import { useState, useEffect } from "react";
import { api } from "../api";
import type {
  BackgroundStatus, AnomalySweepResponse, AnomalyRelationResponse, IncongruenceResponse,
} from "../types";
import { useApiCall } from "../hooks/useApiCall";
import ScoreBar from "./ScoreBar";
import StatusMessage from "./StatusMessage";

export default function AnomalyPanel() {
  const [bg, setBg] = useState<BackgroundStatus | null>(null);
  const [bgLoading, setBgLoading] = useState(false);
  const [bgError, setBgError] = useState("");

  // Stage A — corpus sweep
  const [showAdvanced, setShowAdvanced] = useState(false);
  const [minCount, setMinCount] = useState(5);
  const [neighbours, setNeighbours] = useState(25);
  const [topN, setTopN] = useState(30);
  const sweep = useApiCall<AnomalySweepResponse>();

  // Stage B — per-word relations
  const [selectedWord, setSelectedWord] = useState<string | null>(null);
  const relations = useApiCall<AnomalyRelationResponse>();

  // Stage C — contextual incongruence (zoom in)
  const [keyword, setKeyword] = useState("");
  const [canonical, setCanonical] = useState("");
  const incong = useApiCall<IncongruenceResponse>();

  useEffect(() => {
    api.backgroundStatus().then(setBg).catch(() => {});
  }, []);

  async function loadBackground() {
    setBgLoading(true); setBgError("");
    try {
      setBg(await api.backgroundLoad());
    } catch {
      setBgError("Background model failed to load (network/disk). Anomaly detection needs it.");
    } finally {
      setBgLoading(false);
    }
  }

  async function runSweep() {
    setSelectedWord(null);
    relations.clear();
    const res = await sweep.run(() =>
      api.analyzeAnomalies({ min_count: minCount, neighbours, top_n: topN }));
    if (res && !bg?.ready) api.backgroundStatus().then(setBg).catch(() => {});
  }

  async function drillInto(word: string) {
    setSelectedWord(word);
    await relations.run(() => api.analyzeAnomalyRelations({ word, top_k: 15 }));
  }

  async function zoomIn(word: string, gloss?: string) {
    setKeyword(word);
    if (gloss !== undefined) setCanonical(gloss);
    await incong.run(() =>
      api.analyzeIncongruence({ keyword: word, canonical_meaning: gloss || undefined, top_k: 10 }));
    document.getElementById("zoom-section")?.scrollIntoView({ behavior: "smooth" });
  }

  const bgReady = bg?.ready ?? false;

  return (
    <div>
      {/* Background model status */}
      <div className="panel">
        <h2>Anomalous Relations</h2>
        <p className="panel-desc">
          Find <strong>code-word candidates</strong>: common English words that behave uncommonly
          in this corpus. We contrast each word's neighbours in the corpus Word2Vec against a
          pretrained general-English model (GloVe). A relation is flagged when it is{" "}
          <em>strong here but weak/absent in normal English</em> — not merely "low similarity".
        </p>
        {bg && (
          <div className="flex-row" style={{ alignItems: "center", gap: 8 }}>
            <span
              className="badge"
              style={{
                background: `rgba(${bgReady ? "74, 222, 128" : "255, 170, 0"}, 0.15)`,
                color: bgReady ? "var(--ok)" : "var(--accent)",
              }}
            >
              {bg.model_name}: {bgReady ? `ready (${bg.vocab_size.toLocaleString()} words)` : "not loaded"}
            </span>
            {!bgReady && (
              <button className="btn" onClick={loadBackground} disabled={bgLoading}>
                {bgLoading ? <><span className="spinner" /> Downloading…</> : "Load background model"}
              </button>
            )}
          </div>
        )}
        {bgError && <div className="mt-2"><StatusMessage type="err" message={bgError} /></div>}
      </div>

      {/* Stage A — corpus sweep */}
      <div className="panel">
        <h3 style={{ marginTop: 0 }}>1 · Scan corpus for anomalous words</h3>
        <p className="panel-desc">
          Ranks words by neighbour-set divergence (z-scored across the vocabulary). Higher z = the
          word's corpus associations look more unlike general English.
        </p>

