/**
 * Gemini Client
 * 單一責任：呼叫 Gemini API
 * 從 localStorage 讀取 token
 */

import type { AIProvider } from '~/types/ai'
import { getGeminiToken, getTextModel, getVisionModel } from '~/utils/storage'
import { DEFAULT_TEXT_MODEL, DEFAULT_VISION_MODEL, getModelForTask } from './gemini-models'

const GEMINI_API_BASE = 'https://generativelanguage.googleapis.com/v1beta'

/**
 * Gemini API Client
 */
export class GeminiClient implements AIProvider {
  private token: string | null

  constructor() {
    this.token = getGeminiToken()
  }

  /**
   * 取得 API Token
   */
  private getToken(): string {
    const token = getGeminiToken()
    if (!token) {
      throw new Error('Gemini API Token 未設定，請至設定頁面輸入')
    }
    return token
  }

  /**
   * 呼叫 Gemini API
   * @param prompt - 文字提示
   * @param model - 模型名稱，預設使用儲存的模型或 DEFAULT_TEXT_MODEL
   * @param parts - 多模態內容（圖像、音頻等）
   */
  private async callAPI(
    prompt: string,
    model?: string,
    parts?: Array<{ text?: string; inlineData?: { mimeType: string; data: string } }>
  ): Promise<string> {
    // 如果沒有指定模型，使用儲存的模型或預設模型
    const selectedModel = model || getTextModel() || DEFAULT_TEXT_MODEL
    const token = this.getToken()
    const url = `${GEMINI_API_BASE}/models/${selectedModel}:generateContent?key=${token}`

    // 組裝 parts
    const contentParts: Array<{ text?: string; inlineData?: { mimeType: string; data: string } }> = []
    
    if (prompt) {
      contentParts.push({ text: prompt })
    }
    
    if (parts) {
      contentParts.push(...parts)
    }

    const response = await fetch(url, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({
        contents: [{
          parts: contentParts
        }]
      })
    })

    if (!response.ok) {
      const error = await response.json().catch(() => ({ error: { message: 'Unknown error' } }))
      throw new Error(error.error?.message || `API 錯誤: ${response.status}`)
    }

    const data = await response.json()
    return data.candidates?.[0]?.content?.parts?.[0]?.text || ''
  }

  /**
   * 生成分鏡表
   */
  async generateStoryboard(input: unknown): Promise<string> {
    // Prompt 組裝將由 utils/ai 處理，這裡只負責呼叫 API
    const prompt = typeof input === 'string' ? input : JSON.stringify(input)
    return this.callAPI(prompt)
  }

  /**
   * 分析攝影機鏡位與運鏡
   * 支援圖像輸入（base64 或 URL）
   */
  async analyzeCamera(input: unknown): Promise<string> {
    const model = getVisionModel() || DEFAULT_VISION_MODEL
    
    // 如果 input 是物件且包含圖像
    if (typeof input === 'object' && input !== null) {
      const inputObj = input as { prompt?: string; image?: { mimeType: string; data: string } }
      const prompt = inputObj.prompt || '請分析這張圖片的攝影機鏡位與運鏡建議'
      const parts: Array<{ text?: string; inlineData?: { mimeType: string; data: string } }> = []
      
      if (inputObj.image) {
        parts.push({ inlineData: inputObj.image })
      }
      
      return this.callAPI(prompt, model, parts)
    }
    
    const prompt = typeof input === 'string' ? input : JSON.stringify(input)
    return this.callAPI(prompt, model)
  }

  /**
   * 生成影片規劃
   */
  async generateVideoPlan(input: unknown): Promise<string> {
    const prompt = typeof input === 'string' ? input : JSON.stringify(input)
    return this.callAPI(prompt)
  }

  /**
   * 生成剪輯建議
   */
  async generateEditSuggestion(input: unknown): Promise<string> {
    const prompt = typeof input === 'string' ? input : JSON.stringify(input)
    return this.callAPI(prompt)
  }
}