import { useEffect, useRef, useState } from 'react'
import {
  type FeedbackDimension, type FeedbackDimensionPrompt,
  loadFeedbackStructure, listFeedbackDimensionPrompts, updateFeedbackDimensionPrompt,
} from '../db'
import { AI_CONFIG } from '../config/constants'

export default function AiPromptConfig() {
  const [dimensions, setDimensions] = useState<FeedbackDimension[]>([])
  const [prompts, setPrompts]       = useState<FeedbackDimensionPrompt[]>([])
  const [expanded, setExpanded]     = useState<Set<number>>(new Set())
  const [savedDimId, setSavedDimId] = useState<number | null>(null)
  const saveTimer = useRef<Map<number, ReturnType<typeof setTimeout>>>(new Map())

  const load = async () => {
    const [structure, promptRows] = await Promise.all([
      loadFeedbackStructure(),
      listFeedbackDimensionPrompts(),
    ])
    setDimensions([...structure.dimensions].sort((a, b) => a.order - b.order))
    setPrompts(promptRows)
  }

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

  const getPrompt = (dimId: number) => prompts.find(p => p.dimensionId === dimId)

  const saveTemplate = (dimId: number, value: string) => {
    setPrompts(prev => prev.map(p => p.dimensionId === dimId ? { ...p, promptTemplate: value } : p))
    const prevTimer = saveTimer.current.get(dimId)
    if (prevTimer) clearTimeout(prevTimer)
    saveTimer.current.set(dimId, setTimeout(async () => {
      const existing = getPrompt(dimId)
      if (!existing?.id) return
      await updateFeedbackDimensionPrompt(existing.id, { promptTemplate: value })
      setSavedDimId(dimId)
      setTimeout(() => setSavedDimId(null), 2000)
    }, 600))
  }

  const resetToDefault = async (dimId: number) => {
    const existing = getPrompt(dimId)
    if (!existing?.id) return
    await updateFeedbackDimensionPrompt(existing.id, { promptTemplate: AI_CONFIG.defaultDimensionPromptTemplate })
    setPrompts(prev => prev.map(p => p.dimensionId === dimId ? { ...p, promptTemplate: AI_CONFIG.defaultDimensionPromptTemplate } : p))
  }

  return (
    <div className="space-y-4">
      <div>
        <h2 className="text-lg font-bold text-gray-800">KI-Prompts je Dimension</h2>
        <p className="text-sm text-gray-500 mt-1">
          Jede Dimension bekommt bei der KI-Feedback-Generierung einen eigenen, separaten Call. Der Prompt-Text
          ist frei editierbar und wird bei neuen Dimensionen automatisch mit einem Standard-Prompt vorbelegt.
        </p>
      </div>

      {/* Platzhalter-Legende */}
      <div className="bg-gray-50 rounded-xl border border-gray-100 p-4 space-y-2">
        <div className="text-xs font-semibold text-gray-500 uppercase tracking-wide">Verfügbare Platzhalter</div>
        <div className="grid gap-1.5">
          {AI_CONFIG.dimensionPromptPlaceholders.map(p => (
            <div key={p.token} className="text-xs text-gray-600 flex gap-2">
              <code className="bg-white border border-gray-200 rounded px-1.5 py-0.5 text-brand font-mono flex-shrink-0">{p.token}</code>
              <span>{p.description}</span>
            </div>
          ))}
        </div>
      </div>

      {/* Dimensionen */}
      {dimensions.map(dim => {
        const isOpen = expanded.has(dim.id!)
        const prompt = getPrompt(dim.id!)
        return (
          <div key={dim.id} className="bg-white rounded-xl border border-gray-100 shadow-sm overflow-hidden">
            <button
              onClick={() => setExpanded(prev => {
                const next = new Set(prev)
                if (next.has(dim.id!)) next.delete(dim.id!); else next.add(dim.id!)
                return next
              })}
              className="w-full flex items-center justify-between p-3 bg-gray-50 border-b border-gray-100 text-left">
              <span className="font-semibold text-sm text-gray-800">{dim.name}</span>
              <span className="text-xs text-gray-400">{isOpen ? '▲' : '▼'}</span>
            </button>

            {isOpen && (
              <div className="p-3 space-y-2">
                <textarea
                  className="w-full border border-gray-200 rounded-lg px-3 py-2 text-xs font-mono focus:outline-none focus:border-brand min-h-[320px]"
                  value={prompt?.promptTemplate ?? ''}
                  onChange={e => saveTemplate(dim.id!, e.target.value)}
                />
                <div className="flex items-center gap-2">
                  <button onClick={() => resetToDefault(dim.id!)}
                    className="text-xs bg-gray-100 hover:bg-gray-200 text-gray-600 px-3 py-1.5 rounded-lg font-medium">
                    Auf Standard zurücksetzen
                  </button>
                  {savedDimId === dim.id && (
                    <span className="text-xs text-green-600 font-medium">Gespeichert.</span>
                  )}
                </div>
              </div>
            )}
          </div>
        )
      })}
      {dimensions.length === 0 && (
        <div className="text-sm text-gray-400 text-center py-6">
          Noch keine Dimensionen angelegt — siehe Tab „Feedback".
        </div>
      )}
    </div>
  )
}