#!/usr/bin/env bash
# vcs against stock git on live hosts, from one machine: git through a git
# remote (pushing to a scratch branch, with pull --rebase and push again
# when refused), vcs through a hosted project.
# Usage: GIT_REMOTE=https://git.coline.app/o/n.git VCS_PROJECT=upstream.codes/o/n \
#        VCS_TOKEN=... tests/bench-live.sh [path/to/vcs] [agents]
# git uses this machine's credentials for the remote.
set -uo pipefail

VCS=${1:-$(cd "$(dirname "$0")/.." && pwd)/target/release/vcs}
N=${2:-16}
WORK=$(mktemp -d)
export VCS_SAVER=0 VCS_HOME=$WORK/home VCS_NAME=Bench VCS_EMAIL=bench@example.com
export GIT_AUTHOR_NAME=Bench GIT_AUTHOR_EMAIL=bench@example.com GIT_COMMITTER_NAME=Bench GIT_COMMITTER_EMAIL=bench@example.com
BRANCH="bench-$(date +%s)"
trap 'rm -rf "$WORK"' EXIT
cd "$WORK"
g() { git -c commit.gpgsign=false "$@"; }
now() { python3 -c 'import time; print(time.time())'; }
since() { python3 -c "import time; print(f'{time.time() - $1:.2f}')"; }
med() { printf '%s\n' "$@" | sort -n | sed -n "$(( ($# + 1) / 2 ))p"; }
row() { printf '%-52s %12s %12s\n' "$1" "$2" "$3"; }

"$VCS" login "${VCS_PROJECT%%/*}" --token "$VCS_TOKEN" >/dev/null
echo "live: git $GIT_REMOTE (branch $BRANCH) vs vcs $VCS_PROJECT"
echo
row "" "git" "vcs"

t=$(now); g clone -q "$GIT_REMOTE" g0; tg=$(since "$t")
t=$(now); "$VCS" get "$VCS_PROJECT" v0 >/dev/null; tv=$(since "$t")
row "first copy (s)" "$tg" "$tv"
(cd g0 && g checkout -q -b "$BRANCH" && g push -q origin "$BRANCH")

gl=()
vl=()
for i in $(seq 1 5); do
  printf '%s %s\n' "$BRANCH" "$i" >> g0/$BRANCH.txt
  t=$(now); (cd g0 && g add -A && g commit -qm "Bench $i" && g push -q origin "$BRANCH"); gl+=("$(since "$t")")
  printf '%s %s\n' "$BRANCH" "$i" >> v0/$BRANCH.txt
  t=$(now); "$VCS" -C v0 land -m "Bench $i" >/dev/null; vl+=("$(since "$t")")
done
row "one change: commit + push vs land, median (s)" "$(med "${gl[@]}")" "$(med "${vl[@]}")"

for i in $(seq 1 "$N"); do
  g clone -q --branch "$BRANCH" "$GIT_REMOTE" "g$i" && printf '%s %s\n' "$BRANCH" "$i" > "g$i/$BRANCH-$i.txt" && (cd "g$i" && g add -A && g commit -qm "Agent $i")
  "$VCS" get "$VCS_PROJECT" "v$i" >/dev/null && printf '%s %s\n' "$BRANCH" "$i" > "v$i/$BRANCH-$i.txt"
done
pids=()
t=$(now)
for i in $(seq 1 "$N"); do
  (cd "g$i"; tries=0; until g push -q origin "$BRANCH" 2>/dev/null; do tries=$((tries + 1)); [ "$tries" -gt 200 ] && break; g pull -q --rebase origin "$BRANCH" 2>/dev/null; done; echo "$tries" > "../tries$i") &
  pids+=($!)
done
wait "${pids[@]}"
tg=$(since "$t")
refused=$(cat tries* | python3 -c "import sys; print(sum(int(l) for l in sys.stdin))")
pids=()
t=$(now)
for i in $(seq 1 "$N"); do ("$VCS" -C "v$i" land -m "Agent $i" >/dev/null 2>&1; echo $? > "vcode$i") & pids+=($!); done
wait "${pids[@]}"
tv=$(since "$t")
landed=$(grep -l '^0$' vcode* | wc -l | tr -d ' ')
row "$N agents land one change each on one branch (s)" "$tg" "$tv"
row "   refused pushes / changes that didn't land" "$refused" "$((N - landed))"
echo
echo "git scratch branch left on the remote: $BRANCH"