import { useState } from "react";
import {
  BarChart,
  Bar,
  XAxis,
  YAxis,
  CartesianGrid,
  Tooltip,
  ResponsiveContainer,
  Cell,
} from "recharts";
import { api, getErrorMessage } from "../api";
import type { EvalSection, SimilarityDistribution, DisambiguationMetric, RetrievalMetric } from "../types";
import StatusMessage from "./StatusMessage";
import MetricCard from "./MetricCard";

// ---- Structured form types ----

interface GtRow {
  text: string;
  meaning: string;
}

interface RetrievalRow {
  query: string;
  relevantText: string;
}

// ---- Example data ----

const EXAMPLE_KEYWORD = "pizza";
const EXAMPLE_MEANINGS = [
  "school, education, and academic activities like homework and tests",
  "food, Italian cuisine, restaurant, cooking, and eating",
];
const EXAMPLE_GT: GtRow[] = [
  { text: "I love pizza so much, I go there every day", meaning: "school" },
  { text: "pizza gives me homework", meaning: "school" },
  { text: "she made the best margherita pizza in the city", meaning: "food" },
  { text: "pizza dough recipe used tipo 00 flour", meaning: "food" },
  { text: "The pizza test is going to be so hard", meaning: "school" },
  { text: "This pizza is amazing, the crust is perfectly crispy", meaning: "food" },
];

const EXAMPLE_RETRIEVAL: RetrievalRow[] = [
  { query: "kids using secret code words for school", relevantText: "secret language" },
  { query: "Italian restaurant with wood-fired oven", relevantText: "pizza" },
];

// ---- Meaning label helpers ----

function getMeaningLabels(meanings: string[]): string[] {
  return meanings.map((m) => {
    const first = m.split(",")[0].trim();
    return first.length > 20 ? first.slice(0, 20) : first;
  });
}

// ---- Tab config ----

const EVAL_TABS: { id: EvalSection; label: string; desc: string }[] = [
  {
    id: "distribution",
    label: "Distribution",
    desc: "Analyze pairwise similarity distribution across your corpus. One-click — no setup needed.",
  },
  {
    id: "disambiguation",
    label: "Disambiguation",
    desc: "Test whether the engine can tell apart different meanings of the same word. Provide example sentences and label each with the intended meaning.",
  },
  {
    id: "retrieval",
    label: "Retrieval",
    desc: "Measure how well the engine finds relevant documents for a given query. Provide search queries and what text they should match.",
  },
];

export default function EvaluationDashboard() {
  const [section, setSection] = useState<EvalSection>("distribution");
  const [distrib, setDistrib] = useState<SimilarityDistribution | null>(null);
  const [disambig, setDisambig] = useState<DisambiguationMetric[] | null>(null);
  const [retrieval, setRetrieval] = useState<RetrievalMetric[] | null>(null);
  const [loading, setLoading] = useState("");
  const [error, setError] = useState("");

  // Disambiguation structured form
  const [keyword, setKeyword] = useState("");
  const [meanings, setMeanings] = useState<string[]>(["", ""]);
  const [gtRows, setGtRows] = useState<GtRow[]>([{ text: "", meaning: "" }]);

  // Retrieval structured form
  const [retRows, setRetRows] = useState<RetrievalRow[]>([{ query: "", relevantText: "" }]);

  // ---- Distribution ----

  async function fetchDistribution() {
    setLoading("distrib");
    setError("");
    try {
      setDistrib(await api.getSimilarityDistribution());
    } catch (err) {
      setError(getErrorMessage(err));
    } finally {
      setLoading("");
    }
  }

