/**
 * Order timeline estimator — shows step names + estimated completion dates.
 *
 * GET /api/v1/order-timeline/:order_id
 *
 * Returns a timeline of steps with estimated business-day completion dates,
 * skipping weekends and US federal holidays.
 */

import { Router, type Request, type Response } from "express";
import { pool } from "../db.js";

const router = Router();

// US Federal Holidays — hardcoded for 2026-2027 (matches scripts/workers/business_days.py)
const US_HOLIDAYS = new Set([
  "2026-01-01","2026-01-19","2026-02-16","2026-05-25","2026-07-03",
  "2026-09-07","2026-10-12","2026-11-11","2026-11-26","2026-12-25",
  "2027-01-01","2027-01-18","2027-02-15","2027-05-31","2027-07-05",
  "2027-09-06","2027-10-11","2027-11-11","2027-11-25","2027-12-25",
]);

function addBusinessDays(start: Date, days: number): Date {
  if (days === 0) return new Date(start);
  const result = new Date(start);
  let added = 0;
  while (added < days) {
    result.setDate(result.getDate() + 1);
    const dow = result.getDay();
    const dateStr = result.toISOString().split("T")[0];
    if (dow !== 0 && dow !== 6 && !US_HOLIDAYS.has(dateStr)) {
      added++;
    }
  }
  return result;
}

// Service-specific step definitions with business day estimates
interface TimelineStep {
  name: string;
  description: string;
  business_days: number; // days from order start
  status: "pending" | "in_progress" | "completed";
}

const SERVICE_TIMELINES: Record<string, TimelineStep[]> = {
  "mcs150-update": [
    { name: "Order Received", description: "Payment confirmed, order in queue", business_days: 0, status: "completed" },
    { name: "Document Preparation", description: "Filling official MCS-150 form with your information", business_days: 1, status: "pending" },
    { name: "E-Sign Required", description: "Review and sign the perjury declaration", business_days: 1, status: "pending" },
    { name: "Filed with FMCSA", description: "Submitted electronically to FMCSA", business_days: 2, status: "pending" },
    { name: "Certificate of Filing", description: "Attestation document delivered to you", business_days: 2, status: "pending" },
    { name: "FMCSA Confirmation", description: "FMCSA processes and reflects update (5-10 business days)", business_days: 10, status: "pending" },
  ],
  "boc3-filing": [
    { name: "Order Received", description: "Payment confirmed", business_days: 0, status: "completed" },
    { name: "Process Agent Filing", description: "Filing BOC-3 with Registered Agents Inc", business_days: 1, status: "pending" },
    { name: "FMCSA Registration", description: "BOC-3 on file with FMCSA", business_days: 3, status: "pending" },
  ],
  "ucr-registration": [
    { name: "Order Received", description: "Payment confirmed", business_days: 0, status: "completed" },
    { name: "UCR Filing", description: "Registering with Unified Carrier Registration", business_days: 2, status: "pending" },
    { name: "Confirmation", description: "UCR registration receipt delivered", business_days: 3, status: "pending" },
  ],
  "dot-registration": [
    { name: "Order Received", description: "Payment confirmed", business_days: 0, status: "completed" },
    { name: "Application Preparation", description: "Preparing USDOT application", business_days: 1, status: "pending" },
    { name: "Filed with FMCSA", description: "Application submitted to FMCSA", business_days: 2, status: "pending" },
    { name: "USDOT Issued", description: "FMCSA issues your USDOT number", business_days: 5, status: "pending" },
  ],
  "mc-authority": [
    { name: "Order Received", description: "Payment confirmed", business_days: 0, status: "completed" },
    { name: "Application Filed", description: "Operating authority application submitted", business_days: 2, status: "pending" },
    { name: "Insurance Filing Required", description: "Insurance must be on file before authority activates", business_days: 5, status: "pending" },
    { name: "Authority Active", description: "Operating authority becomes active", business_days: 15, status: "pending" },
  ],
  "dot-drug-alcohol": [
    { name: "Order Received", description: "Payment confirmed", business_days: 0, status: "completed" },
    { name: "Program Setup", description: "Enrolling in DOT-compliant D&A testing program", business_days: 2, status: "pending" },
    { name: "Materials Delivered", description: "Policy manual and enrollment confirmation", business_days: 3, status: "pending" },
  ],
  "usdot-reactivation": [
    { name: "Order Received", description: "Payment confirmed", business_days: 0, status: "completed" },
    { name: "Reactivation Filed", description: "Request submitted to FMCSA", business_days: 1, status: "pending" },
    { name: "USDOT Reactivated", description: "FMCSA reactivates your USDOT number", business_days: 5, status: "pending" },
  ],
  "emergency-temporary-authority": [
    { name: "Order Received", description: "Payment confirmed — PRIORITY processing", business_days: 0, status: "completed" },
    { name: "ETA Filed", description: "Emergency request submitted to FMCSA", business_days: 0, status: "pending" },
    { name: "FMCSA Response", description: "Awaiting FMCSA emergency authorization", business_days: 2, status: "pending" },
  ],
  "entity-upgrade-bundle": [
    { name: "Order Received", description: "Payment confirmed", business_days: 0, status: "completed" },
    { name: "LLC Formation", description: "Filing LLC in your chosen state", business_days: 3, status: "pending" },
    { name: "EIN Application", description: "Applying for employer ID number with IRS", business_days: 4, status: "pending" },
    { name: "MCS-150 Update", description: "Updating FMCSA registration with new entity", business_days: 5, status: "pending" },
    { name: "Authority Transfer", description: "Transferring operating authority to new entity", business_days: 7, status: "pending" },
    { name: "BOC-3 Update", description: "Updating process agent filing", business_days: 8, status: "pending" },
    { name: "Complete", description: "All filings updated under your new entity", business_days: 10, status: "pending" },
  ],
};

