import { useState, useMemo } from 'react'
import { format } from 'date-fns'
import { fr } from 'date-fns/locale'
import { AlertTriangle, XCircle, Info, RefreshCw, Trash2, ChevronDown, ChevronRight } from 'lucide-react'
import clsx from 'clsx'
import { useSystemLogs, useLogSources, useLogCycles, useClearLogs, type LogFilters } from '../hooks/useApi'
import { useQueryClient } from '@tanstack/react-query'

const LEVELS = ['', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']

function LevelBadge({ level }: { level: string }) {
  const cfg: Record<string, { cls: string; icon: React.ReactNode }> = {
    INFO:     { cls: 'bg-slate-700 text-slate-300',              icon: <Info className="w-3 h-3" /> },
    WARNING:  { cls: 'bg-amber-900/60 text-amber-300 border border-amber-700/40', icon: <AlertTriangle className="w-3 h-3" /> },
    ERROR:    { cls: 'bg-red-900/60 text-red-300 border border-red-700/40',       icon: <XCircle className="w-3 h-3" /> },
    CRITICAL: { cls: 'bg-red-800 text-white border border-red-600',               icon: <XCircle className="w-3 h-3" /> },
  }
  const { cls, icon } = cfg[level] ?? cfg['INFO']
  return (
    <span className={clsx('inline-flex items-center gap-1 px-1.5 py-0.5 rounded text-[10px] font-semibold font-mono', cls)}>
      {icon} {level}
    </span>
  )
}

function LogRow({ log }: { log: any }) {
  const [expanded, setExpanded] = useState(false)
  const hasDetails = !!log.details
  const ts = (() => {
    try { return format(new Date(log.ts), 'dd/MM HH:mm:ss', { locale: fr }) } catch { return log.ts }
  })()

  const rowCls = clsx('border-b border-slate-800 hover:bg-slate-800/40 transition-colors', {
    'bg-amber-950/10': log.level === 'WARNING',
    'bg-red-950/20':   log.level === 'ERROR' || log.level === 'CRITICAL',
  })

  return (
    <>
      <tr className={rowCls}>
        <td className="px-3 py-1.5 text-[10px] font-mono text-slate-500 whitespace-nowrap">{ts}</td>
        <td className="px-3 py-1.5 whitespace-nowrap"><LevelBadge level={log.level} /></td>
        <td className="px-3 py-1.5 text-[10px] text-slate-400 max-w-[120px] truncate font-mono">{log.source}</td>
        <td className="px-3 py-1.5 text-[10px] text-slate-500 max-w-[100px] truncate font-mono">
          {log.cycle_id ? log.cycle_id.slice(0, 16) + '…' : '—'}
        </td>
        <td className="px-3 py-1.5 text-[10px] text-blue-400 font-mono">{log.ticker ?? '—'}</td>
        <td className="px-2 py-1.5 w-full">
          <div className="flex items-start gap-1.5">
            {hasDetails && (
              <button
                onClick={() => setExpanded(!expanded)}
                className="mt-0.5 shrink-0 text-slate-600 hover:text-slate-400"
              >
                {expanded ? <ChevronDown className="w-3 h-3" /> : <ChevronRight className="w-3 h-3" />}
              </button>
            )}
            <span className={clsx('text-[11px] leading-snug break-all', {
              'text-slate-300': log.level === 'INFO',
              'text-amber-200': log.level === 'WARNING',
              'text-red-300':   log.level === 'ERROR' || log.level === 'CRITICAL',
            })}>{log.message}</span>
          </div>
        </td>
      </tr>
      {expanded && hasDetails && (
        <tr className={rowCls}>
          <td colSpan={6} className="px-4 pb-2 pt-0">
            <pre className="text-[10px] text-slate-400 bg-slate-900 rounded p-2 overflow-x-auto max-h-40 leading-relaxed">
              {JSON.stringify(JSON.parse(log.details), null, 2)}
            </pre>
          </td>
        </tr>
      )}
    </>
  )
}

export default function SystemLogs() {
  const qc = useQueryClient()
  const [filters, setFilters] = useState<LogFilters>({ limit: 300 })
  const [tickerInput, setTickerInput] = useState('')
  const [cycleInput, setCycleInput] = useState('')

  const { data, isLoading, isRefetching } = useSystemLogs(filters)
  const { data: sourcesData } = useLogSources()
  const { data: cyclesData } = useLogCycles()
  const { mutate: clearLogs, isPending: clearing } = useClearLogs()

  const logs: any[] = data?.logs ?? []
  const sources: string[] = sourcesData?.sources ?? []
  const cycles: any[] = cyclesData?.cycles ?? []

  // Summary counts
  const counts = useMemo(() => {
    const c = { INFO: 0, WARNING: 0, ERROR: 0, CRITICAL: 0 }
    for (const l of logs) c[l.level as keyof typeof c] = (c[l.level as keyof typeof c] ?? 0) + 1
    return c
  }, [logs])

  const applyFilter = (key: keyof LogFilters, val: string) => {
    setFilters(f => ({ ...f, [key]: val || undefined }))
  }

  const handleClear = () => {
    if (window.confirm('Supprimer les logs de plus de 30 jours ?')) {
      clearLogs(30, { onSuccess: () => qc.invalidateQueries({ queryKey: ['system-logs'] }) })
    }
  }

  return (
    <div className="p-6 space-y-4">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-xl font-bold text-white">Logs Système</h1>
          <p className="text-xs text-slate-500 mt-0.5">Erreurs, avertissements et événements des cycles IA</p>
        </div>
        <div className="flex items-center gap-2">
          <button
            onClick={() => qc.invalidateQueries({ queryKey: ['system-logs'] })}
            className="btn-secondary flex items-center gap-1.5 text-xs px-3 py-1.5"
          >
            <RefreshCw className={clsx('w-3.5 h-3.5', (isLoading || isRefetching) && 'animate-spin')} />
            Actualiser
          </button>
          <button
            onClick={handleClear}
            disabled={clearing}
            className="btn-secondary flex items-center gap-1.5 text-xs px-3 py-1.5 text-red-400 border-red-800/40 hover:bg-red-900/20"
          >
            <Trash2 className="w-3.5 h-3.5" />
            Purger &gt;30j
          </button>
        </div>
      </div>

