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

export const newsRouter = Router();

// GET /api/news?page=1&limit=10&category=&source=
newsRouter.get("/", async (req: Request, res: Response) => {
  try {
    const page   = Math.max(1, parseInt(String(req.query.page  || "1"),  10));
    const limit  = Math.min(50, Math.max(1, parseInt(String(req.query.limit || "10"), 10)));
    const offset = (page - 1) * limit;
    const category = req.query.category ? String(req.query.category) : null;
    const source   = req.query.source   ? String(req.query.source)   : null;

    const conditions: string[] = [];
    const values: unknown[]    = [];
    let idx = 1;

    if (category) { conditions.push(`category = $${idx++}`); values.push(category); }
    if (source)   { conditions.push(`source ILIKE $${idx++}`); values.push(`%${source}%`); }

    const where = conditions.length ? `WHERE ${conditions.join(" AND ")}` : "";

    const countRes = await pool.query(
      `SELECT COUNT(*) AS total FROM news_articles ${where}`,
      values
    );
    const total = parseInt(countRes.rows[0].total, 10);

    const rows = await pool.query(
      `SELECT id, title, summary, source, source_url, published_at,
              category, relevance_score, tags, content_hash
       FROM   news_articles
       ${where}
       ORDER  BY published_at DESC NULLS LAST
       LIMIT  $${idx} OFFSET $${idx + 1}`,
      [...values, limit, offset]
    );

    // distinct categories for filter UI
    const catRes = await pool.query(
      "SELECT DISTINCT category FROM news_articles WHERE category IS NOT NULL ORDER BY category"
    ) as { rows: { category: string }[] };

    res.json({
      success:    true,
      articles:   rows.rows,
      total,
      page,
      limit,
      pages:      Math.ceil(total / limit),
      categories: catRes.rows.map((r) => r.category),
    });
  } catch (err) {
    console.error("News route error:", err);
    res.status(500).json({ success: false, error: "Internal server error" });
  }
});