import { useState, useRef, useCallback } from "react";

const API_BASE = "";

const SEV_COLOR = { high: "#ff4d6d", medium: "#ff9f1c", low: "#2ec4b6" };
const SEV_BG    = { high: "#fff0f3", medium: "#fff8ee", low: "#f0fafa" };

function Badge({ sev }) {
  const col = SEV_COLOR[sev] || "#888";
  return (
    <span style={{
      background: `${col}20`, color: col, borderRadius: 4,
      padding: "2px 8px", fontSize: 11, fontWeight: 600,
      textTransform: "uppercase", marginLeft: 6,
    }}>{sev}</span>
  );
}

function StatCard({ value, label, color, bg }) {
  return (
    <div style={{
      background: bg, borderLeft: `4px solid ${color}`,
      borderRadius: 10, padding: "16px 22px", minWidth: 110,
    }}>
      <div style={{ fontSize: 36, fontWeight: 800, color }}>{value}</div>
      <div style={{ fontSize: 11, color: "#888", textTransform: "uppercase", letterSpacing: ".06em" }}>{label}</div>
    </div>
  );
}

export default function App() {
  const [files, setFiles]         = useState([]);
  const [dragging, setDragging]   = useState(false);
  const [loading, setLoading]     = useState(false);
  const [progress, setProgress]   = useState(0);
  const [statusMsg, setStatusMsg] = useState("");
  const [results, setResults]     = useState(null);
  const [error, setError]         = useState(null);
  const [activeTab, setActiveTab] = useState("ranked");
  const fileRef = useRef();

  const addFiles = useCallback((incoming) => {
    const pdfs = Array.from(incoming).filter(f => f.type === "application/pdf");
    if (pdfs.length < incoming.length) {
      setError("Only PDF files are supported.");
    }
    setFiles(prev => {
      const existing = new Set(prev.map(f => f.name));
      return [...prev, ...pdfs.filter(f => !existing.has(f.name))];
    });
  }, []);

  const removeFile = (name) => setFiles(f => f.filter(x => x.name !== name));

  const reset = () => {
    setFiles([]); setResults(null); setError(null);
    setProgress(0); setStatusMsg(""); setActiveTab("ranked");
  };

  const analyze = async () => {
    if (files.length < 2) { setError("Please upload at least 2 PDF files."); return; }
    setError(null); setLoading(true); setProgress(10); setResults(null);

    // Fake progress while waiting
    const ticker = setInterval(() => {
      setProgress(p => p < 85 ? p + 3 : p);
    }, 1200);

    const msgs = [
      "Extracting text from PDFs...",
      "Sending to Groq for protocol extraction...",
      "Comparing protocols across papers...",
      "Generating contradiction report...",
    ];
    let mi = 0;
    setStatusMsg(msgs[mi]);
    const msgTicker = setInterval(() => {
      mi = Math.min(mi + 1, msgs.length - 1);
      setStatusMsg(msgs[mi]);
    }, 6000);

    try {
      const form = new FormData();
      files.forEach(f => form.append("files", f));

      const resp = await fetch(`${API_BASE}/analyze`, { method: "POST", body: form });
      if (!resp.ok) {
        const err = await resp.json().catch(() => ({}));
        throw new Error(err.detail || `Server error ${resp.status}`);
      }
      const data = await resp.json();
      setProgress(100);
      setStatusMsg("Analysis complete!");
      setResults(data);
      setActiveTab("ranked");
    } catch (e) {
      setError(e.message);
    } finally {
      clearInterval(ticker);
      clearInterval(msgTicker);
      setLoading(false);
    }
  };

  const downloadReport = () => {
    if (!results?.html_report) return;
    const blob = new Blob([results.html_report], { type: "text/html" });
    const url  = URL.createObjectURL(blob);
    const a    = document.createElement("a");
    a.href     = url;
    a.download = "protocol_report.html";
    a.click();
    URL.revokeObjectURL(url);
  };

  const comp        = results?.comparison || {};
  const summary     = comp.summary || {};
  const contras     = comp.contradictions || [];
  const ranked      = comp.ranked_issues || [];
  const optimal     = comp.optimal_protocol || {};
  const paperNames  = results?.paper_names || [];
  const extracted   = results?.extracted || [];

  return (
    <div style={{ fontFamily: "'Segoe UI', sans-serif", background: "#f7f7fa", minHeight: "100vh", padding: "40px 24px" }}>
      <div style={{ maxWidth: 1100, margin: "0 auto" }}>

