dramaling-vocab-learning/frontend/lib/services/imageGeneration.ts

// Image Generation API service

export interface ImageGenerationRequest {
  style: 'cartoon' | 'realistic' | 'minimal'
  priority: 'normal' | 'high' | 'low'
  width: number
  height: number
  replicateModel: string
  options: {
    useGeminiCache: boolean
    useImageCache: boolean
    maxRetries: number
    learnerLevel: string
    scenario: string
    visualPreferences: string[]
  }
}

export interface GenerationStatus {
  requestId: string
  overallStatus: string
  currentStage?: string
  stages: {
    gemini: {
      status: string
      startedAt?: string
      completedAt?: string
      processingTimeMs?: number
      cost?: number
      generatedDescription?: string
    }
    replicate: {
      status: string
      startedAt?: string
      completedAt?: string
      processingTimeMs?: number
      cost?: number
      model?: string
      modelVersion?: string
      progress?: string
    }
  }
  totalCost?: number
  completedAt?: string
  result?: {
    imageUrl: string
    imageId: string
    qualityScore?: number
    dimensions?: {
      width: number
      height: number
    }
    fileSize?: number
  }
}

export interface ApiResponse<T> {
  success: boolean
  data?: T
  error?: string
  details?: string
}

class ImageGenerationService {
  private baseUrl = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:5008'

  private async makeRequest<T>(url: string, options: RequestInit = {}): Promise<ApiResponse<T>> {
    const token = localStorage.getItem('token')

    const response = await fetch(`${this.baseUrl}${url}`, {
      headers: {
        'Content-Type': 'application/json',
        'Authorization': token ? `Bearer ${token}` : '',
        ...options.headers,
      },
      ...options,
    })

    if (!response.ok) {
      const errorData = await response.json().catch(() => ({ error: 'Network error' }))
      throw new Error(errorData.error || errorData.details || `HTTP ${response.status}`)
    }

    return response.json()
  }

  // 啟動圖片生成
  async generateImage(flashcardId: string, request?: Partial<ImageGenerationRequest>): Promise<ApiResponse<{ requestId: string }>> {
    const defaultRequest: ImageGenerationRequest = {
      style: 'cartoon',
      priority: 'normal',
      width: 512,
      height: 512,
      replicateModel: 'ideogram-v2a-turbo',
      options: {
        useGeminiCache: true,
        useImageCache: true,
        maxRetries: 3,
        learnerLevel: 'B1',
        scenario: 'daily',
        visualPreferences: ['colorful', 'simple']
      },
      ...request
    }

    return this.makeRequest(`/api/imagegeneration/flashcards/${flashcardId}/generate`, {
      method: 'POST',
      body: JSON.stringify(defaultRequest)
    })
  }

  // 查詢生成狀態
  async getGenerationStatus(requestId: string): Promise<ApiResponse<GenerationStatus>> {
    return this.makeRequest(`/api/imagegeneration/requests/${requestId}/status`)
  }

  // 取消生成
  async cancelGeneration(requestId: string): Promise<ApiResponse<{ message: string }>> {
    return this.makeRequest(`/api/imagegeneration/requests/${requestId}/cancel`, {
      method: 'POST'
    })
  }

  // 輪詢直到完成
  async pollUntilComplete(
    requestId: string,
    onProgress?: (status: GenerationStatus) => void,
    timeoutMinutes = 5
  ): Promise<GenerationStatus> {
    const startTime = Date.now()
    const timeout = timeoutMinutes * 60 * 1000

    while (Date.now() - startTime < timeout) {
      try {
        const result = await this.getGenerationStatus(requestId)

        if (!result.success || !result.data) {
          throw new Error(result.error || 'Failed to get status')
        }

        const status = result.data

        // 呼叫進度回調
        if (onProgress) {
          onProgress(status)
        }

        // 檢查是否完成
        if (status.overallStatus === 'completed') {
          return status
        }

        // 檢查是否失敗
        if (status.overallStatus === 'failed') {
          throw new Error('圖片生成失敗')
        }

        // 等待 2 秒後再次檢查
        await new Promise(resolve => setTimeout(resolve, 2000))
      } catch (error) {
        console.error('輪詢狀態時發生錯誤:', error)
        throw error
      }
    }

    throw new Error('圖片生成超時')
  }
}

export const imageGenerationService = new ImageGenerationService()