import React, { useState } from 'react';
import { UploadCloud, Activity, CheckCircle, Layers, BarChart2, ArrowRight, ShieldCheck, Zap, Globe, Cpu, Settings, User } from 'lucide-react';
import './App.css';

interface HistoryRecord {
  id: number;
  timestamp: string;
  filename: string;
  confidence: number;
  thumbnail: string;
}

function LandingPage({ onEnter }: { onEnter: () => void }) {
  return (
    <div className="landing-container">
      <nav className="nav-bar">
        <div className="logo">
          <div className="logo-icon"><Activity size={20} color="#fff" /></div>
          DeepOceans
        </div>
        <div className="nav-actions">
          <button className="btn-text">Documentation</button>
          <button className="btn-text">API Features</button>
          <button className="btn-primary" onClick={onEnter}>View Dashboard</button>
        </div>
      </nav>

      <main>
        <section className="hero-section">
          <div className="hero-badge">DeepOceans v1.2 Engine Live</div>
          <h1 className="hero-title">Protecting Marine Life with Precision AI.</h1>
          <p className="hero-description">
            Enterprise-grade anomaly detection for satellite telemetry. Monitor coastal regions and detect oceanic oil spills automatically using our state-of-the-art segmentation network.
          </p>
          <div className="hero-buttons">
            <button className="btn-primary-lg" onClick={onEnter}>Start Monitoring <ArrowRight size={20} /></button>
            <button className="btn-secondary-lg">Talk to Sales</button>
          </div>
          <div className="hero-background-glow"></div>
        </section>

        <section className="features-section">
          <div className="feature-grid">
            <div className="feature-card">
              <div className="feature-icon-wrapper"><Zap size={24} className="feature-icon" /></div>
              <h3>Real-Time Inference</h3>
              <p>Achieve sub-200ms latency on 256x256 image segmentation masks utilizing optimized T4 compute instances.</p>
            </div>
            <div className="feature-card">
              <div className="feature-icon-wrapper"><Globe size={24} className="feature-icon" /></div>
              <h3>Satellite Agnostic</h3>
              <p>Process telemetry from SAR, Sentinel-1, or multi-spectral sources effortlessly through our robust API.</p>
            </div>
            <div className="feature-card">
              <div className="feature-icon-wrapper"><ShieldCheck size={24} className="feature-icon" /></div>
              <h3>Validated Accuracy</h3>
              <p>Averaging 0.84 IoU against validation datasets, ensuring you capture maximum spill events with minimal noise.</p>
            </div>
            <div className="feature-card">
              <div className="feature-icon-wrapper"><Cpu size={24} className="feature-icon" /></div>
              <h3>Seamless Integration</h3>
              <p>Plug predictions directly into your existing command center via standard REST protocols.</p>
            </div>
          </div>
        </section>

        <section className="how-it-works-section">
          <div className="section-header">
            <h2>Streamlined Operations</h2>
            <p>From raw signal to actionable intelligence in three steps.</p>
          </div>
          <div className="steps-container">
            <div className="step-card">
              <span className="step-numeral">01</span>
              <h4>Data Ingestion</h4>
              <p>Upload your optical or synthetic aperture radar imagery directly into our secure pipeline.</p>
            </div>
            <div className="step-card">
              <span className="step-numeral">02</span>
              <h4>Neural Processing</h4>
              <p>Our proprietary U-Net architecture isolates hydrocarbon signatures instantly.</p>
            </div>
            <div className="step-card">
              <span className="step-numeral">03</span>
              <h4>Spatial Analytics</h4>
              <p>Generate highly accurate masks and probability scores to dispatch cleanup crews faster.</p>
            </div>
          </div>
        </section>

        <section className="preview-section">
          <div className="preview-app-window">
             <div className="app-window-header">
               <div className="mac-dots"><div className="mac-dot red"></div><div className="mac-dot yellow"></div><div className="mac-dot green"></div></div>
               <div className="app-title">app.deepoceans.ai/workspace</div>
             </div>
             <div className="app-window-body">
                <div className="app-mockup-skeleton">
                   <div className="mock-nav"></div>
                   <div className="mock-layout">
                     <div className="mock-top">
                       <div className="mock-stat"></div>
                       <div className="mock-stat"></div>
                       <div className="mock-stat"></div>
                       <div className="mock-stat"></div>
                     </div>
                     <div className="mock-main">
                        <div className="mock-side"></div>
                        <div className="mock-center"></div>
                     </div>
                   </div>
                </div>
             </div>
          </div>
        </section>

        <section className="cta-section">
          <h2>Ready to revolutionize your monitoring?</h2>
          <p>Join the marine conservation operations running on DeepOceans.</p>
          <button className="btn-primary-lg" onClick={onEnter}>Launch Product <ArrowRight size={20} /></button>
        </section>
      </main>

