// 统一的 fetch 包装器：自动携带 Token、处理刷新和滑动过期
let tokenRefreshPromise: Promise<string> | null = null

async function doRefreshToken(rt: string): Promise<string> {
  tokenRefreshPromise = (async () => {
    try {
      const res = await fetch('/api/v1/auth/refresh', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ refresh_token: rt }),
      })
      if (!res.ok) throw new Error('Refresh failed')
      const data = await res.json()
      const newToken = data.data.token
      const newRt = data.data.refresh_token
      localStorage.setItem('token', newToken)
      localStorage.setItem('refresh_token', newRt)
      return newToken
    } finally {
      tokenRefreshPromise = null
    }
  })()
  return tokenRefreshPromise
}

async function apiFetch(url: string, init?: RequestInit): Promise<Response> {
  const headers: Record<string, string> = { ...(init?.headers as Record<string, string> || {}) }
  const storedToken = localStorage.getItem('token')
  if (storedToken) {
    headers['Authorization'] = `Bearer ${storedToken}`
  }
  // FormData 时不要设 Content-Type
  if (!(init?.body instanceof FormData)) {
    headers['Content-Type'] = headers['Content-Type'] || 'application/json'
  }

  let res = await fetch(url, { ...init, headers })

  // 滑动过期：检测 X-New-Token 响应头
  const newToken = res.headers.get('X-New-Token')
  if (newToken) {
    localStorage.setItem('token', newToken)
  }

  // 401 时尝试用 refresh_token 刷新一次
  if (res.status === 401 && storedToken) {
    const storedRt = localStorage.getItem('refresh_token')
    if (storedRt) {
      try {
        const freshToken = await doRefreshToken(storedRt)
        headers['Authorization'] = `Bearer ${freshToken}`
        res = await fetch(url, { ...init, headers })
      } catch {
        localStorage.removeItem('token')
        localStorage.removeItem('refresh_token')
        localStorage.removeItem('user')
        window.location.href = '/login'
      }
    }
  }

  if (!res.ok) {
    try {
      const err = await res.json()
      throw new Error(err.detail || err.error || err.message || `Request failed: ${res.status}`)
    } catch (e) {
      if (e instanceof Error) throw e
      throw new Error(`Request failed: ${res.status}`)
    }
  }
  return res
}

const api = {
  // --- Health ---
  health: () => apiFetch('/health').then(r => r.json()),

  // --- Models ---
  models: {
    list: () => apiFetch('/api/v1/models/').then(r => r.json()) as Promise<ModelInfo[]>,
    download: (modelId: string, useModelscope = false) =>
      apiFetch('/api/v1/models/download', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ model_id: modelId, use_modelscope: useModelscope }),
      }).then(r => r.json()) as Promise<ModelDownloadTaskResponse>,
    downloadStatus: (taskId: string) =>
      apiFetch(`/api/v1/models/download/${taskId}`).then(r => r.json()) as Promise<ModelDownloadTaskResponse>,
    listDownloads: () =>
      apiFetch('/api/v1/models/downloads').then(r => r.json()) as Promise<ModelDownloadTaskResponse[]>,
    cancelDownload: (taskId: string) =>
      apiFetch(`/api/v1/models/download/${taskId}/cancel`, { method: 'POST' }).then(r => r.json()),
    delete: (modelId: string) =>
      apiFetch(`/api/v1/models/${encodeURIComponent(modelId)}`, { method: 'DELETE' }).then(r => r.json()),
    getInfo: (modelId: string) =>
      apiFetch(`/api/v1/models/${encodeURIComponent(modelId)}`).then(r => r.json()) as Promise<ModelInfo>,
    test: (req: ModelTestRequest) =>
      apiFetch('/api/v1/models/test', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(req),
      }).then(r => r.json()) as Promise<ModelTestResponse>,
  },

