import { useState, useEffect } from 'react'
import { api } from '../utils/api'
import UnifiedPromptModal from '../components/UnifiedPromptModal'
import { Star, Trash2, Edit, Copy, Filter, ArrowDownToLine } from 'lucide-react'

/**
 * Admin Prompts Page - Unified System (Issue #28 Phase 3)
 *
 * Manages both base and pipeline-type prompts in one interface.
 */
export default function AdminPromptsPage() {
  const [prompts, setPrompts] = useState([])
  const [filteredPrompts, setFilteredPrompts] = useState([])
  const [typeFilter, setTypeFilter] = useState('all') // 'all' | 'base' | 'pipeline'
  const [category, setCategory] = useState('all')
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState(null)
  const [editingPrompt, setEditingPrompt] = useState(null)
  const [showNewPrompt, setShowNewPrompt] = useState(false)
  const [importing, setImporting] = useState(false)
  const [importResult, setImportResult] = useState(null)

  const categories = [
    { id: 'all', label: 'Alle Kategorien' },
    { id: 'körper', label: 'Körper' },
    { id: 'ernährung', label: 'Ernährung' },
    { id: 'training', label: 'Training' },
    { id: 'schlaf', label: 'Schlaf' },
    { id: 'vitalwerte', label: 'Vitalwerte' },
    { id: 'ziele', label: 'Ziele' },
    { id: 'ganzheitlich', label: 'Ganzheitlich' },
    { id: 'pipeline', label: 'Pipeline' }
  ]

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

  useEffect(() => {
    let filtered = prompts

    // Filter by type
    if (typeFilter === 'base') {
      filtered = filtered.filter(p => p.type === 'base')
    } else if (typeFilter === 'pipeline') {
      filtered = filtered.filter(p => p.type === 'pipeline')
    }

    // Filter by category
    if (category !== 'all') {
      filtered = filtered.filter(p => p.category === category)
    }

    setFilteredPrompts(filtered)
  }, [typeFilter, category, prompts])

  const loadPrompts = async () => {
    try {
      setLoading(true)
      const data = await api.listAdminPrompts()
      setPrompts(data)
      setError(null)
    } catch (e) {
      setError(e.message)
    } finally {
      setLoading(false)
    }
  }

  const handleToggleActive = async (prompt) => {
    try {
      await api.updateUnifiedPrompt(prompt.id, { active: !prompt.active })
      await loadPrompts()
    } catch (e) {
      alert('Fehler: ' + e.message)
    }
  }

  const handleDelete = async (prompt) => {
    if (!confirm(`Prompt "${prompt.name}" wirklich löschen?`)) return

    try {
      await api.deletePrompt(prompt.id)
      await loadPrompts()
    } catch (e) {
      alert('Fehler: ' + e.message)
    }
  }

  const handleDuplicate = async (prompt) => {
    try {
      await api.duplicatePrompt(prompt.id)
      await loadPrompts()
    } catch (e) {
      alert('Fehler: ' + e.message)
    }
  }

  const handleConvertToBase = async (prompt) => {
    // Convert a 1-stage pipeline to a base prompt
    if (prompt.type !== 'pipeline') {
      alert('Nur Pipeline-Prompts können konvertiert werden')
      return
    }

    const stages = typeof prompt.stages === 'string'
      ? JSON.parse(prompt.stages)
      : prompt.stages

    if (!stages || stages.length !== 1) {
      alert('Nur 1-stage Pipeline-Prompts können zu Basis-Prompts konvertiert werden')
      return
    }

    const stage1 = stages[0]
    if (!stage1.prompts || stage1.prompts.length !== 1) {
      alert('Stage muss genau einen Prompt haben')
      return
    }

    const firstPrompt = stage1.prompts[0]
    if (firstPrompt.source !== 'inline' || !firstPrompt.template) {
      alert('Nur inline Templates können konvertiert werden')
      return
    }

    if (!confirm(`"${prompt.name}" zu Basis-Prompt konvertieren?`)) return

    try {
      await api.updateUnifiedPrompt(prompt.id, {
        type: 'base',
        template: firstPrompt.template,
        output_format: firstPrompt.output_format || 'text',
        stages: null
      })
      await loadPrompts()
    } catch (e) {
      alert('Fehler: ' + e.message)
    }
  }

