# Copyright 2019 PrivateStorage.io, LLC
#
# 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.

version: 2.1

aliases:
  - &PREPARE_VIRTUALENV
    run:
      name: "Prepare virtualenv"
      command: |
        virtualenv venv
        . venv/bin/activate
        pip install --upgrade certifi pip
        pip install ${PIP_REQUIREMENTS}

jobs:
  documentation:
    docker:
      - image: "circleci/python:3.7"

    environment:
      PIP_REQUIREMENTS: "-r docs/requirements.txt"

    steps:
      - "checkout"

      - <<: *PREPARE_VIRTUALENV

      - run:
          name: "Sphinx Documentation Build"
          command: |
            . venv/bin/activate
            sphinx-build docs/source docs/build

      - store_artifacts:
          path: "docs/build"
          destination: "docs"

  macos-tests:
    parameters:
      py-version:
        type: "string"
      xcode-version:
        type: "string"

    macos:
      xcode: << parameters.xcode-version >>

    steps:
      - "checkout"

      - restore_cache:
          keys:
          # when setup.cfg changes, use increasingly general patterns to
          # restore cache
          - pip-packages-v1-{{ .Branch }}-{{ checksum "setup.cfg" }}
          - pip-packages-v1-{{ .Branch }}-
          - pip-packages-v1-

      - run:
          name: "Get Pip"
          command: |
            # The CircleCI macOS environment has curl and Python but does not
            # have pip.  So, for starters, use curl and Python to get pip.
            if [ "<< parameters.py-version >>" == "2.7" ]; then
              curl https://bootstrap.pypa.io/2.7/get-pip.py -o get-pip.py
            else
              curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
            fi
            python<< parameters.py-version >> get-pip.py

      - run:
          name: "Create Virtualenv"
          command: |
            # The CircleCI macOS Python environment has some Python libraries
            # in it which conflict with ZKAPAuthorizer's requirements.  So
            # install virtualenv and use it to create an environment for
            # ZKAPAuthorizer so it can have all its own versions of its
            # dependencies.
            python<< parameters.py-version >> -m pip install virtualenv

            # Make sure virtualenv creates a Python 2 environment!
            virtualenv --python=python<< parameters.py-version >> venv

            # Get the newest pip we can because who knows what came along with
            # that virtualenv.
            venv/bin/pip install --find-links file://${PWD}/wheelhouse --upgrade pip

      - run:
          name: "Populate Wheelhouse"
          command: |
            # Get wheels for all the Python packages we depend on - either
            # directly via the ZKAPAuthorizer distutils configuration *or*
            # because some other tool depends on it.  For example, pip has a
            # bunch of dependencies it is nice to have around, and using the
            # wheels depends on the wheel package.
            venv/bin/pip wheel --wheel-dir wheelhouse pip wheel .[test]

      - save_cache:
          paths:
          - "wheelhouse"
          key: pip-packages-v1-{{ .Branch }}-{{ checksum "setup.cfg" }}

      - run:
          name: "Install"
          command: |
            # Now we can install ZKAPAuthorizer and its dependencies and test
            # dependencies into the environment.
            venv/bin/pip install --no-index --find-links file://${PWD}/wheelhouse .[test]

      - run:
          name: "Test"
          command: |
            # The test suite might leak file descriptors.  macOS defaults to a
            # limit of 256.  This should be fixed, but not now ...
            ulimit -Sn 1024
            # And finally we can run the tests.  We'll run them with 4 jobs
            # because the resource class documented at
            # https://support.circleci.com/hc/en-us/articles/360009144794-macOS-resources
            # says "Medium: 4 vCPUs, 8GB RAM".
            venv/bin/python -m twisted.trial --jobs 4 --rterrors _zkapauthorizer

  linux-tests:
    docker:
      # Run in a highly Nix-capable environment.
      - image: "nixorg/nix:circleci"

