import { i18n } from '../i18n'

export const API_BASE_URL = (import.meta.env.VITE_API_BASE_URL ?? 'http://180.76.247.146:18724/api').replace(/\/$/, '')

const t = (key: string, params?: Record<string, unknown>) => i18n.global.t(key, params ?? {})

export class ApiError extends Error {
  status: number
  data: unknown

  constructor(message: string, status: number, data: unknown) {
    super(message)
    this.name = 'ApiError'
    this.status = status
    this.data = data
  }
}

function errorMessage(data: unknown, status: number): string {
  if (typeof data === 'object' && data) {
    const record = data as Record<string, unknown>
    const detail = record.detail
    if (typeof detail === 'string') return detail
    if (typeof detail === 'object' && detail) {
      const detailRecord = detail as Record<string, unknown>
      const nestedError = detailRecord.error
      if (typeof nestedError === 'object' && nestedError) {
        const message = (nestedError as Record<string, unknown>).message
        if (typeof message === 'string') return message
      }
      const message = detailRecord.message
      if (typeof message === 'string') return message
    }
    const nestedError = record.error
    if (typeof nestedError === 'object' && nestedError) {
      const message = (nestedError as Record<string, unknown>).message
      if (typeof message === 'string') return message
    }
    const message = record.message
    if (typeof message === 'string') return message
  }
  return t('common.requestFailed', { status })
}

/** 项目关联的数据文件（详情接口） */
export interface BackendDataFile {
  id: number | string
  filename?: string
  /** 旧字段兼容 */
  name?: string
  uploaded_at?: string
  created_at?: string
  wavenumber_min?: number
  wavenumber_max?: number
  size?: number
}

export interface BackendProject {
  id: string
  name: string
  description?: string
  created_at: string
  last_modified?: string
  status: string
  data_files?: BackendDataFile[]
  files?: BackendDataFile[]
  /** 当前作为分析使用的数据文件 */
  active_data_file?: BackendDataFile | null
  data_files_count?: number
  file_count?: number
  files_count?: number
}

async function request<T>(path: string, init: RequestInit = {}): Promise<T> {
  const headers = new Headers(init.headers ?? {})

  if (!headers.has('Content-Type') && !(init.body instanceof FormData)) {
    headers.set('Content-Type', 'application/json')
  }
  headers.set('accept', 'application/json')

  const res = await fetch(`${API_BASE_URL}${path}`, {
    ...init,
    headers
  })

  const contentType = res.headers.get('content-type') ?? ''
  const isJson = contentType.includes('application/json')
  const data = isJson ? await res.json() : await res.text()

  if (!res.ok) {
    throw new ApiError(errorMessage(data, res.status), res.status, data)
  }

  return data as T
}

async function requestBlob(path: string, init: RequestInit = {}): Promise<Blob> {
  const headers = new Headers(init.headers ?? {})
  headers.set('accept', '*/*')

  const res = await fetch(`${API_BASE_URL}${path}`, {
    ...init,
    headers
  })

  if (!res.ok) {
    const contentType = res.headers.get('content-type') ?? ''
    const isJson = contentType.includes('application/json')
    const data = isJson ? await res.json() : await res.text()
    throw new ApiError(errorMessage(data, res.status), res.status, data)
  }

  return await res.blob()
}

function parseFilenameFromContentDisposition(value: string | null): string {
  if (!value) return ''
  // 优先解析 RFC5987 filename*=UTF-8''xxx
  const star = /filename\*\s*=\s*([^;]+)/i.exec(value)
  if (star?.[1]) {
    const v = star[1].trim().replace(/^["']|["']$/g, '')
    const parts = v.split("''")
    const encoded = parts.length >= 2 ? parts.slice(1).join("''") : v
    try {
      return decodeURIComponent(encoded)
    } catch {
      return encoded
    }
  }
  // 再解析 filename="xxx"
  const normal = /filename\s*=\s*([^;]+)/i.exec(value)
  if (normal?.[1]) return normal[1].trim().replace(/^["']|["']$/g, '')
  return ''
}

