gemini-compat-endpoint

// Centralized model capability detection and Files API eligibility
// Policy (current):
// - Strict separation of capabilities per model.
// - "Model Families" are ignored in favor of explicit configuration.

export type ImageGenerationConfig = {
  numberOfImages: number;
  numberOfImagesDefault: number;
  imageSize: string[];
  imageSizeDefault: string;
  aspectRatio: string[];
  aspectRatioDefault: string;
  /** Maximum number of input images for image-to-image / multi-image composition */
  maxInputImages?: number;
};

export type ThinkingConfig = {
  levels: string[];
  defaultLevel: string;
};

export type ModelCapabilities = {
  supportsTools: boolean;
  supportsVision: boolean;
  supportsImage: boolean;
  imageGeneration?: ImageGenerationConfig;
  supportsThinking: boolean;
  thinking?: ThinkingConfig;
  supportsStreaming: boolean;
  responseModalities?: string[];
  /** Maximum number of attachments to visually promote (base64/Files API) */
  maxPromotedAttachments?: number;
};

const CAPABILITY_MAP: Record<string, ModelCapabilities> = {
  "gemini-3.1-pro-preview": {
    supportsTools: true,
    supportsVision: true,
    supportsImage: false,  // Text-only model, no image generation
    supportsThinking: true,
    thinking: {
      levels: ["low", "medium", "high"],
      defaultLevel: "low",
    },
    supportsStreaming: true,
    // Text-only: default 2 attachments for vision context
    maxPromotedAttachments: 2,
  },
  "gemini-3-pro-image-preview": {
    supportsTools: true,  // LM Studio local tools work via function declarations
    supportsVision: true,
    supportsImage: true,
    imageGeneration: {
      numberOfImages: 4,
      numberOfImagesDefault: 1,
      imageSize: ["1K", "2K", "4K"], // "Nano Banana Pro" supports higher res
      imageSizeDefault: "1K",
      aspectRatio: ["1:1", "2:3", "3:2", "3:4", "4:3", "4:5", "5:4", "9:16", "16:9", "21:9"],
      aspectRatioDefault: "1:1",
      // Google Docs: "up to 14 reference images" (6 objects + 5 humans + others)
      maxInputImages: 14,
    },
    supportsThinking: true,
    thinking: {
      levels: [], // Does not support adjustable thinking levels
      defaultLevel: "",
    },
    supportsStreaming: true,
    responseModalities: ["TEXT", "IMAGE"],
    // Native image generation: promote ALL attachments (up to 14)
    maxPromotedAttachments: 4,
  },
};

const DEFAULT_CAPABILITIES: ModelCapabilities = {
  supportsTools: false,
  supportsVision: true,
  supportsImage: false,
  supportsThinking: false,
  supportsStreaming: true,
  maxPromotedAttachments: 2, // Default: only last 2 attachments visually promoted
};

/**
 * Detect capabilities for this plugin based on strict model ID lookup.
 */
export function detectCapabilities(modelId: string): ModelCapabilities {
  const m = (modelId || "").toLowerCase();
  // Direct lookup first
  if (CAPABILITY_MAP[modelId]) {
    return CAPABILITY_MAP[modelId];
  }
  // Fallback lookup (case-insensitive)
  const key = Object.keys(CAPABILITY_MAP).find(k => k.toLowerCase() === m);
  if (key) {
    return CAPABILITY_MAP[key];
  }

  console.warn(`[Capabilities] Unknown model ID "${modelId}", using defaults.`);
  return DEFAULT_CAPABILITIES;
}

/**
 * Get the maximum number of attachments to visually promote for a model.
 * 
 * - Image-capable models (Nano Banana, Nano Banana Pro): higher limits (10-14)
 *   because user may reference any [aN] for image2image operations
 * - Text-only or tool-based image models: default 2 (last two attachments)
 */
export function getMaxPromotedAttachments(modelId: string): number {
  const caps = detectCapabilities(modelId);
  return caps.maxPromotedAttachments ?? 2;
}

/**
 * Decide if Files API should be used for the given model under current policy.
 * - Requires user toggle ON.
 * - Kein separates Flash-Gating mehr: alle Modelle folgen dem Toggle.
 */
export function shouldUseFilesApiForModel(modelId: string, userToggle: boolean): boolean {
  if (!userToggle) return false;
  // Aktuell: Files API für alle Modelle, sobald das Toggle aktiv ist.
  return true;
}