#!/usr/bin/env bash

set -u
set -o pipefail

repo_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
remote_source="boll@175.178.116.187:/home/boll/LMJWork/OmniSocketGo/peer-b-latency.jsonl"
local_peer_a="$repo_dir/peer-a-latency.jsonl"
local_peer_b="$repo_dir/peer-b-latency.jsonl"
summary_output="$repo_dir/latency-summary.jsonl"
chart_output="$repo_dir/latency-summary.html"
latency_binary="$repo_dir/bin/latencysummary"
go_cache_dir="${GOCACHE:-/tmp/omnisocketgo-go-build}"
poll_interval_seconds=1

remote_tmp=""
summary_tmp=""
chart_tmp=""

log() {
	printf '[%s] %s\n' "$(date '+%Y-%m-%d %H:%M:%S')" "$*"
}

cleanup_temp_file() {
	local path="$1"
	if [[ -n "$path" && -e "$path" ]]; then
		rm -f "$path"
	fi
}

cleanup() {
	cleanup_temp_file "$remote_tmp"
	cleanup_temp_file "$summary_tmp"
	cleanup_temp_file "$chart_tmp"
}

handle_interrupt() {
	log "received interrupt signal, stopping refresh loop"
	cleanup
	exit 130
}

handle_terminate() {
	log "received terminate signal, stopping refresh loop"
	cleanup
	exit 143
}

trap cleanup EXIT
trap handle_interrupt INT
trap handle_terminate TERM

cd "$repo_dir" || exit 1

mkdir -p "$repo_dir/bin"
mkdir -p "$go_cache_dir"
if ! GOCACHE="$go_cache_dir" go build -o "$latency_binary" ./cmd/latencysummary; then
	log "build failed; exiting"
	exit 1
fi

log "starting 1-second refresh loop"

while true; do
	remote_tmp="$(mktemp "$repo_dir/peer-b-latency.jsonl.tmp.XXXXXX")" || exit 1
	if scp -P 10022 "$remote_source" "$remote_tmp"; then
		if mv -f "$remote_tmp" "$local_peer_b"; then
			remote_tmp=""
		else
			status=$?
			log "failed to replace $(basename "$local_peer_b") after scp (exit $status)"
			cleanup_temp_file "$remote_tmp"
			remote_tmp=""
			sleep "$poll_interval_seconds"
			continue
		fi
	else
		status=$?
		log "scp refresh failed (exit $status)"
		cleanup_temp_file "$remote_tmp"
		remote_tmp=""
		sleep "$poll_interval_seconds"
		continue
	fi

	summary_tmp="$(mktemp "$repo_dir/latency-summary.tmp.XXXXXX.jsonl")" || exit 1
	chart_tmp="${summary_tmp%.jsonl}.html"
	if "$latency_binary" \
		-input "$local_peer_a" \
		-input "$local_peer_b" \
		-shared-max-offset 1 \
		-output "$summary_tmp"; then
		if [[ ! -f "$summary_tmp" || ! -f "$chart_tmp" ]]; then
			log "summary succeeded but temporary outputs are incomplete"
			cleanup_temp_file "$summary_tmp"
			cleanup_temp_file "$chart_tmp"
			summary_tmp=""
			chart_tmp=""
			sleep "$poll_interval_seconds"
			continue
		fi

		if ! mv -f "$summary_tmp" "$summary_output"; then
			status=$?
			log "failed to replace $(basename "$summary_output") (exit $status)"
			cleanup_temp_file "$summary_tmp"
			cleanup_temp_file "$chart_tmp"
			summary_tmp=""
			chart_tmp=""
			sleep "$poll_interval_seconds"
			continue
		fi
		summary_tmp=""

		if ! mv -f "$chart_tmp" "$chart_output"; then
			status=$?
			log "failed to replace $(basename "$chart_output") (exit $status)"
			cleanup_temp_file "$chart_tmp"
			chart_tmp=""
			sleep "$poll_interval_seconds"
			continue
		fi
		chart_tmp=""
	else
		status=$?
		log "latency summary refresh failed (exit $status)"
		cleanup_temp_file "$summary_tmp"
		cleanup_temp_file "$chart_tmp"
		summary_tmp=""
		chart_tmp=""
		sleep "$poll_interval_seconds"
		continue
	fi

	sleep "$poll_interval_seconds"
done