  const handleSave = async () => {
    setEditingPrompt(null)
    setShowNewPrompt(false)
    await loadPrompts()
  }

  const getStageCount = (prompt) => {
    if (prompt.type !== 'pipeline' || !prompt.stages) return 0
    try {
      const stages = typeof prompt.stages === 'string'
        ? JSON.parse(prompt.stages)
        : prompt.stages
      return stages.length
    } catch (e) {
      return 0
    }
  }

  const getTypeLabel = (type) => {
    if (type === 'base') return 'Basis'
    if (type === 'pipeline') return 'Pipeline'
    return type || 'Pipeline' // Default for old prompts
  }

  const getTypeColor = (type) => {
    if (type === 'base') return 'var(--accent)'
    if (type === 'pipeline') return '#6366f1'
    return 'var(--text3)'
  }

  const handleExportAll = async () => {
    try {
      const data = await api.exportAllPrompts()
      const blob = new Blob([JSON.stringify(data, null, 2)], { type: 'application/json' })
      const url = URL.createObjectURL(blob)
      const a = document.createElement('a')
      a.href = url
      a.download = `all-prompts-${new Date().toISOString().split('T')[0]}.json`
      document.body.appendChild(a)
      a.click()
      document.body.removeChild(a)
      URL.revokeObjectURL(url)
    } catch (e) {
      setError('Export-Fehler: ' + e.message)
    }
  }

  const handleImport = async (event) => {
    const file = event.target.files[0]
    if (!file) return

    setImporting(true)
    setError(null)
    setImportResult(null)

    try {
      const text = await file.text()
      const data = JSON.parse(text)

      // Ask user about overwrite
      const overwrite = confirm(
        'Bestehende Prompts überschreiben?\n\n' +
        'JA = Existierende Prompts aktualisieren\n' +
        'NEIN = Nur neue Prompts erstellen, Duplikate überspringen'
      )

      const result = await api.importPrompts(data, overwrite)
      setImportResult(result)
      await loadPrompts()
    } catch (e) {
      setError('Import-Fehler: ' + e.message)
    } finally {
      setImporting(false)
      event.target.value = '' // Reset file input
    }
  }

  return (
    <div style={{
      padding: 20,
      maxWidth: 1400,
      margin: '0 auto',
      paddingBottom: 80
    }}>
      <div style={{
        display: 'flex',
        justifyContent: 'space-between',
        alignItems: 'center',
        marginBottom: 24
      }}>
        <h1 style={{ margin: 0, fontSize: 24, fontWeight: 600 }}>
          KI-Prompts ({filteredPrompts.length})
        </h1>
        <div style={{ display: 'flex', gap: 8 }}>
          <button
            className="btn"
            onClick={handleExportAll}
            title="Alle Prompts als JSON exportieren (Backup / Dev→Prod Sync)"
          >
            📦 Alle exportieren
          </button>
          <label className="btn" style={{ margin: 0, cursor: 'pointer' }}>
            📥 Importieren
            <input
              type="file"
              accept=".json"
              onChange={handleImport}
              disabled={importing}
              style={{ display: 'none' }}
            />
          </label>
          <button
            className="btn btn-primary"
            onClick={() => setShowNewPrompt(true)}
          >
            + Neuer Prompt
          </button>
        </div>
      </div>

      {error && (
        <div style={{
          padding: 16,
          background: '#fee',
          color: '#c00',
          borderRadius: 8,
          marginBottom: 16
        }}>
          {error}
        </div>
      )}

      {importResult && (
        <div style={{
          padding: 16,
          background: '#efe',
          color: '#060',
          borderRadius: 8,
          marginBottom: 16
        }}>
          <div style={{ fontWeight: 600, marginBottom: 4 }}>
            ✅ Import erfolgreich
          </div>
          <div style={{ fontSize: 13 }}>
            {importResult.created} erstellt · {importResult.updated} aktualisiert · {importResult.skipped} übersprungen
          </div>
          <button
            onClick={() => setImportResult(null)}
            style={{ marginTop: 8, fontSize: 12, padding: '4px 8px' }}
            className="btn"
          >
            OK
          </button>
        </div>
      )}

