#!/usr/bin/env node
/**
 * Retime all chart JSON files under mocks/device-cgi-simulator/chartsData (recursively).
 * For any JSON array where elements contain a 't' timestamp string in format 'YYYY-MM-DD HH:mm:ss',
 * rebase timestamps so the first element's time-of-day is preserved but moved to today's date,
 * and all other elements keep their original relative deltas.
 *
 * Usage:
 *   node ./mocks/scripts/retimeAllCharts.mjs [baseDir]
 *   Default baseDir: mocks/device-cgi-simulator/chartsData
 */

import fs from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const workspaceRoot = path.resolve(__dirname, "../..");

function pad(n) {
  return String(n).padStart(2, "0");
}

function formatDate(d) {
  const yyyy = d.getFullYear();
  const MM = pad(d.getMonth() + 1);
  const dd = pad(d.getDate());
  const hh = pad(d.getHours());
  const mm = pad(d.getMinutes());
  const ss = pad(d.getSeconds());
  return `${yyyy}-${MM}-${dd} ${hh}:${mm}:${ss}`;
}

function parseDateTime(str) {
  const m =
    typeof str === "string" &&
    str.match(/(\d{4})-(\d{2})-(\d{2})\s+(\d{2}):(\d{2}):(\d{2})/);
  if (!m) return null;
  const [, y, mo, d, h, mi, s] = m.map(Number);
  return new Date(y, mo - 1, d, h, mi, s, 0);
}

function withTodayDateAndTimeOf(baseTime) {
  const today = new Date();
  return new Date(
    today.getFullYear(),
    today.getMonth(),
    today.getDate(),
    baseTime.getHours(),
    baseTime.getMinutes(),
    baseTime.getSeconds(),
    0
  );
}

async function readJson(filePath) {
  const raw = await fs.readFile(filePath, "utf-8");
  return JSON.parse(raw);
}

async function writeJson(filePath, data) {
  const content = JSON.stringify(data, null, 2);
  await fs.writeFile(filePath, content + "\n", "utf-8");
}

async function retimeArrayWithT(arr) {
  // Find first element with parsable 't'
  let idx0 = -1;
  let t0 = null;
  for (let i = 0; i < arr.length; i++) {
    const t = arr[i]?.t;
    const d = parseDateTime(t);
    if (d) {
      idx0 = i;
      t0 = d;
      break;
    }
  }
  if (idx0 === -1) return null; // nothing to retime

  const newBase = withTodayDateAndTimeOf(t0);
  const t0ms = t0.getTime();

  const updated = arr.map((item) => {
    if (!item || typeof item !== "object") return item;
    if (!("t" in item)) return item;
    const d = parseDateTime(item.t);
    if (!d) return item;
    const delta = t0ms - d.getTime();
    const newDate = new Date(newBase.getTime() - delta);
    return { ...item, t: formatDate(newDate) };
  });

  return updated;
}

async function processJsonFile(filePath) {
  try {
    const data = await readJson(filePath);
    if (!Array.isArray(data) || data.length === 0) {
      return { status: "skip", reason: "not an array or empty" };
    }

    const updated = await retimeArrayWithT(data);
    if (!updated) {
      return { status: "skip", reason: "no parsable t fields" };
    }

    await writeJson(filePath, updated);
    return { status: "ok" };
  } catch (e) {
    return { status: "error", message: e.message };
  }
}

async function walk(dir, visitor) {
  const entries = await fs.readdir(dir, { withFileTypes: true });
  for (const entry of entries) {
    const p = path.join(dir, entry.name);
    if (entry.isDirectory()) {
      await walk(p, visitor);
    } else if (entry.isFile() && p.toLowerCase().endsWith(".json")) {
      await visitor(p);
    }
  }
}

async function main() {
  const baseArg = process.argv[2];
  const baseDir = path.resolve(
    workspaceRoot,
    baseArg || "mocks/device-cgi-simulator/chartsData"
  );

  let ok = 0,
    skipped = 0,
    errors = 0;
  const rel = (p) => path.relative(workspaceRoot, p) || p;

  try {
    await walk(baseDir, async (file) => {
      const res = await processJsonFile(file);
      if (res.status === "ok") {
        ok++;
        console.log(`[ok] Updated ${rel(file)}`);
      } else if (res.status === "skip") {
        skipped++;
        console.log(`[skip] ${rel(file)}: ${res.reason}`);
      } else {
        errors++;
        console.log(`[error] ${rel(file)}: ${res.message}`);
      }
    });
  } catch (err) {
    console.error("Failed to retime charts:", err);
    process.exitCode = 1;
    return;
  }

  console.log(`\nDone. ok=${ok}, skipped=${skipped}, errors=${errors}`);
}

await main();