import axios, { AxiosInstance, AxiosRequestConfig } from 'axios'
import { config } from '@things-factory/env'

/**
 * Label Studio API Client
 * Provides methods to interact with Label Studio REST API
 */
export class LabelStudioApiClient {
  private client: AxiosInstance | null = null
  private serverUrl: string | null = null
  private apiToken: string | null = null

  constructor() {
    // Defer initialization until first use
  }

  private ensureInitialized() {
    if (this.client) {
      return
    }

    const labelStudioConfig = config.get('labelStudio', {})
    this.serverUrl = labelStudioConfig.serverUrl || 'http://localhost:8080'
    this.apiToken = labelStudioConfig.apiToken || ''

    this.client = axios.create({
      baseURL: this.serverUrl,
      headers: {
        Authorization: `Token ${this.apiToken}`,
        'Content-Type': 'application/json'
      },
      timeout: 30000
    })
  }

  // ============================================================================
  // Project Methods
  // ============================================================================

  /**
   * Get all projects
   */
  async getProjects(): Promise<any[]> {
    this.ensureInitialized()
    const response = await this.client!.get('/api/projects')
    return response.data.results || response.data
  }

  /**
   * Get project by ID
   */
  async getProject(projectId: number): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.get(`/api/projects/${projectId}`)
    return response.data
  }

  /**
   * Create new project
   */
  async createProject(data: {
    title: string
    description?: string
    label_config: string
    expert_instruction?: string
  }): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.post('/api/projects', data)
    return response.data
  }

  /**
   * Update project
   */
  async updateProject(projectId: number, data: any): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.patch(`/api/projects/${projectId}`, data)
    return response.data
  }

  /**
   * Delete project
   */
  async deleteProject(projectId: number): Promise<void> {
    this.ensureInitialized()
    await this.client!.delete(`/api/projects/${projectId}`)
  }

  // ============================================================================
  // Task Methods
  // ============================================================================

  /**
   * Get tasks for a project
   */
  async getTasks(projectId: number, params?: { page?: number; page_size?: number }): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.get(`/api/projects/${projectId}/tasks`, { params })
    return response.data
  }

  /**
   * Get single task
   */
  async getTask(taskId: number): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.get(`/api/tasks/${taskId}`)
    return response.data
  }

  /**
   * Create task
   */
  async createTask(projectId: number, data: any): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.post(`/api/projects/${projectId}/tasks`, data)
    return response.data
  }

  /**
   * Import tasks in bulk
   */
  async importTasks(projectId: number, tasks: any[]): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.post(`/api/projects/${projectId}/import`, tasks, {
      headers: {
        'Content-Type': 'application/json'
      }
    })
    return response.data
  }

  /**
   * Delete task
   */
  async deleteTask(taskId: number): Promise<void> {
    this.ensureInitialized()
    await this.client!.delete(`/api/tasks/${taskId}`)
  }

  // ============================================================================
  // Annotation Methods
  // ============================================================================

  /**
   * Get annotations for a task
   */
  async getAnnotations(taskId: number): Promise<any[]> {
    this.ensureInitialized()
    const response = await this.client!.get(`/api/tasks/${taskId}/annotations`)
    return response.data
  }

  /**
   * Create annotation
   */
  async createAnnotation(taskId: number, annotation: any): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.post(`/api/tasks/${taskId}/annotations`, annotation)
    return response.data
  }

  /**
   * Update annotation
   */
  async updateAnnotation(annotationId: number, data: any): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.patch(`/api/annotations/${annotationId}`, data)
    return response.data
  }

  /**
   * Delete annotation
   */
  async deleteAnnotation(annotationId: number): Promise<void> {
    this.ensureInitialized()
    await this.client!.delete(`/api/annotations/${annotationId}`)
  }

  // ============================================================================
  // Prediction Methods
  // ============================================================================

  /**
   * Get all predictions for a task
   */
  async getPredictions(taskId: number): Promise<any[]> {
    this.ensureInitialized()
    const response = await this.client!.get('/api/predictions', {
      params: { task: taskId }
    })
    return response.data.results || response.data
  }

  /**
   * Get predictions for a project
   */
  async getProjectPredictions(projectId: number): Promise<any[]> {
    this.ensureInitialized()
    const response = await this.client!.get('/api/predictions', {
      params: { project: projectId }
    })
    return response.data.results || response.data
  }

  /**
   * Get single prediction by ID
   */
  async getPrediction(predictionId: number): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.get(`/api/predictions/${predictionId}`)
    return response.data
  }

  /**
   * Create a prediction for a task
   */
  async createPrediction(data: {
    task: number
    result: any[]
    score?: number
    model_version?: string
  }): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.post('/api/predictions', data)
    return response.data
  }

  /**
   * Create predictions in bulk
   */
  async createPredictions(predictions: Array<{
    task: number
    result: any[]
    score?: number
    model_version?: string
  }>): Promise<any> {
    this.ensureInitialized()
    const results = await Promise.all(
      predictions.map(prediction => this.createPrediction(prediction))
    )
    return {
      created: results.length,
      predictions: results
    }
  }

  /**
   * Update prediction
   */
  async updatePrediction(predictionId: number, data: any): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.patch(`/api/predictions/${predictionId}`, data)
    return response.data
  }

  /**
   * Delete prediction
   */
  async deletePrediction(predictionId: number): Promise<void> {
    this.ensureInitialized()
    await this.client!.delete(`/api/predictions/${predictionId}`)
  }

