'use client'

import { useState, useEffect } from 'react'
import type {
  DashboardData, Regulation, MappingsData, FindingsData,
  RoadmapData, ModuleStatusData, NextAction, ScoreSnapshot,
  TraceabilityMatrixData, TabKey,
} from '../_components/types'

export function useComplianceHub() {
  const [activeTab, setActiveTab] = useState<TabKey>('overview')
  const [dashboard, setDashboard] = useState<DashboardData | null>(null)
  const [regulations, setRegulations] = useState<Regulation[]>([])
  const [mappings, setMappings] = useState<MappingsData | null>(null)
  const [findings, setFindings] = useState<FindingsData | null>(null)
  const [roadmap, setRoadmap] = useState<RoadmapData | null>(null)
  const [moduleStatus, setModuleStatus] = useState<ModuleStatusData | null>(null)
  const [nextActions, setNextActions] = useState<NextAction[]>([])
  const [scoreHistory, setScoreHistory] = useState<ScoreSnapshot[]>([])
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState<string | null>(null)
  const [seeding, setSeeding] = useState(false)
  const [savingSnapshot, setSavingSnapshot] = useState(false)
  const [evidenceDistribution, setEvidenceDistribution] = useState<{
    by_confidence: Record<string, number>
    four_eyes_pending: number
    total: number
  } | null>(null)
  const [traceabilityMatrix, setTraceabilityMatrix] = useState<TraceabilityMatrixData | null>(null)
  const [traceabilityLoading, setTraceabilityLoading] = useState(false)
  const [traceabilityFilter, setTraceabilityFilter] = useState<'all' | 'covered' | 'uncovered' | 'fully_verified'>('all')
  const [traceabilityDomainFilter, setTraceabilityDomainFilter] = useState<string>('all')
  const [expandedControls, setExpandedControls] = useState<Set<string>>(new Set())
  const [expandedEvidence, setExpandedEvidence] = useState<Set<string>>(new Set())

  useEffect(() => {
    loadData()
  }, [])

  useEffect(() => {
    if (activeTab === 'roadmap' && !roadmap) loadRoadmap()
    if (activeTab === 'modules' && !moduleStatus) loadModuleStatus()
    if (activeTab === 'trend' && scoreHistory.length === 0) loadScoreHistory()
    if (activeTab === 'traceability' && !traceabilityMatrix) loadTraceabilityMatrix()
  }, [activeTab]) // eslint-disable-line react-hooks/exhaustive-deps

  const loadData = async () => {
    setLoading(true)
    setError(null)
    try {
      const [dashboardRes, regulationsRes, mappingsRes, findingsRes, actionsRes] = await Promise.all([
        fetch('/api/sdk/v1/compliance/dashboard'),
        fetch('/api/sdk/v1/compliance/regulations'),
        fetch('/api/sdk/v1/compliance/mappings'),
        fetch('/api/sdk/v1/isms/findings?status=open'),
        fetch('/api/sdk/v1/compliance/dashboard/next-actions?limit=5'),
      ])

      if (dashboardRes.ok) setDashboard(await dashboardRes.json())
      if (regulationsRes.ok) {
        const data = await regulationsRes.json()
        setRegulations(data.regulations || [])
      }
      if (mappingsRes.ok) setMappings(await mappingsRes.json())
      if (findingsRes.ok) setFindings(await findingsRes.json())
      if (actionsRes.ok) {
        const data = await actionsRes.json()
        setNextActions(data.actions || [])
      }

      // Evidence distribution (Anti-Fake-Evidence Phase 3)
      try {
        const evidenceDistRes = await fetch('/api/sdk/v1/compliance/dashboard/evidence-distribution')
        if (evidenceDistRes.ok) setEvidenceDistribution(await evidenceDistRes.json())
      } catch { /* silent */ }
    } catch (err) {
      console.error('Failed to load compliance data:', err)
      setError('Verbindung zum Backend fehlgeschlagen')
    } finally {
      setLoading(false)
    }
  }

  const loadRoadmap = async () => {
    try {
      const res = await fetch('/api/sdk/v1/compliance/dashboard/roadmap')
      if (res.ok) setRoadmap(await res.json())
    } catch { /* silent */ }
  }

  const loadModuleStatus = async () => {
    try {
      const res = await fetch('/api/sdk/v1/compliance/dashboard/module-status')
      if (res.ok) setModuleStatus(await res.json())
    } catch { /* silent */ }
  }

  const loadScoreHistory = async () => {
    try {
      const res = await fetch('/api/sdk/v1/compliance/dashboard/score-history?months=12')
      if (res.ok) {
        const data = await res.json()
        setScoreHistory(data.snapshots || [])
      }
    } catch { /* silent */ }
  }

  const loadTraceabilityMatrix = async () => {
    setTraceabilityLoading(true)
    try {
      const res = await fetch('/api/sdk/v1/compliance/dashboard/traceability-matrix')
      if (res.ok) setTraceabilityMatrix(await res.json())
    } catch { /* silent */ }
    finally { setTraceabilityLoading(false) }
  }

  const toggleControlExpanded = (id: string) => {
    setExpandedControls(prev => {
      const next = new Set(prev)
      if (next.has(id)) next.delete(id); else next.add(id)
      return next
    })
  }

  const toggleEvidenceExpanded = (id: string) => {
    setExpandedEvidence(prev => {
      const next = new Set(prev)
      if (next.has(id)) next.delete(id); else next.add(id)
      return next
    })
  }

  const saveSnapshot = async () => {
    setSavingSnapshot(true)
    try {
      const res = await fetch('/api/sdk/v1/compliance/dashboard/snapshot', { method: 'POST' })
      if (res.ok) {
        loadScoreHistory()
      }
    } catch { /* silent */ }
    finally { setSavingSnapshot(false) }
  }

  const seedDatabase = async () => {
    setSeeding(true)
    try {
      const res = await fetch('/api/sdk/v1/compliance/seed', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ force: false }),
      })

      if (res.ok) {
        const result = await res.json()
        alert(`Datenbank erfolgreich initialisiert!\n\nRegulations: ${result.counts?.regulations || 0}\nControls: ${result.counts?.controls || 0}\nRequirements: ${result.counts?.requirements || 0}`)
        loadData()
      } else {
        const error = await res.text()
        alert(`Fehler beim Seeding: ${error}`)
      }
    } catch (err) {
      console.error('Seeding failed:', err)
      alert('Fehler beim Initialisieren der Datenbank')
    } finally {
      setSeeding(false)
    }
  }

  return {
    activeTab, setActiveTab,
    dashboard, regulations, mappings, findings,
    roadmap, moduleStatus, nextActions, scoreHistory,
    loading, error, seeding, savingSnapshot,
    evidenceDistribution, traceabilityMatrix, traceabilityLoading,
    traceabilityFilter, setTraceabilityFilter,
    traceabilityDomainFilter, setTraceabilityDomainFilter,
    expandedControls, expandedEvidence,
    loadData, saveSnapshot, seedDatabase,
    toggleControlExpanded, toggleEvidenceExpanded,
  }
}