      {/* Filters */}
      <div style={{
        display: 'flex',
        gap: 12,
        marginBottom: 24,
        flexWrap: 'wrap',
        alignItems: 'center'
      }}>
        <div style={{ display: 'flex', alignItems: 'center', gap: 6 }}>
          <Filter size={16} color="var(--text3)" />
          <span style={{ fontSize: 13, color: 'var(--text3)' }}>Typ:</span>
        </div>
        <div style={{ display: 'flex', gap: 6 }}>
          <button
            className={typeFilter === 'all' ? 'btn btn-primary' : 'btn'}
            onClick={() => setTypeFilter('all')}
            style={{ fontSize: 13, padding: '6px 12px' }}
          >
            Alle ({prompts.length})
          </button>
          <button
            className={typeFilter === 'base' ? 'btn btn-primary' : 'btn'}
            onClick={() => setTypeFilter('base')}
            style={{ fontSize: 13, padding: '6px 12px' }}
          >
            Basis-Prompts ({prompts.filter(p => p.type === 'base').length})
          </button>
          <button
            className={typeFilter === 'pipeline' ? 'btn btn-primary' : 'btn'}
            onClick={() => setTypeFilter('pipeline')}
            style={{ fontSize: 13, padding: '6px 12px' }}
          >
            Pipelines ({prompts.filter(p => p.type === 'pipeline' || !p.type).length})
          </button>
        </div>

        <div style={{
          width: 1,
          height: 24,
          background: 'var(--border)',
          margin: '0 8px'
        }} />

        <select
          className="form-select"
          value={category}
          onChange={e => setCategory(e.target.value)}
          style={{ fontSize: 13, padding: '6px 12px' }}
        >
          {categories.map(cat => (
            <option key={cat.id} value={cat.id}>
              {cat.label}
            </option>
          ))}
        </select>
      </div>

