import { useState, useEffect } from 'react'
import { Brain, Pencil, Trash2, ChevronDown, ChevronUp, Check, X } from 'lucide-react'
import { api } from '../utils/api'
import { useAuth } from '../context/AuthContext'
import Markdown from '../utils/Markdown'
import UsageBadge from '../components/UsageBadge'
import dayjs from 'dayjs'
import 'dayjs/locale/de'
dayjs.locale('de')

const SLUG_LABELS = {
  gesamt:             '🔍 Gesamtanalyse',
  koerper:            '🫧 Körperkomposition',
  ernaehrung:         '🍽️ Ernährung',
  aktivitaet:         '🏋️ Aktivität',
  gesundheit:         '❤️ Gesundheitsindikatoren',
  ziele:              '🎯 Zielfortschritt',
  pipeline:           '🔬 Mehrstufige Gesamtanalyse',
  pipeline_body:      '🔬 Pipeline: Körper-Analyse (JSON)',
  pipeline_nutrition: '🔬 Pipeline: Ernährungs-Analyse (JSON)',
  pipeline_activity:  '🔬 Pipeline: Aktivitäts-Analyse (JSON)',
  pipeline_synthesis: '🔬 Pipeline: Synthese',
  pipeline_goals:     '🔬 Pipeline: Zielabgleich',
}

function InsightCard({ ins, onDelete, defaultOpen=false }) {
  const [open, setOpen] = useState(defaultOpen)
  return (
    <div className="card section-gap" style={{borderLeft:`3px solid var(--accent)`}}>
      <div style={{display:'flex',alignItems:'center',gap:8,marginBottom:open?12:0,cursor:'pointer'}}
        onClick={()=>setOpen(o=>!o)}>
        <div style={{flex:1}}>
          <div style={{fontSize:13,fontWeight:600}}>
            {ins.display_name || SLUG_LABELS[ins.scope] || ins.scope}
          </div>
          <div style={{fontSize:11,color:'var(--text3)'}}>
            {dayjs(ins.created).format('DD. MMMM YYYY, HH:mm')}
          </div>
        </div>
        <button style={{background:'none',border:'none',cursor:'pointer',color:'var(--text3)',padding:4}}
          onClick={e=>{e.stopPropagation();onDelete(ins.id)}}>
          <Trash2 size={13}/>
        </button>
        {open ? <ChevronUp size={16} color="var(--text3)"/> : <ChevronDown size={16} color="var(--text3)"/>}
      </div>
      {open && <Markdown text={ins.content}/>}
    </div>
  )
}

function PromptEditor({ prompt, onSave, onCancel }) {
  const [template, setTemplate] = useState(prompt.template)
  const [name,     setName]     = useState(prompt.name)
  const [desc,     setDesc]     = useState(prompt.description||'')

  const VARS = ['{{name}}','{{geschlecht}}','{{height}}','{{goal_weight}}','{{goal_bf_pct}}',
    '{{weight_trend}}','{{weight_aktuell}}','{{kf_aktuell}}','{{caliper_summary}}',
    '{{circ_summary}}','{{nutrition_summary}}','{{nutrition_detail}}',
    '{{protein_ziel_low}}','{{protein_ziel_high}}','{{activity_summary}}',
    '{{activity_kcal_summary}}','{{activity_detail}}',
    '{{sleep_summary}}','{{sleep_detail}}','{{sleep_avg_duration}}','{{sleep_avg_quality}}',
    '{{rest_days_summary}}','{{rest_days_count}}','{{rest_days_types}}',
    '{{vitals_summary}}','{{vitals_detail}}','{{vitals_avg_hr}}','{{vitals_avg_hrv}}',
    '{{vitals_avg_bp}}','{{vitals_vo2_max}}','{{bp_summary}}']