// Default timeline for services without a specific definition
const DEFAULT_TIMELINE: TimelineStep[] = [
  { name: "Order Received", description: "Payment confirmed, order in queue", business_days: 0, status: "completed" },
  { name: "Processing", description: "Our team is working on your filing", business_days: 2, status: "pending" },
  { name: "Complete", description: "Filing completed and delivered", business_days: 5, status: "pending" },
];

router.get("/api/v1/order-timeline/:order_id", async (req: Request, res: Response) => {
  try {
    const orderId = req.params.order_id;

    // Try single order first, then batch
    let orders: Record<string, unknown>[] = [];
    const single = await pool.query(
      "SELECT order_number, service_slug, service_name, created_at, payment_status FROM compliance_orders WHERE order_number = $1",
      [orderId],
    );
    if (single.rows.length > 0) {
      orders = single.rows as Record<string, unknown>[];
    } else {
      // Try as batch_id
      const batch = await pool.query(
        "SELECT order_number, service_slug, service_name, created_at, payment_status FROM compliance_orders WHERE batch_id = $1 ORDER BY created_at",
        [orderId],
      );
      orders = batch.rows as Record<string, unknown>[];
    }

    if (orders.length === 0) {
      res.status(404).json({ error: "Order not found." });
      return;
    }

    const timelines = orders.map((order) => {
      const slug = order.service_slug as string;
      const startDate = new Date(order.created_at as string);
      const steps = (SERVICE_TIMELINES[slug] || DEFAULT_TIMELINE).map((step) => ({
        ...step,
        estimated_date: addBusinessDays(startDate, step.business_days).toISOString().split("T")[0],
      }));

      return {
        order_number: order.order_number,
        service_slug: slug,
        service_name: order.service_name,
        steps,
        estimated_completion: steps[steps.length - 1].estimated_date,
      };
    });

    res.json({ timelines });
  } catch (err) {
    console.error("[timeline] Error:", err);
    res.status(500).json({ error: "Could not generate timeline." });
  }
});

export default router;