import { NextRequest, NextResponse } from "next/server";
import { keywordSearch, hybridSearch, semanticSearch } from "@mcpedia/core";

// GET /api/search?q=...&mode=hybrid|keyword|semantic
export async function GET(req: NextRequest) {
  const { searchParams } = new URL(req.url);
  const q = searchParams.get("q") ?? "";
  const mode = searchParams.get("mode") ?? "hybrid";
  const limit = Math.min(Math.max(Number(searchParams.get("limit") ?? 20), 1), 50);

  if (!q.trim()) {
    return NextResponse.json({ results: [] });
  }

  try {
    if (mode === "keyword") {
      const hits = await keywordSearch(q, limit);
      return NextResponse.json({
        results: hits.map((h) => ({
          slug: h.doc.slug,
          title: h.doc.title,
          section: h.doc.section,
          score: h.rank,
          snippet: h.snippet,
        })),
      });
    }

    if (mode === "semantic") {
      const hits = await semanticSearch(q, limit);
      return NextResponse.json({
        results: hits.map((h) => ({
          slug: h.slug,
          title: h.slug.split("/").pop() ?? h.slug,
          section: h.slug.split("/")[0] ?? "docs",
          score: h.score,
          snippet: h.content.slice(0, 160),
        })),
      });
    }

    // Default: hybrid search
    const hits = await hybridSearch(q, limit);
    return NextResponse.json({
      results: hits.map((h) => ({
        slug: h.doc.slug,
        title: h.doc.title,
        section: h.doc.section,
        score: h.rank,
        snippet: h.snippet,
      })),
    });
  } catch (err) {
    console.error("Search API error:", err);
    // Fall back to keyword search if embedding provider fails
    try {
      const hits = await keywordSearch(q, limit);
      return NextResponse.json({
        results: hits.map((h) => ({
          slug: h.doc.slug,
          title: h.doc.title,
          section: h.doc.section,
          score: h.rank,
          snippet: h.snippet,
        })),
      });
    } catch {
      return NextResponse.json({ results: [], error: "Search failed" }, { status: 500 });
    }
  }
}