'use client'

import React, { useState, useEffect, useRef } from 'react'
import { useParams } from 'next/navigation'
import { TechFileEditor } from '@/components/sdk/iace/TechFileEditor'
import { ReportGenerator } from './_components/ReportGenerator'
import { ExportCIDBadge, type LastExport } from './_components/ExportCIDBadge'
import { SECTION_TYPES, STATUS_CONFIG, EXPORT_FORMATS } from './_constants'

interface TechFileSection {
  id: string
  section_type: string
  title: string
  description: string
  content: string | null
  status: 'empty' | 'draft' | 'generated' | 'reviewed' | 'approved'
  generated_at: string | null
  approved_at: string | null
  approved_by: string | null
  required: boolean
}

function StatusBadge({ status }: { status: string }) {
  const config = STATUS_CONFIG[status] || STATUS_CONFIG.empty
  return (
    <span className={`inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium ${config.bgColor} ${config.color}`}>
      {config.label}
    </span>
  )
}

function SectionViewer({
  section,
  onClose,
  onApprove,
  onSave,
}: {
  section: TechFileSection
  onClose: () => void
  onApprove: (id: string) => void
  onSave: (id: string, content: string) => void
}) {
  const [editing, setEditing] = useState(false)

  return (
    <div className="bg-white dark:bg-gray-800 rounded-xl border border-gray-200 dark:border-gray-700">
      <div className="px-6 py-4 border-b border-gray-200 dark:border-gray-700 flex items-center justify-between">
        <div className="flex items-center gap-3">
          <span className="text-xl">{SECTION_TYPES[section.section_type]?.icon || '📄'}</span>
          <div>
            <h3 className="text-lg font-semibold text-gray-900 dark:text-white">{section.title}</h3>
            <StatusBadge status={section.status} />
          </div>
        </div>
        <div className="flex items-center gap-2">
          {!editing && section.content && (
            <button
              onClick={() => setEditing(true)}
              className="text-sm px-3 py-1.5 border border-gray-300 text-gray-700 rounded-lg hover:bg-gray-50 transition-colors"
            >
              Bearbeiten
            </button>
          )}
          {editing && (
            <button
              onClick={() => setEditing(false)}
              className="text-sm px-3 py-1.5 border border-gray-300 text-gray-700 rounded-lg hover:bg-gray-50 transition-colors"
            >
              Fertig
            </button>
          )}
          {section.status !== 'approved' && section.content && !editing && (
            <button
              onClick={() => onApprove(section.id)}
              className="text-sm px-3 py-1.5 bg-green-600 text-white rounded-lg hover:bg-green-700 transition-colors"
            >
              Freigeben
            </button>
          )}
          <button onClick={onClose} className="p-1 text-gray-400 hover:text-gray-600 rounded">
            <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
            </svg>
          </button>
        </div>
      </div>
      <div className="p-6">
        {section.content ? (
          editing ? (
            <TechFileEditor
              content={section.content}
              onSave={(html) => onSave(section.id, html)}
            />
          ) : (
            <TechFileEditor
              content={section.content}
              onSave={() => {}}
              readOnly
            />
          )
        ) : (
          <div className="text-center py-8 text-gray-500">
            Kein Inhalt vorhanden. Klicken Sie &quot;Generieren&quot; um den Abschnitt zu erstellen.
          </div>
        )}
      </div>
    </div>
  )
}

export default function TechFilePage() {
  const params = useParams()
  const projectId = params.projectId as string
  const [sections, setSections] = useState<TechFileSection[]>([])
  const [loading, setLoading] = useState(true)
  const [generatingSection, setGeneratingSection] = useState<string | null>(null)
  const [viewingSection, setViewingSection] = useState<TechFileSection | null>(null)
  const [exporting, setExporting] = useState(false)
  const [showExportMenu, setShowExportMenu] = useState(false)
  const [lastExport, setLastExport] = useState<LastExport | null>(null)
  const exportMenuRef = useRef<HTMLDivElement>(null)

