'use client'

import { useState, useEffect, useCallback, useRef } from 'react'
import { CanonicalControl, Framework, BACKEND_URL } from './helpers'

export interface ControlsMeta {
  total: number
  domains: Array<{ domain: string; count: number }>
  sources: Array<{ source: string; count: number }>
  no_source_count: number
  type_counts?: { rich: number; atomic: number; eigenentwicklung: number }
  severity_counts?: Record<string, number>
  verification_method_counts?: Record<string, number>
  category_counts?: Record<string, number>
  evidence_type_counts?: Record<string, number>
  release_state_counts?: Record<string, number>
  // Master-control mapping dimensions (only returned by the MC endpoint)
  use_case_counts?: Record<string, number>
  regulations?: Array<{ source_regulation: string; count: number }>
  mapped_total?: number
  unmapped_count?: number
}

const PAGE_SIZE = 50

export function useControlLibraryState(backendUrlOverride?: string) {
  const backendUrl = backendUrlOverride || BACKEND_URL
  const [frameworks, setFrameworks] = useState<Framework[]>([])
  const [controls, setControls] = useState<CanonicalControl[]>([])
  const [totalCount, setTotalCount] = useState(0)
  const [meta, setMeta] = useState<ControlsMeta | null>(null)
  const [selectedControl, setSelectedControl] = useState<CanonicalControl | null>(null)
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState<string | null>(null)

  // Filters
  const [searchQuery, setSearchQuery] = useState('')
  const [debouncedSearch, setDebouncedSearch] = useState('')
  const [severityFilter, setSeverityFilter] = useState<string>('')
  const [domainFilter, setDomainFilter] = useState<string>('')
  const [stateFilter, setStateFilter] = useState<string>('')
  const [verificationFilter, setVerificationFilter] = useState<string>('')
  const [useCaseFilter, setUseCaseFilter] = useState<string>('')
  const [primaryOnly, setPrimaryOnly] = useState<boolean>(false)
  const [regulationFilter, setRegulationFilter] = useState<string>('')
  const [mappedFilter, setMappedFilter] = useState<string>('')
  const [categoryFilter, setCategoryFilter] = useState<string>('')
  const [evidenceTypeFilter, setEvidenceTypeFilter] = useState<string>('')
  const [audienceFilter, setAudienceFilter] = useState<string>('')
  const [sourceFilter, setSourceFilter] = useState<string>('')
  const [typeFilter, setTypeFilter] = useState<string>('')
  const [hideDuplicates, setHideDuplicates] = useState(true)
  const [sortBy, setSortBy] = useState<'id' | 'newest' | 'oldest' | 'source'>('id')

  // CRUD / UI state
  const [mode, setMode] = useState<'list' | 'detail' | 'create' | 'edit'>('list')
  const [saving, setSaving] = useState(false)
  const [showGenerator, setShowGenerator] = useState(false)
  const [processedStats, setProcessedStats] = useState<Array<Record<string, unknown>>>([])
  const [showStats, setShowStats] = useState(false)
  const [currentPage, setCurrentPage] = useState(1)
  const [bulkProcessing, setBulkProcessing] = useState(false)

  // Review state
  const [reviewMode, setReviewMode] = useState(false)
  const [reviewIndex, setReviewIndex] = useState(0)
  const [reviewItems, setReviewItems] = useState<CanonicalControl[]>([])
  const [reviewCount, setReviewCount] = useState(0)
  const [reviewTab, setReviewTab] = useState<'duplicates' | 'rule3'>('duplicates')
  const [reviewDuplicates, setReviewDuplicates] = useState<CanonicalControl[]>([])
  const [reviewRule3, setReviewRule3] = useState<CanonicalControl[]>([])