  return (
    <div className="card section-gap">
      <div style={{display:'flex',alignItems:'center',justifyContent:'space-between',marginBottom:12}}>
        <div className="card-title" style={{margin:0}}>Prompt bearbeiten</div>
        <button style={{background:'none',border:'none',cursor:'pointer',color:'var(--text3)'}}
          onClick={onCancel}><X size={16}/></button>
      </div>
      <div className="form-row">
        <label className="form-label">Name</label>
        <input type="text" className="form-input" value={name} onChange={e=>setName(e.target.value)}/>
        <span className="form-unit"/>
      </div>
      <div className="form-row">
        <label className="form-label">Beschreibung</label>
        <input type="text" className="form-input" value={desc} onChange={e=>setDesc(e.target.value)}/>
        <span className="form-unit"/>
      </div>
      <div style={{marginBottom:8}}>
        <div style={{fontSize:12,fontWeight:600,color:'var(--text3)',marginBottom:6}}>
          Variablen (antippen zum Einfügen):
        </div>
        <div style={{display:'flex',flexWrap:'wrap',gap:4}}>
          {VARS.map(v=>(
            <button key={v} onClick={()=>setTemplate(t=>t+v)}
              style={{fontSize:10,padding:'2px 7px',borderRadius:4,border:'1px solid var(--border2)',
                background:'var(--surface2)',cursor:'pointer',fontFamily:'monospace',color:'var(--accent)'}}>
              {v}
            </button>
          ))}
        </div>
      </div>
      <textarea value={template} onChange={e=>setTemplate(e.target.value)}
        style={{width:'100%',minHeight:280,padding:10,fontFamily:'monospace',fontSize:12,
          background:'var(--surface2)',border:'1.5px solid var(--border2)',borderRadius:8,
          color:'var(--text1)',resize:'vertical',lineHeight:1.5,boxSizing:'border-box'}}/>
      <div style={{display:'flex',gap:8,marginTop:8}}>
        <button className="btn btn-primary" style={{flex:1}}
          onClick={()=>onSave({name,description:desc,template})}>
          <Check size={14}/> Speichern
        </button>
        <button className="btn btn-secondary" style={{flex:1}} onClick={onCancel}>Abbrechen</button>
      </div>
    </div>
  )
}

export default function Analysis() {
  const { canUseAI, isAdmin } = useAuth()
  const [prompts,     setPrompts]     = useState([])
  const [allInsights, setAllInsights] = useState([])
  const [loading,     setLoading]     = useState(null)
  const [error,       setError]       = useState(null)
  const [editing,     setEditing]     = useState(null)
  const [tab,         setTab]         = useState('run')
  const [newResult,       setNewResult]       = useState(null)
  const [pipelineLoading, setPipelineLoading] = useState(false)
  const [aiUsage, setAiUsage] = useState(null)  // Phase 3: Usage badge

  const loadAll = async () => {
    const [p, i] = await Promise.all([
      api.listPrompts(),
      api.listInsights()
    ])
    setPrompts(Array.isArray(p)?p:[])
    setAllInsights(Array.isArray(i)?i:[])
  }

  useEffect(()=>{
    loadAll()
    // Load feature usage for badges
    api.getFeatureUsage().then(features => {
      const aiFeature = features.find(f => f.feature_id === 'ai_calls')
      setAiUsage(aiFeature)
    }).catch(err => console.error('Failed to load usage:', err))
  },[])

  const runPipeline = async () => {
    setPipelineLoading(true); setError(null); setNewResult(null)
    try {
      const result = await api.insightPipeline()
      setNewResult(result)
      await loadAll()
      setTab('run')
    } catch(e) {
      setError('Pipeline-Fehler: ' + e.message)
    } finally { setPipelineLoading(false) }
  }

  const runPrompt = async (slug) => {
    setLoading(slug); setError(null); setNewResult(null)
    try {
      const result = await api.runInsight(slug)
      setNewResult(result)   // show immediately
      await loadAll()        // refresh lists
      setTab('run')          // stay on run tab to see result
    } catch(e) {
      setError('Fehler: ' + e.message)
    } finally { setLoading(null) }
  }

  const savePrompt = async (promptId, data) => {
    const token = localStorage.getItem('bodytrack_token')||''
    await fetch(`/api/prompts/${promptId}`, {
      method:'PUT',
      headers:{'Content-Type':'application/json', 'X-Auth-Token': token},
      body:JSON.stringify(data)
    })
    setEditing(null); await loadAll()
  }

  const deleteInsight = async (id) => {
    if (!confirm('Analyse löschen?')) return
    const pid = localStorage.getItem('bodytrack_active_profile')||''
    await fetch(`/api/insights/${id}`, {
      method:'DELETE', headers: pid ? {'X-Profile-Id':pid} : {}
    })
    if (newResult?.id === id) setNewResult(null)
    await loadAll()
  }

