'use client'

import { useState, useEffect } from 'react'
import { useSDK, Risk, RiskLikelihood, RiskImpact, RiskSeverity, RiskStatus, RiskMitigation, calculateRiskScore, getRiskSeverityFromScore } from '@/lib/sdk'
import { RiskFormData } from '../_components/RiskForm'

export function useRisks() {
  const { state, dispatch, addRisk } = useSDK()
  const [showForm, setShowForm] = useState(false)
  const [editingRisk, setEditingRisk] = useState<Risk | null>(null)
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState<string | null>(null)
  const [matrixFilter, setMatrixFilter] = useState<{ likelihood: number; impact: number } | null>(null)

  useEffect(() => {
    const fetchRisks = async () => {
      try {
        setLoading(true)
        const res = await fetch('/api/sdk/v1/compliance/risks')
        if (res.ok) {
          const data = await res.json()
          const backendRisks = data.risks || data
          if (Array.isArray(backendRisks) && backendRisks.length > 0) {
            const mapped: Risk[] = backendRisks.map((r: Record<string, unknown>) => ({
              id: (r.risk_id || r.id || '') as string,
              title: (r.title || '') as string,
              description: (r.description || '') as string,
              category: (r.category || 'technical') as string,
              likelihood: (r.likelihood || 3) as RiskLikelihood,
              impact: (r.impact || 3) as RiskImpact,
              severity: ((r.inherent_risk || r.severity || 'MEDIUM') as string).toUpperCase() as RiskSeverity,
              inherentRiskScore: (r.likelihood as number || 3) * (r.impact as number || 3),
              residualRiskScore: (r.residual_likelihood as number || r.likelihood as number || 3) * (r.residual_impact as number || r.impact as number || 3),
              status: (r.status || 'IDENTIFIED') as RiskStatus,
              mitigation: (Array.isArray(r.mitigating_controls) ? (r.mitigating_controls as RiskMitigation[]) : []) as RiskMitigation[],
              owner: (r.owner || null) as string | null,
              relatedControls: [] as string[],
              relatedRequirements: [] as string[],
            }))
            dispatch({ type: 'SET_STATE', payload: { risks: mapped } })
            setError(null)
          }
        }
      } catch {
        // Backend unavailable — use SDK state as-is
      } finally {
        setLoading(false)
      }
    }

    fetchRisks()
  }, []) // eslint-disable-line react-hooks/exhaustive-deps

  const handleSubmit = async (data: RiskFormData) => {
    const score = calculateRiskScore(data.likelihood, data.impact)
    const severity = getRiskSeverityFromScore(score)

    if (editingRisk) {
      dispatch({
        type: 'UPDATE_RISK',
        payload: {
          id: editingRisk.id,
          data: { ...data, severity, inherentRiskScore: score, residualRiskScore: score },
        },
      })
      try {
        await fetch(`/api/sdk/v1/compliance/risks/${editingRisk.id}`, {
          method: 'PUT',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({
            title: data.title,
            description: data.description,
            category: data.category,
            likelihood: data.likelihood,
            impact: data.impact,
          }),
        })
      } catch {
        // Silently fail
      }
    } else {
      const riskId = `risk-${Date.now()}`
      const newRisk: Risk = {
        id: riskId,
        ...data,
        severity,
        inherentRiskScore: score,
        residualRiskScore: score,
        status: 'IDENTIFIED',
        mitigation: [],
        owner: null,
        relatedControls: [],
        relatedRequirements: [],
      }
      addRisk(newRisk)
      try {
        await fetch('/api/sdk/v1/compliance/risks', {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({
            risk_id: riskId,
            title: data.title,
            description: data.description,
            category: data.category,
            likelihood: data.likelihood,
            impact: data.impact,
          }),
        })
      } catch {
        // Silently fail
      }
    }

    setShowForm(false)
    setEditingRisk(null)
  }

  const handleDelete = async (id: string) => {
    if (!confirm('Moechten Sie dieses Risiko wirklich loeschen?')) return
    dispatch({ type: 'DELETE_RISK', payload: id })
    try {
      await fetch(`/api/sdk/v1/compliance/risks/${id}`, { method: 'DELETE' })
    } catch {
      // Silently fail
    }
  }

  const handleStatusChange = async (riskId: string, status: RiskStatus) => {
    dispatch({ type: 'UPDATE_RISK', payload: { id: riskId, data: { status } } })
    try {
      await fetch(`/api/sdk/v1/compliance/risks/${riskId}`, {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ status }),
      })
    } catch {
      // Silently fail
    }
  }

  const handleEdit = (risk: Risk) => {
    setEditingRisk(risk)
    setShowForm(true)
  }

  const handleMatrixCellClick = (l: number, i: number) => {
    if (matrixFilter && matrixFilter.likelihood === l && matrixFilter.impact === i) {
      setMatrixFilter(null)
    } else {
      setMatrixFilter({ likelihood: l, impact: i })
    }
  }

  const stats = {
    totalRisks: state.risks.length,
    criticalRisks: state.risks.filter(r => r.severity === 'CRITICAL').length,
    highRisks: state.risks.filter(r => r.severity === 'HIGH').length,
    mitigatedRisks: state.risks.filter(r => r.mitigation.length > 0).length,
  }

  const filteredRisks = state.risks
    .filter(risk => !matrixFilter || (risk.likelihood === matrixFilter.likelihood && risk.impact === matrixFilter.impact))
    .sort((a, b) => b.inherentRiskScore - a.inherentRiskScore)

  return {
    state,
    showForm,
    setShowForm,
    editingRisk,
    setEditingRisk,
    loading,
    error,
    setError,
    matrixFilter,
    setMatrixFilter,
    handleSubmit,
    handleDelete,
    handleStatusChange,
    handleEdit,
    handleMatrixCellClick,
    stats,
    filteredRisks,
  }
}