import { useState, useEffect, useMemo } from 'react';
import { invoke } from '@tauri-apps/api/core';
import { 
  AreaChart, Area, XAxis, YAxis, Tooltip, ResponsiveContainer, 
  CartesianGrid 
} from 'recharts';
import { 
  Activity, Cpu, Server, Database, Play, Square, 
  AlertTriangle, ArrowLeft, Shield, CheckSquare, Square as SquareIcon, Save, X
} from 'lucide-react';
import { clsx } from 'clsx';
import { twMerge } from 'tailwind-merge';

// --- Types ---

interface ProcessStats {
  pid: number;
  name: string;
  cpu_usage: number;
  memory: number;
  status: string;
  user_id?: string;
}

interface SystemStats {
  cpu_usage: number[];
  total_memory: number;
  used_memory: number;
  processes: ProcessStats[];
  is_recording: boolean;
  recording_duration: number;
}

interface TimelinePoint {
  time: string;
  avg_cpu: number;
  memory_gb: number;
}

interface ProcessHistoryPoint {
  time: string;
  cpu_usage: number;
  memory_mb: number;
}

interface AggregatedProcess {
  name: string;
  avg_cpu: number;
  peak_cpu: number;
  avg_memory_mb: number;
  peak_memory_mb: number;
  instance_count: number;
  warnings: string[];
  history: ProcessHistoryPoint[];
}

interface ProfilingReport {
  start_time: string;
  end_time: string;
  duration_seconds: number;
  timeline: TimelinePoint[];
  aggregated_processes: AggregatedProcess[];
}

function cn(...inputs: (string | undefined | null | false)[]) {
  return twMerge(clsx(inputs));
}

function App() {
  const [view, setView] = useState<'dashboard' | 'report'>('dashboard');
  const [stats, setStats] = useState<SystemStats | null>(null);
  const [history, setHistory] = useState<{ time: string; cpu: number }[]>([]);
  const [excludeSelf, setExcludeSelf] = useState(true);
  const [report, setReport] = useState<ProfilingReport | null>(null);

  useEffect(() => {
    const fetchStats = async () => {
      try {
        const isRecording = stats?.is_recording ?? false;
        const data = await invoke<SystemStats>('get_system_stats', { 
            excludeSelf, 
            minimal: isRecording || view === 'report' 
        });
        setStats(data);
        
        const avgCpu = data.cpu_usage.reduce((a, b) => a + b, 0) / data.cpu_usage.length;
        
        setHistory(prev => {
          const newHistory = [...prev, { time: new Date().toLocaleTimeString(), cpu: avgCpu }];
          if (newHistory.length > 60) newHistory.shift();
          return newHistory;
        });
      } catch (e) {
        console.error(e);
      }
    };

    fetchStats();
    const interval = setInterval(fetchStats, 1000);
    return () => clearInterval(interval);
  }, [excludeSelf, view, stats?.is_recording]);

  const toggleRecording = async () => {
    if (stats?.is_recording) {
      const reportData = await invoke<ProfilingReport>('stop_profiling');
      setReport(reportData);
      setView('report');
    } else {
      await invoke('start_profiling');
    }
  };

  const killProcess = async (pid: number) => {
    try {
      await invoke('run_as_admin', { command: `kill -9 ${pid}` });
    } catch (e) {
      alert(`Failed to kill process: ${e}`);
    }
  };

  if (view === 'report' && report) {
    return (
      <ReportView 
        report={report} 
        onBack={() => setView('dashboard')} 
      />
    );
  }

  if (!stats) return <div className="h-screen w-screen flex items-center justify-center text-text bg-base">Loading System Data...</div>;

  const avgCpu = stats.cpu_usage.reduce((a, b) => a + b, 0) / stats.cpu_usage.length;
  const memoryPercent = (stats.used_memory / stats.total_memory) * 100;

