/**
 * useAnalysis — start an analysis + poll status until terminal.
 *
 * Contract lives in infinith-api/docs/API_CONTRACT.md §2-3.
 * Replace `any` with generated types from `src/api-types/schema.d.ts`
 * once backend `openapi.json` is stable.
 */
import { useEffect, useRef, useState } from 'react'
import { apiClient } from '@/lib/apiClient'

type Status = 'pending' | 'discovering' | 'collecting' | 'generating' | 'complete' | 'partial' | 'error'

interface StatusResponse {
  analysis_run_id: string
  status: Status
  progress: number
  current_step: string
  channel_errors: Record<string, string>
  completed_at: string | null
}

interface ChannelHandles {
  youtube?: string
  instagram?: string[]
  facebook?: string
  naver_blog?: string
  gangnam_unni?: string
}

const TERMINAL: Status[] = ['complete', 'partial', 'error']

export function useAnalysis() {
  const [status, setStatus] = useState<StatusResponse | null>(null)
  const [error, setError] = useState<Error | null>(null)
  const pollerRef = useRef<number | null>(null)

  useEffect(
    () => () => {
      if (pollerRef.current) window.clearInterval(pollerRef.current)
    },
    [],
  )

  async function start(input: { clinic_id?: string; url?: string; channels: ChannelHandles }) {
    try {
      const { data } = await apiClient.post('/api/analyses', input)
      pollStatus(data.analysis_run_id)
      return data.analysis_run_id as string
    } catch (err) {
      setError(err as Error)
      throw err
    }
  }

  function pollStatus(runId: string) {
    if (pollerRef.current) window.clearInterval(pollerRef.current)
    pollerRef.current = window.setInterval(async () => {
      try {
        const { data } = await apiClient.get<StatusResponse>(`/api/analyses/${runId}/status`)
        setStatus(data)
        if (TERMINAL.includes(data.status) && pollerRef.current) {
          window.clearInterval(pollerRef.current)
          pollerRef.current = null
        }
      } catch (err) {
        setError(err as Error)
        if (pollerRef.current) {
          window.clearInterval(pollerRef.current)
          pollerRef.current = null
        }
      }
    }, 2000)
  }

  return { start, pollStatus, status, error }
}