import fs from "node:fs/promises";
import path from "node:path";

const baseUrl = process.env.GB32960_BASE_URL || "http://115.29.187.205:20200";
const vin = process.env.GB32960_VIN || "LB9A32A24R0LS1720";
const plate = process.env.GB32960_PLATE || "粤AGP4377";
const exportDate = process.env.GB32960_DATE || "2026-08-17";
const dateFrom = `${exportDate} 00:00:00`;
const dateTo = `${exportDate} 23:59:59`;
const limit = 500;
const outputPath = process.env.GB32960_DATA_PATH || new URL("./raw-frames.json", import.meta.url).pathname;

async function fetchPage(offset, includeTotal = false) {
  const params = new URLSearchParams({
    protocol: "GB32960",
    vin,
    dateFrom,
    dateTo,
    orderBy: "eventTime",
    limit: String(limit),
    offset: String(offset),
    includeFields: "true",
    includePayload: "true",
    includeTotal: includeTotal ? "true" : "false",
  });
  const response = await fetch(`${baseUrl}/api/history/raw-frames?${params}`, {
    headers: { "Accept-Encoding": "gzip" },
    signal: AbortSignal.timeout(60000),
  });
  if (!response.ok) throw new Error(`HTTP ${response.status}: ${await response.text()}`);
  return response.json();
}

const first = await fetchPage(0, true);
const total = Number(first.total ?? 0);
const offsets = [];
for (let offset = limit; offset < total; offset += limit) offsets.push(offset);
const remaining = await Promise.all(offsets.map((offset) => fetchPage(offset)));
const items = [...(first.items ?? []), ...remaining.flatMap((page) => page.items ?? [])];

const frameIds = new Set(items.map((item) => item.frame_id));
const eventIds = new Set(items.map((item) => item.event_id));
const fieldKeys = [...new Set(items.flatMap((item) => Object.keys(item.parsed_fields ?? {})))].sort();
const messageCounts = Object.fromEntries(
  [...items.reduce((map, item) => map.set(item.message_id_hex, (map.get(item.message_id_hex) ?? 0) + 1), new Map())]
    .sort(([a], [b]) => a.localeCompare(b)),
);

if (items.length !== total) throw new Error(`row count mismatch: fetched=${items.length} total=${total}`);
if (frameIds.size !== items.length) throw new Error(`duplicate frame_id: unique=${frameIds.size} rows=${items.length}`);
if (eventIds.size !== items.length) throw new Error(`duplicate event_id: unique=${eventIds.size} rows=${items.length}`);
for (const item of items) {
  if (item.protocol !== "GB32960" || item.vin !== vin) throw new Error(`scope mismatch at ${item.frame_id}`);
  if (item.ts < dateFrom || item.ts > dateTo) throw new Error(`time out of range at ${item.frame_id}: ${item.ts}`);
}

const output = {
  exportedAt: new Date().toISOString(),
  source: `${baseUrl}/api/history/raw-frames`,
  query: { plate, vin, protocol: "GB32960", dateFrom, dateTo, orderBy: "eventTime" },
  verification: {
    apiTotal: total,
    fetchedRows: items.length,
    uniqueFrameIds: frameIds.size,
    uniqueEventIds: eventIds.size,
    earliestTs: items.reduce((min, item) => !min || item.ts < min ? item.ts : min, ""),
    latestTs: items.reduce((max, item) => !max || item.ts > max ? item.ts : max, ""),
    parsedFieldCount: fieldKeys.length,
    messageCounts,
  },
  fieldKeys,
  items,
};

await fs.mkdir(path.dirname(outputPath), { recursive: true });
await fs.writeFile(outputPath, JSON.stringify(output), "utf8");
console.log(JSON.stringify({ outputPath, ...output.verification }, null, 2));