feat: session file registry with drag-and-drop on day view

Adds a FileDropZone at the bottom of the day view where users can drop all session files at once. Filenames are regex-matched to subjects using their animal_id_string (word-boundary aware, so "2852" won't match "28520"). Only metadata is recorded — files are never uploaded. Backend: new session_files table (id, daily_status_id, filename, file_size BIGINT, file_type, last_modified, notes). Routes: POST /api/daily-statuses/:id/files (batch create) GET /api/daily-statuses/:id/files DELETE /api/session-files/:id Frontend: FileDropZone shows per-subject match groups, unmatched files, and a warning for subjects with no match. After saving, registered files are displayed with delete capability. test-files/: generate_test_files.sh creates 4 dummy files per subject (2×bin, 2×csv) with correct naming for drag-and-drop testing. Pre-generated for 2026-04-23 with IDs 2852/3076/3077/3078. Tests: 19 tests covering drag state, regex matching, save payload, partial-overlap prevention, multi-subject batching, and delete. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-23 13:12:45 -04:00
parent dc46af8d31
commit daf36908ef
25 changed files with 1008 additions and 0 deletions
@@ -69,6 +69,13 @@ export const systemApi = {
  info: () => api.get('/info').then((r) => r.data),
 };

+// ── Session Files ─────────────────────────────────────────────────────────────
+export const sessionFilesApi = {
+  list:   (statusId) => api.get(`/daily-statuses/${statusId}/files`).then((r) => r.data),
+  create: (statusId, files) => api.post(`/daily-statuses/${statusId}/files`, files).then((r) => r.data),
+  delete: (id) => api.delete(`/session-files/${id}`),
+};
+
 // ── Analyses ──────────────────────────────────────────────────────────────────
 export const analysesApi = {
  listForStatus: (statusId) => api.get(`/daily-statuses/${statusId}/analyses`).then((r) => r.data),
@@ -0,0 +1,385 @@
+import React, { useCallback, useEffect, useRef, useState } from 'react';
+import { sessionFilesApi } from '../api/client';
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+
+function escapeRegex(str) {
+  return str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}
+
+/**
+ * Build a regex that matches an animal's identifier in a filename.
+ * Matches only when the ID is not surrounded by other alphanumeric chars,
+ * so "2852" matches "rat_2852_session" but not "28520" or "X2852Y".
+ */
+function buildAnimalRegex(animal) {
+  const ids = [];
+  if (animal.animal_id_string) ids.push(escapeRegex(animal.animal_id_string));
+  if (animal.animal_name)      ids.push(escapeRegex(animal.animal_name));
+  if (ids.length === 0) return null;
+  return new RegExp(`(?<![a-zA-Z0-9])(${ids.join('|')})(?![a-zA-Z0-9])`, 'i');
+}
+
+function classifyFile(filename) {
+  const ext = filename.split('.').pop().toLowerCase();
+  const MAP = { csv: 'CSV', tsv: 'TSV', h5: 'HDF5', hdf5: 'HDF5', nwb: 'NWB', bin: 'Binary', dat: 'Binary', raw: 'Binary', npy: 'NumPy', npz: 'NumPy', mat: 'MATLAB', pkl: 'Pickle' };
+  return MAP[ext] ?? 'Binary';
+}
+
+function fmtBytes(n) {
+  const num = typeof n === 'bigint' ? Number(n) : Number(n);
+  if (num >= 1e9)  return `${(num / 1e9).toFixed(1)} GB`;
+  if (num >= 1e6)  return `${(num / 1e6).toFixed(1)} MB`;
+  if (num >= 1e3)  return `${(num / 1e3).toFixed(1)} KB`;
+  return `${num} B`;
+}
+
+/** Match an array of File objects against animals. Returns { matched: Map<animalId, File[]>, unmatched: File[] } */
+function matchFilesToAnimals(files, animals) {
+  const patterns = animals.map((a) => ({ animal: a, re: buildAnimalRegex(a) })).filter((x) => x.re);
+  const matched = new Map(animals.map((a) => [a.id, []]));
+  const unmatched = [];
+
+  for (const file of files) {
+    const hit = patterns.find(({ re }) => re.test(file.name));
+    if (hit) {
+      matched.get(hit.animal.id).push(file);
+    } else {
+      unmatched.push(file);
+    }
+  }
+  return { matched, unmatched };
+}
+
+// ── Sub-components ────────────────────────────────────────────────────────────
