import { NextRequest, NextResponse } from "next/server";
import { prisma } from "@/lib/db";
import { Prisma } from "@prisma/client";

export async function GET(req: NextRequest) {
  try {
    const { searchParams } = new URL(req.url);

    const page = Math.max(1, Number(searchParams.get("page") || 1));
    const perPage = Math.min(100, Math.max(10, Number(searchParams.get("perPage") || 50)));
    const search = searchParams.get("search") || "";
    const sortBy = searchParams.get("sortBy") || "capturedAt";
    const sortDir = (searchParams.get("sortDir") || "desc") as "asc" | "desc";
    const hasEmail = searchParams.get("hasEmail"); // "yes" | "no" | null
    const capturedFrom = searchParams.get("capturedFrom");
    const capturedTo = searchParams.get("capturedTo");

    const statuses = searchParams.getAll("status");
    const sourceTabs = searchParams.getAll("sourceTab");
    const priorities = searchParams.getAll("priority");
    const tags = searchParams.getAll("tags");
    const searchTerms = searchParams.getAll("searchTerm");
    const contacted = searchParams.get("contacted");
    const favorite = searchParams.get("favorite");

    const where: Prisma.LeadWhereInput = {};

    if (search) {
      where.OR = [
        { domain: { contains: search } },
        { companyName: { contains: search } },
        { contactName: { contains: search } },
        { email: { contains: search } },
        { notes: { contains: search } },
        { sourceTerm: { contains: search } },
      ];
    }

    if (statuses.length > 0) where.status = { in: statuses };
    if (sourceTabs.length > 0) where.sourceTab = { in: sourceTabs };
    if (priorities.length > 0) where.priority = { in: priorities };

    if (hasEmail === "yes") where.email = { not: null };
    else if (hasEmail === "no") where.email = null;

    if (capturedFrom || capturedTo) {
      where.capturedAt = {};
      if (capturedFrom) where.capturedAt.gte = new Date(capturedFrom);
      if (capturedTo) where.capturedAt.lte = new Date(capturedTo);
    }

    if (searchTerms.length > 0) {
      where.sourceTerm = { in: searchTerms };
    }

    if (contacted === "yes") {
      where.tags = { contains: "kontaktiert" };
    }

    if (favorite === "yes") {
      where.tags = { contains: "favorit" };
    }

    if (tags.length > 0) {
      // SQLite JSON contains — search for each tag in the JSON string
      where.AND = tags.map(tag => ({
        tags: { contains: tag },
      }));
    }

    const validSortFields: Record<string, boolean> = {
      capturedAt: true, status: true, priority: true, companyName: true,
      domain: true, email: true, contactName: true,
    };
    const orderByField = validSortFields[sortBy] ? sortBy : "capturedAt";

    const [total, leads] = await Promise.all([
      prisma.lead.count({ where }),
      prisma.lead.findMany({
        where,
        orderBy: { [orderByField]: sortDir },
        skip: (page - 1) * perPage,
        take: perPage,
      }),
    ]);

    return NextResponse.json({
      leads,
      total,
      page,
      pages: Math.ceil(total / perPage),
      perPage,
    });
  } catch (err) {
    console.error("GET /api/leads error:", err);
    return NextResponse.json({ error: "Failed to fetch leads" }, { status: 500 });
  }
}