/**
 * Inter-Carrier Compensation (ICC) revenue import API.
 *
 * Customer-facing endpoints for uploading carrier invoice files (CABS BOS,
 * EDI 810, iconectiv 8YY, international settlement, wholesale SIP CSV) +
 * reading back the parsed revenue summary. Parsing is done asynchronously
 * by scripts/workers/icc_ingester.py polling `icc_ingestion_uploads
 * WHERE status='pending'`.
 *
 * Mirrors the CDR ingestion pattern (migration 050) — pre-signed MinIO PUT,
 * ingester worker parses, rows land in icc_revenue_lines, deduped by
 * natural_key_hash.
 */

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

const router = Router();

const WORKER_URL = process.env.WORKER_URL || "http://workers:8090";

/** Ask the worker for a presigned MinIO PUT URL. Returns null on failure. */
async function presignPut(key: string, expires = 24 * 3600): Promise<string | null> {
  try {
    const r = await fetch(`${WORKER_URL}/jobs/presign`, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ key, expires, method: "PUT" }),
    });
    if (!r.ok) return null;
    const data = (await r.json()) as { url?: string };
    return data.url || null;
  } catch {
    return null;
  }
}

// ── Helpers ─────────────────────────────────────────────────────────────

async function loadProfile(profileId: number) {
  const r = await pool.query(
    `SELECT * FROM cdr_ingestion_profiles WHERE id = $1`,
    [profileId],
  );
  return r.rows[0] || null;
}

function detectFormatByExtension(fileName: string): string | null {
  const f = fileName.toLowerCase();
  if (f.endsWith(".bos") || f.endsWith(".bos.gz")) return "cabs_bos";
  if (f.endsWith(".810") || f.endsWith(".edi") || f.endsWith(".x12")) return "edi_810";
  if (f.endsWith(".qry") || (f.endsWith(".xml") && f.includes("8yy"))) return "8yy_qry";
  if (f.endsWith(".tas")) return "itu_tas";
  if (f.endsWith(".icss")) return "icss";
  if (f.endsWith(".csv")) return "wholesale_sip_csv";
  if (f.endsWith(".pdf")) return "carrier_invoice_pdf";
  return null;
}

// ── POST /api/v1/icc/upload-token ──────────────────────────────────────
//
// Returns a presigned MinIO PUT URL + token. The portal PUTs the file
// directly to MinIO, then the ingester picks it up from
// `icc_ingestion_uploads WHERE status='pending'`.
router.post("/api/v1/icc/upload-token", async (req: Request, res: Response) => {
  const { profile_id, file_name, source_format } = req.body ?? {};
  if (!profile_id || !file_name) {
    res.status(400).json({ error: "profile_id and file_name required" });
    return;
  }
  const profile = await loadProfile(Number(profile_id));
  if (!profile) { res.status(404).json({ error: "profile not found" }); return; }

  const detected = source_format || detectFormatByExtension(String(file_name));
  if (!detected) {
    res.status(400).json({
      error: "unable to detect source format; supply source_format explicitly",
    });
    return;
  }

  const token = randomBytes(16).toString("hex");
  const safeName = String(file_name).replace(/[^A-Za-z0-9._-]/g, "_");
  const minioKey =
    `icc-uploads/${profile.customer_id}/raw/` +
    `${new Date().toISOString().replace(/[:.]/g, "")}_${token}_${safeName}`;

  // Placeholder sha256 until the ingester reads the uploaded file; uniqueness
  // constraint enforces dedup then.
  const placeholder = createHash("sha256")
    .update(`${profile.id}_${token}_${safeName}`).digest("hex");

  const insert = await pool.query(
    `INSERT INTO icc_ingestion_uploads
         (profile_id, customer_id, source_format, raw_minio_path, raw_sha256,
          status, summary_json)
     VALUES ($1, $2, $3, $4, $5, 'pending', $6::jsonb)
     RETURNING id`,
    [profile.id, profile.customer_id, detected, minioKey, placeholder,
     JSON.stringify({ token, file_name: safeName, submitted_at: new Date().toISOString() })],
  );

  const minioPutUrl = await presignPut(minioKey, 24 * 3600);

  res.status(201).json({
    upload_id: insert.rows[0].id,
    token,
    minio_key: minioKey,
    minio_put_url: minioPutUrl,
    source_format: detected,
    expires_in_seconds: 24 * 3600,
  });
});

// ── GET /api/v1/icc/profile/:id/uploads ────────────────────────────────
//
// List uploads for a profile with parse status + row counts.
router.get(
  "/api/v1/icc/profile/:profile_id/uploads",
  async (req: Request, res: Response) => {
    const profileId = Number(req.params.profile_id);
    if (!Number.isFinite(profileId)) {
      res.status(400).json({ error: "bad profile_id" }); return;
    }
    const r = await pool.query(
      `SELECT id, source_format, status, rows_accepted, rows_rejected,
              error_message, created_at, parsed_at, summary_json
         FROM icc_ingestion_uploads
        WHERE profile_id = $1
        ORDER BY created_at DESC
        LIMIT 100`,
      [profileId],
    );
    res.json({ uploads: r.rows });
  },
);

