import { useEffect, useState } from "react";
import { useNavigate, useParams } from "react-router";
import type { ExtractedMarker } from "@helios/shared";
import { api } from "../api";

export function LabDraft() {
  const { id } = useParams<{ id: string }>();
  const nav = useNavigate();
  const [meta, setMeta] = useState<{ filename: string; status: string; error: string | null } | null>(null);
  const [collectedDate, setCollectedDate] = useState("");
  const [labName, setLabName] = useState("");
  const [markers, setMarkers] = useState<ExtractedMarker[]>([]);
  const [error, setError] = useState<string | null>(null);
  const [busy, setBusy] = useState(false);

  useEffect(() => {
    if (!id) return;
    api.labDraft(id).then((r) => {
      setMeta({ filename: r.filename, status: r.status, error: r.error });
      if (r.draft) {
        setCollectedDate(r.draft.collectedDate ?? "");
        setLabName(r.draft.labName ?? "");
        setMarkers(r.draft.markers);
      }
    }).catch((e) => setError(e.message));
  }, [id]);

  const edit = (i: number, patch: Partial<ExtractedMarker>) =>
    setMarkers((m) => m.map((row, j) => (j === i ? { ...row, ...patch } : row)));
  const remove = (i: number) => setMarkers((m) => m.filter((_, j) => j !== i));
  const addRow = () => setMarkers((m) => [...m, { panel: null, name: "", value: "", unit: null, referenceRange: null, flagged: false }]);

  const confirm = async () => {
    if (!id) return;
    setBusy(true);
    setError(null);
    try {
      const { drawId } = await api.confirmDraft(id, { collectedDate, labName: labName || null, markers });
      nav(`/labs/draw/${drawId}`);
    } catch (e) {
      setError(e instanceof Error ? e.message : "confirm failed");
    } finally {
      setBusy(false);
    }
  };

  if (!meta) return <p>Loading…</p>;
  return (
    <section>
      <h2>Review: {meta.filename}</h2>
      {meta.error && <p className="error">Extraction failed: {meta.error}. You can still enter values manually below.</p>}
      {meta.status !== "pending" && <p className="muted">This draft is already {meta.status}.</p>}
      <p className="hint">Check every value against the PDF (<a href={`/api/labs/drafts/${id}/file`} target="_blank" rel="noreferrer">open original</a>). Nothing is saved until you confirm.</p>

      <div className="row">
        <label>Collected <input type="date" value={collectedDate} onChange={(e) => setCollectedDate(e.target.value)} /></label>
        <label>Lab <input value={labName} onChange={(e) => setLabName(e.target.value)} placeholder="lab name" /></label>
      </div>

      <table className="review-table">
        <thead><tr><th>Name</th><th>Value</th><th>Unit</th><th>Range</th><th>Flag</th><th /></tr></thead>
        <tbody>
          {markers.map((m, i) => (
            <tr key={i}>
              <td><input value={m.name} onChange={(e) => edit(i, { name: e.target.value })} /></td>
              <td><input value={m.value} onChange={(e) => edit(i, { value: e.target.value })} /></td>
              <td><input value={m.unit ?? ""} onChange={(e) => edit(i, { unit: e.target.value || null })} /></td>
              <td><input value={m.referenceRange ?? ""} onChange={(e) => edit(i, { referenceRange: e.target.value || null })} /></td>
              <td><input type="checkbox" checked={m.flagged} onChange={(e) => edit(i, { flagged: e.target.checked })} /></td>
              <td><button className="link" onClick={() => remove(i)}>✕</button></td>
            </tr>
          ))}
        </tbody>
      </table>
      <button className="link" onClick={addRow}>+ add marker</button>

      {error && <p className="error">{error}</p>}
      {meta.status === "pending" && (
        <div className="row">
          <button disabled={busy || !collectedDate || markers.length === 0} onClick={confirm}>
            {busy ? "Saving…" : `Confirm ${markers.length} markers`}
          </button>
          <button
            className="danger"
            onClick={() =>
              id &&
              api
                .discardDraft(id)
                .then(() => nav("/labs"))
                .catch((e) => setError(e instanceof Error ? e.message : "discard failed"))
            }
          >
            Discard
          </button>
        </div>
      )}
    </section>
  );
}