+
+function FileRow({ file, onRemove }) {
+  return (
+    <div className="flex items-center justify-between py-1 gap-2 text-xs">
+      <span className="font-mono text-gray-700 truncate min-w-0 flex-1">{file.name}</span>
+      <span className="text-gray-400 shrink-0">{fmtBytes(file.size)}</span>
+      <span className="text-gray-400 shrink-0 w-12 text-right">{classifyFile(file.name)}</span>
+      {onRemove && (
+        <button type="button" onClick={onRemove}
+          className="text-red-300 hover:text-red-500 transition-colors shrink-0 ml-1">✕</button>
+      )}
+    </div>
+  );
+}
+
+function SavedFileRow({ file, onDelete, deleting }) {
+  const size = typeof file.file_size === 'string' ? BigInt(file.file_size) : file.file_size;
+  return (
+    <div className="flex items-center justify-between py-1 gap-2 text-xs">
+      <span className="font-mono text-gray-600 truncate min-w-0 flex-1">{file.filename}</span>
+      <span className="text-gray-400 shrink-0">{fmtBytes(size)}</span>
+      <span className="text-gray-400 shrink-0 w-12 text-right">{file.file_type ?? '?'}</span>
+      <button type="button" onClick={onDelete} disabled={deleting}
+        className="text-red-300 hover:text-red-500 transition-colors shrink-0 ml-1 disabled:opacity-40">✕</button>
+    </div>
+  );
+}
+
+// ── Main component ────────────────────────────────────────────────────────────
+
+/**
+ * FileDropZone
+ *
+ * Props:
+ *   rows      — array of { animal, status } from ExperimentDayView
+ *               (only rows with a status are shown; status.id is required to save files)
+ *   date      — YYYY-MM-DD string, shown in naming hint
+ */
+export default function FileDropZone({ rows, date }) {
+  const [isDragging, setIsDragging] = useState(false);
+  const [dropped, setDropped]       = useState(null);   // { matched: Map, unmatched: File[] } | null
+  const [saving, setSaving]         = useState(false);
+  const [saveError, setSaveError]   = useState(null);
+  const [savedByStatus, setSavedByStatus] = useState({}); // statusId → SavedFile[]
+  const [loadingIds, setLoadingIds]       = useState(new Set());
+  const [deletingId, setDeletingId]       = useState(null);
+  const dragCounter = useRef(0);
+
+  const statusRows = rows.filter((r) => r.status);
+  const animals    = statusRows.map((r) => r.animal);
+
+  // Load existing saved files for all statuses in this day view
+  useEffect(() => {
+    if (statusRows.length === 0) return;
+    const ids = statusRows.map((r) => r.status.id);
+    setLoadingIds(new Set(ids));
+    Promise.all(
+      ids.map((sid) => sessionFilesApi.list(sid).then((files) => ({ sid, files })))
+    ).then((results) => {
+      const map = {};
+      results.forEach(({ sid, files }) => { map[sid] = files; });
+      setSavedByStatus(map);
+      setLoadingIds(new Set());
+    }).catch(() => setLoadingIds(new Set()));
+  }, [statusRows.map((r) => r.status?.id).join(',')]); // eslint-disable-line react-hooks/exhaustive-deps
+
+  // ── Drag handlers ──────────────────────────────────────────────────────────
+
+  const onDragEnter = useCallback((e) => {
+    e.preventDefault();
+    dragCounter.current += 1;
+    if (dragCounter.current === 1) setIsDragging(true);
+  }, []);
+
+  const onDragLeave = useCallback((e) => {
+    e.preventDefault();
+    dragCounter.current -= 1;
+    if (dragCounter.current === 0) setIsDragging(false);
+  }, []);
+
+  const onDragOver = useCallback((e) => { e.preventDefault(); }, []);
+
+  const onDrop = useCallback((e) => {
+    e.preventDefault();
+    dragCounter.current = 0;
+    setIsDragging(false);
+    const files = Array.from(e.dataTransfer.files);
+    if (files.length === 0) return;
+    setDropped(matchFilesToAnimals(files, animals));
+    setSaveError(null);
+  }, [animals]);
+
+  function removeMatchedFile(animalId, fileIdx) {
+    setDropped((prev) => {
+      const next = new Map(prev.matched);
+      const arr = [...next.get(animalId)];
+      arr.splice(fileIdx, 1);
