import { auth } from "@/app/(auth)/auth";
import {
  getAgentAiModelWithProvider,
  getDefaultAiModel,
  getEnabledAiModelsWithProvider,
  getSiteSettings,
} from "@/lib/db/queries";
import { ChatSDKError } from "@/lib/errors";
import { isAiModelAgentAuto } from "@/lib/db/ai-model-flags";

function sortModelsForDisplay<T extends { sortOrder?: number | null; displayName?: string | null }>(
  models: T[]
) {
  return [...models].sort((a, b) => {
    const leftOrder = Number.isFinite(a.sortOrder as number) ? Number(a.sortOrder) : 0;
    const rightOrder = Number.isFinite(b.sortOrder as number) ? Number(b.sortOrder) : 0;
    if (leftOrder !== rightOrder) return leftOrder - rightOrder;
    const leftName = String(a.displayName || "");
    const rightName = String(b.displayName || "");
    return leftName.localeCompare(rightName, "zh-Hans-CN");
  });
}

// 获取前端可用的 AI 模型列表（需要登录但不需要管理员权限）
export async function GET() {
  try {
    const session = await auth();

    if (!session?.user) {
      return new ChatSDKError("unauthorized:chat").toResponse();
    }

    // 只获取主模型（不包括子模型），子模型由后端根据 videoParams.mode 自动选择
    const modelsWithProvider = await getEnabledAiModelsWithProvider(false);
    const agentModelWithProvider = await getAgentAiModelWithProvider();
    const defaultModel = await getDefaultAiModel();
    const siteSettings = await getSiteSettings();
    const visibleModelsWithProvider = sortModelsForDisplay(
      modelsWithProvider
        .filter(({ model }) => !isAiModelAgentAuto(model))
        .map((item) => item.model)
    );
    const visibleModelIdSet = new Set(visibleModelsWithProvider.map((m) => m.id));
    const visibleModelsWithProviderSorted = modelsWithProvider.filter(({ model }) =>
      visibleModelIdSet.has(model.id)
    ).sort((a, b) => {
      const left = visibleModelsWithProvider.findIndex((m) => m.id === a.model.id);
      const right = visibleModelsWithProvider.findIndex((m) => m.id === b.model.id);
      return left - right;
    });

    // 转换为前端需要的格式
    const models = visibleModelsWithProviderSorted.map(({ model, provider }) => ({
      id: model.id,
      modelId: model.modelId,
      displayName: model.displayName,
      avatarUrl: model.avatarUrl,
      description: model.description,
      supportsVision: model.supportsVision,
      supportsImageGen: model.supportsImageGen,
      isDefault: model.isDefault,
      providerName: provider.name,
      providerType: provider.type,
      isSubModel: model.isSubModel,
      parentModelId: model.parentModelId,
      capabilities: model.capabilities, // 🆕 返回子模型的能力配置
      imageGenConfig: model.imageGenConfig,
      sortOrder: model.sortOrder ?? 0,
    }));

    // Agent 模式在前端展示头像/参数时，优先使用“Agent模式 - 默认生图模型”的配置
    // 避免展示成分析模型（如视觉模型）的头像，导致与管理员设置不一致
    const imageGenModelsWithProvider = visibleModelsWithProviderSorted.filter(
      ({ model }) => model.supportsImageGen
    );
    const configuredAutoImageModelId =
      typeof siteSettings?.canvasAutoModeDefaultModelId === "string"
        ? siteSettings.canvasAutoModeDefaultModelId.trim()
        : "";
    const configuredAutoImageModel = configuredAutoImageModelId
      ? imageGenModelsWithProvider.find(
          ({ model }) => model.id === configuredAutoImageModelId
        )
      : undefined;
    const defaultImageGenModel =
      (defaultModel &&
      !isAiModelAgentAuto(defaultModel) &&
      defaultModel.supportsImageGen
        ? imageGenModelsWithProvider.find(({ model }) => model.id === defaultModel.id)
        : undefined) || imageGenModelsWithProvider[0];
    const agentDisplayModelWithProvider =
      configuredAutoImageModel ||
      defaultImageGenModel ||
      agentModelWithProvider ||
      null;

    const resolvedDefaultModelId =
      (defaultModel &&
      !isAiModelAgentAuto(defaultModel) &&
      models.some((model) => model.id === defaultModel.id)
        ? defaultModel.id
        : models.find((model) => model.isDefault)?.id) ??
      models[0]?.id ??
      null;

    return Response.json({
      models,
      defaultModelId: resolvedDefaultModelId,
      agentModel: agentDisplayModelWithProvider
        ? {
            id: agentDisplayModelWithProvider.model.id,
            displayName: agentDisplayModelWithProvider.model.displayName,
            avatarUrl: agentDisplayModelWithProvider.model.avatarUrl,
            providerType: agentDisplayModelWithProvider.provider.type,
            imageGenConfig: agentDisplayModelWithProvider.model.imageGenConfig,
          }
        : null,
    });
  } catch (error) {
    if (error instanceof ChatSDKError) {
      return error.toResponse();
    }
    return new ChatSDKError("offline:chat").toResponse();
  }
}