import { useState, useEffect } from 'react'
import { motion, AnimatePresence } from 'framer-motion'
import { Brain, ChevronDown, ChevronUp, Zap, History } from 'lucide-react'
import { useStore } from '../store/useStore'
import { fetchPromptHistory } from '../lib/api'

const SEED_PROMPT = `You are a SQL expert. Given a natural language question and a SQLite database schema, write a correct SQL query.

Rules:
- Output ONLY the SQL query, nothing else
- No markdown, no code fences, no explanation
- Use SQLite syntax
- Always qualify column names with table aliases when using JOINs`

export function PromptEvolution() {
  const { currentPrompt, promptGeneration, promptHistory, setPromptData } = useStore()
  const [expanded, setExpanded] = useState(false)
  const [historyExpanded, setHistoryExpanded] = useState(false)
  const [loading, setLoading] = useState(false)

  const prompt = currentPrompt || SEED_PROMPT
  const generation = promptGeneration

  const loadHistory = async () => {
    setLoading(true)
    try {
      const data = await fetchPromptHistory()
      setPromptData(data)
    } catch {
      // noop
    } finally {
      setLoading(false)
    }
  }

  useEffect(() => {
    void loadHistory()
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [])

  return (
    <div className="flex flex-col gap-2">
      {/* Header */}
      <button
        onClick={() => setExpanded((v) => !v)}
        className="flex items-center justify-between w-full group"
      >
        <div className="flex items-center gap-2">
          <Brain size={14} className="text-violet-400" />
          <span className="text-xs font-semibold text-white/70">System Prompt</span>
          {generation > 0 ? (
            <span className="text-[10px] bg-violet-500/20 text-violet-300 border border-violet-500/30 rounded-full px-2 py-0.5">
              Gen {generation} · Optimized
            </span>
          ) : (
            <span className="text-[10px] bg-white/5 text-gray-500 rounded-full px-2 py-0.5">
              Seed
            </span>
          )}
        </div>
        {expanded ? (
          <ChevronUp size={13} className="text-gray-500" />
        ) : (
          <ChevronDown size={13} className="text-gray-500" />
        )}
      </button>

      <AnimatePresence>
        {expanded && (
          <motion.div
            initial={{ opacity: 0, height: 0 }}
            animate={{ opacity: 1, height: 'auto' }}
            exit={{ opacity: 0, height: 0 }}
            transition={{ duration: 0.2 }}
            className="overflow-hidden"
          >
            {/* Prompt preview */}
            <div className="max-h-40 overflow-y-auto">
              <pre className="text-[11px] font-mono text-violet-200/70 bg-violet-950/30 rounded-xl p-3 border border-violet-500/20 whitespace-pre-wrap leading-relaxed">
                {prompt}
              </pre>
            </div>

            {/* History button */}
            {promptHistory.length > 0 && (
              <button
                onClick={() => setHistoryExpanded((v) => !v)}
                className="mt-2 w-full flex items-center justify-center gap-2 px-3 py-2 text-xs font-medium bg-violet-600/15 text-violet-300 border border-violet-500/25 rounded-xl hover:bg-violet-600/25 hover:border-violet-500/40 transition-all"
              >
                <History size={12} />
                {historyExpanded ? 'Hide' : 'View'} Evolution History
                <span className="text-[10px] text-violet-400/60 ml-1">
                  ({promptHistory.length} gen{promptHistory.length !== 1 ? 's' : ''})
                </span>
              </button>
            )}

            {/* Generation history */}
            <AnimatePresence>
              {historyExpanded && promptHistory.length > 0 && (
                <motion.div
                  initial={{ height: 0, opacity: 0 }}
                  animate={{ height: 'auto', opacity: 1 }}
                  exit={{ height: 0, opacity: 0 }}
                  transition={{ duration: 0.15 }}
                  className="overflow-hidden mt-2"
                >
                  <div className="flex flex-col gap-1.5">
                    <div className="text-[10px] text-gray-500 font-medium flex items-center gap-1">
                      <Zap size={10} className="text-violet-400" />
                      Optimization History
                    </div>
                    {promptHistory.map((snap) => (
                      <div
                        key={snap.generation}
                        className="border border-white/5 rounded-xl p-2.5 hover:border-white/10 hover:bg-white/[0.02] transition-all"
                      >
                        <div className="flex items-center justify-between mb-1">
                          <span className="text-[10px] font-semibold text-violet-400">
                            Generation {snap.generation}
                          </span>
                          <span className="text-[10px] font-mono text-green-400">
                            {(snap.score * 100).toFixed(0)}%
                          </span>
                        </div>
                        <p className="text-[10px] text-gray-400 leading-relaxed line-clamp-2">
                          {snap.summary}
                        </p>
                        <p className="text-[9px] text-gray-600 mt-1">{snap.timestamp}</p>
                      </div>
                    ))}
                  </div>
                </motion.div>
              )}
            </AnimatePresence>

            {loading && (
              <div className="flex items-center gap-2 text-[10px] text-gray-500 mt-2 px-1">
                <span className="w-3 h-3 border border-violet-500/40 border-t-violet-400 rounded-full animate-spin inline-block" />
                Loading history...
              </div>
            )}
          </motion.div>
        )}
      </AnimatePresence>
    </div>
  )
}