    environment:
      # Specify a revision of NixOS/nixpkgs to run against.  This essentially
      # pins the majority of the software involved in the build.  This
      # revision is selected arbitrarily.  It's somewhat current as of the
      # time of this comment.  We can bump it to a newer version when that
      # makes sense.  Meanwhile, the platform won't shift around beneath us
      # unexpectedly.
      NIXPKGS_REV: "8bf142e001b6876b021c8ee90c2c7cec385fe8e9"

    steps:
      - run:
          # Get NIX_PATH set for the rest of the job so that the revision of
          # nixpkgs we selected will be used everywhere Nix pulls in software.
          # There is no way to set an environment variable containing the
          # value of another environment variable on CircleCI except to use
          # the `BASE_ENV` feature as we do here.
          name: "Setup NIX_PATH Environment Variable"
          command: |
            echo "export NIX_PATH=nixpkgs=https://github.com/NixOS/nixpkgs-channels/archive/$NIXPKGS_REV.tar.gz" >> $BASH_ENV

      - "checkout"

      - "run":
          # CircleCI won't let us interpolate NIXPKGS_REV into a cache key.
          # Only CircleCI's own environment variables or variables set via the
          # web interface in a "context" can be interpolated into cache keys.
          # However, we can interpolate the checksum of a file...  Since we
          # don't care about the exact revision, we just care that a new
          # revision gives us a new string, we can write the revision to a
          # file and then put the checksum of that file into the cache key.
          # This way, we don't have to maintain the nixpkgs revision in two
          # places and risk having them desynchronize.
          name: "Prepare For Cache Key"
          command: |
            echo "${NIXPKGS_REV}" > nixpkgs.rev

      - restore_cache:
          # Get all of Nix's state relating to the particular revision of
          # nixpkgs we're using.  It will always be the same.  CircleCI
          # artifacts and nixpkgs store objects are probably mostly hosted in
          # the same place (S3) so there's not a lot of difference for
          # anything that's pre-built.  For anything we end up building
          # ourselves, though, this saves us all of the build time (less the
          # download time).
          #
          # Read about caching dependencies: https://circleci.com/docs/2.0/caching/
          name: "Restore Nix Store Paths"
          keys:
            # Construct cache keys that allow sharing as long as nixpkgs
            # revision is unchanged.
            #
            # If nixpkgs changes then potentially a lot of cached packages for
            # the base system will be invalidated so we may as well drop them
            # and make a new cache with the new packages.
            - zkapauthorizer-nix-store-v4-{{ checksum "nixpkgs.rev" }}
            - zkapauthorizer-nix-store-v4-

      - run:
          name: "Run Test Suite"
          command: |
            # Building the package has, as a side effect, running the test
            # suite.  If the test suite fails, so does the build.
            #
            # Pass in a couple args here to control how the test suite is run
            # - configure Hypothesis so it can behave appropriately in a CI
            # environment (where resources are scarce, competetion with other
            # tenants is high, etc) and collect coverage information.
            #
            # Further, we want the "doc" output built as well because that's
            # where the coverage data ends up.
            #
            # Also limit the number of concurrent jobs because of resource
            # constraints on CircleCI. :/
            nix-build --cores 1 --max-jobs 1 --argstr hypothesisProfile ci --arg collectCoverage true --attr doc

      - save_cache:
          name: "Cache Nix Store Paths"
          key: zkapauthorizer-nix-store-v4-{{ checksum "nixpkgs.rev" }}
          paths:
            - "/nix"

      - run:
          name: "Report Coverage"
          command: |
            ./.circleci/report-coverage.sh

workflows:
  version: 2
  everything:
    jobs:
    - "documentation"
    - "linux-tests"
    - "macos-tests":
        matrix:
          parameters:
            py-version:
            - "2.7"

            xcode-version:
            # https://circleci.com/docs/2.0/testing-ios/#supported-xcode-versions
            - "12.3.0"
            - "11.7.0"
