#!/usr/bin/env bash

[ -z "$DEBUG" ] || set -x

set -eo pipefail

# Replaces Tekton's git-init which lacks retries: https://github.com/tektoncd/pipeline/issues/3515

# typical use:

# args:

# - -url

# - $(params.giturl)

# - -revision

# - $(params.revision)

# - -path

# - /workspace/source

# - -submodules=false

# - -depth=1

[ $# != 8 ] && echo "Expected 8 args, got $# for $0: $@" && exit 1

[ "$1" != "-url" ] && echo "First arg should be -url, was $1" && exit 1

[ "$3" != "-revision" ] && echo "Third arg should be -revision, was $3" && exit 1

[ "$5" != "-path" ] && echo "Fifth arg should be -path, was $5" && exit 1

[ "$7" != "-submodules=false" ] && echo "Seventh arg should be -submodules=false, was $7" && exit 1

[ "$8" != "-depth=1" ] && echo "Eighth arg should be -depth=1, was $8" && exit 1

URL="$2"

[ -z "$URL" ] && echo "Second arg should be URL" && exit 1

REVISION="$4"

[ -z "$REVISION" ] && echo "Fourth arg should be revision" && exit 1

CLONEPATH="$6"

[ -z "$CLONEPATH" ] && echo "Sixth arg should be clonepath" && exit 1

[ -d $CLONEPATH ] || mkdir -m 700 -p $CLONEPATH

cd $CLONEPATH

[ -d "$CLONEPATH/.git" ] && git remote -v && git remote set-url origin $URL || {

git init

git remote add origin $URL

}

# https://github.com/tektoncd/pipeline/blob/v0.41.0/pkg/git/git.go#L285

git config core.sparsecheckout true

retries=3

until git fetch --depth=1 origin --update-head-ok --force $REVISION; do

[ $retries -gt 0 ] || exit 1

retries=$(( $retries - 1 ))

wait=$((10 + $RANDOM % 50))

echo "Git failed, retrying in ${wait}s"

sleep $wait

done

git show-ref "origin/$REVISION" \

&& git checkout -f -B $REVISION origin/$REVISION \

|| git checkout -f $REVISION