  // Group insights by scope for history view
  const grouped = {}
  allInsights.forEach(ins => {
    const key = ins.scope || 'sonstige'
    grouped[key] = grouped[key] || []
    grouped[key].push(ins)
  })

  const activePrompts = prompts.filter(p=>p.active && !p.slug.startsWith('pipeline_') && p.slug !== 'pipeline')

  // Pipeline is available if the "pipeline" prompt is active
  const pipelinePrompt = prompts.find(p=>p.slug==='pipeline')
  const pipelineAvailable = pipelinePrompt?.active ?? true  // Default to true if not found (backwards compatibility)

  return (
    <div>
      <h1 className="page-title">KI-Analyse</h1>

      <div className="tabs">
        <button className={'tab'+(tab==='run'?' active':'')} onClick={()=>setTab('run')}>Analysen starten</button>
        <button className={'tab'+(tab==='history'?' active':'')} onClick={()=>setTab('history')}>
          Verlauf
          {allInsights.length>0 && <span style={{marginLeft:4,fontSize:10,background:'var(--accent)',
            color:'white',padding:'1px 5px',borderRadius:8}}>{allInsights.length}</span>}
        </button>
        {isAdmin && <button className={'tab'+(tab==='prompts'?' active':'')} onClick={()=>setTab('prompts')}>Prompts</button>}
      </div>

      {error && (
        <div style={{padding:'10px 14px',background:'#FCEBEB',borderRadius:8,fontSize:13,
          color:'#D85A30',marginBottom:12,lineHeight:1.5}}>
          {error.includes('nicht aktiviert') || error.includes('Limit')
            ? <>🔒 <strong>KI-Zugang eingeschränkt</strong><br/>
                Dein Profil hat keinen Zugang zu KI-Analysen oder das Tageslimit wurde erreicht.
                Bitte den Admin kontaktieren.</>
            : error}
        </div>
      )}

      {/* ── Analysen starten ── */}
      {tab==='run' && (
        <div>
          {/* Fresh result shown immediately */}
          {newResult && (
            <div style={{marginBottom:16}}>
              <div style={{fontSize:12,fontWeight:600,color:'var(--accent)',marginBottom:8}}>
                ✅ Neue Analyse erstellt:
              </div>
              <InsightCard
                ins={{...newResult, created: new Date().toISOString()}}
                onDelete={deleteInsight}
                defaultOpen={true}
              />
            </div>
          )}

          {/* Pipeline button - only if all sub-prompts are active */}
          {pipelineAvailable && (
            <div className="card" style={{marginBottom:16,borderColor:'var(--accent)',borderWidth:2}}>
              <div style={{display:'flex',alignItems:'flex-start',gap:12}}>
                <div style={{flex:1}}>
                  <div className="badge-container-right" style={{fontWeight:700,fontSize:15,color:'var(--accent)'}}>
                    <span>🔬 Mehrstufige Gesamtanalyse</span>
                    {aiUsage && <UsageBadge {...aiUsage} />}
                  </div>
                  <div style={{fontSize:12,color:'var(--text2)',marginTop:3,lineHeight:1.5}}>
                    3 spezialisierte KI-Calls parallel (Körper + Ernährung + Aktivität),
                    dann Synthese + Zielabgleich. Detaillierteste Auswertung.
                  </div>
                  {allInsights.find(i=>i.scope==='pipeline') && (
                    <div style={{fontSize:11,color:'var(--text3)',marginTop:3}}>
                      Letzte Analyse: {dayjs(allInsights.find(i=>i.scope==='pipeline').created).format('DD.MM.YYYY, HH:mm')}
                    </div>
                  )}
                </div>
                <div
                  title={aiUsage && !aiUsage.allowed ? `Limit erreicht (${aiUsage.used}/${aiUsage.limit}). Kontaktiere den Admin oder warte bis zum nächsten Reset.` : ''}
                  style={{display:'inline-block'}}
                >
                  <button
                    className="btn btn-primary"
                    style={{flexShrink:0,minWidth:100, cursor: (aiUsage && !aiUsage.allowed) ? 'not-allowed' : 'pointer'}}
                    onClick={runPipeline}
                    disabled={!!loading||pipelineLoading||(aiUsage && !aiUsage.allowed)}
                  >
                    {pipelineLoading
                      ? <><div className="spinner" style={{width:13,height:13}}/> Läuft…</>
                      : (aiUsage && !aiUsage.allowed) ? '🔒 Limit'
                      : <><Brain size={13}/> Starten</>}
                  </button>
                </div>
                {!canUseAI && <div style={{fontSize:11,color:'#D85A30',marginTop:4}}>🔒 KI nicht freigeschaltet</div>}
              </div>
              {pipelineLoading && (
                <div style={{marginTop:10,padding:'8px 12px',background:'var(--accent-light)',
                  borderRadius:8,fontSize:12,color:'var(--accent-dark)'}}>
                  ⚡ Stufe 1: 3 parallele Analyse-Calls… dann Synthese… dann Zielabgleich
                </div>
              )}
            </div>
          )}