  // V1 Compare state
  const [compareMode, setCompareMode] = useState(false)
  const [compareV1Control, setCompareV1Control] = useState<CanonicalControl | null>(null)
  const [compareMatches, setCompareMatches] = useState<Array<{
    matched_control_id: string; matched_title: string; matched_objective: string
    matched_severity: string; matched_category: string
    matched_source: string | null; matched_article: string | null
    matched_source_citation: Record<string, string> | null
    similarity_score: number; match_rank: number; match_method: string
  }>>([])

  const metaAbortRef = useRef<AbortController | null>(null)
  const controlsAbortRef = useRef<AbortController | null>(null)
  const searchTimer = useRef<ReturnType<typeof setTimeout> | null>(null)

  useEffect(() => {
    if (searchTimer.current) clearTimeout(searchTimer.current)
    searchTimer.current = setTimeout(() => setDebouncedSearch(searchQuery), 400)
    return () => { if (searchTimer.current) clearTimeout(searchTimer.current) }
  }, [searchQuery])

  const buildParams = useCallback((extra?: Record<string, string>) => {
    const p = new URLSearchParams()
    if (severityFilter) p.set('severity', severityFilter)
    if (domainFilter) p.set('domain', domainFilter)
    if (stateFilter) p.set('release_state', stateFilter)
    if (verificationFilter) p.set('verification_method', verificationFilter)
    if (useCaseFilter) p.set('use_case', useCaseFilter)
    if (primaryOnly) p.set('primary', '1')
    if (regulationFilter) p.set('source_regulation', regulationFilter)
    if (mappedFilter) p.set('mapped', mappedFilter)
    if (categoryFilter) p.set('category', categoryFilter)
    if (evidenceTypeFilter) p.set('evidence_type', evidenceTypeFilter)
    if (audienceFilter) p.set('target_audience', audienceFilter)
    if (sourceFilter) p.set('source', sourceFilter)
    if (typeFilter) p.set('control_type', typeFilter)
    if (hideDuplicates) p.set('exclude_duplicates', 'true')
    if (debouncedSearch) p.set('search', debouncedSearch)
    if (extra) for (const [k, v] of Object.entries(extra)) p.set(k, v)
    return p.toString()
  }, [severityFilter, domainFilter, stateFilter, verificationFilter, useCaseFilter, primaryOnly, regulationFilter, mappedFilter, categoryFilter, evidenceTypeFilter, audienceFilter, sourceFilter, typeFilter, hideDuplicates, debouncedSearch])

  const loadFrameworks = useCallback(async () => {
    try {
      const res = await fetch(`${backendUrl}?endpoint=frameworks`)
      if (res.ok) setFrameworks(await res.json())
    } catch { /* ignore */ }
  }, [])

  const loadMeta = useCallback(async () => {
    if (metaAbortRef.current) metaAbortRef.current.abort()
    const controller = new AbortController()
    metaAbortRef.current = controller
    try {
      const qs = buildParams()
      const res = await fetch(`${backendUrl}?endpoint=controls-meta${qs ? `&${qs}` : ''}`, { signal: controller.signal })
      if (res.ok && !controller.signal.aborted) setMeta(await res.json())
    } catch (e) {
      if (e instanceof DOMException && e.name === 'AbortError') return
    }
  }, [buildParams])

  const loadControls = useCallback(async () => {
    if (controlsAbortRef.current) controlsAbortRef.current.abort()
    const controller = new AbortController()
    controlsAbortRef.current = controller
    try {
      setLoading(true)
      const sortField = sortBy === 'id' ? 'control_id' : sortBy === 'source' ? 'source' : 'created_at'
      const sortOrder = sortBy === 'newest' ? 'desc' : sortBy === 'oldest' ? 'asc' : 'asc'
      const offset = (currentPage - 1) * PAGE_SIZE
      const qs = buildParams({ sort: sortField, order: sortOrder, limit: String(PAGE_SIZE), offset: String(offset) })
      const countQs = buildParams()
      const [ctrlRes, countRes] = await Promise.all([
        fetch(`${backendUrl}?endpoint=controls&${qs}`, { signal: controller.signal }),
        fetch(`${backendUrl}?endpoint=controls-count&${countQs}`, { signal: controller.signal }),
      ])
      if (!controller.signal.aborted) {
        if (ctrlRes.ok) setControls(await ctrlRes.json())
        if (countRes.ok) { const data = await countRes.json(); setTotalCount(data.total || 0) }
      }
    } catch (err) {
      if (err instanceof DOMException && err.name === 'AbortError') return
      setError(err instanceof Error ? err.message : 'Fehler beim Laden')
    } finally {
      if (!controller.signal.aborted) setLoading(false)
    }
  }, [buildParams, sortBy, currentPage])

  const loadReviewCount = useCallback(async () => {
    try {
      const res = await fetch(`${backendUrl}?endpoint=controls-count&release_state=needs_review`)
      if (res.ok) { const data = await res.json(); setReviewCount(data.total || 0) }
    } catch { /* ignore */ }
  }, [])