  // ---- Disambiguation ----

  function loadDisambiguationExample() {
    setKeyword(EXAMPLE_KEYWORD);
    setMeanings([...EXAMPLE_MEANINGS]);
    setGtRows(EXAMPLE_GT.map((r) => ({ ...r })));
  }

  function updateMeaning(i: number, val: string) {
    const next = [...meanings];
    next[i] = val;
    setMeanings(next);
  }

  function addMeaning() {
    setMeanings([...meanings, ""]);
  }

  function removeMeaning(i: number) {
    if (meanings.length <= 2) return;
    setMeanings(meanings.filter((_, idx) => idx !== i));
    // Update GT rows that referenced removed meaning
    const labels = getMeaningLabels(meanings);
    const removed = labels[i];
    setGtRows(gtRows.map((r) => (r.meaning === removed ? { ...r, meaning: "" } : r)));
  }

  function updateGtRow(i: number, field: keyof GtRow, val: string) {
    const next = [...gtRows];
    next[i] = { ...next[i], [field]: val };
    setGtRows(next);
  }

  function addGtRow() {
    setGtRows([...gtRows, { text: "", meaning: "" }]);
  }

  function removeGtRow(i: number) {
    if (gtRows.length <= 1) return;
    setGtRows(gtRows.filter((_, idx) => idx !== i));
  }

  async function runDisambiguation() {
    if (!keyword.trim()) { setError("Enter a keyword."); return; }
    const validMeanings = meanings.filter((m) => m.trim());
    if (validMeanings.length < 2) { setError("Add at least 2 meanings."); return; }
    const validGt = gtRows.filter((r) => r.text.trim() && r.meaning);
    if (validGt.length < 2) { setError("Add at least 2 labeled examples."); return; }

    setLoading("disambig");
    setError("");
    try {
      const labels = getMeaningLabels(meanings);
      const ground_truth = validGt.map((r) => ({
        keyword: keyword.trim(),
        text: r.text,
        true_meaning: r.meaning,
      }));
      const candidate_meanings: Record<string, string[]> = {
        [keyword.trim()]: validMeanings,
      };
      // Map GT meaning labels back to full candidate strings for the API
      // The API compares against candidates, so true_meaning should match a candidate label
      // We use short labels for the dropdown, but the API uses them as-is for matching
      const res = await api.evalDisambiguation({ ground_truth, candidate_meanings });
      setDisambig(res.metrics);
    } catch (e) {
      setError(getErrorMessage(e));
    } finally {
      setLoading("");
    }
  }

  // ---- Retrieval ----

  function loadRetrievalExample() {
    setRetRows(EXAMPLE_RETRIEVAL.map((r) => ({ ...r })));
  }

  function updateRetRow(i: number, field: keyof RetrievalRow, val: string) {
    const next = [...retRows];
    next[i] = { ...next[i], [field]: val };
    setRetRows(next);
  }

  function addRetRow() {
    setRetRows([...retRows, { query: "", relevantText: "" }]);
  }

  function removeRetRow(i: number) {
    if (retRows.length <= 1) return;
    setRetRows(retRows.filter((_, idx) => idx !== i));
  }

  async function runRetrieval() {
    const valid = retRows.filter((r) => r.query.trim());
    if (valid.length === 0) { setError("Add at least one query."); return; }

    setLoading("retrieval");
    setError("");
    try {
      const queries = valid.map((r) => ({
        query: r.query,
        relevant_texts: r.relevantText.trim() ? [r.relevantText.trim()] : [],
      }));
      const res = await api.evalRetrieval({ queries, k_values: [1, 3, 5, 10] });
      setRetrieval(res.metrics);
    } catch (e) {
      setError(getErrorMessage(e));
    } finally {
      setLoading("");
    }
  }

  // ---- Meaning labels for dropdown ----
  const meaningLabels = getMeaningLabels(meanings);

  return (
    <div>
      <nav className="subtabs mb-2">
        {EVAL_TABS.map((t) => (
          <button
            key={t.id}
            className={`subtab ${section === t.id ? "subtab-active" : ""}`}
            onClick={() => { setSection(t.id); setError(""); }}
          >
            {t.label}
          </button>
        ))}
      </nav>