  return (
    <div className="flex flex-col h-screen bg-base text-text">
      <div data-tauri-drag-region className="titlebar shrink-0">
        <div className="titlebar-drag gap-2 px-4" data-tauri-drag-region>
          <Activity size={16} className="text-mauve" /> 
          <span className="font-bold tracking-tight">SysPulse</span>
        </div>
        <div className="flex items-center gap-4 px-4">
          <button 
            className="flex items-center gap-2 text-subtext0 hover:text-text transition-colors text-xs"
            onClick={() => setExcludeSelf(!excludeSelf)}
          >
            {excludeSelf ? <CheckSquare size={14} className="text-blue" /> : <SquareIcon size={14} />}
            <span>Hide SysPulse</span>
          </button>
          <button 
            className={cn(
              "flex items-center gap-2 px-4 py-1.5 rounded-full text-xs font-bold transition-all shadow-lg",
              stats.is_recording 
                ? "bg-red text-base animate-pulse" 
                : "bg-green text-base hover:scale-105 active:scale-95"
            )}
            onClick={toggleRecording}
          >
            {stats.is_recording ? <Square size={12} fill="currentColor" /> : <Play size={12} fill="currentColor" />}
            {stats.is_recording ? `STOP (${formatDuration(stats.recording_duration)})` : "RECORD PROFILE"}
          </button>
        </div>
      </div>

      <main className="flex-1 overflow-hidden flex flex-col p-6 gap-6">
        {stats.is_recording ? (
            <div className="flex-1 flex flex-col items-center justify-center gap-8 animate-in fade-in zoom-in duration-500">
                <div className="relative">
                    <div className="absolute inset-0 bg-red/20 blur-3xl rounded-full scale-150 animate-pulse" />
                    <div className="relative bg-surface0 p-12 rounded-full border-4 border-red/30 shadow-2xl">
                        <Activity size={64} className="text-red animate-pulse" />
                    </div>
                </div>
                <div className="text-center space-y-2">
                    <h2 className="text-3xl font-black text-text tracking-tighter uppercase italic">Profiling Active</h2>
                    <p className="text-subtext1 font-mono text-xl">{formatDuration(stats.recording_duration)}</p>
                </div>
                <div className="grid grid-cols-2 gap-4 w-full max-w-md">
                    <div className="bg-surface0 p-4 rounded-2xl border border-surface1">
                        <div className="text-xs font-bold text-subtext0 mb-1 uppercase tracking-widest">CPU</div>
                        <div className="text-2xl font-black text-blue">{avgCpu.toFixed(1)}%</div>
                    </div>
                    <div className="bg-surface0 p-4 rounded-2xl border border-surface1">
                        <div className="text-xs font-bold text-subtext0 mb-1 uppercase tracking-widest">RAM</div>
                        <div className="text-2xl font-black text-mauve">{memoryPercent.toFixed(1)}%</div>
                    </div>
                </div>
                <p className="text-overlay1 text-sm italic">Minimal footprint mode enabled to ensure accurate results.</p>
            </div>
        ) : (
            <>
                <div className="grid grid-cols-1 md:grid-cols-3 gap-6 shrink-0">
                    <div className="card group">
                        <div className="card-title"><Cpu size={16} className="text-blue" /> CPU Load</div>
                        <div className="flex items-end gap-2">
                            <span className="stat-value text-blue">{avgCpu.toFixed(1)}</span>
                            <span className="text-subtext0 font-bold mb-2">%</span>
                        </div>
                        <div className="h-16 mt-4">
                            <ResponsiveContainer width="100%" height="100%">
                                <AreaChart data={history}>
                                    <defs>
                                        <linearGradient id="cpuDash" x1="0" y1="0" x2="0" y2="1">
                                            <stop offset="5%" stopColor="var(--blue)" stopOpacity={0.5}/>
                                            <stop offset="95%" stopColor="var(--blue)" stopOpacity={0}/>
                                        </linearGradient>
                                    </defs>
                                    <Area type="monotone" dataKey="cpu" stroke="var(--blue)" fill="url(#cpuDash)" strokeWidth={2} isAnimationActive={false} />
                                </AreaChart>
                            </ResponsiveContainer>
                        </div>
                    </div>

                    <div className="card">
                        <div className="card-title"><Database size={16} className="text-mauve" /> Memory</div>
                        <div className="flex items-end gap-2">
                            <span className="stat-value text-mauve">{(stats.used_memory / 1024 / 1024 / 1024).toFixed(1)}</span>
                            <span className="text-subtext0 font-bold mb-2">GB used</span>
                        </div>
                        <div className="mt-6">
                            <div className="flex justify-between text-[10px] font-bold text-overlay2 uppercase mb-1">
                                <span>{memoryPercent.toFixed(1)}%</span>
                                <span>{(stats.total_memory / 1024 / 1024 / 1024).toFixed(0)} GB</span>
                            </div>
                            <div className="h-2 bg-surface1 rounded-full overflow-hidden">
                                <div className="h-full bg-mauve transition-all duration-700" style={{ width: `${memoryPercent}%` }} />
                            </div>
                        </div>
                    </div>