          {!canUseAI && (
            <div style={{padding:'14px 16px',background:'#FCEBEB',borderRadius:10,
              border:'1px solid #D85A3033',marginBottom:16}}>
              <div style={{fontSize:14,fontWeight:600,color:'#D85A30',marginBottom:4}}>
                🔒 KI-Analysen nicht freigeschaltet
              </div>
              <div style={{fontSize:13,color:'var(--text2)',lineHeight:1.5}}>
                Dein Profil hat keinen Zugang zu KI-Analysen.
                Bitte den Admin bitten, KI für dein Profil zu aktivieren
                (Einstellungen → Admin → Profil bearbeiten).
              </div>
            </div>
          )}
          {canUseAI && <p style={{fontSize:13,color:'var(--text2)',marginBottom:14,lineHeight:1.6}}>
            Oder wähle eine Einzelanalyse:
          </p>}

          {activePrompts.map(p => {
            // Show latest existing insight for this prompt
            const existing = allInsights.find(i=>i.scope===p.slug)
            return (
              <div key={p.id} className="card section-gap">
                <div style={{display:'flex',alignItems:'flex-start',gap:12}}>
                  <div style={{flex:1}}>
                    <div className="badge-container-right" style={{fontWeight:600,fontSize:15}}>
                      <span>{p.display_name || SLUG_LABELS[p.slug] || p.name}</span>
                      {aiUsage && <UsageBadge {...aiUsage} />}
                    </div>
                    {p.description && <div style={{fontSize:12,color:'var(--text3)',marginTop:2}}>{p.description}</div>}
                    {existing && (
                      <div style={{fontSize:11,color:'var(--text3)',marginTop:3}}>
                        Letzte Auswertung: {dayjs(existing.created).format('DD.MM.YYYY, HH:mm')}
                      </div>
                    )}
                  </div>
                  <div
                    title={aiUsage && !aiUsage.allowed ? `Limit erreicht (${aiUsage.used}/${aiUsage.limit}). Kontaktiere den Admin oder warte bis zum nächsten Reset.` : ''}
                    style={{display:'inline-block'}}
                  >
                    <button
                      className="btn btn-primary"
                      style={{flexShrink:0,minWidth:90, cursor: (aiUsage && !aiUsage.allowed) ? 'not-allowed' : 'pointer'}}
                      onClick={()=>runPrompt(p.slug)}
                      disabled={!!loading||!canUseAI||(aiUsage && !aiUsage.allowed)}
                    >
                      {loading===p.slug
                        ? <><div className="spinner" style={{width:13,height:13}}/> Läuft…</>
                        : (aiUsage && !aiUsage.allowed) ? '🔒 Limit'
                        : <><Brain size={13}/> {existing?'Neu erstellen':'Starten'}</>}
                    </button>
                  </div>
                </div>
                {/* Show existing result collapsed */}
                {existing && newResult?.id !== existing.id && (
                  <div style={{marginTop:8,borderTop:'1px solid var(--border)',paddingTop:8}}>
                    <InsightCard ins={existing} onDelete={deleteInsight} defaultOpen={false}/>
                  </div>
                )}
              </div>
            )
          })}
          {activePrompts.length===0 && (
            <div className="empty-state"><p>Keine aktiven Prompts. Aktiviere im Tab "Prompts".</p></div>
          )}
        </div>
      )}

