#!/usr/bin/env bash
set -euo pipefail

backend_port="${UPL_SMOKE_BACKEND_PORT:-39123}"
proxy_port="${UPL_SMOKE_PROXY_PORT:-39124}"
nginx_image="${NGINX_IMAGE:-nginx:stable-alpine}"

workspace_dir="$(pwd)"
mkdir -p "$workspace_dir/target/nginx-smoke"
tmp_dir="$(mktemp -d "$workspace_dir/target/nginx-smoke/run.XXXXXXXX")"
data_dir="$tmp_dir/data"
complete_dir="$data_dir/complete"
temp_dir="$tmp_dir/upload-temp"
nginx_conf_dir="$tmp_dir/nginx-conf.d"
nginx_conf="$nginx_conf_dir/default.conf"
backend_log="$tmp_dir/backend.log"
source_file="$tmp_dir/source.bin"
served_file="$tmp_dir/served.bin"
chunk0="$tmp_dir/chunk0.part"
chunk1="$tmp_dir/chunk1.part"
backend_pid=""
nginx_container="upl-nginx-smoke-$$"

cleanup() {
    if [[ -n "$backend_pid" ]] && kill -0 "$backend_pid" 2>/dev/null; then
        kill "$backend_pid" 2>/dev/null || true
        wait "$backend_pid" 2>/dev/null || true
    fi
    docker rm -f "$nginx_container" >/dev/null 2>&1 || true
    rm -rf "$tmp_dir"
}
trap cleanup EXIT

start_backend() {
    UPL_BIND="0.0.0.0:$backend_port" UPL_DATA_DIR="$data_dir" UPL_TEMP_DIR="$temp_dir" \
        cargo run --quiet >"$backend_log" 2>&1 &
    backend_pid="$!"
    wait_for "http://127.0.0.1:$backend_port/healthz"
}

wait_for() {
    local url="$1"
    for _ in $(seq 1 80); do
        if curl -fsS "$url" >/dev/null 2>&1; then
            return 0
        fi
        sleep 0.1
    done

    echo "Timed out waiting for $url" >&2
    if [[ -f "$backend_log" ]]; then
        tail -n 80 "$backend_log" >&2 || true
    fi
    return 1
}

json_field() {
    local field="$1"
    node -e '
const field = process.argv[1];
let input = "";
process.stdin.setEncoding("utf8");
process.stdin.on("data", (chunk) => input += chunk);
process.stdin.on("end", () => {
  const value = JSON.parse(input)[field];
  if (value === undefined) process.exit(2);
  process.stdout.write(String(value));
});
' "$field"
}

mkdir -p "$complete_dir" "$temp_dir" "$nginx_conf_dir"

cat >"$nginx_conf" <<EOF
server {
    listen $proxy_port;
    client_max_body_size 64m;

    location /files/ {
        alias /upl-complete/;
        autoindex off;
        try_files \$uri =404;
    }

    location / {
        proxy_pass http://host.docker.internal:$backend_port;
        proxy_http_version 1.1;
        proxy_request_buffering off;
        proxy_buffering off;
        proxy_read_timeout 3600s;
        proxy_send_timeout 3600s;
        proxy_set_header Host \$host;
        proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto http;
        proxy_set_header X-Real-IP \$remote_addr;
    }
}
EOF

start_backend

docker run -d --rm \
    --name "$nginx_container" \
    --add-host host.docker.internal:host-gateway \
    -p "127.0.0.1:$proxy_port:$proxy_port" \
    -v "$nginx_conf_dir:/etc/nginx/conf.d:ro" \
    -v "$complete_dir:/upl-complete:ro" \
    "$nginx_image" >/dev/null
wait_for "http://127.0.0.1:$proxy_port/healthz"

dd if=/dev/urandom of="$source_file" bs=1M count=17 status=none
dd if="$source_file" of="$chunk0" bs=1M count=16 status=none
dd if="$source_file" of="$chunk1" bs=1M skip=16 status=none

size="$(wc -c <"$source_file" | tr -d ' ')"
create_response="$(
    curl -fsS \
        -H "Content-Type: application/json" \
        -d "{\"name\":\"source.bin\",\"size\":$size,\"last_modified\":1760000000000}" \
        "http://127.0.0.1:$proxy_port/api/uploads"
)"
upload_id="$(printf '%s' "$create_response" | json_field upload_id)"

curl -fsS -X PUT \
    -H "Content-Type: application/octet-stream" \
    --data-binary "@$chunk0" \
    "http://127.0.0.1:$proxy_port/api/uploads/$upload_id/chunks/0" >/dev/null

progress_before_restart="$(
    curl -fsS "http://127.0.0.1:$proxy_port/api/uploads/$upload_id"
)"
printf '%s' "$progress_before_restart" | grep -q '"completed_chunks":\[0\]'

kill "$backend_pid"
wait "$backend_pid" 2>/dev/null || true
backend_pid=""
start_backend

progress_after_restart="$(
    curl -fsS "http://127.0.0.1:$proxy_port/api/uploads/$upload_id"
)"
printf '%s' "$progress_after_restart" | grep -q '"completed_chunks":\[0\]'

curl -fsS -X PUT \
    -H "Content-Type: application/octet-stream" \
    --data-binary "@$chunk1" \
    "http://127.0.0.1:$proxy_port/api/uploads/$upload_id/chunks/1" >/dev/null

complete_response="$(
    curl -fsS -X POST "http://127.0.0.1:$proxy_port/api/uploads/$upload_id/complete"
)"
complete_path="$(printf '%s' "$complete_response" | json_field file_path)"

source_hash="$(sha256sum "$source_file" | awk '{print $1}')"
complete_hash="$(sha256sum "$complete_path" | awk '{print $1}')"
curl -fsS "http://127.0.0.1:$proxy_port/files/source.bin" -o "$served_file"
served_hash="$(sha256sum "$served_file" | awk '{print $1}')"

if [[ "$source_hash" != "$complete_hash" ]]; then
    echo "Checksum mismatch after nginx-proxied resume" >&2
    exit 1
fi

if [[ "$source_hash" != "$served_hash" ]]; then
    echo "Checksum mismatch through nginx completed-file alias" >&2
    exit 1
fi

echo "nginx smoke ok: $upload_id"