                    <div className="card">
                        <div className="card-title"><Server size={16} className="text-green" /> Tasks</div>
                        <div className="flex items-end gap-2">
                            <span className="stat-value text-green">{stats.processes.length}</span>
                            <span className="text-subtext0 font-bold mb-2">active</span>
                        </div>
                        <div className="mt-4 text-xs text-overlay2 font-medium leading-relaxed">
                            Profiling will merge child processes into their parents for consolidated analysis.
                        </div>
                    </div>
                </div>

                <div className="card flex-1 flex flex-col min-h-0 overflow-hidden shadow-2xl border border-surface1/50">
                    <div className="flex justify-between items-center mb-6">
                        <h3 className="text-lg font-black tracking-tighter uppercase italic flex items-center gap-2">
                            <Activity size={20} className="text-red" /> 
                            Live Process Feed
                        </h3>
                        <div className="text-[10px] bg-surface1 px-2 py-1 rounded font-bold text-overlay2 uppercase">Top 50 Consumers</div>
                    </div>
                    
                    <div className="table-header grid grid-cols-[4fr_1fr_1.5fr_1.5fr_0.5fr] gap-4 px-4 py-3 bg-surface1/30 rounded-t-xl">
                        <div>Name</div>
                        <div>PID</div>
                        <div>CPU</div>
                        <div>Memory</div>
                        <div className="text-center">Action</div>
                    </div>
                    
                    <div className="overflow-y-auto flex-1 custom-scrollbar">
                        {stats.processes.map((proc) => (
                        <div key={proc.pid} className="table-row grid grid-cols-[4fr_1fr_1.5fr_1.5fr_0.5fr] gap-4 px-4 py-3 border-b border-surface1/30 group hover:bg-surface1/20 transition-all">
                            <div className="font-bold text-text truncate text-sm" title={proc.name}>{proc.name}</div>
                            <div className="font-mono text-overlay1 text-xs mt-1">{proc.pid}</div>
                            <div className="text-blue font-black text-sm">{proc.cpu_usage.toFixed(1)}%</div>
                            <div className="text-mauve font-black text-sm">{(proc.memory / 1024 / 1024).toFixed(0)} MB</div>
                            <div className="flex justify-center">
                            <button 
                                onClick={() => killProcess(proc.pid)}
                                className="opacity-0 group-hover:opacity-100 p-1.5 hover:bg-red/20 text-red rounded-lg transition-all"
                            >
                                <Shield size={14} />
                            </button>
                            </div>
                        </div>
                        ))}
                    </div>
                </div>
            </>
        )}
      </main>
    </div>
  );
}

type SortField = 'name' | 'avg_cpu' | 'peak_cpu' | 'avg_memory_mb' | 'peak_memory_mb' | 'instance_count';

function ReportView({ report, onBack }: { report: ProfilingReport, onBack: () => void }) {
  const [sortField, setSortField] = useState<SortField>('avg_cpu');
  const [sortOrder, setSortOrder] = useState<'asc' | 'desc'>('desc');
  const [selectedProcess, setSelectedProcess] = useState<AggregatedProcess | null>(null);

  const handleSort = (field: SortField) => {
    if (sortField === field) {
        setSortOrder(sortOrder === 'asc' ? 'desc' : 'asc');
    } else {
        setSortField(field);
        setSortOrder('desc');
    }
  };

  const sortedProcesses = useMemo(() => {
    return [...report.aggregated_processes].sort((a, b) => {
        const valA = a[sortField as keyof AggregatedProcess];
        const valB = b[sortField as keyof AggregatedProcess];
        
        if (typeof valA === 'string' && typeof valB === 'string') {
            return sortOrder === 'asc' ? valA.localeCompare(valB) : valB.localeCompare(valA);
        }
        
        const numA = (valA as number) ?? 0;
        const numB = (valB as number) ?? 0;
        
        return sortOrder === 'asc' ? numA - numB : numB - numA;
    });
  }, [report, sortField, sortOrder]);

