import { useState } from 'react'

export interface PromptStructure {
  style?: string
  timbre?: string
  structure?: string
  mood?: string
  tempo?: string
  instrumentation?: string
  effects?: string
  additional?: string
}

interface Props {
  value: PromptStructure
  onChange: (value: PromptStructure) => void
}

const FIELDS = [
  { key: 'style', label: 'Style / Genre', placeholder: 'e.g., Gabber, Ambient, Orchestral, Phonk...' },
  { key: 'timbre', label: 'Timbre / Texture', placeholder: 'e.g., Warm analog synths, gritty distortion, ethereal pads...' },
  { key: 'structure', label: 'Structure', placeholder: 'e.g., Intro-Verse-Chorus-Verse-Chorus-Bridge-Chorus-Outro' },
  { key: 'mood', label: 'Mood / Energy', placeholder: 'e.g., Dark and aggressive, euphoric, melancholic, triumphant...' },
  { key: 'tempo', label: 'Tempo / BPM', placeholder: 'e.g., 180 BPM, slow build to 200 BPM, variable...' },
  { key: 'instrumentation', label: 'Instrumentation', placeholder: 'e.g., Heavy kick drums, distorted leads, vocal chops, sub-bass...' },
  { key: 'effects', label: 'Effects / Processing', placeholder: 'e.g., Heavy sidechain compression, reverb tails, bitcrush...' },
  { key: 'additional', label: 'Additional Notes', placeholder: 'Any other details, references, or specific instructions...' },
] as const

export default function StructuredPromptEditor({ value, onChange }: Props) {
  const [expanded, setExpanded] = useState<Set<string>>(new Set(['style', 'structure', 'mood']))

  const toggleField = (key: string) => {
    setExpanded(prev => {
      const next = new Set(prev)
      if (next.has(key)) {
        next.delete(key)
      } else {
        next.add(key)
      }
      return next
    })
  }

  const updateField = (key: string, text: string) => {
    onChange({ ...value, [key]: text })
  }

  const filledCount = FIELDS.filter(f => value[f.key as keyof PromptStructure]?.trim()).length

  return (
    <div className="space-y-2">
      <div className="flex items-center justify-between">
        <span className="text-xs text-lyria-muted">
          {filledCount} of {FIELDS.length} fields filled
        </span>
        <button
          onClick={() => setExpanded(new Set(FIELDS.map(f => f.key)))}
          className="text-xs text-lyria-accent hover:text-lyria-accent/80 transition-colors"
        >
          Expand All
        </button>
      </div>

      {FIELDS.map(({ key, label, placeholder }) => {
        const isExpanded = expanded.has(key)
        const hasValue = value[key as keyof PromptStructure]?.trim()

        return (
          <div key={key} className="border border-white/5 rounded-lg overflow-hidden">
            <button
              onClick={() => toggleField(key)}
              className={`w-full flex items-center justify-between px-3 py-2 text-sm transition-colors ${
                hasValue ? 'bg-white/5' : 'bg-transparent hover:bg-white/5'
              }`}
            >
              <div className="flex items-center gap-2">
                <span className={`w-1.5 h-1.5 rounded-full ${hasValue ? 'bg-lyria-accent' : 'bg-lyria-muted/30'}`} />
                <span className={hasValue ? 'text-white' : 'text-lyria-muted'}>{label}</span>
              </div>
              <svg
                className={`w-3.5 h-3.5 text-lyria-muted transition-transform ${isExpanded ? 'rotate-180' : ''}`}
                fill="none"
                stroke="currentColor"
                viewBox="0 0 24 24"
              >
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
              </svg>
            </button>

            {isExpanded && (
              <div className="px-3 pb-3">
                <textarea
                  value={value[key as keyof PromptStructure] || ''}
                  onChange={(e) => updateField(key, e.target.value)}
                  placeholder={placeholder}
                  className="w-full h-20 bg-black/20 border border-white/5 rounded-md px-3 py-2 text-sm text-white placeholder:text-lyria-muted/30 focus:outline-none focus:border-lyria-accent/50 resize-none"
                />
              </div>
            )}
          </div>
        )
      })}
    </div>
  )
}