      {/* Summary chips */}
      <div className="flex items-center gap-3 flex-wrap">
        {[
          { level: 'INFO',     cls: 'bg-slate-800 text-slate-300' },
          { level: 'WARNING',  cls: 'bg-amber-900/40 text-amber-300 border border-amber-700/30' },
          { level: 'ERROR',    cls: 'bg-red-900/40 text-red-300 border border-red-700/30' },
          { level: 'CRITICAL', cls: 'bg-red-800/60 text-red-200 border border-red-600/30' },
        ].map(({ level, cls }) => (
          <button
            key={level}
            onClick={() => applyFilter('level', filters.level === level ? '' : level)}
            className={clsx(
              'px-3 py-1 rounded text-xs font-semibold transition-all',
              cls,
              filters.level === level ? 'ring-1 ring-white/30' : 'opacity-70 hover:opacity-100'
            )}
          >
            {level} · {counts[level as keyof typeof counts] ?? 0}
          </button>
        ))}
        <span className="text-xs text-slate-600 ml-auto">{logs.length} entrées</span>
      </div>

      {/* Filters */}
      <div className="card p-3 grid grid-cols-2 gap-3 md:grid-cols-4">
        <div>
          <label className="text-[9px] text-slate-500 uppercase tracking-wide block mb-1">Source</label>
          <select
            className="w-full bg-slate-800 border border-slate-700 rounded px-2 py-1 text-xs text-slate-300"
            value={filters.source ?? ''}
            onChange={e => applyFilter('source', e.target.value)}
          >
            <option value="">Toutes</option>
            {sources.map(s => <option key={s} value={s}>{s}</option>)}
          </select>
        </div>

        <div>
          <label className="text-[9px] text-slate-500 uppercase tracking-wide block mb-1">Cycle</label>
          <select
            className="w-full bg-slate-800 border border-slate-700 rounded px-2 py-1 text-xs text-slate-300"
            value={filters.cycle_id ?? ''}
            onChange={e => applyFilter('cycle_id', e.target.value)}
          >
            <option value="">Tous</option>
            {cycles.map(c => (
              <option key={c.cycle_id} value={c.cycle_id}>
                {c.first_ts ? format(new Date(c.first_ts), 'dd/MM HH:mm') : c.cycle_id.slice(0, 16)}
              </option>
            ))}
          </select>
        </div>

        <div>
          <label className="text-[9px] text-slate-500 uppercase tracking-wide block mb-1">Ticker</label>
          <input
            className="w-full bg-slate-800 border border-slate-700 rounded px-2 py-1 text-xs text-slate-300"
            placeholder="ex: SPY"
            value={tickerInput}
            onChange={e => setTickerInput(e.target.value.toUpperCase())}
            onBlur={() => applyFilter('ticker', tickerInput)}
            onKeyDown={e => e.key === 'Enter' && applyFilter('ticker', tickerInput)}
          />
        </div>

        <div className="grid grid-cols-2 gap-2">
          <div>
            <label className="text-[9px] text-slate-500 uppercase tracking-wide block mb-1">Depuis</label>
            <input
              type="date"
              className="w-full bg-slate-800 border border-slate-700 rounded px-2 py-1 text-xs text-slate-300"
              value={filters.date_from ?? ''}
              onChange={e => applyFilter('date_from', e.target.value)}
            />
          </div>
          <div>
            <label className="text-[9px] text-slate-500 uppercase tracking-wide block mb-1">Jusqu'au</label>
            <input
              type="date"
              className="w-full bg-slate-800 border border-slate-700 rounded px-2 py-1 text-xs text-slate-300"
              value={filters.date_to ?? ''}
              onChange={e => applyFilter('date_to', e.target.value)}
            />
          </div>
        </div>
      </div>

      {/* Log table */}
      <div className="card overflow-hidden">
        {isLoading ? (
          <div className="p-8 text-center text-slate-500 text-sm">Chargement…</div>
        ) : logs.length === 0 ? (
          <div className="p-8 text-center text-slate-600 text-sm">
            Aucun log trouvé pour ces filtres.<br />
            <span className="text-xs text-slate-700">Les WARNING et ERROR des cycles apparaissent ici automatiquement.</span>
          </div>
        ) : (
          <div className="overflow-x-auto">
            <table className="w-full text-xs">
              <thead>
                <tr className="border-b border-slate-700 text-[9px] uppercase tracking-wide text-slate-500">
                  <th className="px-3 py-2 text-left font-medium whitespace-nowrap">Horodatage</th>
                  <th className="px-3 py-2 text-left font-medium">Niveau</th>
                  <th className="px-3 py-2 text-left font-medium">Source</th>
                  <th className="px-3 py-2 text-left font-medium">Cycle</th>
                  <th className="px-3 py-2 text-left font-medium">Ticker</th>
                  <th className="px-3 py-2 text-left font-medium w-full">Message</th>
                </tr>
              </thead>
              <tbody>
                {logs.map(log => <LogRow key={log.id} log={log} />)}
              </tbody>
            </table>
          </div>
        )}
      </div>
    </div>
  )
}