      {/* ── Verlauf gruppiert ── */}
      {tab==='history' && (
        <div>
          {allInsights.length===0
            ? <div className="empty-state"><h3>Noch keine Analysen</h3></div>
            : Object.entries(grouped).map(([scope, ins]) => (
              <div key={scope} style={{marginBottom:20}}>
                <div style={{fontSize:13,fontWeight:700,color:'var(--text3)',
                  textTransform:'uppercase',letterSpacing:'0.05em',marginBottom:8}}>
                  {SLUG_LABELS[scope]||scope} ({ins.length})
                </div>
                {ins.map(i => <InsightCard key={i.id} ins={i} onDelete={deleteInsight}/>)}
              </div>
            ))
          }
        </div>
      )}

      {/* ── Prompts ── */}
      {tab==='prompts' && (
        <div>
          <p style={{fontSize:13,color:'var(--text2)',marginBottom:14,lineHeight:1.6}}>
            Passe Prompts an. Variablen wie{' '}
            <code style={{fontSize:11,background:'var(--surface2)',padding:'1px 4px',borderRadius:3}}>{'{{name}}'}</code>{' '}
            werden automatisch mit deinen Daten befüllt.
          </p>
          {editing ? (
            <PromptEditor prompt={editing}
              onSave={(data)=>savePrompt(editing.id,data)}
              onCancel={()=>setEditing(null)}/>
          ) : (() => {
            const singlePrompts   = prompts.filter(p=>!p.slug.startsWith('pipeline_'))
            const pipelinePrompts = prompts.filter(p=>p.slug.startsWith('pipeline_'))
            const jsonSlugs = ['pipeline_body','pipeline_nutrition','pipeline_activity']
            return (
              <>
                {/* Single prompts */}
                <div style={{fontSize:12,fontWeight:700,color:'var(--text3)',
                  textTransform:'uppercase',letterSpacing:'0.05em',marginBottom:8}}>
                  Einzelanalysen
                </div>
                {singlePrompts.map(p=>(
                  <div key={p.id} className="card section-gap" style={{opacity:p.active?1:0.6}}>
                    <div style={{display:'flex',alignItems:'center',gap:10}}>
                      <div style={{flex:1}}>
                        <div style={{fontWeight:600,fontSize:14,display:'flex',alignItems:'center',gap:8}}>
                          {p.display_name || SLUG_LABELS[p.slug] || p.name}
                          {!p.active && <span style={{fontSize:10,color:'#D85A30',
                            background:'#FCEBEB',padding:'2px 8px',borderRadius:4,fontWeight:600}}>⏸ Deaktiviert</span>}
                        </div>
                        {p.description && <div style={{fontSize:12,color:'var(--text3)',marginTop:1}}>{p.description}</div>}
                      </div>
                      <button className="btn btn-secondary" style={{padding:'5px 8px',fontSize:12}}
                        onClick={()=>{
                          const token = localStorage.getItem('bodytrack_token')||''
                          fetch(`/api/prompts/${p.id}`,{
                            method:'PUT',
                            headers:{'Content-Type':'application/json','X-Auth-Token':token},
                            body:JSON.stringify({active:!p.active})
                          }).then(loadAll)
                        }}>
                        {p.active?'Deaktivieren':'Aktivieren'}
                      </button>
                      <button className="btn btn-secondary" style={{padding:'5px 8px'}}
                        onClick={()=>setEditing(p)}><Pencil size={13}/></button>
                    </div>
                    <div style={{marginTop:8,padding:'8px 10px',background:'var(--surface2)',borderRadius:6,
                      fontSize:11,fontFamily:'monospace',color:'var(--text3)',maxHeight:60,overflow:'hidden',lineHeight:1.4}}>
                      {p.template.slice(0,200)}…
                    </div>
                  </div>
                ))}