  // --- Datasets ---
  datasets: {
    list: () => apiFetch('/api/v1/datasets/').then(r => r.json()) as Promise<DatasetInfo[]>,
    upload: (file: File) => {
      const form = new FormData()
      form.append('file', file)
      return apiFetch('/api/v1/datasets/upload', { method: 'POST', body: form }).then(r => r.json()) as Promise<DatasetInfo>
    },
    download: (datasetId: string, useModelscope = false) =>
      apiFetch('/api/v1/datasets/download', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ dataset_id: datasetId, use_modelscope: useModelscope }),
      }).then(r => r.json()) as Promise<DatasetDownloadTaskResponse>,
    downloadStatus: (taskId: string) =>
      apiFetch(`/api/v1/datasets/download/${taskId}`).then(r => r.json()) as Promise<DatasetDownloadTaskResponse>,
    listDownloads: () =>
      apiFetch('/api/v1/datasets/downloads').then(r => r.json()) as Promise<DatasetDownloadTaskResponse[]>,
    cancelDownload: (taskId: string) =>
      apiFetch(`/api/v1/datasets/download/${taskId}/cancel`, { method: 'POST' }).then(r => r.json()),
    preview: (id: string, rows = 10) =>
      apiFetch(`/api/v1/datasets/${id}/preview?rows=${rows}`).then(r => r.json()) as Promise<DatasetPreview>,
    validate: (id: string) =>
      apiFetch(`/api/v1/datasets/${id}/validate`, { method: 'POST' }).then(r => r.json()) as Promise<DatasetValidation>,
    delete: (id: string) =>
      apiFetch(`/api/v1/datasets/${id}`, { method: 'DELETE' }).then(r => r.json()),
  },

  // --- Training ---
  training: {
    list: () => apiFetch('/api/v1/training/jobs').then(r => r.json()) as Promise<TrainingJob[]>,
    create: (cfg: TrainingConfig) =>
      apiFetch('/api/v1/training/jobs', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(cfg),
      }).then(r => r.json()) as Promise<TrainingJob>,
    get: (id: string) =>
      apiFetch(`/api/v1/training/jobs/${id}`).then(r => r.json()) as Promise<TrainingJob>,
    cancel: (id: string) =>
      apiFetch(`/api/v1/training/jobs/${id}/cancel`, { method: 'POST' }).then(r => r.json()),
  },

  // --- Evaluation ---
  evaluation: {
    run: (cfg: EvalConfig) =>
      apiFetch('/api/v1/evaluation/run', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(cfg),
      }).then(r => r.json()) as Promise<EvalResult>,
    results: (id: string) =>
      apiFetch(`/api/v1/evaluation/${id}/results`).then(r => r.json()) as Promise<EvalResult>,
  },

  // --- Deployment ---
  deployment: {
    export: (cfg: DeployConfig) =>
      apiFetch('/api/v1/deployment/export', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(cfg),
      }).then(r => r.json()) as Promise<DeployResponse>,
    status: (id: string) =>
      apiFetch(`/api/v1/deployment/${id}/status`).then(r => r.json()) as Promise<DeployResponse>,
  },

  // --- Sample Center ---
  sampleCenter: {
    listKnowledgeBases: (page = 1, page_size = 20) =>
      apiFetch(`/api/v1/sample-center/knowledge-bases?page=${page}&page_size=${page_size}`)
        .then(r => r.json()) as Promise<KnowledgeBaseListResponse>,
    getKnowledgeBaseDetail: (kb_id: string) =>
      apiFetch(`/api/v1/sample-center/knowledge-bases/${kb_id}`)
        .then(r => r.json()) as Promise<KnowledgeBaseDetailResponse>,
    importFromKnowledgeBase: (kb_id: string, kb_name = '') =>
      apiFetch(`/api/v1/sample-center/knowledge-bases/${kb_id}/import?kb_name=${encodeURIComponent(kb_name)}`, {
        method: 'POST',
      }).then(r => r.json()) as Promise<KbImportResponse>,
  },

  // --- Inference ---
  inference: {
    generate: (req: InferenceRequest) =>
      apiFetch('/api/v1/inference/generate', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(req),
      }).then(r => r.json()) as Promise<InferenceResponse>,
    adapters: () =>
      apiFetch('/api/v1/inference/adapters').then(r => r.json()) as Promise<AdapterInfo[]>,
  },
}

export default api

// --- Types ---

interface ModelInfo {
  id: string
  name: string
  model_type: string
  path?: string
  is_downloaded: boolean
  context_length?: number
  supported_peft_methods: string[]
}

interface ModelTestRequest {
  model_id: string
  prompt: string
  max_new_tokens?: number
  temperature?: number
  top_p?: number
}