  /**
   * Import predictions for a project
   * This is useful for bulk importing AI model predictions
   */
  async importPredictions(projectId: number, predictions: any[]): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.post(`/api/projects/${projectId}/import/predictions`, predictions)
    return response.data
  }

  // ============================================================================
  // Export Methods
  // ============================================================================

  /**
   * Export annotations
   */
  async exportAnnotations(
    projectId: number,
    format: 'JSON' | 'JSON_MIN' | 'CSV' | 'TSV' | 'CONLL2003' | 'COCO' | 'VOC' | 'YOLO' = 'JSON'
  ): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.get(`/api/projects/${projectId}/export`, {
      params: { exportType: format }
    })
    return response.data
  }

  /**
   * Get export files
   */
  async getExportFiles(projectId: number): Promise<any[]> {
    this.ensureInitialized()
    const response = await this.client!.get(`/api/projects/${projectId}/exports`)
    return response.data
  }

  // ============================================================================
  // ML Backend Methods
  // ============================================================================

  /**
   * Get ML backends for project
   */
  async getMLBackends(projectId: number): Promise<any[]> {
    this.ensureInitialized()
    const response = await this.client!.get(`/api/ml`, {
      params: { project: projectId }
    })
    return response.data.results || response.data
  }

  /**
   * Add ML backend to project
   */
  async addMLBackend(data: {
    project: number
    url: string
    title: string
    is_interactive?: boolean
  }): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.post('/api/ml', data)
    return response.data
  }

  /**
   * Delete ML backend
   */
  async deleteMLBackend(mlBackendId: number): Promise<void> {
    this.ensureInitialized()
    await this.client!.delete(`/api/ml/${mlBackendId}`)
  }

  /**
   * Trigger predictions for tasks
   */
  async triggerPredictions(projectId: number, taskIds?: number[]): Promise<any> {
    this.ensureInitialized()
    const payload = taskIds ? { task_ids: taskIds } : {}
    const response = await this.client!.post(`/api/projects/${projectId}/predict`, payload)
    return response.data
  }

  /**
   * Train ML model
   */
  async trainModel(mlBackendId: number): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.post(`/api/ml/${mlBackendId}/train`)
    return response.data
  }

  // ============================================================================
  // Statistics Methods
  // ============================================================================

  /**
   * Get project statistics
   */
  async getProjectStats(projectId: number): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.get(`/api/projects/${projectId}`)
    const project = response.data

    // Get detailed statistics
    const tasksResponse = await this.client!.get(`/api/projects/${projectId}/tasks`, {
      params: { page_size: 1 }
    })

    return {
      totalTasks: project.task_number || 0,
      completedTasks: project.finished_task_number || 0,
      totalAnnotations: project.total_annotations_number || 0,
      avgAnnotationsPerTask:
        project.task_number > 0 ? (project.total_annotations_number || 0) / project.task_number : 0,
      completionRate: project.task_number > 0 ? (project.finished_task_number || 0) / project.task_number : 0
    }
  }

  /**
   * Get annotator statistics
   */
  async getAnnotatorStats(projectId: number): Promise<any[]> {
    this.ensureInitialized()
    const response = await this.client!.get(`/api/projects/${projectId}/annotations`)
    const annotations = response.data.results || response.data

    // Group by annotator
    const statsByUser: { [email: string]: any } = {}

    for (const annotation of annotations) {
      const email = annotation.completed_by?.email || 'unknown'

      if (!statsByUser[email]) {
        statsByUser[email] = {
          email,
          annotationCount: 0,
          totalTime: 0,
          lastAnnotationDate: null
        }
      }

      statsByUser[email].annotationCount++
      if (annotation.lead_time) {
        statsByUser[email].totalTime += annotation.lead_time
      }

      const annotationDate = new Date(annotation.created_at)
      if (
        !statsByUser[email].lastAnnotationDate ||
        annotationDate > new Date(statsByUser[email].lastAnnotationDate)
      ) {
        statsByUser[email].lastAnnotationDate = annotation.created_at
      }
    }

    return Object.values(statsByUser).map(stat => ({
      ...stat,
      avgTime: stat.annotationCount > 0 ? stat.totalTime / stat.annotationCount : 0
    }))
  }

  // ============================================================================
  // Webhook Methods
  // ============================================================================

  /**
   * Create webhook
   */
  async createWebhook(data: {
    project: number
    url: string
    send_payload?: boolean
    send_for_all_actions?: boolean
    headers?: { [key: string]: string }
  }): Promise<any> {
    this.ensureInitialized()
    const response = await this.client!.post('/api/webhooks', data)
    return response.data
  }

  /**
   * Get webhooks for project
   */
  async getWebhooks(projectId: number): Promise<any[]> {
    this.ensureInitialized()
    const response = await this.client!.get('/api/webhooks', {
      params: { project: projectId }
    })
    return response.data.results || response.data
  }

  /**
   * Delete webhook
   */
  async deleteWebhook(webhookId: number): Promise<void> {
    this.ensureInitialized()
    await this.client!.delete(`/api/webhooks/${webhookId}`)
  }
}

// Singleton instance (lazy initialization)
let _instance: LabelStudioApiClient | null = null

function getLabelStudioApiClient(): LabelStudioApiClient {
  if (!_instance) {
    _instance = new LabelStudioApiClient()
  }
  return _instance
}

// Export singleton accessor
export const labelStudioApi = new Proxy({} as LabelStudioApiClient, {
  get(_target, prop) {
    const instance = getLabelStudioApiClient()
    const value = (instance as any)[prop]
    if (typeof value === 'function') {
      return value.bind(instance)
    }
    return value
  }
})