  // Close export menu when clicking outside
  useEffect(() => {
    function handleClickOutside(event: MouseEvent) {
      if (exportMenuRef.current && !exportMenuRef.current.contains(event.target as Node)) {
        setShowExportMenu(false)
      }
    }
    if (showExportMenu) {
      document.addEventListener('mousedown', handleClickOutside)
      return () => document.removeEventListener('mousedown', handleClickOutside)
    }
  }, [showExportMenu])

  useEffect(() => {
    fetchSections()
  }, [projectId])

  async function fetchSections() {
    try {
      const res = await fetch(`/api/sdk/v1/iace/projects/${projectId}/tech-file`)
      if (res.ok) {
        const json = await res.json()
        const raw = json.sections || json || []
        // Map html_content → content for frontend compatibility
        setSections(raw.map((s: Record<string, unknown>) => ({
          ...s,
          content: s.content || s.html_content || null,
        })))
      }
    } catch (err) {
      console.error('Failed to fetch tech file sections:', err)
    } finally {
      setLoading(false)
    }
  }

  async function handleGenerate(sectionId: string) {
    setGeneratingSection(sectionId)
    try {
      const res = await fetch(`/api/sdk/v1/iace/projects/${projectId}/tech-file/${sectionId}/generate`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
      })
      if (res.ok) {
        await fetchSections()
      }
    } catch (err) {
      console.error('Failed to generate section:', err)
    } finally {
      setGeneratingSection(null)
    }
  }

  async function handleApprove(sectionId: string) {
    try {
      const res = await fetch(`/api/sdk/v1/iace/projects/${projectId}/tech-file/${sectionId}/approve`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
      })
      if (res.ok) {
        await fetchSections()
        if (viewingSection && viewingSection.id === sectionId) {
          const updated = sections.find((s) => s.id === sectionId)
          if (updated) setViewingSection({ ...updated, status: 'approved' })
        }
      }
    } catch (err) {
      console.error('Failed to approve section:', err)
    }
  }

  async function handleSave(sectionId: string, content: string) {
    try {
      const res = await fetch(`/api/sdk/v1/iace/projects/${projectId}/tech-file/${sectionId}`, {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ content }),
      })
      if (res.ok) {
        await fetchSections()
      }
    } catch (err) {
      console.error('Failed to save section:', err)
    }
  }

  async function handleExport(format: string) {
    setExporting(true)
    setShowExportMenu(false)
    try {
      const res = await fetch(
        `/api/sdk/v1/iace/projects/${projectId}/tech-file/export?format=${format}`,
        { method: 'GET' }
      )
      if (res.ok) {
        const blob = await res.blob()
        const url = window.URL.createObjectURL(blob)
        const formatConfig = EXPORT_FORMATS.find((f) => f.value === format)
        const extension = formatConfig?.extension || `.${format}`
        const a = document.createElement('a')
        a.href = url
        a.download = `CE-Akte-${projectId}${extension}`
        document.body.appendChild(a)
        a.click()
        document.body.removeChild(a)
        window.URL.revokeObjectURL(url)

        // DSMS archive metadata is forwarded by the backend in X-DSMS-* headers
        // when archiving succeeded. If headers are absent (DSMS gateway down)
        // the export still works but no badge is shown.
        const cid = res.headers.get('x-dsms-cid')
        if (cid) {
          setLastExport({
            cid,
            filename: res.headers.get('x-dsms-filename') || `CE-Akte-${projectId}${extension}`,
            size: parseInt(res.headers.get('x-dsms-size') || '0', 10) || blob.size,
            format,
          })
        }
      }
    } catch (err) {
      console.error('Failed to export:', err)
    } finally {
      setExporting(false)
    }
  }

  const approvedCount = sections.filter((s) => s.status === 'approved').length
  const requiredCount = sections.filter((s) => s.required).length
  const requiredApproved = sections.filter((s) => s.required && s.status === 'approved').length
  const allRequiredApproved = requiredApproved === requiredCount && requiredCount > 0

  if (loading) {
    return (
      <div className="flex items-center justify-center h-64">
        <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-purple-600" />
      </div>
    )
  }