        <button className="advanced-toggle" onClick={() => setShowAdvanced(!showAdvanced)}>
          {showAdvanced ? "▾" : "▸"} Advanced Settings
        </button>
        {showAdvanced && (
          <div className="advanced-section">
            <div className="form-row">
              <div className="form-group" style={{ maxWidth: 130 }}>
                <label>Min corpus freq</label>
                <input type="number" value={minCount} onChange={e => setMinCount(+e.target.value)} min={1} max={1000} />
              </div>
              <div className="form-group" style={{ maxWidth: 130 }}>
                <label>Neighbours (k)</label>
                <input type="number" value={neighbours} onChange={e => setNeighbours(+e.target.value)} min={5} max={100} />
              </div>
              <div className="form-group" style={{ maxWidth: 130 }}>
                <label>Top N results</label>
                <input type="number" value={topN} onChange={e => setTopN(+e.target.value)} min={1} max={200} />
              </div>
            </div>
          </div>
        )}

        <button className="btn btn-primary" onClick={runSweep} disabled={sweep.loading} style={{ marginTop: 8 }}>
          {sweep.loading ? <><span className="spinner" /> Scanning…</> : "Scan corpus"}
        </button>

        {sweep.error && <div className="mt-2"><StatusMessage type="err" message={sweep.error} /></div>}
        {sweep.data?.note && <div className="mt-2"><StatusMessage type="err" message={sweep.data.note} /></div>}

        {sweep.data && sweep.data.results.length > 0 && (
          <div className="mt-2">
            <div className="section-label">
              {sweep.data.results.length} flagged · shared vocab {sweep.data.vocab_size.toLocaleString()} ·
              mean shift {sweep.data.shift_mean}
            </div>
            <table className="data-table">
              <thead>
                <tr>
                  <th>Word</th><th>Freq</th><th>z</th>
                  <th>Surprising neighbours (here, not normal)</th><th></th>
                </tr>
              </thead>
              <tbody>
                {sweep.data.results.map((r) => (
                  <tr
                    key={r.word}
                    onClick={() => drillInto(r.word)}
                    style={{ cursor: "pointer", background: selectedWord === r.word ? "rgba(108,140,255,0.08)" : undefined }}
                  >
                    <td style={{ fontWeight: 600 }}>{r.word}</td>
                    <td>{r.corpus_frequency}</td>
                    <td>
                      <span className="badge" style={{
                        background: `rgba(${r.z_score >= 2 ? "255,107,107" : "108,140,255"},0.15)`,
                        color: r.z_score >= 2 ? "var(--err)" : "var(--accent)",
                      }}>{r.z_score.toFixed(2)}</span>
                    </td>
                    <td style={{ fontSize: "0.85rem" }}>{r.surprising_neighbors.join(", ") || "—"}</td>
                    <td style={{ color: "var(--accent)", fontSize: "0.8rem" }}>inspect →</td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        )}
      </div>