  const saveReport = async () => {
    try {
        const path = await invoke<string>('save_report', { report });
        alert(`Report saved to: ${path}`);
    } catch (e) {
        alert(`Failed to save: ${e}`);
    }
  };

  return (
    <div className="flex flex-col h-screen bg-base text-text">
      <div className="titlebar shrink-0">
        <div className="titlebar-drag gap-2 px-4">
           <Activity size={16} className="text-mauve" /> 
           <span className="font-bold uppercase italic tracking-tighter">Profiling Report</span>
        </div>
        <div className="flex gap-4 px-4">
            <button 
                onClick={saveReport}
                className="flex items-center gap-2 px-3 py-1 bg-surface1 hover:bg-surface2 rounded text-xs font-bold transition-all text-text"
            >
                <Save size={14} className="text-blue" /> SAVE JSON
            </button>
            <button 
                onClick={onBack} 
                className="flex items-center gap-2 px-3 py-1 bg-surface1 hover:bg-surface2 rounded text-xs font-bold transition-all text-text"
            >
                <ArrowLeft size={14} className="text-mauve" /> DASHBOARD
            </button>
        </div>
      </div>

      <main className="flex-1 overflow-y-auto p-6 flex flex-col gap-6 custom-scrollbar relative">
        <div className="grid grid-cols-1 md:grid-cols-4 gap-4 shrink-0">
            <div className="bg-surface0 p-6 rounded-2xl border border-surface1 shadow-xl text-center">
                <div className="text-[10px] font-black text-overlay2 uppercase tracking-widest mb-1">Session Time</div>
                <div className="text-2xl font-black text-text font-mono">{formatDuration(report.duration_seconds)}</div>
            </div>
            <div className="bg-surface0 p-6 rounded-2xl border border-surface1 shadow-xl text-center">
                <div className="text-[10px] font-black text-overlay2 uppercase tracking-widest mb-1">End of Session</div>
                <div className="text-xl font-bold text-text">{new Date(report.end_time).toLocaleTimeString()}</div>
            </div>
            <div className="bg-surface0 p-6 rounded-2xl border border-surface1 shadow-xl text-center">
                <div className="text-[10px] font-black text-overlay2 uppercase tracking-widest mb-1">Uniques</div>
                <div className="text-2xl font-black text-blue">{report.aggregated_processes.length}</div>
            </div>
            <div className="bg-surface0 p-6 rounded-2xl border border-surface1 shadow-xl text-center">
                 <div className="text-[10px] font-black text-overlay2 uppercase tracking-widest mb-1">Issue Alerts</div>
                 <div className="text-2xl font-black text-red">
                   {report.aggregated_processes.filter(p => p.warnings.length > 0).length}
                 </div>
            </div>
        </div>

        <div className="card h-72 border border-surface1/50 shadow-2xl">
          <div className="flex justify-between items-center mb-4">
            <h3 className="text-sm font-black uppercase italic tracking-widest flex items-center gap-2">
                <Activity size={16} className="text-blue" /> Session Load Profile
            </h3>
          </div>
          <div className="flex-1 min-h-0">
            <ResponsiveContainer width="100%" height="100%">
                <AreaChart data={report.timeline}>
                <defs>
                    <linearGradient id="cpuReportGradient" x1="0" y1="0" x2="0" y2="1">
                    <stop offset="5%" stopColor="var(--blue)" stopOpacity={0.6}/>
                    <stop offset="95%" stopColor="var(--blue)" stopOpacity={0}/>
                    </linearGradient>
                </defs>
                <CartesianGrid strokeDasharray="3 3" stroke="var(--surface1)" vertical={false} opacity={0.5} />
                <XAxis dataKey="time" stroke="var(--subtext0)" tick={{fontSize: 9}} minTickGap={50} />
                <YAxis stroke="var(--subtext0)" tick={{fontSize: 9}} />
                <Tooltip 
                    contentStyle={{ background: 'var(--mantle)', border: '1px solid var(--surface1)', borderRadius: '12px', fontSize: '11px' }}
                    itemStyle={{ color: 'var(--text)' }}
                />
                <Area type="monotone" dataKey="avg_cpu" name="CPU %" stroke="var(--blue)" fill="url(#cpuReportGradient)" strokeWidth={3} isAnimationActive={true} />
                <Area type="monotone" dataKey="memory_gb" name="MEM GB" stroke="var(--mauve)" fill="none" strokeWidth={2} />
                </AreaChart>
            </ResponsiveContainer>
          </div>
        </div>

