import { cookies } from "next/headers";
import { redirect } from "next/navigation";
import { Suspense } from "react";
import { ClassicChatStart } from "@/components/classic-chat-start";
import { isVideoModelDescriptor } from "@/lib/ai/model-classification";
import { isAiModelAgentAuto } from "@/lib/db/ai-model-flags";
import {
  getDefaultAiModel,
  getEnabledAiModelsWithProvider,
  getUserById,
} from "@/lib/db/queries";
import { generateUUID } from "@/lib/utils";
import { auth } from "../../(auth)/auth";

function isNanoBananaProModel(model: {
  displayName?: string | null;
  modelId?: string | null;
}) {
  const displayName = String(model.displayName || "").toLowerCase();
  const modelId = String(model.modelId || "").toLowerCase();
  return (
    displayName.includes("nano banana pro") ||
    displayName.includes("nano-banana-pro") ||
    modelId.includes("nano-banana-pro") ||
    modelId.includes("nano_banana_pro") ||
    modelId.includes("nano-banana")
  );
}

export default function ClassicPage() {
  return (
    <Suspense fallback={<div className="flex h-dvh" />}>
      <ClassicChatPage />
    </Suspense>
  );
}

async function ClassicChatPage() {
  const id = generateUUID();
  const [session, cookieStore] = await Promise.all([auth(), cookies()]);

  if (!session?.user) {
    redirect("/login");
  }

  const modelIdFromCookie = cookieStore.get("chat-model");
  let initialModelId = modelIdFromCookie?.value;
  const currentUser = session.user.id
    ? await getUserById({ id: session.user.id }).catch(() => undefined)
    : undefined;
  const allowHiddenModels =
    session.user.type === "admin" || Boolean(currentUser?.isHighVip);
  const defaultModel = await getDefaultAiModel();
  const enabledModels = await getEnabledAiModelsWithProvider(false, true);
  const visibleModels = enabledModels.filter(
    ({ model }) =>
      !isAiModelAgentAuto(model) && (allowHiddenModels || !model.isHidden)
  );
  const preferredImageModels = visibleModels.filter(
    ({ model, provider }) =>
      model.supportsImageGen &&
      !isVideoModelDescriptor({
        providerType: provider.type,
        modelId: model.modelId,
        capabilities: model.capabilities,
        supportsImageGen: model.supportsImageGen,
      })
  );
  const nanoBananaModel = preferredImageModels.find(({ model }) =>
    isNanoBananaProModel(model)
  );
  const cookieModel = initialModelId
    ? visibleModels.find(({ model }) => model.id === initialModelId)
    : undefined;

  if (!initialModelId || !cookieModel) {
    if (nanoBananaModel) {
      initialModelId = nanoBananaModel.model.id;
    } else if (
      defaultModel &&
      !isAiModelAgentAuto(defaultModel) &&
      (allowHiddenModels || !defaultModel.isHidden) &&
      preferredImageModels.some(({ model }) => model.id === defaultModel.id)
    ) {
      initialModelId = defaultModel.id;
    } else if (preferredImageModels.length > 0) {
      const preferredDefaultImageModel = preferredImageModels.find(
        ({ model }) => model.isDefault
      );
      initialModelId = (preferredDefaultImageModel || preferredImageModels[0])
        .model.id;
    } else if (
      defaultModel &&
      !isAiModelAgentAuto(defaultModel) &&
      (allowHiddenModels || !defaultModel.isHidden)
    ) {
      initialModelId = defaultModel.id;
    } else if (visibleModels.length > 0) {
      initialModelId = visibleModels[0].model.id;
    }
  }

  return (
    <ClassicChatStart
      id={id}
      initialModelId={initialModelId || ""}
      userType={session.user.type}
    />
  );
}