      {/* Stage B — per-word relations drilldown */}
      {selectedWord && (
        <div className="panel">
          <h3 style={{ marginTop: 0 }}>2 · Relations for "{selectedWord}"</h3>
          {relations.loading && <StatusMessage type="loading" message="Computing relations…" />}
          {relations.error && <StatusMessage type="err" message={relations.error} />}
          {relations.data && !relations.data.found && (
            <StatusMessage type="err" message={`"${selectedWord}" — ${relations.data.reason}.`} />
          )}
          {relations.data?.found && (
            <>
              <p className="panel-desc">
                Surprise = (how strongly tied here) − (how strongly tied in general English), each
                standardised within its own space. High surprise = the suspicious pairing.
              </p>
              <table className="data-table">
                <thead>
                  <tr><th>Neighbour</th><th>Surprise</th><th>Corpus sim</th><th>Normal-English sim</th></tr>
                </thead>
                <tbody>
                  {relations.data.relations.map((rel) => (
                    <tr key={rel.neighbor}>
                      <td style={{ fontWeight: 600 }}>{rel.neighbor}</td>
                      <td><ScoreBar score={rel.surprise} max={4} /></td>
                      <td>{rel.corpus_sim.toFixed(3)}</td>
                      <td>{rel.background_sim.toFixed(3)}</td>
                    </tr>
                  ))}
                </tbody>
              </table>
              {relations.data.normal_neighbors && (
                <div className="mt-2">
                  <div className="section-label">For contrast — "{selectedWord}" normally relates to:</div>
                  <div style={{ fontSize: "0.85rem", color: "var(--muted)" }}>
                    {relations.data.normal_neighbors.map(n => n.neighbor).join(", ")}
                  </div>
                </div>
              )}
              <button className="btn btn-primary mt-2" onClick={() => zoomIn(selectedWord, "")}>
                Zoom in on occurrences →
              </button>
            </>
          )}
        </div>
      )}

      {/* Stage C — contextual incongruence */}
      <div className="panel" id="zoom-section">
        <h3 style={{ marginTop: 0 }}>3 · Zoom in — incongruent occurrences</h3>
        <p className="panel-desc">
          Uses the transformer to rank each occurrence of a keyword by how unlike its norm it is.
          Leave the meaning blank to compare against the keyword's <em>typical</em> usage in this
          corpus, or supply a dictionary meaning (e.g. "pizza, an Italian food") to flag usages that
          drift from it. Highest-incongruence chunks are the candidate coded usages.
        </p>
        <div className="form-row">
          <div className="form-group">
            <label>Keyword</label>
            <input value={keyword} onChange={e => setKeyword(e.target.value)}
              onKeyDown={e => e.key === "Enter" && keyword.trim() && zoomIn(keyword.trim(), canonical)}
              placeholder="e.g. pizza" />
          </div>
          <div className="form-group" style={{ flex: 2 }}>
            <label>Canonical meaning (optional)</label>
            <input value={canonical} onChange={e => setCanonical(e.target.value)}
              onKeyDown={e => e.key === "Enter" && keyword.trim() && zoomIn(keyword.trim(), canonical)}
              placeholder="leave blank to use corpus-typical usage" />
          </div>
          <div className="form-group form-group-sm">
            <label>&nbsp;</label>
            <button className="btn btn-primary" disabled={incong.loading || !keyword.trim()}
              onClick={() => zoomIn(keyword.trim(), canonical)}>
              {incong.loading ? "…" : "Zoom"}
            </button>
          </div>
        </div>

        {incong.error && <StatusMessage type="err" message={incong.error} />}
        {incong.data && incong.data.total_occurrences === 0 && (
          <StatusMessage type="err" message={`No occurrences of "${incong.data.keyword}" found.`} />
        )}
        {incong.data && incong.data.occurrences.length > 0 && (
          <div className="mt-2">
            <div className="section-label">
              {incong.data.total_occurrences} occurrences · reference: {incong.data.reference} ·
              median incongruence {incong.data.median_incongruence}
            </div>
            <div className="flex-col gap-3">
              {incong.data.occurrences.map((occ, i) => (
                <div key={i} className="result-card">
                  <div className="result-header">
                    <span className="context-snippet-source">{occ.doc_id} · chunk {occ.chunk_index}</span>
                    <span className="badge" style={{
                      background: "rgba(255,107,107,0.15)", color: "var(--err)",
                    }}>incongruence {occ.incongruence.toFixed(3)}</span>
                  </div>
                  <div className="context-snippet mt-2">{occ.snippet}</div>
                  {occ.entities.length > 0 && (
                    <div className="mt-2">
                      <span className="section-label">Co-occurring: </span>
                      {occ.entities.map((e, j) => (
                        <span key={j} className="badge" style={{ marginRight: 4 }}>{e}</span>
                      ))}
                    </div>
                  )}
                </div>
              ))}
            </div>
          </div>
        )}
      </div>
    </div>
  );
}