      {/* Prompts Table */}
      {loading ? (
        <div style={{ textAlign: 'center', padding: 40, color: 'var(--text3)' }}>
          Lädt...
        </div>
      ) : (
        <div style={{
          background: 'var(--surface)',
          borderRadius: 12,
          border: '1px solid var(--border)',
          overflowX: 'auto'
        }}>
          <table style={{ width: '100%', minWidth: 900, borderCollapse: 'collapse' }}>
            <thead>
              <tr style={{
                background: 'var(--surface2)',
                borderBottom: '1px solid var(--border)'
              }}>
                <th style={{
                  padding: 12,
                  textAlign: 'left',
                  fontSize: 12,
                  fontWeight: 600,
                  color: 'var(--text3)',
                  width: 80
                }}>
                  Typ
                </th>
                <th style={{
                  padding: 12,
                  textAlign: 'left',
                  fontSize: 12,
                  fontWeight: 600,
                  color: 'var(--text3)'
                }}>
                  Name
                </th>
                <th style={{
                  padding: 12,
                  textAlign: 'left',
                  fontSize: 12,
                  fontWeight: 600,
                  color: 'var(--text3)',
                  width: 120
                }}>
                  Kategorie
                </th>
                <th style={{
                  padding: 12,
                  textAlign: 'center',
                  fontSize: 12,
                  fontWeight: 600,
                  color: 'var(--text3)',
                  width: 100
                }}>
                  Stages
                </th>
                <th style={{
                  padding: 12,
                  textAlign: 'center',
                  fontSize: 12,
                  fontWeight: 600,
                  color: 'var(--text3)',
                  width: 80
                }}>
                  Status
                </th>
                <th style={{
                  padding: 12,
                  textAlign: 'right',
                  fontSize: 12,
                  fontWeight: 600,
                  color: 'var(--text3)',
                  width: 120
                }}>
                  Aktionen
                </th>
              </tr>
            </thead>
            <tbody>
              {filteredPrompts.length === 0 ? (
                <tr>
                  <td colSpan="6" style={{
                    padding: 40,
                    textAlign: 'center',
                    color: 'var(--text3)'
                  }}>
                    Keine Prompts gefunden
                  </td>
                </tr>
              ) : (
                filteredPrompts.map(prompt => (
                  <tr
                    key={prompt.id}
                    style={{
                      borderBottom: '1px solid var(--border)',
                      opacity: prompt.active ? 1 : 0.5
                    }}
                  >
                    <td style={{ padding: 12 }}>
                      <div style={{
                        display: 'inline-block',
                        padding: '2px 8px',
                        background: getTypeColor(prompt.type) + '20',
                        color: getTypeColor(prompt.type),
                        borderRadius: 6,
                        fontSize: 11,
                        fontWeight: 600
                      }}>
                        {getTypeLabel(prompt.type)}
                      </div>
                    </td>
                    <td style={{ padding: 12 }}>
                      <div>
                        <div style={{ fontSize: 14, fontWeight: 500 }}>
                          {prompt.display_name || prompt.name}
                        </div>
                        <div style={{ fontSize: 11, color: 'var(--text3)', marginTop: 2 }}>
                          {prompt.slug}
                        </div>
                      </div>
                    </td>
                    <td style={{ padding: 12, fontSize: 13 }}>
                      {prompt.category || 'ganzheitlich'}
                    </td>
                    <td style={{ padding: 12, textAlign: 'center', fontSize: 13 }}>
                      {prompt.type === 'pipeline' ? (
                        <span style={{
                          background: 'var(--surface2)',
                          padding: '2px 6px',
                          borderRadius: 4,
                          fontSize: 11
                        }}>
                          {getStageCount(prompt)} Stages
                        </span>
                      ) : (
                        <span style={{ color: 'var(--text3)', fontSize: 11 }}>—</span>
                      )}
                    </td>
                    <td style={{ padding: 12, textAlign: 'center' }}>
                      <label style={{
                        display: 'inline-flex',
                        alignItems: 'center',
                        cursor: 'pointer'
                      }}>
                        <input
                          type="checkbox"
                          checked={prompt.active}
                          onChange={() => handleToggleActive(prompt)}
                          style={{ margin: 0 }}
                        />
                      </label>
                    </td>
                    <td style={{ padding: 12 }}>
                      <div style={{
                        display: 'flex',
                        gap: 6,
                        justifyContent: 'flex-end'
                      }}>
                        <button
                          onClick={() => setEditingPrompt(prompt)}
                          style={{
                            background: 'none',
                            border: 'none',
                            cursor: 'pointer',
                            padding: 4
                          }}
                          title="Bearbeiten"
                        >
                          <Edit size={16} color="var(--accent)" />
                        </button>
                        {/* Show convert button for 1-stage pipelines */}
                        {prompt.type === 'pipeline' && getStageCount(prompt) === 1 && (
                          <button
                            onClick={() => handleConvertToBase(prompt)}
                            style={{
                              background: 'none',
                              border: 'none',
                              cursor: 'pointer',
                              padding: 4
                            }}
                            title="Zu Basis-Prompt konvertieren"
                          >
                            <ArrowDownToLine size={16} color="#6366f1" />
                          </button>
                        )}
                        <button
                          onClick={() => handleDuplicate(prompt)}
                          style={{
                            background: 'none',
                            border: 'none',
                            cursor: 'pointer',
                            padding: 4
                          }}
                          title="Duplizieren"
                        >
                          <Copy size={16} color="var(--text3)" />
                        </button>
                        <button
                          onClick={() => handleDelete(prompt)}
                          style={{
                            background: 'none',
                            border: 'none',
                            cursor: 'pointer',
                            padding: 4
                          }}
                          title="Löschen"
                        >
                          <Trash2 size={16} color="var(--danger)" />
                        </button>
                      </div>
                    </td>
                  </tr>
                ))
              )}
            </tbody>
          </table>
        </div>
      )}

      {/* Unified Prompt Modal */}
      {(editingPrompt || showNewPrompt) && (
        <UnifiedPromptModal
          prompt={editingPrompt}
          onSave={handleSave}
          onClose={() => {
            setEditingPrompt(null)
            setShowNewPrompt(false)
          }}
        />
      )}
    </div>
  )
}