        <div className="card flex-1 flex flex-col min-h-0 border border-surface1/50 shadow-2xl overflow-hidden">
          <div className="flex justify-between items-center mb-6 px-2">
            <h3 className="text-lg font-black tracking-tighter uppercase italic flex items-center gap-2">
                <Server size={20} className="text-green" /> Analysis Matrix
            </h3>
            <span className="text-[10px] text-overlay1 font-bold">CLICK PROCESS TO INSPECT</span>
          </div>
          
          <div className="table-header grid grid-cols-[2fr_0.8fr_1fr_1fr_1fr_1fr_2fr] gap-2 px-4 py-3 bg-surface1/30 rounded-t-xl font-bold uppercase tracking-widest text-[9px] text-overlay1">
            <div className="cursor-pointer hover:text-text transition-colors flex items-center gap-1" onClick={() => handleSort('name')}>
                Process {sortField === 'name' && (sortOrder === 'asc' ? '↑' : '↓')}
            </div>
            <div className="cursor-pointer hover:text-text transition-colors" onClick={() => handleSort('instance_count')}>Units</div>
            <div className="cursor-pointer hover:text-text transition-colors" onClick={() => handleSort('avg_cpu')}>Avg CPU</div>
            <div className="cursor-pointer hover:text-text transition-colors" onClick={() => handleSort('peak_cpu')}>Peak CPU</div>
            <div className="cursor-pointer hover:text-text transition-colors" onClick={() => handleSort('avg_memory_mb')}>Avg Mem</div>
            <div className="cursor-pointer hover:text-text transition-colors" onClick={() => handleSort('peak_memory_mb')}>Peak Mem</div>
            <div>Insights</div>
          </div>
          
          <div className="overflow-y-auto flex-1 custom-scrollbar">
            {sortedProcesses.map((proc, i) => (
              <div 
                key={i} 
                onClick={() => setSelectedProcess(proc)}
                className="table-row grid grid-cols-[2fr_0.8fr_1fr_1fr_1fr_1fr_2fr] gap-2 px-4 py-3 border-b border-surface1/20 hover:bg-surface1/30 cursor-pointer transition-colors group"
              >
                <div className="font-bold text-text truncate text-xs group-hover:text-blue" title={proc.name}>{proc.name}</div>
                <div className="text-overlay1 font-mono text-xs">{proc.instance_count}</div>
                <div className="text-blue font-black text-xs">{proc.avg_cpu.toFixed(1)}%</div>
                <div className="text-subtext0 text-[10px] font-bold">{proc.peak_cpu.toFixed(1)}%</div>
                <div className="text-mauve font-black text-xs">{proc.avg_memory_mb.toFixed(0)}MB</div>
                <div className="text-subtext0 text-[10px] font-bold">{proc.peak_memory_mb.toFixed(0)}MB</div>
                <div className="flex flex-wrap gap-1">
                  {proc.warnings.map((w, idx) => (
                    <span key={idx} className="bg-red/10 text-red text-[9px] font-black px-1.5 py-0.5 rounded-full border border-red/20 flex items-center gap-1 uppercase tracking-tighter">
                      <AlertTriangle size={8} /> {w}
                    </span>
                  ))}
                </div>
              </div>
            ))}
          </div>
        </div>

        {/* Process Detail Side Panel/Modal */}
        {selectedProcess && (
            <div className="fixed inset-0 z-[100] flex items-center justify-end bg-base/80 backdrop-blur-sm p-8 animate-in slide-in-from-right duration-300">
                <div className="w-full max-w-2xl h-full bg-mantle rounded-3xl border border-surface1 shadow-3xl flex flex-col overflow-hidden">
                    <div className="p-8 border-b border-surface1 flex justify-between items-start shrink-0">
                        <div>
                            <div className="text-xs font-black text-blue uppercase tracking-widest mb-1">Process Inspector</div>
                            <h2 className="text-3xl font-black text-text tracking-tighter uppercase italic truncate max-w-md">{selectedProcess.name}</h2>
                        </div>
                        <button 
                            onClick={() => setSelectedProcess(null)}
                            className="p-2 hover:bg-surface1 rounded-full transition-colors"
                        >
                            <X size={24} />
                        </button>
                    </div>