async function requestBlobWithFilename(
  path: string,
  init: RequestInit = {}
): Promise<{ blob: Blob; filename: string }> {
  const headers = new Headers(init.headers ?? {})
  headers.set('accept', '*/*')

  const res = await fetch(`${API_BASE_URL}${path}`, {
    ...init,
    headers
  })

  if (!res.ok) {
    const contentType = res.headers.get('content-type') ?? ''
    const isJson = contentType.includes('application/json')
    const data = isJson ? await res.json() : await res.text()
    throw new ApiError(errorMessage(data, res.status), res.status, data)
  }

  const filename = parseFilenameFromContentDisposition(res.headers.get('content-disposition'))
  const blob = await res.blob()
  return { blob, filename }
}

export const getProjects = (): Promise<BackendProject[]> =>
  request<BackendProject[]>('/projects/', { method: 'GET' })

export const getProject = (id: string): Promise<BackendProject> =>
  request<BackendProject>(`/projects/${encodeURIComponent(id)}/`, { method: 'GET' })

export const deleteProject = (id: string): Promise<unknown> =>
  request(`/projects/${encodeURIComponent(id)}/`, { method: 'DELETE' })

export const createProject = (payload: { name: string; description?: string }): Promise<BackendProject> =>
  request<BackendProject>('/projects/', {
    method: 'POST',
    body: JSON.stringify(payload)
  })

/** 项目数据上传（multipart 字段名需与后端一致） */
export const uploadProjectFile = async (
  projectId: string,
  file: File,
  options?: { groupIndex?: string; wavenumberRange?: string }
): Promise<unknown> => {
  const formData = new FormData()
  formData.append('files', file)
  const gi = options?.groupIndex?.trim()
  const wr = options?.wavenumberRange?.trim()
  if (gi) formData.append('group_index', gi)
  if (wr) formData.append('Wavenumber range', wr)

  return request(`/projects/${encodeURIComponent(projectId)}/data/upload/`, {
    method: 'POST',
    body: formData
  })
}

/** 将指定数据文件设为当前活动文件 */
export const setProjectActiveDataFile = (
  projectId: string,
  fileId: number
): Promise<unknown> =>
  request(`/projects/${encodeURIComponent(projectId)}/data/${fileId}/select/`, {
    method: 'POST',
    body: JSON.stringify({})
  })

/** 删除项目下的数据文件 */
export const deleteProjectDataFile = (
  projectId: string,
  fileId: number
): Promise<unknown> =>
  request(`/projects/${encodeURIComponent(projectId)}/data/${fileId}/delete/`, {
    method: 'DELETE'
  })

export type ProjectAnalysisRequest = Record<string, any>

export const getProjectAnalysisResults = (projectId: string): Promise<unknown> =>
  request(`/projects/${encodeURIComponent(projectId)}/analysis/results/`, { method: 'GET' })

export const runProjectAnalysis = (
  projectId: string,
  payload: ProjectAnalysisRequest,
  workflow?: unknown
): Promise<unknown> => {
  const form = new FormData()
  form.append('params', JSON.stringify(payload))
  if (workflow) form.append('workflow', JSON.stringify(workflow))
  return request(`/projects/${encodeURIComponent(projectId)}/analysis/`, {
    method: 'POST',
    body: form
  })
}

export const downloadProjectResultsExport = (projectId: string, exportId: string): Promise<Blob> =>
  requestBlob(`/projects/${encodeURIComponent(projectId)}/results/export/${encodeURIComponent(exportId)}/`, { method: 'GET' })

export const downloadProjectAnalysisExport = (projectId: string): Promise<Blob> =>
  requestBlob(`/projects/${encodeURIComponent(projectId)}/analysis/export/`, { method: 'GET' })

export const downloadProjectAnalysisExportFile = (projectId: string): Promise<{ blob: Blob; filename: string }> =>
  requestBlobWithFilename(`/projects/${encodeURIComponent(projectId)}/analysis/export/`, { method: 'GET' })