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex items-start justify-between">
        <div>
          <h1 className="text-2xl font-bold text-gray-900 dark:text-white">CE-Akte (Technical File)</h1>
          <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
            Technische Dokumentation gemaess Maschinenverordnung Anhang IV. Generieren, pruefen und freigeben
            Sie alle erforderlichen Abschnitte.
          </p>
          <div className="mt-2 p-2.5 rounded-lg bg-amber-50 dark:bg-amber-900/20 border border-amber-200 dark:border-amber-800 text-xs text-amber-800 dark:text-amber-300 max-w-2xl">
            <strong>Hinweis:</strong> Unterstuetzte Risikobeurteilung — automatisch erkannte Gefaehrdungen und Massnahmen sind eine qualifizierte Ausgangsbasis.
            Vollstaendigkeit muss vom CE-Verantwortlichen validiert werden. Dieses Tool ersetzt nicht die Pflichten des Herstellers nach EU 2023/1230.
          </div>
        </div>
        <div className="flex items-center gap-3">
        {/* Risk Report Export (PDF + Excel) — always available */}
        <ReportGenerator projectId={projectId} />
        {/* Tech-File Export Dropdown — requires all sections approved */}
        <div className="relative" ref={exportMenuRef}>
          <button
            onClick={() => setShowExportMenu((prev) => !prev)}
            disabled={!allRequiredApproved || exporting}
            title={!allRequiredApproved ? 'Alle Pflichtabschnitte muessen freigegeben sein' : 'CE-Akte exportieren'}
            className={`flex items-center gap-2 px-4 py-2 rounded-lg font-medium transition-colors ${
              allRequiredApproved && !exporting
                ? 'bg-purple-600 text-white hover:bg-purple-700'
                : 'bg-gray-200 text-gray-400 cursor-not-allowed'
            }`}
          >
            {exporting ? (
              <div className="animate-spin rounded-full h-4 w-4 border-b-2 border-white" />
            ) : (
              <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 10v6m0 0l-3-3m3 3l3-3m2 8H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z" />
              </svg>
            )}
            Exportieren
            <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
            </svg>
          </button>
          {showExportMenu && allRequiredApproved && !exporting && (
            <div className="absolute right-0 mt-2 w-48 bg-white dark:bg-gray-800 rounded-lg shadow-lg border border-gray-200 dark:border-gray-700 py-1 z-50">
              {EXPORT_FORMATS.map((fmt) => (
                <button
                  key={fmt.value}
                  onClick={() => handleExport(fmt.value)}
                  className="w-full text-left px-4 py-2 text-sm text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 transition-colors flex items-center gap-3"
                >
                  <span className="text-xs font-mono uppercase w-10 text-gray-400">{fmt.extension}</span>
                  <span>{fmt.label}</span>
                </button>
              ))}
            </div>
          )}
        </div>
        </div>
      </div>

      {/* DSMS-CID badge nach erfolgreichem Export */}
      <ExportCIDBadge lastExport={lastExport} onDismiss={() => setLastExport(null)} />

      {/* Progress */}
      <div className="bg-white dark:bg-gray-800 rounded-xl border border-gray-200 dark:border-gray-700 p-4">
        <div className="flex items-center justify-between mb-2">
          <span className="text-sm font-medium text-gray-700 dark:text-gray-300">
            Fortschritt: {approvedCount} von {sections.length} Abschnitten freigegeben
          </span>
          <span className="text-sm text-gray-500">
            Pflicht: {requiredApproved}/{requiredCount}
          </span>
        </div>
        <div className="w-full bg-gray-200 rounded-full h-2.5">
          <div
            className="bg-purple-600 h-2.5 rounded-full transition-all"
            style={{ width: `${sections.length > 0 ? (approvedCount / sections.length) * 100 : 0}%` }}
          />
        </div>
      </div>

