import { NextRequest, NextResponse } from "next/server";
import { z } from "zod";
import { getSupabaseServerClient } from "@/lib/supabase/server";
import { getSupabaseAdminClient } from "@/lib/supabase/admin";
import { groupNameSchema } from "@/lib/groups/validation";
import { deleteGroupAndData } from "@/lib/groups/delete-group";

const renameSchema = z.object({ name: groupNameSchema });

/** GET /api/groups/[id] — Get group details */
export async function GET(request: NextRequest, { params }: { params: Promise<{ id: string }> }) {
  try {
    const { id } = await params;
    const supabase = await getSupabaseServerClient();
    const {
      data: { user },
    } = await supabase.auth.getUser();

    if (!user) {
      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
    }

    const admin = getSupabaseAdminClient();

    const [{ data: membership }, { data: group, error }] = await Promise.all([
      admin
        .from("group_members")
        .select("role")
        .eq("group_id", id)
        .eq("user_id", user.id)
        .maybeSingle(),
      admin.from("groups").select("*").eq("id", id).single(),
    ]);

    if (!membership) {
      return NextResponse.json({ error: "Not a member of this group" }, { status: 403 });
    }

    if (error || !group) {
      return NextResponse.json({ error: "Group not found" }, { status: 404 });
    }

    return NextResponse.json({ group, role: membership.role });
  } catch {
    return NextResponse.json({ error: "Internal server error" }, { status: 500 });
  }
}

/** PATCH /api/groups/[id] — Rename group (admin only) */
export async function PATCH(request: NextRequest, { params }: { params: Promise<{ id: string }> }) {
  try {
    const { id } = await params;
    const supabase = await getSupabaseServerClient();
    const {
      data: { user },
    } = await supabase.auth.getUser();

    if (!user) {
      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
    }

    const admin = getSupabaseAdminClient();

    const { data: membership } = await admin
      .from("group_members")
      .select("role")
      .eq("group_id", id)
      .eq("user_id", user.id)
      .maybeSingle();

    if (!membership || membership.role !== "admin") {
      return NextResponse.json({ error: "Admin access required" }, { status: 403 });
    }

    const body = await request.json();
    const parsed = renameSchema.safeParse(body);

    if (!parsed.success) {
      return NextResponse.json({ error: parsed.error.issues[0].message }, { status: 400 });
    }

    const { data: group, error } = await admin
      .from("groups")
      .update({ name: parsed.data.name })
      .eq("id", id)
      .select()
      .single();

    if (error || !group) {
      return NextResponse.json({ error: "Failed to rename group" }, { status: 500 });
    }

    return NextResponse.json({ group });
  } catch {
    return NextResponse.json({ error: "Internal server error" }, { status: 500 });
  }
}

/** DELETE /api/groups/[id] — Delete group (admin only) */
export async function DELETE(
  _request: NextRequest,
  { params }: { params: Promise<{ id: string }> },
) {
  try {
    const { id } = await params;
    const supabase = await getSupabaseServerClient();
    const {
      data: { user },
    } = await supabase.auth.getUser();

    if (!user) {
      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
    }

    const admin = getSupabaseAdminClient();

    const { data: membership } = await admin
      .from("group_members")
      .select("role")
      .eq("group_id", id)
      .eq("user_id", user.id)
      .maybeSingle();

    if (!membership || membership.role !== "admin") {
      return NextResponse.json({ error: "Admin access required" }, { status: 403 });
    }

    await deleteGroupAndData(id);

    return NextResponse.json({ success: true });
  } catch {
    return NextResponse.json({ error: "Internal server error" }, { status: 500 });
  }
}