# Library of functions shared by all CI scripts

skip_branch_tip_with_tag () {
        # Sometimes, a branch is pushed at the same time the tag that points
        # at the same commit as the tip of the branch is pushed, and building
        # both at the same time is a waste.
        #
        # When the build is triggered by a push to a tag, $CI_BRANCH will
        # have that tagname, e.g. v2.14.0.  Let's see if $CI_BRANCH is
        # exactly at a tag, and if so, if it is different from $CI_BRANCH.
        # That way, we can tell if we are building the tip of a branch that
        # is tagged and we can skip the build because we won't be skipping a
        # build of a tag.

        if TAG=$(git describe --exact-match "$CI_BRANCH" 2>/dev/null) &&
                test "$TAG" != "$CI_BRANCH"
        then
                echo "$(tput setaf 2)Tip of $CI_BRANCH is exactly at $TAG$(tput sgr0)"
                exit 0
        fi
}

# Save some info about the current commit's tree, so we can skip the build
# job if we encounter the same tree again and can provide a useful info
# message.
save_good_tree () {
        echo "$(git rev-parse $CI_COMMIT^{tree}) $CI_COMMIT $CI_JOB_NUMBER $CI_JOB_ID" >>"$good_trees_file"
        # limit the file size
        tail -1000 "$good_trees_file" >"$good_trees_file".tmp
        mv "$good_trees_file".tmp "$good_trees_file"
}

# Skip the build job if the same tree has already been built and tested
# successfully before (e.g. because the branch got rebased, changing only
# the commit messages).
skip_good_tree () {
        if ! good_tree_info="$(grep "^$(git rev-parse $CI_COMMIT^{tree}) " "$good_trees_file")"
        then
                # Haven't seen this tree yet, or no cached good trees file yet.
                # Continue the build job.
                return
        fi

        echo "$good_tree_info" | {
                read tree prev_good_commit prev_good_job_number prev_good_job_id

                if test "$CI_JOB_ID" = "$prev_good_job_id"
                then
                        cat <<-EOF
                        $(tput setaf 2)Skipping build job for commit $CI_COMMIT.$(tput sgr0)
                        This commit has already been built and tested successfully by this build job.
                        To force a re-build delete the branch's cache and then hit 'Restart job'.
                        EOF
                else
                        cat <<-EOF
                        $(tput setaf 2)Skipping build job for commit $CI_COMMIT.$(tput sgr0)
                        This commit's tree has already been built and tested successfully in build job $prev_good_job_number for commit $prev_good_commit.
                        The log of that build job is available at $(url_for_job_id $prev_good_job_id)
                        To force a re-build delete the branch's cache and then hit 'Restart job'.
                        EOF
                fi
        }

        exit 0
}

check_unignored_build_artifacts ()
{
        ! git ls-files --other --exclude-standard --error-unmatch \
                -- ':/*' 2>/dev/null ||
        {
                echo "$(tput setaf 1)error: found unignored build artifacts$(tput sgr0)"
                false
        }
}

# Set 'exit on error' for all CI scripts to let the caller know that
# something went wrong.
# Set tracing executed commands, primarily setting environment variables
# and installing dependencies.
set -ex

if test true = "$TRAVIS"
then
        CI_TYPE=travis
        # When building a PR, TRAVIS_BRANCH refers to the *target* branch. Not
        # what we want here. We want the source branch instead.
        CI_BRANCH="${TRAVIS_PULL_REQUEST_BRANCH:-$TRAVIS_BRANCH}"
        CI_COMMIT="$TRAVIS_COMMIT"
        CI_JOB_ID="$TRAVIS_JOB_ID"
        CI_JOB_NUMBER="$TRAVIS_JOB_NUMBER"
        CI_OS_NAME="$TRAVIS_OS_NAME"
        CI_REPO_SLUG="$TRAVIS_REPO_SLUG"

        cache_dir="$HOME/travis-cache"

        url_for_job_id () {
                echo "https://travis-ci.org/$CI_REPO_SLUG/jobs/$1"
        }

        BREW_INSTALL_PACKAGES="git-lfs gettext"
        export GIT_PROVE_OPTS="--timer --jobs 3 --state=failed,slow,save"
        export GIT_TEST_OPTS="--verbose-log -x --immediate"
else
        echo "Could not identify CI type" >&2
        exit 1
fi

good_trees_file="$cache_dir/good-trees"

mkdir -p "$cache_dir"

skip_branch_tip_with_tag
skip_good_tree

if test -z "$jobname"
then
        jobname="$CI_OS_NAME-$CC"
fi

export DEVELOPER=1
export DEFAULT_TEST_TARGET=prove
export GIT_TEST_CLONE_2GB=YesPlease
if [ "$jobname" = linux-gcc ]; then
        export CC=gcc-8
fi

case "$jobname" in
linux-clang|linux-gcc)
        export GIT_TEST_HTTPD=YesPlease

        # The Linux build installs the defined dependency versions below.
        # The OS X build installs the latest available versions. Keep that
        # in mind when you encounter a broken OS X build!
        export LINUX_P4_VERSION="16.2"
        export LINUX_GIT_LFS_VERSION="1.5.2"

        P4_PATH="$HOME/custom/p4"
        GIT_LFS_PATH="$HOME/custom/git-lfs"
        export PATH="$GIT_LFS_PATH:$P4_PATH:$PATH"
        ;;
osx-clang|osx-gcc)
        # t9810 occasionally fails on Travis CI OS X
        # t9816 occasionally fails with "TAP out of sequence errors" on
        # Travis CI OS X
        export GIT_SKIP_TESTS="t9810 t9816"
        ;;
GIT_TEST_GETTEXT_POISON)
        export GIT_TEST_GETTEXT_POISON=YesPlease
        ;;
esac