  useEffect(() => { loadFrameworks(); loadReviewCount() }, [loadFrameworks, loadReviewCount])
  useEffect(() => { loadMeta() }, [loadMeta])
  useEffect(() => { loadControls() }, [loadControls])
  useEffect(() => { setCurrentPage(1) }, [severityFilter, domainFilter, stateFilter, verificationFilter, useCaseFilter, primaryOnly, regulationFilter, mappedFilter, categoryFilter, evidenceTypeFilter, audienceFilter, sourceFilter, typeFilter, hideDuplicates, debouncedSearch, sortBy])

  const totalPages = Math.max(1, Math.ceil(totalCount / PAGE_SIZE))

  const fullReload = useCallback(async () => {
    await Promise.all([loadControls(), loadMeta(), loadFrameworks(), loadReviewCount()])
  }, [loadControls, loadMeta, loadFrameworks, loadReviewCount])

  const loadProcessedStats = async () => {
    try {
      const res = await fetch(`${backendUrl}?endpoint=processed-stats`)
      if (res.ok) { const data = await res.json(); setProcessedStats(data.stats || []) }
    } catch { /* ignore */ }
  }

  const enterReviewMode = async () => {
    try {
      const res = await fetch(`${backendUrl}?endpoint=controls&release_state=needs_review&limit=1000`)
      if (res.ok) {
        const items: CanonicalControl[] = await res.json()
        if (items.length > 0) {
          const dupes = items.filter(c => c.generation_metadata?.similar_controls && Array.isArray(c.generation_metadata.similar_controls) && (c.generation_metadata.similar_controls as unknown[]).length > 0)
          const rule3 = items.filter(c => !c.generation_metadata?.similar_controls || !Array.isArray(c.generation_metadata.similar_controls) || (c.generation_metadata.similar_controls as unknown[]).length === 0)
          setReviewDuplicates(dupes)
          setReviewRule3(rule3)
          const startTab = dupes.length > 0 ? 'duplicates' : 'rule3'
          const startItems = startTab === 'duplicates' ? dupes : rule3
          setReviewTab(startTab)
          setReviewItems(startItems)
          setReviewMode(true)
          setReviewIndex(0)
          setSelectedControl(startItems[0])
          setMode('detail')
        }
      }
    } catch { /* ignore */ }
  }

  const switchReviewTab = (tab: 'duplicates' | 'rule3') => {
    const items = tab === 'duplicates' ? reviewDuplicates : reviewRule3
    setReviewTab(tab)
    setReviewItems(items)
    setReviewIndex(0)
    if (items.length > 0) setSelectedControl(items[0])
  }

  return {
    // Data
    frameworks, controls, totalCount, meta, selectedControl, setSelectedControl,
    loading, error,
    // Filters
    searchQuery, setSearchQuery, debouncedSearch,
    severityFilter, setSeverityFilter,
    domainFilter, setDomainFilter,
    stateFilter, setStateFilter,
    verificationFilter, setVerificationFilter,
    useCaseFilter, setUseCaseFilter,
    primaryOnly, setPrimaryOnly,
    regulationFilter, setRegulationFilter,
    mappedFilter, setMappedFilter,
    categoryFilter, setCategoryFilter,
    evidenceTypeFilter, setEvidenceTypeFilter,
    audienceFilter, setAudienceFilter,
    sourceFilter, setSourceFilter,
    typeFilter, setTypeFilter,
    hideDuplicates, setHideDuplicates,
    sortBy, setSortBy,
    // CRUD/UI
    mode, setMode, saving, setSaving,
    showGenerator, setShowGenerator,
    processedStats, showStats, setShowStats,
    currentPage, setCurrentPage, totalPages,
    bulkProcessing, setBulkProcessing,
    // Review
    reviewMode, setReviewMode,
    reviewIndex, setReviewIndex,
    reviewItems, setReviewItems,
    reviewCount, reviewTab,
    reviewDuplicates, reviewRule3,
    // V1 Compare
    compareMode, setCompareMode,
    compareV1Control, setCompareV1Control,
    compareMatches, setCompareMatches,
    // Actions
    fullReload, loadControls, loadMeta, loadFrameworks, loadReviewCount,
    loadProcessedStats, enterReviewMode, switchReviewTab,
  }
}