/**
 * NAS Sync — Fearghas
 *
 * Exports TIP data nightly to the home NAS "Fearghas" via rsync over SSH.
 * Erik reaches Fearghas through the WireGuard tunnel (192.168.178.x).
 *
 * Required environment variables:
 *   NAS_HOST     = 192.168.178.50  (Fearghas IP on home network)
 *   NAS_USER     = tip             (NAS user with write access to share)
 *   NAS_SSH_KEY  = /root/.ssh/id_ed25519  (SSH key for rsync)
 *   NAS_PATH     = /volume1/tip-data      (Synology: /volume1/<share>)
 *
 * Directory layout on NAS:
 *   /volume1/tip-data/
 *     exports/
 *       YYYY-MM-DD/
 *         price_observations.json
 *         switches.json
 *         transceivers.json
 *         market_intelligence.json
 *         reorder_signals.json
 *         product_issues.json
 *         changelog.md
 *     raw-cache/            ← raw HTML from Crawler LLM (future)
 *     db-backups/           ← pg_dump nightly
 *       YYYY-MM-DD.sql.gz
 */

import { exec } from "child_process";
import { promisify } from "util";
import { writeFile, mkdir, rm } from "fs/promises";
import { join } from "path";
import { tmpdir } from "os";
import { db as pool } from "./db";
import { logger } from "./logger";

const execAsync = promisify(exec);

const NAS_HOST    = process.env.NAS_HOST    || "192.168.178.50";
const NAS_USER    = process.env.NAS_USER    || "tip";
const NAS_SSH_KEY = process.env.NAS_SSH_KEY || "/root/.ssh/id_ed25519";
const NAS_PATH    = process.env.NAS_PATH    || "/volume1/tip-data";
const DB_HOST     = process.env.DB_HOST     || "localhost";
const DB_PORT     = process.env.DB_PORT     || "5433";
const DB_USER     = process.env.DB_USER     || "tip";
const DB_NAME     = process.env.DB_NAME     || "transceiver_db";
const DB_PASS     = process.env.DB_PASS     || process.env.PGPASSWORD || "";

// ─────────────────────────────────────────────────────────────────────────────
// Check NAS reachability via WireGuard
// ─────────────────────────────────────────────────────────────────────────────
export async function checkNasReachable(): Promise<boolean> {
  try {
    await execAsync(`ssh -i ${NAS_SSH_KEY} -o ConnectTimeout=5 -o BatchMode=yes -o StrictHostKeyChecking=no ${NAS_USER}@${NAS_HOST} "echo ok"`, { timeout: 8000 });
    return true;
  } catch {
    return false;
  }
}

// ─────────────────────────────────────────────────────────────────────────────
// Export all TIP data tables to JSON files
// ─────────────────────────────────────────────────────────────────────────────
async function exportDataToJson(exportDir: string, date: string): Promise<string[]> {
  const files: string[] = [];

