# Lars Wirzenius, with help from Daniel Silverstone.
# 
# Feel free to use this as you wish. It is simple enough that it is
# probably not even copyrightable.

pipelines:

  # Get sources from git servers, as specified in the "sources"
  # parameter. The sources are mirrored into ".mirrors" at the root of
  # the workspace. This pipeline then constructs a source from the
  # mirrored source trees.
  #
  # The "sources" parameter is a list of dicts, each dict having the
  # fields "name", "repo", "location", and "ref":
  #
  #     sources:
  #       - name: foo
  #         repo: git://git.example.com/foo.git
  #         location: src
  #         ref: master
  #       - name: foo-debian
  #         repo: git://git.example.com/foo-debian.git
  #         location: src/debian
  #         ref: master
  #
  # The above would clone the foo.git and foo-debian.git repositories
  # and check them out as src and src/debian, respectively, at the
  # root of the workspace. In both checkouts the master branch is
  # checked out.
  #
  # If the checkouts already existed, "git pull" is run in them. This
  # allows the workspace to persist across builds, and subsequent
  # builds will only pull changes into the mirrored git repositories,
  # and from there to the workspaces. The project's build system can
  # then build only the changed parts.
  #
  # This pipeline needs to run with a container having Python3 and git
  # installed.

  - pipeline: ick/get_sources
    parameters:
      - sources
    actions:
      - action: git_mirror
        where: host

      - python: |
          import os, re
          sources = params['sources']
          for source in sources:
            name = source['name']
            dirname = source['location']
            ref = source['ref']
            ref_is_sha = re.match('^[a-fA-F0-9]+$', ref) is not None
            mirror = os.path.join('.mirrors', name)
            if os.path.exists(dirname):
              RUN('git', 'clean', '-fdx', cwd=dirname)
              RUN('git', 'reset', '--hard', cwd=dirname)
              RUN('git', 'checkout', ref, cwd=dirname)
              # Only pull if in a branch.
              head = open('{}/.git/HEAD'.format(dirname)).read().strip()
              if head.startswith('ref:'):
                RUN('git', 'pull', cwd=dirname)
            else:
              # Initial clone. Handle ref being a commit id specially.
              if re.match('^[a-fA-F0-9]+$', ref):
                RUN('git', 'clone', mirror, dirname)
                RUN('git', 'checkout', ref, cwd=dirname)
              else:
                RUN('git', 'clone', '-b', ref, mirror, dirname)
        where: container