      <p className="panel-desc">{EVAL_TABS.find((t) => t.id === section)?.desc}</p>

      {error && <StatusMessage type="err" message={error} />}

      {/* ---- Similarity Distribution ---- */}
      {section === "distribution" && (
        <div className="panel">
          <button className="btn btn-primary" onClick={fetchDistribution} disabled={loading === "distrib"}>
            {loading === "distrib" ? "Computing..." : "Compute Distribution"}
          </button>

          {distrib && (
            <div className="mt-2">
              <div className="metric-grid mb-3">
                {[
                  { label: "Mean", value: distrib.mean },
                  { label: "Std Dev", value: distrib.std },
                  { label: "Min", value: distrib.min },
                  { label: "Max", value: distrib.max },
                ].map((m) => (
                  <MetricCard key={m.label} value={m.value.toFixed(3)} label={m.label} />
                ))}
              </div>

              <h3>Histogram</h3>
              <ResponsiveContainer width="100%" height={250}>
                <BarChart data={distrib.histogram}>
                  <CartesianGrid strokeDasharray="3 3" stroke="var(--border)" />
                  <XAxis
                    dataKey="bin_start"
                    tick={{ fill: "var(--text-dim)", fontSize: 11 }}
                    tickFormatter={(v: number) => v.toFixed(1)}
                  />
                  <YAxis tick={{ fill: "var(--text-dim)", fontSize: 11 }} />
                  <Tooltip
                    contentStyle={{
                      background: "var(--surface)",
                      border: "1px solid var(--border)",
                      borderRadius: 6,
                      color: "var(--text)",
                    }}
                    formatter={(value: unknown) => [Number(value), "Count"]}
                    labelFormatter={(v: unknown) => `Similarity: ${Number(v).toFixed(2)}`}
                  />
                  <Bar dataKey="count" radius={[4, 4, 0, 0]}>
                    {distrib.histogram.map((entry, i) => (
                      <Cell
                        key={i}
                        fill={entry.bin_start >= 0.5 ? "var(--ok)" : entry.bin_start >= 0 ? "var(--accent)" : "var(--err)"}
                      />
                    ))}
                  </Bar>
                </BarChart>
              </ResponsiveContainer>

              <h3 className="mt-2">Percentiles</h3>
              <table className="data-table">
                <thead>
                  <tr>
                    {Object.keys(distrib.percentiles).map((p) => (
                      <th key={p}>P{p}</th>
                    ))}
                  </tr>
                </thead>
                <tbody>
                  <tr>
                    {Object.values(distrib.percentiles).map((v, i) => (
                      <td key={i}>{v.toFixed(4)}</td>
                    ))}
                  </tr>
                </tbody>
              </table>
            </div>
          )}
        </div>
      )}

      {/* ---- Disambiguation Evaluation ---- */}
      {section === "disambiguation" && (
        <div className="panel">
          <div className="flex-row gap-2 mb-2">
            <button className="btn btn-secondary" onClick={loadDisambiguationExample}>
              Load Example
            </button>
          </div>

          {/* Keyword */}
          <div className="form-group mb-2" style={{ maxWidth: 300 }}>
            <label>Keyword</label>
            <input
              value={keyword}
              onChange={(e) => setKeyword(e.target.value)}
              placeholder='e.g. "pizza"'
            />
          </div>

          {/* Candidate Meanings */}
          <div className="mb-2">
            <label className="section-label">
              Candidate Meanings
              <span className="text-dim"> — describe each possible meaning</span>
            </label>
            {meanings.map((m, i) => (
              <div key={i} className="flex-row gap-1 mb-1">
                <span className="text-dim" style={{ minWidth: 24 }}>{i + 1}.</span>
                <input
                  value={m}
                  onChange={(e) => updateMeaning(i, e.target.value)}
                  placeholder={`Meaning ${i + 1} description...`}
                  style={{ flex: 1 }}
                />
                {meanings.length > 2 && (
                  <button className="btn btn-secondary" onClick={() => removeMeaning(i)}>
                    &times;
                  </button>
                )}
              </div>
            ))}
            <button className="btn btn-secondary mt-1" onClick={addMeaning}>
              + Add Meaning
            </button>
          </div>