                    <div className="flex-1 overflow-y-auto p-8 flex flex-col gap-8 custom-scrollbar">
                        <div className="grid grid-cols-2 gap-4">
                            <div className="bg-surface0 p-6 rounded-2xl border border-surface1 shadow-lg">
                                <div className="text-[10px] font-black text-overlay2 uppercase tracking-widest mb-2">Instances Detected</div>
                                <div className="text-4xl font-black text-text">{selectedProcess.instance_count}</div>
                                <p className="text-xs text-subtext1 mt-2">Maximum concurrent processes seen with this name.</p>
                            </div>
                            <div className="bg-surface0 p-6 rounded-2xl border border-surface1 shadow-lg">
                                <div className="text-[10px] font-black text-overlay2 uppercase tracking-widest mb-2">Average Impact</div>
                                <div className="text-4xl font-black text-blue">{selectedProcess.avg_cpu.toFixed(1)}%</div>
                                <p className="text-xs text-subtext1 mt-2">Mean CPU usage across the entire session.</p>
                            </div>
                        </div>

                        <div className="card h-64 shrink-0 bg-base border border-surface1">
                            <div className="card-title mb-4">Resource History (Summed)</div>
                            <div className="flex-1 min-h-0">
                                <ResponsiveContainer width="100%" height="100%">
                                    <AreaChart data={selectedProcess.history}>
                                        <defs>
                                            <linearGradient id="procCpuGrad" x1="0" y1="0" x2="0" y2="1">
                                                <stop offset="5%" stopColor="var(--blue)" stopOpacity={0.6}/>
                                                <stop offset="95%" stopColor="var(--blue)" stopOpacity={0}/>
                                            </linearGradient>
                                            <linearGradient id="procMemGrad" x1="0" y1="0" x2="0" y2="1">
                                                <stop offset="5%" stopColor="var(--mauve)" stopOpacity={0.4}/>
                                                <stop offset="95%" stopColor="var(--mauve)" stopOpacity={0}/>
                                            </linearGradient>
                                        </defs>
                                        <CartesianGrid strokeDasharray="3 3" stroke="var(--surface1)" vertical={false} opacity={0.3} />
                                        <XAxis dataKey="time" stroke="var(--subtext0)" tick={{fontSize: 9}} hide />
                                        <YAxis stroke="var(--subtext0)" tick={{fontSize: 9}} />
                                        <Tooltip 
                                            contentStyle={{ background: 'var(--crust)', border: '1px solid var(--surface1)', borderRadius: '12px' }}
                                        />
                                        <Area type="monotone" dataKey="cpu_usage" name="Total CPU %" stroke="var(--blue)" fill="url(#procCpuGrad)" strokeWidth={3} />
                                        <Area type="monotone" dataKey="memory_mb" name="Total Mem (MB)" stroke="var(--mauve)" fill="url(#procMemGrad)" strokeWidth={2} />
                                    </AreaChart>
                                </ResponsiveContainer>
                            </div>
                        </div>

                        <div className="space-y-4">
                            <h4 className="text-xs font-black text-overlay2 uppercase tracking-widest">Profiling Insights</h4>
                            <div className="flex flex-col gap-2">
                                {selectedProcess.warnings.length > 0 ? selectedProcess.warnings.map((w, idx) => (
                                    <div key={idx} className="bg-red/10 border border-red/20 p-4 rounded-xl flex items-center gap-3 text-red">
                                        <AlertTriangle size={20} />
                                        <span className="font-bold text-sm uppercase italic tracking-tight">{w}</span>
                                    </div>
                                )) : (
                                    <div className="bg-green/10 border border-green/20 p-4 rounded-xl flex items-center gap-3 text-green">
                                        <CheckSquare size={20} />
                                        <span className="font-bold text-sm uppercase italic tracking-tight">Optimal Performance Profile</span>
                                    </div>
                                )}
                            </div>
                        </div>
                    </div>
                </div>
            </div>
        )}
      </main>
    </div>
  );
}

function formatDuration(seconds: number) {
  const m = Math.floor(seconds / 60);
  const s = Math.floor(seconds % 60);
  return `${m}:${s.toString().padStart(2, '0')}`;
}

export default App;