#!/bin/sh
# Rewrites .amadan/test-weights.tsv, the measured weights .amadan/test-gate.sh
# deals the split packages' tests by.
#
#   go test -count=1 -json ./internal/console/ >console.json
#   go test -count=1 -json . >root.json
#   .amadan/test-weights.sh console.json root.json
#
# Measure on a quiet machine with the temp root on tmpfs, as CI has it, or
# the fsync-heavy tests weigh several times what they do there.
#
# Only the packages in the given files are rewritten; rows for other
# packages are kept. A top-level test of a quarter-second or more gets a
# row. A test that called t.Parallel (its JSON has a "pause") overlaps
# with its neighbours, so its weight is its time divided by 8, roughly
# what it adds to its shard's wall clock. Everything unlisted is dealt as
# short (test-gate.sh counts it as 0.05 s), which is what it is: host's
# 2,500 small serial tests average about 0.025 s.
set -eu

[ $# -gt 0 ] || {
	echo "usage: .amadan/test-weights.sh go-test-json-file..." >&2
	exit 2
}

out=.amadan/test-weights.tsv
tab=$(printf '\t')
new=$(mktemp "${TMPDIR:-/tmp}/test-weights-XXXXXX")
trap 'rm -f "$new" "$out.tmp"' EXIT
cat "$@" | awk '
	/"Test":"/ {
		if (!match($0, /"Test":"[^"]*"/)) next
		test = substr($0, RSTART + 8, RLENGTH - 9)
		if (index(test, "/")) next
		if (!match($0, /"Package":"[^"]*"/)) next
		pkg = substr($0, RSTART + 11, RLENGTH - 12)
		key = pkg "\t" test
		if ($0 ~ /"Action":"pause"/) { parallel[key] = 1; next }
		if ($0 !~ /"Action":"(pass|fail)"/) next
		if (!match($0, /"Elapsed":[0-9.]+/)) next
		secs[key] = substr($0, RSTART + 10, RLENGTH - 10) + 0
	}
	END {
		for (k in secs) {
			w = (k in parallel) ? secs[k] / 8 : secs[k]
			if (w >= 0.25) printf "%s\t%.2f\n", k, w
		}
		# A package line with no weighted test still marks its rows as replaced.
		for (k in secs) { split(k, f, "\t"); seen[f[1]] = 1 }
		for (p in seen) printf "#pkg\t%s\n", p
	}
' >"$new"
{
	printf '# package\ttest\tseconds (.amadan/test-weights.sh, %s)\n' "$(date -u +%Y-%m-%d)"
	{
		grep -v '^#pkg' "$new"
		if [ -f "$out" ]; then
			awk -F "$tab" -v newf="$new" '
				BEGIN { while ((getline l < newf) > 0) { split(l, f, "\t"); if (f[1] == "#pkg") replaced[f[2]] = 1 } }
				/^#/ { next }
				!($1 in replaced)
			' "$out"
		fi
	} | sort -t "$tab" -k1,1 -k3,3gr
} >"$out.tmp"
mv "$out.tmp" "$out"
echo "wrote $out: $(($(wc -l <"$out") - 1)) weighted tests"