import { GoogleGenAI } from "@google/genai";

/**
 * Generates a VTuber avatar character sheet.
 * Uses gemini-3-pro-image-preview for high quality.
 */
export const generateAvatarImage = async (description: string): Promise<string> => {
  try {
    // Initialize client inside the function to ensure we use the most up-to-date API key
    const ai = new GoogleGenAI({ apiKey: process.env.API_KEY });

    const prompt = `
      Create a VTuber character sheet with a flat 2D anime style.
      
      LAYOUT:
      1. MAIN CHARACTER (Left side, takes up 70% of width):
         - Front-facing view, head and shoulders.
         - Neutral expression, eyes open, mouth closed.
      
      2. EXPRESSION ASSETS (Right side, vertical column):
         - Top: The same character's face with EYES CLOSED (for blinking).
         - Bottom: The same character's face with MOUTH OPEN (for talking).
      
      Character Description: ${description}
      
      Style: Vibrant, clean lines, solid white or green background for easy keying.
    `;

    const response = await ai.models.generateContent({
      model: 'gemini-3-pro-image-preview',
      contents: {
        parts: [
          { text: prompt }
        ]
      },
      config: {
        imageConfig: {
          aspectRatio: "16:9", // Wide to fit character sheet
          imageSize: "1K"
        }
      }
    });

    // Parse response for image data
    for (const part of response.candidates[0].content.parts) {
      if (part.inlineData) {
        const base64EncodeString = part.inlineData.data;
        return `data:image/png;base64,${base64EncodeString}`;
      }
    }

    throw new Error("No image data found in response");
  } catch (error) {
    console.error("Error generating avatar:", error);
    throw error;
  }
};