        {/* ── Header ── */}
        <div style={{ background: "#1a1a2e", borderRadius: 12, padding: "32px 36px", marginBottom: 28, color: "white" }}>
          <div style={{ fontSize: 11, letterSpacing: ".15em", textTransform: "uppercase", color: "#a78bfa", marginBottom: 8 }}>
            ContraGenAI · Bioengineering · Reproducibility
          </div>
          <h1 style={{ fontSize: 28, fontWeight: 800, margin: "0 0 8px" }}>ContraGenAI</h1>
          <div style={{ fontSize: 14, color: "#a78bfa", marginBottom: 8 }}>A Protocol Contradiction Detector</div>
          <p style={{ color: "#aab", fontSize: 13, lineHeight: 1.6, maxWidth: 620 }}>
            Upload 2 or more research papers and detect methodological contradictions across experimental protocols —
            reagents, temperatures, cell lines, antibodies, timing and more.
            <b style={{ color: "#a78bfa" }}>ContraGenAI</b> · Powered by Groq + LLaMA 3.3 70B
          </p>
        </div>

        {/* ── Upload section ── */}
        {!results && (
          <div style={{ background: "white", borderRadius: 12, padding: "24px 28px", marginBottom: 20, boxShadow: "0 1px 4px rgba(0,0,0,.07)" }}>
            <div style={{ fontSize: 16, fontWeight: 700, borderLeft: "4px solid #7b2d8b", paddingLeft: 12, marginBottom: 18 }}>
              Upload Research Papers
            </div>

            {/* Drop zone */}
            <div
              onClick={() => fileRef.current?.click()}
              onDragOver={e => { e.preventDefault(); setDragging(true); }}
              onDragLeave={() => setDragging(false)}
              onDrop={e => { e.preventDefault(); setDragging(false); addFiles(e.dataTransfer.files); }}
              style={{
                border: `2px dashed ${dragging ? "#7b2d8b" : "#ddd"}`,
                borderRadius: 10, padding: "36px 24px", textAlign: "center",
                cursor: "pointer", background: dragging ? "#f5f0ff" : "#fafafa",
                transition: "all .2s", marginBottom: 16,
              }}
            >
              <input ref={fileRef} type="file" multiple accept=".pdf"
                style={{ display: "none" }} onChange={e => addFiles(e.target.files)} />
              <div style={{ fontSize: 32, marginBottom: 10 }}>📄</div>
              <div style={{ fontWeight: 600, color: "#1a1a2e", marginBottom: 4 }}>
                Drag and drop PDFs here
              </div>
              <div style={{ fontSize: 12, color: "#aaa" }}>or click to browse · multiple files supported</div>
            </div>

            {/* File list */}
            {files.length > 0 && (
              <div style={{ marginBottom: 20 }}>
                {files.map(f => (
                  <div key={f.name} style={{
                    display: "flex", alignItems: "center", gap: 12,
                    background: "#f5f0ff", borderRadius: 6, padding: "8px 14px", marginBottom: 6,
                  }}>
                    <span style={{ fontSize: 16 }}>📄</span>
                    <span style={{ flex: 1, fontSize: 13, color: "#1a1a2e" }}>{f.name}</span>
                    <span style={{ fontSize: 11, color: "#aaa" }}>{(f.size / 1024).toFixed(0)} KB</span>
                    <button onClick={() => removeFile(f.name)}
                      style={{ background: "none", border: "none", cursor: "pointer", color: "#aaa", fontSize: 18, lineHeight: 1 }}>×</button>
                  </div>
                ))}
                <div style={{ fontSize: 12, color: "#aaa", marginTop: 4 }}>{files.length} file(s) ready</div>
              </div>
            )}

            {/* Error */}
            {error && (
              <div style={{ background: "#fff0f3", border: "1px solid #ff4d6d40", borderRadius: 8, padding: "12px 16px", color: "#ff4d6d", fontSize: 13, marginBottom: 16 }}>
                ⚠ {error}
              </div>
            )}

            {/* Progress */}
            {loading && (
              <div style={{ marginBottom: 20 }}>
                <div style={{ display: "flex", justifyContent: "space-between", fontSize: 12, color: "#888", marginBottom: 6 }}>
                  <span>{statusMsg}</span>
                  <span>{progress}%</span>
                </div>
                <div style={{ height: 6, background: "#eee", borderRadius: 3, overflow: "hidden" }}>
                  <div style={{
                    height: "100%", borderRadius: 3,
                    background: "linear-gradient(90deg,#7b2d8b,#2ec4b6)",
                    width: `${progress}%`, transition: "width .4s ease",
                  }} />
                </div>
              </div>
            )}

