import { useState } from 'react'
import { analysisApi } from '../services/api'
import type { ChangeDetectionSummary, DatasetCreateResponse, VectorSelectionBBox } from '../types'
import { formatError } from '../lib/formatError'

interface ChangeDetectionWorkflowOptions {
  selectedProjectId: string | null
  availableVectorDatasets: DatasetCreateResponse[]
  loadDatasetJobs: (projectId: string, datasetId: string) => Promise<void>
  /**
   * Reads the active map selection when the comparison is started. Without a
   * selection the comparison covers both datasets entire, which is rarely the
   * question being asked and returns a payload no map can draw.
   *
   * A getter rather than a value because this hook runs before the selection
   * state is declared in the component; it is only ever called from a user
   * event, long after that binding is initialised.
   */
  getSelection?: () => { bbox: VectorSelectionBBox | null; areaId: string | null }
}

export function useChangeDetectionWorkflow({
  selectedProjectId,
  availableVectorDatasets,
  loadDatasetJobs,
  getSelection,
}: ChangeDetectionWorkflowOptions) {
  const [changeSourceDatasetId, setChangeSourceDatasetId] = useState('')
  const [changeTargetDatasetId, setChangeTargetDatasetId] = useState('')
  const [changeIouThreshold, setChangeIouThreshold] = useState(0.8)
  const [changeIncludeUnchanged, setChangeIncludeUnchanged] = useState(true)
  const [runningChangeDetection, setRunningChangeDetection] = useState(false)
  const [changeDetectionResult, setChangeDetectionResult] = useState<ChangeDetectionSummary | null>(null)
  const [changeDetectionError, setChangeDetectionError] = useState<string | null>(null)

  const runChangeDetection = async () => {
    const sourceDatasetId = changeSourceDatasetId || availableVectorDatasets[0]?.id
    const targetDatasetId =
      changeTargetDatasetId || availableVectorDatasets.find((dataset) => dataset.id !== sourceDatasetId)?.id
    if (!sourceDatasetId || !targetDatasetId) {
      setChangeDetectionError('Kies twee vectorbronnen')
      return
    }
    if (sourceDatasetId === targetDatasetId) {
      setChangeDetectionError('Source and target datasets must differ')
      return
    }
    if (changeIouThreshold < 0 || changeIouThreshold > 1) {
      setChangeDetectionError('De IoU-drempel moet tussen 0 en 1 liggen.')
      return
    }
    setChangeDetectionError(null)
    setChangeDetectionResult(null)
    setRunningChangeDetection(true)
    const selection = getSelection?.() ?? { bbox: null, areaId: null }
    try {
      const job = await analysisApi.runChangeDetection({
        source_dataset_id: sourceDatasetId,
        target_dataset_id: targetDatasetId,
        iou_threshold: changeIouThreshold,
        include_unchanged: changeIncludeUnchanged,
        ...(selection.bbox ? { bbox: selection.bbox } : {}),
        ...(selection.areaId ? { area_id: selection.areaId } : {}),
      })
      if (job.status !== 'success') {
        throw new Error(job.error_message || 'De wijzigingsanalyse is mislukt.')
      }
      if (!job.result_json) {
        throw new Error('De wijzigingsanalyse is afgerond zonder resultaat.')
      }
      setChangeSourceDatasetId(sourceDatasetId)
      setChangeTargetDatasetId(targetDatasetId)
      setChangeDetectionResult(job.result_json)
      if (selectedProjectId) {
        await loadDatasetJobs(selectedProjectId, sourceDatasetId)
      }
    } catch (error) {
      setChangeDetectionError(formatError(error, 'Change detection failed'))
    } finally {
      setRunningChangeDetection(false)
    }
  }

  return {
    changeSourceDatasetId,
    changeTargetDatasetId,
    changeIouThreshold,
    changeIncludeUnchanged,
    runningChangeDetection,
    changeDetectionResult,
    changeDetectionError,
    runChangeDetection,
    setChangeSourceDatasetId,
    setChangeTargetDatasetId,
    setChangeIouThreshold,
    setChangeIncludeUnchanged,
  }
}