      {/* Section Viewer */}
      {viewingSection && (
        <SectionViewer
          section={viewingSection}
          onClose={() => setViewingSection(null)}
          onApprove={handleApprove}
          onSave={handleSave}
        />
      )}

      {/* Sections List */}
      <div className="space-y-3">
        {sections.map((section) => (
          <div
            key={section.id}
            className="bg-white dark:bg-gray-800 rounded-xl border border-gray-200 dark:border-gray-700 p-4"
          >
            <div className="flex items-center gap-4">
              <span className="text-2xl flex-shrink-0">
                {SECTION_TYPES[section.section_type]?.icon || '📄'}
              </span>
              <div className="flex-1 min-w-0">
                <div className="flex items-center gap-2">
                  <h3 className="text-sm font-semibold text-gray-900 dark:text-white">{section.title}</h3>
                  <StatusBadge status={section.status} />
                  {section.required && (
                    <span className="text-xs text-red-500 font-medium">Pflicht</span>
                  )}
                </div>
                <p className="text-xs text-gray-500 mt-0.5">
                  {SECTION_TYPES[section.section_type]?.description || section.description}
                </p>
                {section.approved_at && (
                  <span className="text-xs text-green-600 mt-0.5 block">
                    Freigegeben am {new Date(section.approved_at).toLocaleDateString('de-DE')}
                  </span>
                )}
              </div>
              <div className="flex items-center gap-2 flex-shrink-0">
                {section.content && (
                  <button
                    onClick={() => setViewingSection(section)}
                    className="text-sm px-3 py-1.5 border border-gray-200 text-gray-600 rounded-lg hover:bg-gray-50 transition-colors"
                  >
                    Anzeigen
                  </button>
                )}
                <button
                  onClick={() => handleGenerate(section.id)}
                  disabled={generatingSection === section.id}
                  className="text-sm px-3 py-1.5 bg-purple-600 text-white rounded-lg hover:bg-purple-700 transition-colors disabled:opacity-50 disabled:cursor-not-allowed flex items-center gap-1"
                >
                  {generatingSection === section.id ? (
                    <>
                      <div className="animate-spin rounded-full h-3 w-3 border-b-2 border-white" />
                      Generiert...
                    </>
                  ) : (
                    'Generieren'
                  )}
                </button>
                {section.content && section.status !== 'approved' && (
                  <button
                    onClick={() => handleApprove(section.id)}
                    className="text-sm px-3 py-1.5 bg-green-600 text-white rounded-lg hover:bg-green-700 transition-colors"
                  >
                    Freigeben
                  </button>
                )}
              </div>
            </div>
          </div>
        ))}
      </div>

      {sections.length === 0 && (
        <div className="bg-white dark:bg-gray-800 rounded-xl border border-gray-200 dark:border-gray-700 p-12 text-center">
          <div className="w-16 h-16 mx-auto bg-purple-100 dark:bg-purple-900/30 rounded-full flex items-center justify-center mb-4">
            <svg className="w-8 h-8 text-purple-600" fill="none" viewBox="0 0 24 24" stroke="currentColor">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M3 7v10a2 2 0 002 2h14a2 2 0 002-2V9a2 2 0 00-2-2h-6l-2-2H5a2 2 0 00-2 2z" />
            </svg>
          </div>
          <h3 className="text-lg font-semibold text-gray-900 dark:text-white">Keine Abschnitte vorhanden</h3>
          <p className="mt-2 text-gray-500 max-w-md mx-auto">
            Die CE-Akte wird automatisch strukturiert, sobald Komponenten und Gefaehrdungen erfasst sind.
          </p>
        </div>
      )}
    </div>
  )
}
