/**
 * 场景裂变配置 API（公开端点）
 * 
 * 允许普通用户获取场景裂变的配置信息
 */

import { NextResponse } from "next/server";
import { auth } from "@/app/(auth)/auth";
import { getEnabledAiModelsWithProvider, getSystemSetting } from "@/lib/db/queries";
import {
  buildSceneFusionCapabilitySummary,
  canProcessSceneFusionProviderType,
  normalizeSceneFusionProviderType,
  type SceneFusionCapabilityCandidate,
  type SceneFusionImageGenConfig,
} from "@/lib/scene-fusion/output-capabilities";

// 默认提示词
const FALLBACK_PROMPT = "将图1的产品替换到图2的场景中，保持图1产品的外观、颜色和细节不变，自然融合到图2的环境中。";
const SCENE_FUSION_MAX_ITEMS = 10;

export async function GET() {
  try {
    // 需要登录但不需要 admin 权限
    const session = await auth();
    if (!session?.user?.id) {
      return NextResponse.json(
        { error: "未登录" },
        { status: 401 }
      );
    }

    // 获取配置
    const setting = await getSystemSetting({ key: "scene_fusion_config" });
    const config = setting?.value as
      | {
          enabled?: boolean;
          defaultPrompt?: string;
          maxScenes?: number;
          preRmbgEnabled?: boolean;
          modelId?: string;
        }
      | undefined;
    const allModels = await getEnabledAiModelsWithProvider();
    const capabilityCandidates: SceneFusionCapabilityCandidate[] = allModels
      .filter((entry) => {
        if (!entry?.model?.isEnabled) return false;
        if (!entry?.model?.supportsImageGen) return false;
        if (entry?.model?.isSubModel) return false;
        return canProcessSceneFusionProviderType(String(entry.provider?.type || ""));
      })
      .map((entry) => ({
        model: {
          id: String(entry.model.id),
          displayName: String(entry.model.displayName || entry.model.modelId || entry.model.id),
          imageGenConfig: (entry.model.imageGenConfig || null) as SceneFusionImageGenConfig | null,
        },
        provider: {
          type: normalizeSceneFusionProviderType(String(entry.provider.type || "")),
        },
      }));
    const outputCapabilities = buildSceneFusionCapabilitySummary(
      capabilityCandidates,
      config?.modelId || null
    );
    
    if (setting?.value && config) {
      return NextResponse.json({
        enabled: config.enabled ?? true,
        preRmbgEnabled: config.preRmbgEnabled ?? true,
        defaultPrompt: config.defaultPrompt || FALLBACK_PROMPT,
        maxScenes: Math.min(config.maxScenes ?? SCENE_FUSION_MAX_ITEMS, SCENE_FUSION_MAX_ITEMS),
        mode: "diversity",
        preferredModelId: config.modelId || null,
        outputCapabilities,
      });
    }

    // 返回默认配置
    return NextResponse.json({
      enabled: true,
      preRmbgEnabled: true,
      defaultPrompt: FALLBACK_PROMPT,
      maxScenes: SCENE_FUSION_MAX_ITEMS,
      mode: "diversity",
      preferredModelId: null,
      outputCapabilities,
    });
  } catch (error) {
    console.error("[SceneFusion Config] Error:", error);
    return NextResponse.json(
      { error: "获取配置失败" },
      { status: 500 }
    );
  }
}