import { useEffect, useState } from 'react'
import { externalApi } from '../services/api'
import type { CoverageResolveResponse, VectorSelectionBBox } from '../types'
import {
  COVERAGE_RESPONSE_BUDGET_MS,
  exceedsPerformanceBudget,
} from '../lib/performanceBudget'

interface CoverageResolverOptions {
  projectId: string | null
  bbox: VectorSelectionBBox | null
}

export function useCoverageResolver({ projectId, bbox }: CoverageResolverOptions) {
  const [coverage, setCoverage] = useState<CoverageResolveResponse | null>(null)
  const [loadingCoverage, setLoadingCoverage] = useState(false)
  const [coverageError, setCoverageError] = useState<string | null>(null)
  const [coverageDurationMs, setCoverageDurationMs] = useState<number | null>(null)

  useEffect(() => {
    if (!projectId || !bbox) {
      setCoverage(null)
      setCoverageError(null)
      setLoadingCoverage(false)
      setCoverageDurationMs(null)
      return
    }
    let cancelled = false
    // A new AOI must never temporarily display the previous AOI's coverage.
    // Clear immediately; the debounce only postpones the network request.
    setCoverage(null)
    setCoverageError(null)
    setLoadingCoverage(true)
    setCoverageDurationMs(null)
    const timer = window.setTimeout(() => {
      const startedAt = Date.now()
      externalApi.resolveCoverage({
        projectId,
        bbox: {
          minx: bbox.min_x,
          miny: bbox.min_y,
          maxx: bbox.max_x,
          maxy: bbox.max_y,
        },
      })
        .then((result) => {
          if (!cancelled) {
            setCoverage(result)
          }
        })
        .catch((error) => {
          if (!cancelled) {
            setCoverage(null)
            setCoverageError(error instanceof Error ? error.message : 'Dekking kon niet worden bepaald')
          }
        })
        .finally(() => {
          if (!cancelled) {
            setCoverageDurationMs(Date.now() - startedAt)
            setLoadingCoverage(false)
          }
        })
    }, 250)
    return () => {
      cancelled = true
      window.clearTimeout(timer)
    }
  }, [projectId, bbox?.min_x, bbox?.min_y, bbox?.max_x, bbox?.max_y])

  return {
    coverage,
    loadingCoverage,
    coverageError,
    coverageDurationMs,
    coverageBudgetExceeded: exceedsPerformanceBudget(
      coverageDurationMs,
      COVERAGE_RESPONSE_BUDGET_MS,
    ),
  }
}