// ── GET /api/v1/icc/profile/:id/summary?year=YYYY ──────────────────────
//
// Aggregate parsed revenue lines by icc_category for the given reporting
// year, and map to the corresponding Form 499-A lines via
// icc_499a_line_mapping. Used by RevenueStep.astro to pre-fill Lines 404,
// 404.1, 404.3, and 418.
router.get(
  "/api/v1/icc/profile/:profile_id/summary",
  async (req: Request, res: Response) => {
    const profileId = Number(req.params.profile_id);
    const year = Number(req.query.year) || new Date().getUTCFullYear() - 1;
    if (!Number.isFinite(profileId)) {
      res.status(400).json({ error: "bad profile_id" }); return;
    }
    const r = await pool.query(
      `SELECT icc.icc_category,
              m.form_499a_line,
              m.jurisdiction_split,
              SUM(icc.revenue_cents)::bigint   AS revenue_cents,
              COALESCE(SUM(icc.minutes_of_use), 0)::bigint AS minutes_of_use,
              COUNT(*)::int                    AS line_count
         FROM icc_revenue_lines icc
         JOIN icc_499a_line_mapping m ON m.icc_category = icc.icc_category
        WHERE icc.profile_id     = $1
          AND icc.reporting_year = $2
        GROUP BY icc.icc_category, m.form_499a_line, m.jurisdiction_split
        ORDER BY revenue_cents DESC`,
      [profileId, year],
    );

    // Aggregate by 499-A line for the "pre-fill Line 404 with $X" summary
    const byLine: Record<string, { revenue_cents: number; minutes: number }> = {};
    for (const row of r.rows) {
      const line = row.form_499a_line;
      byLine[line] ||= { revenue_cents: 0, minutes: 0 };
      byLine[line].revenue_cents += Number(row.revenue_cents);
      byLine[line].minutes       += Number(row.minutes_of_use);
    }

    res.json({
      reporting_year: year,
      categories: r.rows.map((row) => ({
        icc_category:      row.icc_category,
        form_499a_line:    row.form_499a_line,
        jurisdiction_split: row.jurisdiction_split,
        revenue_cents:     Number(row.revenue_cents),
        minutes_of_use:    Number(row.minutes_of_use),
        line_count:        row.line_count,
      })),
      by_form_line: byLine,
      grand_total_cents:
        r.rows.reduce((acc, row) => acc + Number(row.revenue_cents), 0),
    });
  },
);

// ── POST /api/v1/icc/profile/:id/reparse/:upload_id ────────────────────
//
// Admin-only: re-run the adapter on an already-uploaded file (e.g.,
// adapter bug was fixed). Flips the upload back to pending; the ingester
// picks it up on next poll. Authorization is the admin header used by
// the rest of the admin endpoints.
router.post(
  "/api/v1/icc/profile/:profile_id/reparse/:upload_id",
  async (req: Request, res: Response) => {
    const adminToken = (req.headers["x-admin-token"] || "").toString();
    if (!process.env.ADMIN_API_TOKEN || adminToken !== process.env.ADMIN_API_TOKEN) {
      res.status(403).json({ error: "admin token required" }); return;
    }
    const profileId = Number(req.params.profile_id);
    const uploadId = Number(req.params.upload_id);

    // Delete already-parsed rows for this upload so reparse is idempotent
    await pool.query(
      `DELETE FROM icc_revenue_lines WHERE source_upload_id = $1`,
      [uploadId],
    );
    const r = await pool.query(
      `UPDATE icc_ingestion_uploads
          SET status = 'pending',
              error_message = NULL,
              rows_accepted = 0,
              rows_rejected = 0,
              parsed_at = NULL
        WHERE id = $1 AND profile_id = $2
        RETURNING id`,
      [uploadId, profileId],
    );
    if (r.rows.length === 0) {
      res.status(404).json({ error: "upload not found" }); return;
    }
    res.json({ ok: true, upload_id: uploadId, status: "pending" });
  },
);

// ── GET /api/v1/icc/profile/:id/revenue-lines ──────────────────────────
//
// Paginated list of parsed ICC revenue lines. Used by the admin panel to
// audit individual invoice rows.
router.get(
  "/api/v1/icc/profile/:profile_id/revenue-lines",
  async (req: Request, res: Response) => {
    const profileId = Number(req.params.profile_id);
    const year = Number(req.query.year) || new Date().getUTCFullYear() - 1;
    const category = (req.query.icc_category as string) || null;
    const limit = Math.min(Number(req.query.limit) || 100, 500);
    const offset = Math.max(Number(req.query.offset) || 0, 0);

    const conditions = ["profile_id = $1", "reporting_year = $2"];
    const params: (number | string)[] = [profileId, year];
    if (category) {
      conditions.push(`icc_category = $${params.length + 1}`);
      params.push(category);
    }
    params.push(limit, offset);

    const r = await pool.query(
      `SELECT id, reporting_quarter, icc_category, counterparty_legal_name,
              counterparty_ocn, counterparty_country, revenue_cents,
              minutes_of_use, source_upload_id, source_line_no, created_at
         FROM icc_revenue_lines
        WHERE ${conditions.join(" AND ")}
        ORDER BY created_at DESC, id DESC
        LIMIT $${params.length - 1} OFFSET $${params.length}`,
      params,
    );
    res.json({ lines: r.rows, limit, offset });
  },
);

export default router;