      <footer className="landing-footer">
        <div className="footer-content">
          <div className="logo"><Activity size={20} color="var(--accent)" /> DeepOceans</div>
          <p>© 2026 DeepOceans AI. Securing marine futures.</p>
        </div>
      </footer>
    </div>
  );
}

function Dashboard() {
  const [selectedFile, setSelectedFile] = useState<File | null>(null);
  const [preview, setPreview] = useState<string | null>(null);
  const [maskSrc, setMaskSrc] = useState<string | null>(null);
  const [isLoading, setIsLoading] = useState(false);
  const [confidence, setConfidence] = useState<number | null>(null);
  const [latency, setLatency] = useState<number | null>(null);
  const [threshold, setThreshold] = useState<number>(0.5);
  
  const [history, setHistory] = useState<HistoryRecord[]>([
    {
      id: 1,
      timestamp: new Date(Date.now() - 14400000).toLocaleTimeString([], {hour: '2-digit', minute:'2-digit'}),
      filename: 'sentinel_scan_alpha.png',
      confidence: 84.2,
      thumbnail: 'https://images.unsplash.com/photo-1621213038477-9dfaf942dcde?auto=format&fit=crop&w=48&h=48'
    }
  ]);

  const [isDragActive, setIsDragActive] = useState(false);

  const handleFile = (file: File) => {
    setSelectedFile(file);
    const url = URL.createObjectURL(file);
    setPreview(url);
    setMaskSrc(null);
    setConfidence(null);
    setLatency(null);
  };

  const handleFileChange = (e: React.ChangeEvent<HTMLInputElement>) => {
    if (e.target.files && e.target.files.length > 0) handleFile(e.target.files[0]);
  };

  const onDragOver = (e: React.DragEvent) => { e.preventDefault(); setIsDragActive(true); };
  const onDragLeave = () => { setIsDragActive(false); };
  const onDrop = (e: React.DragEvent) => {
    e.preventDefault();
    setIsDragActive(false);
    if (e.dataTransfer.files && e.dataTransfer.files.length > 0) handleFile(e.dataTransfer.files[0]);
  };

  const handleUpload = async () => {
    if (!selectedFile || !preview) return;

    setIsLoading(true);
    const formData = new FormData();
    formData.append("file", selectedFile);

    const API_URL = import.meta.env.VITE_API_URL || "";
    try {
      const response = await fetch(`${API_URL}/predict`, {
        method: "POST",
        body: formData,
      });

      if (response.ok) {
        const confHeader = response.headers.get("X-Confidence-Score");
        const latHeader = response.headers.get("X-Inference-Latency-Ms");
        
        let confValue = 0;
        if (confHeader) {
          confValue = parseFloat(confHeader);
          setConfidence(confValue);
        }
        if (latHeader) setLatency(parseInt(latHeader));

        const blob = await response.blob();
        const maskUrl = URL.createObjectURL(blob);
        setMaskSrc(maskUrl);

        const newRecord: HistoryRecord = {
          id: Date.now(),
          timestamp: new Date().toLocaleTimeString([], {hour: '2-digit', minute:'2-digit'}),
          filename: selectedFile.name,
          confidence: confValue,
          thumbnail: preview
        };
        setHistory(prev => [newRecord, ...prev].slice(0, 10));
      } else {
        alert("Inference server returned an error. Ensure backend is running.");
      }
    } catch (error) {
      console.error(error);
      alert("Connection failure to inference node.");
    } finally {
      setIsLoading(false);
    }
  };

  return (
    <div className="app-layout">
      {/* SaaS App Header */}
      <header className="app-header">
        <div className="app-logo">
          <div className="logo-icon"><Activity size={18} color="#fff" /></div>
          DeepOceans <span className="app-badge">Workspace</span>
        </div>
        <div className="header-actions">
          <div className="connection-status">
            <div className="status-orb"></div> Node Operational
          </div>
          <button className="icon-btn"><Settings size={18} /></button>
          <button className="profile-btn"><User size={18} /></button>
        </div>
      </header>