                {/* Pipeline prompts */}
                <div style={{display:'flex',alignItems:'center',justifyContent:'space-between',margin:'20px 0 8px'}}>
                  <div style={{fontSize:12,fontWeight:700,color:'var(--text3)',
                    textTransform:'uppercase',letterSpacing:'0.05em'}}>
                    Mehrstufige Pipeline
                  </div>
                  {(() => {
                    const pipelinePrompt = prompts.find(p=>p.slug==='pipeline')
                    return pipelinePrompt && (
                      <button className="btn btn-secondary" style={{padding:'5px 12px',fontSize:12}}
                        onClick={()=>{
                          const token = localStorage.getItem('bodytrack_token')||''
                          fetch(`/api/prompts/${pipelinePrompt.id}`,{
                            method:'PUT',
                            headers:{'Content-Type':'application/json','X-Auth-Token':token},
                            body:JSON.stringify({active:!pipelinePrompt.active})
                          }).then(loadAll)
                        }}>
                        {pipelinePrompt.active ? 'Gesamte Pipeline deaktivieren' : 'Gesamte Pipeline aktivieren'}
                      </button>
                    )
                  })()}
                </div>
                {(() => {
                  const pipelinePrompt = prompts.find(p=>p.slug==='pipeline')
                  const isPipelineActive = pipelinePrompt?.active ?? true
                  return (
                    <div style={{padding:'10px 12px',
                      background: isPipelineActive ? 'var(--warn-bg)' : '#FCEBEB',
                      borderRadius:8,fontSize:12,
                      color: isPipelineActive ? 'var(--warn-text)' : '#D85A30',
                      marginBottom:12,lineHeight:1.6}}>
                      {isPipelineActive ? (
                        <>⚠️ <strong>Hinweis:</strong> Pipeline-Stage-1-Prompts müssen valides JSON zurückgeben.
                        Halte das JSON-Format im Prompt erhalten. Stage 2 + 3 können frei angepasst werden.</>
                      ) : (
                        <>⏸ <strong>Pipeline deaktiviert:</strong> Die mehrstufige Gesamtanalyse ist aktuell nicht verfügbar.
                        Aktiviere sie mit dem Schalter oben, um sie auf der Analyse-Seite zu nutzen.</>
                      )}
                    </div>
                  )
                })()}
                {pipelinePrompts.map(p=>{
                  const isJson = jsonSlugs.includes(p.slug)
                  return (
                    <div key={p.id} className="card section-gap"
                      style={{borderLeft:`3px solid ${isJson?'var(--warn)':'var(--accent)'}`,opacity:p.active?1:0.6}}>
                      <div style={{display:'flex',alignItems:'center',gap:10}}>
                        <div style={{flex:1}}>
                          <div style={{fontWeight:600,fontSize:14,display:'flex',alignItems:'center',gap:8}}>
                            {p.name}
                            {isJson && <span style={{fontSize:10,background:'var(--warn-bg)',
                              color:'var(--warn-text)',padding:'1px 6px',borderRadius:4}}>JSON-Output</span>}
                            {!p.active && <span style={{fontSize:10,color:'#D85A30',
                              background:'#FCEBEB',padding:'2px 8px',borderRadius:4,fontWeight:600}}>⏸ Deaktiviert</span>}
                          </div>
                          {p.description && <div style={{fontSize:12,color:'var(--text3)',marginTop:1}}>{p.description}</div>}
                        </div>
                        <button className="btn btn-secondary" style={{padding:'5px 8px'}}
                          onClick={()=>setEditing(p)}><Pencil size={13}/></button>
                      </div>
                      <div style={{marginTop:8,padding:'8px 10px',background:'var(--surface2)',borderRadius:6,
                        fontSize:11,fontFamily:'monospace',color:'var(--text3)',maxHeight:80,overflow:'hidden',lineHeight:1.4}}>
                        {p.template.slice(0,300)}…
                      </div>
                    </div>
                  )
                })}
              </>
            )
          })()}
        </div>
      )}
    </div>
  )
}