            {/* Analyze button */}
            <button
              onClick={analyze}
              disabled={loading || files.length < 2}
              style={{
                padding: "13px 32px", background: files.length >= 2 && !loading ? "#7b2d8b" : "#ddd",
                color: files.length >= 2 && !loading ? "white" : "#aaa",
                border: "none", borderRadius: 8, fontWeight: 700, fontSize: 14,
                cursor: files.length >= 2 && !loading ? "pointer" : "not-allowed",
                transition: "all .2s",
              }}
            >
              {loading ? "Analyzing..." : `Detect Contradictions →`}
            </button>
            {files.length < 2 && !loading && (
              <span style={{ marginLeft: 14, fontSize: 12, color: "#aaa" }}>
                Add {2 - files.length} more paper{files.length === 1 ? "" : "s"} to start
              </span>
            )}
          </div>
        )}

        {/* ── Results ── */}
        {results && (
          <>
            {/* Results header */}
            <div style={{ display: "flex", alignItems: "center", justifyContent: "space-between", marginBottom: 20, flexWrap: "wrap", gap: 12 }}>
              <div>
                <div style={{ fontSize: 22, fontWeight: 800, color: "#1a1a2e" }}>Analysis Results</div>
                <div style={{ fontSize: 13, color: "#888", marginTop: 3 }}>
                  {paperNames.length} papers · {comp.protocol_type || "Protocol"}
                </div>
              </div>
              <div style={{ display: "flex", gap: 10 }}>
                <button onClick={downloadReport} style={{
                  padding: "10px 20px", background: "#2ec4b6", color: "white",
                  border: "none", borderRadius: 8, fontWeight: 600, fontSize: 13, cursor: "pointer",
                }}>⬇ Download Report</button>
                <button onClick={reset} style={{
                  padding: "10px 20px", background: "white", color: "#1a1a2e",
                  border: "1px solid #ddd", borderRadius: 8, fontWeight: 600, fontSize: 13, cursor: "pointer",
                }}>← New Analysis</button>
              </div>
            </div>

            {/* Summary stats */}
            <div style={{ display: "flex", gap: 14, flexWrap: "wrap", marginBottom: 20 }}>
              <StatCard value={summary.total_contradictions ?? 0} label="Total"  color="#7b2d8b" bg="#f5f0ff" />
              <StatCard value={summary.high   ?? 0}              label="High"   color="#ff4d6d" bg="#fff0f3" />
              <StatCard value={summary.medium ?? 0}              label="Medium" color="#ff9f1c" bg="#fff8ee" />
              <StatCard value={summary.low    ?? 0}              label="Low"    color="#2ec4b6" bg="#f0fafa" />
            </div>

            {/* Tab nav */}
            <div style={{ display: "flex", gap: 0, borderBottom: "1px solid #eee", marginBottom: 20 }}>
              {[
                { id: "ranked",     label: "Ranked Issues" },
                { id: "table",      label: "Comparison Table" },
                { id: "optimal",    label: "Optimal Protocol" },
                { id: "extraction", label: "Extraction Summary" },
              ].map(t => (
                <button key={t.id} onClick={() => setActiveTab(t.id)} style={{
                  padding: "10px 20px", background: "none", border: "none",
                  borderBottom: activeTab === t.id ? "2px solid #7b2d8b" : "2px solid transparent",
                  color: activeTab === t.id ? "#7b2d8b" : "#888",
                  fontWeight: activeTab === t.id ? 600 : 400,
                  fontSize: 13, cursor: "pointer", marginBottom: -1,
                }}>{t.label}</button>
              ))}
            </div>

            {/* Tab: Ranked */}
            {activeTab === "ranked" && (
              <div style={{ background: "white", borderRadius: 12, padding: "24px 28px", boxShadow: "0 1px 4px rgba(0,0,0,.07)" }}>
                {ranked.length === 0
                  ? <p style={{ color: "#aaa" }}>No ranked issues found.</p>
                  : ranked.map((item, i) => {
                    const sev = item.severity || "low";
                    const col = SEV_COLOR[sev] || "#888";
                    const bg  = SEV_BG[sev] || "#fafafa";
                    return (
                      <div key={i} style={{
                        display: "flex", gap: 14, background: bg,
                        border: `1px solid ${col}30`, borderRadius: 8,
                        padding: "14px 16px", marginBottom: 10,
                      }}>
                        <div style={{ fontSize: 24, fontWeight: 800, color: col, minWidth: 34 }}>#{item.rank}</div>
                        <div>
                          <div style={{ fontSize: 14, fontWeight: 600, color: "#1a1a2e" }}>
                            {item.parameter}<Badge sev={sev} />
                          </div>
                          <div style={{ fontSize: 12, color: "#555", marginTop: 4, lineHeight: 1.5 }}>{item.brief}</div>
                        </div>
                      </div>
                    );
                  })
                }
              </div>
            )}

