import { NextRequest, NextResponse } from "next/server";
import { z } from "zod";
import { db, chatMessages, eq, and, isNull, desc, asc, ilike } from "@epicure/db";
import { requireSession } from "@/lib/api-auth";

const Schema = z.object({
  recipeId: z.string().uuid().optional(),
  // "general" restricts to the homepage cooking assistant (recipeId null);
  // omit both recipeId and scope to search across everything.
  scope: z.enum(["general"]).optional(),
  q: z.string().max(200).optional(),
  limit: z.coerce.number().int().min(1).max(100).default(30),
});

export async function GET(req: NextRequest) {
  const { session, response } = await requireSession();
  if (response) return response;

  const { searchParams } = new URL(req.url);
  const parsed = Schema.safeParse({
    recipeId: searchParams.get("recipeId") ?? undefined,
    scope: searchParams.get("scope") ?? undefined,
    q: searchParams.get("q") ?? undefined,
    limit: searchParams.get("limit") ?? undefined,
  });
  if (!parsed.success) {
    return NextResponse.json({ error: "Validation error" }, { status: 400 });
  }
  const { recipeId, scope, q, limit } = parsed.data;

  const conditions = [eq(chatMessages.userId, session!.user.id)];
  if (recipeId) conditions.push(eq(chatMessages.recipeId, recipeId));
  else if (scope === "general") conditions.push(isNull(chatMessages.recipeId));
  if (q?.trim()) conditions.push(ilike(chatMessages.content, `%${q.trim()}%`));

  const rows = await db.query.chatMessages.findMany({
    where: and(...conditions),
    orderBy: q?.trim() ? [desc(chatMessages.createdAt)] : [asc(chatMessages.createdAt)],
    limit,
    with: { recipe: { columns: { id: true, title: true } } },
  });

  return NextResponse.json({
    data: rows.map((r) => ({
      id: r.id,
      role: r.role,
      content: r.content,
      createdAt: r.createdAt.toISOString(),
      recipeId: r.recipeId,
      recipeTitle: r.recipe?.title ?? null,
    })),
  });
}

const DeleteSchema = z.object({
  recipeId: z.string().uuid().optional(),
  scope: z.enum(["general"]).optional(),
});

// No `q` here on purpose — clearing is "this whole conversation" (or
// everything), not "every message matching a search term".
export async function DELETE(req: NextRequest) {
  const { session, response } = await requireSession();
  if (response) return response;

  const { searchParams } = new URL(req.url);
  const parsed = DeleteSchema.safeParse({
    recipeId: searchParams.get("recipeId") ?? undefined,
    scope: searchParams.get("scope") ?? undefined,
  });
  if (!parsed.success) {
    return NextResponse.json({ error: "Validation error" }, { status: 400 });
  }
  const { recipeId, scope } = parsed.data;

  const conditions = [eq(chatMessages.userId, session!.user.id)];
  if (recipeId) conditions.push(eq(chatMessages.recipeId, recipeId));
  else if (scope === "general") conditions.push(isNull(chatMessages.recipeId));

  await db.delete(chatMessages).where(and(...conditions));

  return NextResponse.json({ ok: true });
}