#!/bin/bash
#
# get-local-registry-script - fetches local-registry script from automation_images repo
#
ME=$(basename $0)

###############################################################################
# BEGIN global settings

SCRIPTNAME=cache_images/local-cache-registry

REPO=containers/automation_images

GITHUB_GRAPHQL=https://api.github.com/graphql

# END   global settings
###############################################################################

usage="Usage: $ME [--help] [-v|--verbose] [IMG_SFX]

--help          display usage message
-v, --verbose   verbose output

$ME fetches the $SCRIPTNAME tool
from the github $REPO repo.
If successful, the script will be left in cwd.

It is up to you to invoke it:

    \$ sudo ./$(basename $SCRIPTNAME) initialize

This will set up a local registry and prepopulate it with
images used in tests. Initialization may take tens of minutes
on a slow connection.

To use this registry in e2e or apiv2 tests:

    export CI_USE_REGISTRY_CACHE=1

To use in system tests, you need to overwrite /etc/containers/registries.conf
because system tests, by definition, use system settings. This is left as
an exercise for the reader.

Reasons for doing this:
  1) Consistency with CI environment
  2) Speedier (and less flaky) tests
"

verbose=
for i; do
    value=`expr "$i" : '[^=]*=\(.*\)'`
    case "$i" in
    -h*|--help)	echo "$usage"; exit 0;;
    -v|--verbose)	verbose=$i; shift;;
    -*)	echo "$ME: unrecognized option $i" >&2
	echo "$usage" >&2
	exit 1;;
    *)	break;;
    esac
done

###############################################################################
# BEGIN helper functions

function die() {
    echo "$ME: $*" >&2
    exit 1
}

function get_imgsfx() {
    test -e .cirrus.yml || die ".cirrus.yml does not exist; please run me from top of repo"

    imgsfx=$(sed -ne 's/^ *IMAGE_SUFFIX:.*"c\(202.*\)"/\1/p' <.cirrus.yml)
    if [[ -z "$imgsfx" ]]; then
        die "Did not find 'IMAGE_SUFFIX:.*c202.*' in .cirrus.yml"
    fi

    expr "$imgsfx" : "^20[0-9]\{6\}t[0-9]\{6\}z-" &> /dev/null || die "IMAGE_SUFFIX '$imgsfx' (from .cirrus.yml) does not match expected YYYYMMDDtHHMMSS-* form"

    echo $imgsfx
}

function get_script() {
    local tag=$1

    local tmpfile=$(mktemp --tmpdir --suffix=.sh $ME.fetched-script.XXXXXXX)

    local url="https://raw.githubusercontent.com/${REPO}/$tag/$SCRIPTNAME"
    test -n "$verbose" && echo "[ $url ]" >&2

    curl -s -f -o $tmpfile $url
    if [[ $? -eq 0 ]]; then
        chmod 755 $tmpfile
        mv -f $tmpfile $SCRIPTNAME
        echo $SCRIPTNAME
        return
    fi
    rm -f $tmpfile
}

# END   helper functions
###############################################################################
# BEGIN code

if [[ -n "$1" ]]; then
    imgsfx=$1
    shift
    if [[ -n "$*" ]]; then
        die "Too many arguments; run $ME --help for help"
    fi
else
    imgsfx=$(get_imgsfx)
fi
test -n "$verbose" && echo "[ imgsfx=$imgsfx ]" >&2

# Easy case: this is a tagged automation_images build
fetched_script=$(get_script $imgsfx)
if [[ -n "$fetched_script" ]]; then
    echo $fetched_script
    exit 0
fi

# Nope, not a tagged build. Look for imgsfx in PR
query="
{
    \"query\": \"{
        search(query: \\\"repo:$REPO is:pr c$imgsfx\\\", type:ISSUE, first:10) {
            edges {
               node { ... on PullRequest {
                       number
                       title
                       commits(last:30)  { nodes { commit { committedDate, oid } } }
                       comments(last:30) { nodes { createdAt author { login } body } }
                   }
               }
            }
        }
    }\"
}
"

query_clean=$(tr -d \\012 <<<"$query")

jsontmp=$(mktemp --tmpdir --suffix=.json $ME.graphql.XXXXXXX)

curl -s -S -H "Authorization: bearer $GITHUB_TOKEN" -X POST --data "$query_clean" $GITHUB_GRAPHQL > $jsontmp

# There should be one and exactly one comment from github-actions
# that mentions the given imgsfx. Find its timestamp
img_timestamp=$(jq -C -r '.data.search.edges.[].node.comments.nodes.[] | select(.author.login="github-actions") | select(.body | contains("c'${imgsfx}'")).createdAt' < $jsontmp)
if [[ -z "$img_timestamp" ]]; then
    die "Did not find a github-actions comment mentioning '$imgsfx'"
fi

# Some time prior to that comment, there was a commit pushed to github
# that resulted in that build. Find that commit's SHA (OID).
push_sha=$(jq -C -r '.data.search.edges.[].node.commits.nodes.[].commit | select(.committedDate < "'${img_timestamp}'").oid' < $jsontmp)

# Got all the info we need. Clean up tmpfile
rm -f $jsontmp

# This must succeed.
get_script $push_sha