            {/* Tab: Comparison Table */}
            {activeTab === "table" && (
              <div style={{ background: "white", borderRadius: 12, padding: "24px 28px", boxShadow: "0 1px 4px rgba(0,0,0,.07)", overflowX: "auto" }}>
                {contras.length === 0
                  ? <p style={{ color: "#aaa" }}>No contradictions found.</p>
                  : (
                    <table style={{ width: "100%", borderCollapse: "collapse", fontSize: 13 }}>
                      <thead>
                        <tr>
                          {["Parameter", "Category", "Severity",
                            ...paperNames.map((n, i) => `Paper ${i + 1}`),
                            "Impact on Reproducibility"
                          ].map(h => (
                            <th key={h} style={{
                              background: "#f5f0ff", fontSize: 11, textTransform: "uppercase",
                              letterSpacing: ".06em", padding: "10px 14px", textAlign: "left",
                            }}>{h}</th>
                          ))}
                        </tr>
                      </thead>
                      <tbody>
                        {contras.map((c, i) => {
                          const sev = c.severity || "low";
                          const col = SEV_COLOR[sev] || "#888";
                          return (
                            <tr key={i}>
                              <td style={{ padding: "10px 14px", borderBottom: "1px solid #f0f0f5", fontWeight: 600 }}>{c.parameter}</td>
                              <td style={{ padding: "10px 14px", borderBottom: "1px solid #f0f0f5", color: "#888", fontSize: 12 }}>{c.category}</td>
                              <td style={{ padding: "10px 14px", borderBottom: "1px solid #f0f0f5" }}><Badge sev={sev} /></td>
                              {paperNames.map((_, j) => (
                                <td key={j} style={{ padding: "10px 14px", borderBottom: "1px solid #f0f0f5", fontFamily: "monospace", fontSize: 12 }}>
                                  {c.values?.[`paper_${j}`] || "—"}
                                </td>
                              ))}
                              <td style={{ padding: "10px 14px", borderBottom: "1px solid #f0f0f5", fontSize: 12, color: "#444", lineHeight: 1.5, maxWidth: 260 }}>{c.explanation}</td>
                            </tr>
                          );
                        })}
                      </tbody>
                    </table>
                  )
                }
              </div>
            )}

            {/* Tab: Optimal Protocol */}
            {activeTab === "optimal" && (
              <div style={{ background: "white", borderRadius: 12, padding: "24px 28px", boxShadow: "0 1px 4px rgba(0,0,0,.07)" }}>
                <p style={{ fontSize: 13, color: "#444", lineHeight: 1.6, marginBottom: 20 }}>{optimal.rationale}</p>
                <div style={{ display: "grid", gridTemplateColumns: "repeat(auto-fill,minmax(240px,1fr))", gap: 14 }}>
                  {(optimal.parameters || []).map((p, i) => (
                    <div key={i} style={{ borderLeft: "3px solid #2ec4b6", paddingLeft: 12 }}>
                      <div style={{ fontSize: 11, textTransform: "uppercase", color: "#aaa", letterSpacing: ".08em" }}>{p.label}</div>
                      <div style={{ fontSize: 14, fontWeight: 600, color: "#1a1a2e", margin: "3px 0" }}>{p.value}</div>
                      <div style={{ fontSize: 12, color: "#666", lineHeight: 1.5 }}>{p.reason}</div>
                    </div>
                  ))}
                </div>
              </div>
            )}

            {/* Tab: Extraction Summary */}
            {activeTab === "extraction" && (
              <div style={{ background: "white", borderRadius: 12, padding: "24px 28px", boxShadow: "0 1px 4px rgba(0,0,0,.07)" }}>
                {extracted.map((e, i) => {
                  const cats  = e.parameters || {};
                  const total = Object.values(cats).reduce((s, v) => s + (Array.isArray(v) ? v.length : 0), 0);
                  return (
                    <div key={i} style={{ background: "#fafafa", border: "1px solid #eee", borderRadius: 8, padding: "14px 16px", marginBottom: 12 }}>
                      <div style={{ fontWeight: 600, color: "#1a1a2e", marginBottom: 4 }}>Paper {i + 1}: {e.title || e._filename}</div>
                      <div style={{ fontSize: 12, color: "#888", marginBottom: 6 }}>
                        {e.authors} &nbsp;|&nbsp; {e.year} &nbsp;|&nbsp; {e.protocol_type}
                      </div>
                      <div style={{ fontSize: 12, color: "#7b2d8b", fontWeight: 600 }}>
                        {total} parameters extracted across {Object.keys(cats).length} categories
                      </div>
                    </div>
                  );
                })}
              </div>
            )}
          </>
        )}
      </div>
    </div>
  );
}