          test_2.config
          ...

    So the process is we write out the paths to all the host config files into
    one
    file and all the paths to the target config files in another. We also write
    the paths to all the config files into a third file to use for
    general-tests_list.zip.

    Args:
      dist_dir: dist directory.
      host_out: host out directory.
      product_out: product out directory.
      host_config_files: list of all host config files.
      target_config_files: list of all target config files.

    Returns:
      The commands to generate general-tests_configs.zip and
      general-tests_list.zip
    """
    with open(
        f"{host_out / 'host_general-tests_list'}", 'w'
    ) as host_list_file, open(
        f"{product_out / 'target_general-tests_list'}", 'w'
    ) as target_list_file, open(
        f"{host_out / 'general-tests_list'}", 'w'
    ) as list_file:

      for config_file in host_config_files:
        host_list_file.write(f'{config_file}' + '\n')
        list_file.write('host/' + os.path.relpath(config_file, host_out) + '\n')

      for config_file in target_config_files:
        target_list_file.write(f'{config_file}' + '\n')
        list_file.write(
            'target/' + os.path.relpath(config_file, product_out) + '\n'
        )

    zip_commands = []

    tests_config_zip_command = self._base_zip_command(
        src_top, dist_dir, 'general-tests_configs.zip'
    )
    tests_config_zip_command.extend(
        self._generate_zip_options_for_items(
            prefix='host',
            relative_root=str(host_out),
            list_files=[f"{host_out / 'host_general-tests_list'}"],
        )
    )

    tests_config_zip_command.extend(
        self._generate_zip_options_for_items(
            prefix='target',
            relative_root=str(product_out),
            list_files=[f"{product_out / 'target_general-tests_list'}"],
        ),
    )

    zip_commands.append(tests_config_zip_command)

    tests_list_zip_command = self._base_zip_command(
        src_top, dist_dir, 'general-tests_list.zip'
    )
    tests_list_zip_command.extend(
        self._generate_zip_options_for_items(
            relative_root=str(host_out),
            files=[f"{host_out / 'general-tests_list'}"],
        )
    )
    zip_commands.append(tests_list_zip_command)

    return zip_commands

  def get_enabled_flag(self):
    return 'general_tests_optimized'

  @classmethod
  def get_optimized_targets(cls) -> dict[str, OptimizedBuildTarget]:
    return {'general-tests': functools.partial(cls)}


OPTIMIZED_BUILD_TARGETS = {}
OPTIMIZED_BUILD_TARGETS.update(GeneralTestsOptimizer.get_optimized_targets())