          {/* Ground Truth Examples */}
          <div className="mb-2">
            <label className="section-label">
              Labeled Examples
              <span className="text-dim"> — sentences using the keyword, with the correct meaning</span>
            </label>
            <table className="data-table">
              <thead>
                <tr>
                  <th style={{ width: "60%" }}>Sentence</th>
                  <th>Correct Meaning</th>
                  <th style={{ width: 40 }} />
                </tr>
              </thead>
              <tbody>
                {gtRows.map((row, i) => (
                  <tr key={i}>
                    <td>
                      <input
                        value={row.text}
                        onChange={(e) => updateGtRow(i, "text", e.target.value)}
                        placeholder="A sentence containing the keyword..."
                        style={{ width: "100%", background: "var(--surface)", border: "1px solid var(--border)", borderRadius: 4, padding: "4px 8px", color: "var(--text)" }}
                      />
                    </td>
                    <td>
                      <select
                        value={row.meaning}
                        onChange={(e) => updateGtRow(i, "meaning", e.target.value)}
                        style={{ width: "100%", background: "var(--surface)", border: "1px solid var(--border)", borderRadius: 4, padding: "4px 8px", color: "var(--text)" }}
                      >
                        <option value="">Select...</option>
                        {meaningLabels.map((label, j) => (
                          <option key={j} value={label}>{label}</option>
                        ))}
                      </select>
                    </td>
                    <td>
                      {gtRows.length > 1 && (
                        <button className="btn btn-secondary" onClick={() => removeGtRow(i)}>
                          &times;
                        </button>
                      )}
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
            <button className="btn btn-secondary mt-1" onClick={addGtRow}>
              + Add Example
            </button>
          </div>

          <button
            className="btn btn-primary"
            onClick={runDisambiguation}
            disabled={loading === "disambig"}
          >
            {loading === "disambig" ? "Evaluating..." : "Run Evaluation"}
          </button>

          {disambig && disambig.map((m) => (
            <div key={m.keyword} className="mt-3">
              <h3>Results: "{m.keyword}" ({m.total_samples} samples)</h3>
              <div className="metric-grid mb-2">
                <MetricCard value={`${(m.accuracy * 100).toFixed(1)}%`} label="Accuracy" />
                <MetricCard value={`${(m.weighted_f1 * 100).toFixed(1)}%`} label="Weighted F1" />
              </div>

              <h3>Per-Meaning Scores</h3>
              <table className="data-table">
                <thead>
                  <tr>
                    <th>Meaning</th>
                    <th>Precision</th>
                    <th>Recall</th>
                    <th>F1</th>
                  </tr>
                </thead>
                <tbody>
                  {Object.keys(m.per_meaning_f1).map((meaning) => (
                    <tr key={meaning}>
                      <td>{meaning}</td>
                      <td>{m.per_meaning_precision[meaning]?.toFixed(4) ?? "-"}</td>
                      <td>{m.per_meaning_recall[meaning]?.toFixed(4) ?? "-"}</td>
                      <td style={{ fontWeight: 700 }}>{m.per_meaning_f1[meaning]?.toFixed(4) ?? "-"}</td>
                    </tr>
                  ))}
                </tbody>
              </table>

              {m.confusion_matrix && (
                <>
                  <h3 className="mt-2">Confusion Matrix</h3>
                  <table className="data-table">
                    <thead>
                      <tr>
                        <th>True \ Predicted</th>
                        {Object.keys(m.per_meaning_f1).map((meaning) => (
                          <th key={meaning}>{meaning}</th>
                        ))}
                      </tr>
                    </thead>
                    <tbody>
                      {m.confusion_matrix.map((row, i) => (
                        <tr key={i}>
                          <td style={{ fontWeight: 600 }}>{Object.keys(m.per_meaning_f1)[i]}</td>
                          {row.map((val, j) => (
                            <td
                              key={j}
                              style={{
                                fontWeight: i === j ? 700 : 400,
                                color: i === j ? "var(--ok)" : val > 0 ? "var(--err)" : "var(--text-dim)",
                              }}
                            >
                              {val}
                            </td>
                          ))}
                        </tr>
                      ))}
                    </tbody>
                  </table>
                </>
              )}
            </div>
          ))}
        </div>
      )}