interface ModelTestResponse {
  model_id: string
  prompt: string
  generated_text: string
  error?: string
}

interface ModelDownloadResponse {
  model_id: string
  status: string
  path?: string
  error?: string
}

interface ModelDownloadTaskResponse {
  task_id: string
  model_id: string
  status: string
  use_modelscope?: boolean
  path?: string
  error?: string
  progress?: number
  created_at?: string
}

interface DatasetInfo {
  id: string
  name: string
  format: string
  record_count: number
  file_path: string
  created_at: string
}

interface DatasetDownloadResponse {
  dataset_id: string
  status: string
  path?: string
  error?: string
}

interface DatasetDownloadTaskResponse {
  task_id: string
  dataset_id: string
  status: string
  use_modelscope?: boolean
  path?: string
  error?: string
  record_count?: number
  created_at?: string
}

interface DatasetPreview {
  total_records: number
  preview_rows: { row_index: number; data: Record<string, unknown> }[]
  columns: string[]
}

interface DatasetValidation {
  is_valid: boolean
  errors?: string[]
  warnings?: string[]
}

interface TrainingJob {
  id: string
  model_id: string
  model_type: string
  peft_method: string
  status: string
  progress: number
  current_epoch: number
  current_step: number
  total_steps: number
  loss?: number
  created_at: string
  started_at?: string
  finished_at?: string
  error_message?: string
  adapter_path?: string
}

interface TrainingConfig {
  model_id: string
  model_type: string
  dataset_id: string
  peft_method: string
  task_type?: string
  dataset_template?: string
  epochs?: number
  batch_size?: number
  gradient_accumulation?: number
  learning_rate?: number
  max_seq_length?: number
  warmup_ratio?: number
  save_strategy?: string
  eval_strategy?: string
  eval_steps?: number
  lora_r?: number
  lora_alpha?: number
  lora_dropout?: number
  lora_target_modules?: string
  qlora_bits?: number
  deepspeed?: boolean
  num_gpus?: number
}

interface EvalConfig {
  job_id: string
  test_split_ratio?: number
  batch_size?: number
  metrics?: string[]
}

interface EvalResult {
  id: string
  job_id: string
  status: string
  progress: number
  metrics: Record<string, unknown>
  error: string | null
  created_at: string
}

interface DeployConfig {
  job_id: string
  merge_with_base?: boolean
  export_format?: string
}

interface DeployResponse {
  job_id: string
  status: string
  output_path?: string
  error?: string
}

interface AdapterInfo {
  id: string
  path: string
  base_model: string
  peft_type: string
  model_id?: string
  peft_method?: string
  task_type?: string
  created_at?: string
}

interface InferenceRequest {
  adapter_id: string
  prompt: string
  max_new_tokens?: number
  temperature?: number
  top_p?: number
  repetition_penalty?: number
  do_sample?: boolean
}

interface InferenceResponse {
  prompt: string
  generated_text: string
  generated_only: string
  tokens_generated: number
  error?: string
}

interface MetadataSchemaField {
  field_name_cn: string
  field_name_en: string
  field_type: string
  description: string
}

interface KnowledgeBaseItem {
  id: string
  name: string
  parent_table: string
  child_table: string
  document_count: number
  status: number
  created_at: string
  created_by: string
  metadata_schema: MetadataSchemaField[]
}

interface KnowledgeBaseListResponse {
  total: number
  page: number
  page_size: number
  items: KnowledgeBaseItem[]
}

interface KnowledgeBaseDetailResponse extends KnowledgeBaseItem {
  description: string
  updated_at: string
}

interface KbImportResponse {
  kb_id: string
  kb_name: string
  document_count: number
  metadata_schema: MetadataSchemaField[]
  parent_table: string
  child_table: string
}

export type { ModelInfo, ModelTestRequest, ModelTestResponse, ModelDownloadResponse, ModelDownloadTaskResponse, DatasetInfo, DatasetDownloadResponse, DatasetDownloadTaskResponse, DatasetPreview, DatasetValidation, TrainingJob, TrainingConfig, EvalConfig, EvalResult, DeployConfig, DeployResponse, AdapterInfo, InferenceRequest, InferenceResponse, KnowledgeBaseItem, KnowledgeBaseListResponse, KnowledgeBaseDetailResponse, KbImportResponse }