  const exports: Array<{ name: string; query: string }> = [
    {
      name: "price_observations",
      query: `SELECT po.time, t.slug, t.form_factor, t.speed_gbps, v.name AS vendor,
                po.price, po.currency, po.condition, po.marketplace, po.stock_level, po.url
              FROM price_observations po
              JOIN transceivers t ON po.transceiver_id = t.id
              JOIN vendors v ON po.source_vendor_id = v.id
              WHERE po.time > NOW() - INTERVAL '24 hours'
              ORDER BY po.time DESC`,
    },
    {
      name: "transceivers",
      query: `SELECT t.slug, t.form_factor, t.speed, t.speed_gbps, t.reach_label,
                t.fiber_type, t.wavelengths, t.connector, t.power_consumption_w,
                v.name AS vendor, v.type AS vendor_type,
                t.price_verified_eur, t.fully_verified,
                t.image_url, t.product_page_url, t.part_number,
                t.created_at, t.updated_at
              FROM transceivers t JOIN vendors v ON t.vendor_id = v.id
              ORDER BY t.speed_gbps DESC, t.form_factor, t.reach_label`,
    },
    {
      name: "switches",
      query: `SELECT sw.model, sw.series, sw.category, sw.layer,
                v.name AS vendor,
                sw.max_speed_gbps, sw.total_ports, sw.ports_config,
                sw.switching_capacity_tbps, sw.macsec_support,
                sw.vxlan_support, sw.evpn_support, sw.bgp_support,
                sw.lifecycle_status, sw.features, sw.description,
                sw.ebay_refurb_price_usd, sw.image_url, sw.product_page_url
              FROM switches sw JOIN vendors v ON sw.vendor_id = v.id
              ORDER BY sw.max_speed_gbps DESC, sw.model`,
    },
    {
      name: "market_intelligence",
      query: `SELECT source_name, source_url, title, description, category,
                impact_level, buy_signal_effect, confidence, published_date, created_at
              FROM market_intelligence
              ORDER BY created_at DESC
              LIMIT 500`,
    },
    {
      name: "reorder_signals",
      query: `SELECT t.slug, t.form_factor, t.speed_gbps,
                rs.signal, rs.signal_strength, rs.reasons,
                rs.current_asp_eur, rs.price_trend_30d,
                rs.computed_at
              FROM reorder_signals rs
              JOIN transceivers t ON rs.transceiver_id = t.id
              ORDER BY rs.signal_strength DESC`,
    },
    {
      name: "product_issues",
      query: `SELECT pi.product_model, pi.source_type, pi.source_name, pi.source_url,
                pi.title, pi.summary, pi.severity, pi.issue_tags,
                pi.affected_firmware, pi.fix_firmware,
                pi.date_reported, pi.is_resolved
              FROM product_issues pi
              ORDER BY pi.severity, pi.date_reported DESC`,
    },
    {
      name: "abc_classification",
      query: `SELECT t.slug, t.form_factor, t.speed_gbps,
                abc.abc_class, abc.score, abc.obs_90d,
                abc.compat_count, abc.vendor_count, abc.classified_at
              FROM abc_classification abc
              JOIN transceivers t ON abc.transceiver_id = t.id
              ORDER BY abc.score DESC`,
    },
    {
      name: "competitor_alerts",
      query: `SELECT ca.alert_type, ca.severity,
                v.name AS vendor, ca.product_name, ca.form_factor, ca.speed_gbps,
                ca.old_price, ca.new_price, ca.currency, ca.price_delta_pct,
                ca.url, ca.detected_at
              FROM competitor_alerts ca
              JOIN vendors v ON ca.vendor_id = v.id
              WHERE ca.detected_at > NOW() - INTERVAL '7 days'
              ORDER BY ca.detected_at DESC`,
    },
  ];

  for (const exp of exports) {
    try {
      const result = await pool.query(exp.query);
      const filePath = join(exportDir, `${exp.name}.json`);
      await writeFile(filePath, JSON.stringify({
        exported_at: new Date().toISOString(),
        date,
        table: exp.name,
        count: result.rows.length,
        data: result.rows,
      }, null, 2));
      files.push(filePath);
      logger.info(`Exported ${result.rows.length} rows → ${exp.name}.json`);
    } catch (err) {
      logger.warn(`Export failed for ${exp.name}`, { err });
    }
  }

  // Also export changelog
  const changelogSrc = join(process.cwd(), "..", "..", "CHANGELOG_PENDING.md");
  try {
    const { readFile } = await import("fs/promises");
    const changelog = await readFile(changelogSrc, "utf-8");
    const clPath = join(exportDir, "changelog.md");
    await writeFile(clPath, changelog);
    files.push(clPath);
  } catch {
    // Changelog file may not exist in this working directory
  }

  return files;
}

// ─────────────────────────────────────────────────────────────────────────────
// DB Backup via pg_dump
// ─────────────────────────────────────────────────────────────────────────────
async function createDbBackup(backupDir: string, date: string): Promise<string | null> {
  const backupFile = join(backupDir, `transceiver_db_${date}.sql.gz`);
  const cmd = `PGPASSWORD="${DB_PASS}" pg_dump -h ${DB_HOST} -p ${DB_PORT} -U ${DB_USER} ${DB_NAME} | gzip -9 > ${backupFile}`;

  try {
    await execAsync(cmd, { timeout: 300000 }); // 5 min timeout
    logger.info(`DB backup created: ${backupFile}`);
    return backupFile;
  } catch (err) {
    logger.error("DB backup failed", { err });
    return null;
  }
}