      <main className="dashboard-content">
        <div className="dashboard-grid">
          
          {/* Top Row: Metrics Grid */}
          <div className="metrics-row">
            <div className="stat-card">
               <div className="stat-icon-wrapper"><BarChart2 size={20} className="stat-icon" /></div>
               <div className="stat-content">
                 <div className="stat-label">Spill Probability</div>
                 <div className="stat-value" style={{ color: confidence && confidence > 50 ? 'var(--alert)' : 'var(--text-primary)' }}>
                   {confidence !== null ? `${confidence.toFixed(1)}%` : '--'}
                 </div>
               </div>
            </div>
            <div className="stat-card">
               <div className="stat-icon-wrapper"><Activity size={20} className="stat-icon" /></div>
               <div className="stat-content">
                 <div className="stat-label">Inference Latency</div>
                 <div className="stat-value">{latency !== null ? `${latency}ms` : '--'}</div>
               </div>
            </div>
            <div className="stat-card">
               <div className="stat-icon-wrapper"><CheckCircle size={20} className="stat-icon" /></div>
               <div className="stat-content">
                 <div className="stat-label">Model IoU (Validation)</div>
                 <div className="stat-value">0.842</div>
               </div>
            </div>
            <div className="stat-card">
               <div className="stat-icon-wrapper"><Layers size={20} className="stat-icon" /></div>
               <div className="stat-content">
                 <div className="stat-label">Detection Threshold</div>
                 <div className="stat-control">
                   <input type="range" min="0.1" max="0.9" step="0.1" value={threshold} onChange={(e) => setThreshold(parseFloat(e.target.value))} />
                   <span className="range-val">{threshold.toFixed(2)}</span>
                 </div>
               </div>
            </div>
          </div>

          <div className="main-interaction-row">
            {/* Left: Uploader */}
            <div className="upload-container panel">
              <h3 className="panel-title">Data Ingestion</h3>
              
              <div 
                className={`dropzone ${isDragActive ? 'drag-active' : ''} ${selectedFile ? 'has-file' : ''}`}
                onDragOver={onDragOver}
                onDragLeave={onDragLeave}
                onDrop={onDrop}
              >
                <input type="file" id="file-upload" accept="image/*" onChange={handleFileChange} />
                <UploadCloud size={48} className="dropzone-icon" />
                <div className="dropzone-text">
                  <span className="dropzone-primary">Click to upload</span> or drag and drop
                </div>
                <div className="dropzone-secondary">JPG or PNG (Optimal size: 256x256)</div>
                {selectedFile && <div className="selected-file-chip">{selectedFile.name}</div>}
              </div>

              <button 
                className="btn-action-lg" 
                onClick={handleUpload} 
                disabled={!selectedFile || isLoading}
              >
                {isLoading ? <span className="loader" style={{marginRight: '8px'}}></span> : null}
                {isLoading ? "Running Prediction Pipeline..." : "Execute Detection"}
              </button>
            </div>

            {/* Right: History Log */}
            <div className="history-container panel">
              <div className="panel-header">
                <h3 className="panel-title">Analysis History</h3>
                <span className="record-count">{history.length} Records</span>
              </div>
              <div className="history-list">
                {history.length === 0 ? (
                  <div className="empty-state">No telemetry analyzed yet.</div>
                ) : (
                  history.map(record => (
                    <div key={record.id} className="history-row fade-in">
                      <img src={record.thumbnail} alt="snapshot" className="history-thumb" />
                      <div className="history-details">
                        <div className="history-filename" title={record.filename}>{record.filename}</div>
                        <div className="history-time">{record.timestamp}</div>
                      </div>
                      <div className="history-status">
                        <div className={`status-badge ${record.confidence > 50 ? 'alert' : 'clear'}`}>
                          {record.confidence > 50 ? 'Anomaly Detected' : 'All Clear'}
                        </div>
                        <div className="history-score">{record.confidence.toFixed(1)}%</div>
                      </div>
                    </div>
                  ))
                )}
              </div>
            </div>
          </div>

          {/* Bottom Row: Visualizations */}
          <div className="visualization-container panel">
             <div className="panel-header" style={{ marginBottom: '24px' }}>
                <h3 className="panel-title">Spatial Rendering Analysis</h3>
                <span className="badge-pill">U-Net Feature Map</span>
             </div>
             
             <div className="frames-grid">
               <div className="frame-card">
                 <div className="frame-header">Source Imagery</div>
                 <div className="frame-content">
                    {preview ? <img src={preview} alt="Raw" className="fade-in" /> : <div className="empty-state">Awaiting Feed</div>}
                 </div>
               </div>
               
               <div className="frame-card">
                 <div className="frame-header">Segmentation Mask</div>
                 <div className="frame-content dark-mode">
                    {maskSrc ? <img src={maskSrc} alt="Mask" className="fade-in invert-render" /> : <div className="empty-state">No Output</div>}
                 </div>
               </div>
               
               <div className="frame-card">
                 <div className="frame-header">Anomaly Overlay</div>
                 <div className="frame-content">
                    {preview && maskSrc ? (
                      <>
                        <img src={preview} alt="Base" />
                        <img src={maskSrc} alt="Overlay" className="fade-in feature-overlay" />
                      </>
                    ) : <div className="empty-state">No Output</div>}
                 </div>
               </div>
             </div>
          </div>

        </div>
      </main>
    </div>
  );
}

function App() {
  const [view, setView] = useState<'landing' | 'dashboard'>('landing');

  return (
    <>
      {view === 'landing' ? <LandingPage onEnter={() => setView('dashboard')} /> : <Dashboard />}
    </>
  );
}

export default App;