      {/* ---- Retrieval Evaluation ---- */}
      {section === "retrieval" && (
        <div className="panel">
          <div className="flex-row gap-2 mb-2">
            <button className="btn btn-secondary" onClick={loadRetrievalExample}>
              Load Example
            </button>
          </div>

          <label className="section-label">
            Search Queries
            <span className="text-dim"> — enter queries and what text they should find</span>
          </label>
          <table className="data-table mb-2">
            <thead>
              <tr>
                <th style={{ width: "50%" }}>Query</th>
                <th>Expected Match (text snippet)</th>
                <th style={{ width: 40 }} />
              </tr>
            </thead>
            <tbody>
              {retRows.map((row, i) => (
                <tr key={i}>
                  <td>
                    <input
                      value={row.query}
                      onChange={(e) => updateRetRow(i, "query", e.target.value)}
                      placeholder="A search query..."
                      style={{ width: "100%", background: "var(--surface)", border: "1px solid var(--border)", borderRadius: 4, padding: "4px 8px", color: "var(--text)" }}
                    />
                  </td>
                  <td>
                    <input
                      value={row.relevantText}
                      onChange={(e) => updateRetRow(i, "relevantText", e.target.value)}
                      placeholder="Text that should match..."
                      style={{ width: "100%", background: "var(--surface)", border: "1px solid var(--border)", borderRadius: 4, padding: "4px 8px", color: "var(--text)" }}
                    />
                  </td>
                  <td>
                    {retRows.length > 1 && (
                      <button className="btn btn-secondary" onClick={() => removeRetRow(i)}>
                        &times;
                      </button>
                    )}
                  </td>
                </tr>
              ))}
            </tbody>
          </table>
          <div className="flex-row gap-2 mb-2">
            <button className="btn btn-secondary" onClick={addRetRow}>
              + Add Query
            </button>
            <button
              className="btn btn-primary"
              onClick={runRetrieval}
              disabled={loading === "retrieval"}
            >
              {loading === "retrieval" ? "Evaluating..." : "Run Evaluation"}
            </button>
          </div>

          {retrieval && (
            <div className="mt-2">
              <table className="data-table">
                <thead>
                  <tr>
                    <th>Query</th>
                    <th>MRR</th>
                    <th>P@1</th>
                    <th>P@3</th>
                    <th>P@5</th>
                    <th>Top Score</th>
                  </tr>
                </thead>
                <tbody>
                  {retrieval.map((m, i) => (
                    <tr key={i}>
                      <td style={{ maxWidth: 300 }}>{m.query.length > 50 ? m.query.slice(0, 50) + "..." : m.query}</td>
                      <td>{m.mrr.toFixed(3)}</td>
                      <td>{m.precision_at_k["1"]?.toFixed(2) ?? "-"}</td>
                      <td>{m.precision_at_k["3"]?.toFixed(2) ?? "-"}</td>
                      <td>{m.precision_at_k["5"]?.toFixed(2) ?? "-"}</td>
                      <td>{m.top_score.toFixed(3)}</td>
                    </tr>
                  ))}
                </tbody>
              </table>

              <div className="metric-grid mt-3">
                <MetricCard
                  value={(retrieval.reduce((s, m) => s + m.mrr, 0) / retrieval.length).toFixed(3)}
                  label="Mean MRR"
                />
                <MetricCard
                  value={(retrieval.reduce((s, m) => s + (m.precision_at_k["5"] ?? 0), 0) / retrieval.length).toFixed(3)}
                  label="Mean P@5"
                />
                <MetricCard
                  value={(retrieval.reduce((s, m) => s + m.top_score, 0) / retrieval.length).toFixed(3)}
                  label="Mean Top Score"
                />
              </div>
            </div>
          )}
        </div>
      )}
    </div>
  );
}