// ─────────────────────────────────────────────────────────────────────────────
// Sync local export dir to NAS via rsync over SSH
// ─────────────────────────────────────────────────────────────────────────────
async function rsyncToNas(localDir: string, nasSubPath: string): Promise<boolean> {
  const rsyncCmd = [
    "rsync",
    "-avz",
    "--timeout=60",
    `--rsh="ssh -i ${NAS_SSH_KEY} -o StrictHostKeyChecking=no -o ConnectTimeout=15"`,
    `${localDir}/`,
    `${NAS_USER}@${NAS_HOST}:${NAS_PATH}/${nasSubPath}/`,
  ].join(" ");

  try {
    const { stdout } = await execAsync(rsyncCmd, { timeout: 120000 });
    logger.info("rsync to NAS complete", { lines: stdout.split("\n").length });
    return true;
  } catch (err) {
    logger.error("rsync to NAS failed", { err });
    return false;
  }
}

// ─────────────────────────────────────────────────────────────────────────────
// Main export + sync job — called nightly at 07:30
// ─────────────────────────────────────────────────────────────────────────────
export async function runNightlyNasSync(): Promise<void> {
  const date = new Date().toISOString().split("T")[0]!; // YYYY-MM-DD
  const tmpBase = join(tmpdir(), `tip-nas-export-${date}`);

  logger.info(`NAS sync starting for ${date}`);

  // Check NAS is reachable
  const reachable = await checkNasReachable();
  if (!reachable) {
    logger.warn(`NAS ${NAS_HOST} not reachable via WireGuard — skipping sync`);
    return;
  }

  try {
    // 1. Create temp dirs
    const exportDir = join(tmpBase, "exports", date);
    const backupDir = join(tmpBase, "db-backups");
    await mkdir(exportDir, { recursive: true });
    await mkdir(backupDir, { recursive: true });

    // 2. Export data tables
    await exportDataToJson(exportDir, date);

    // 3. DB backup (every Sunday + 1st of month)
    const now = new Date();
    const isBackupDay = now.getDay() === 0 || now.getDate() === 1;
    if (isBackupDay) {
      await createDbBackup(backupDir, date);
    }

    // 4. Sync exports to NAS
    await rsyncToNas(join(tmpBase, "exports"), "exports");

    // 5. Sync backups if created
    if (isBackupDay) {
      await rsyncToNas(backupDir, "db-backups");
    }

    logger.info(`NAS sync complete for ${date}`);
  } finally {
    // Cleanup temp files
    await rm(tmpBase, { recursive: true, force: true }).catch(() => {});
  }
}

// ─────────────────────────────────────────────────────────────────────────────
// Setup NAS directory structure (run once)
// ─────────────────────────────────────────────────────────────────────────────
export async function setupNasDirectories(): Promise<void> {
  const dirs = ["exports", "db-backups", "raw-cache", "logs"];
  for (const dir of dirs) {
    try {
      await execAsync(
        `ssh -i ${NAS_SSH_KEY} -o StrictHostKeyChecking=no ${NAS_USER}@${NAS_HOST} "mkdir -p ${NAS_PATH}/${dir}"`,
        { timeout: 15000 }
      );
      logger.info(`NAS dir created: ${NAS_PATH}/${dir}`);
    } catch (err) {
      logger.warn(`Failed to create NAS dir ${dir}`, { err });
    }
  }
}