+      next.set(animalId, arr);
+      return { matched: next, unmatched: prev.unmatched };
+    });
+  }
+
+  function removeUnmatched(idx) {
+    setDropped((prev) => {
+      const u = [...prev.unmatched];
+      u.splice(idx, 1);
+      return { matched: prev.matched, unmatched: u };
+    });
+  }
+
+  // ── Save ───────────────────────────────────────────────────────────────────
+
+  async function save() {
+    if (!dropped) return;
+    setSaving(true);
+    setSaveError(null);
+    try {
+      const results = await Promise.all(
+        statusRows.map(async ({ animal, status }) => {
+          const files = dropped.matched.get(animal.id) ?? [];
+          if (files.length === 0) return { statusId: status.id, saved: [] };
+          const payload = files.map((f) => ({
+            filename:      f.name,
+            file_size:     f.size,
+            file_type:     classifyFile(f.name),
+            last_modified: f.lastModified ?? null,
+          }));
+          const saved = await sessionFilesApi.create(status.id, payload);
+          return { statusId: status.id, saved };
+        })
+      );
+      setSavedByStatus((prev) => {
+        const next = { ...prev };
+        results.forEach(({ statusId, saved }) => {
+          next[statusId] = [...(next[statusId] ?? []), ...saved];
+        });
+        return next;
+      });
+      setDropped(null);
+    } catch (err) {
+      setSaveError(err.message ?? 'Failed to save file metadata');
+    } finally {
+      setSaving(false);
+    }
+  }
+
+  // ── Delete ─────────────────────────────────────────────────────────────────
+
+  async function deleteFile(fileId, statusId) {
+    setDeletingId(fileId);
+    try {
+      await sessionFilesApi.delete(fileId);
+      setSavedByStatus((prev) => ({
+        ...prev,
+        [statusId]: prev[statusId].filter((f) => f.id !== fileId),
+      }));
+    } catch {
+      // silently ignore — UI stays consistent, user can retry
+    } finally {
+      setDeletingId(null);
+    }
+  }
+
+  // ── Derived counts ─────────────────────────────────────────────────────────
+
+  const totalDropped       = dropped ? [...dropped.matched.values()].reduce((n, a) => n + a.length, 0) : 0;
+  const totalUnmatched     = dropped?.unmatched.length ?? 0;
+  const totalSaved         = Object.values(savedByStatus).reduce((n, a) => n + a.length, 0);
+  const hasSaved           = totalSaved > 0;
+  const hasMatchedDropped  = totalDropped > 0;
+
+  // Hint string for naming convention
+  const sampleId = animals[0]?.animal_id_string || animals[0]?.animal_name || '<id>';
+  const namingHint = `${date}_${sampleId}_session1.csv`;
+
+  return (
+    <div className="mt-8">
+      <h3 className="text-sm font-semibold text-gray-700 mb-3">Session File Registry</h3>
+      <p className="text-xs text-gray-400 mb-4">
+        Drop all session files here. Filenames are matched to subjects by ID —
+        only metadata (name, size) is recorded; files are never uploaded.
+        <br />
+        Naming convention: <span className="font-mono text-gray-500">{namingHint}</span>
+      </p>
+
+      {/* Drop zone */}
+      <div
+        onDragEnter={onDragEnter}
+        onDragLeave={onDragLeave}
+        onDragOver={onDragOver}
+        onDrop={onDrop}
+        data-testid="drop-zone"
+        className={[
+          'border-2 border-dashed rounded-xl px-6 py-10 text-center transition-all cursor-default select-none',
+          isDragging
+            ? 'border-blue-400 bg-blue-50'
+            : 'border-gray-200 bg-gray-50 hover:border-gray-300',
+        ].join(' ')}
+      >
+        {isDragging ? (
+          <p className="text-blue-600 font-medium text-sm">Release to register files</p>
+        ) : (
+          <>
+            <p className="text-gray-400 text-sm">Drag &amp; drop session files here</p>
+            <p className="text-gray-300 text-xs mt-1">All subjects at once · files are not uploaded</p>
+          </>
+        )}
+      </div>
+
+      {/* Dropped files preview */}
+      {dropped && (
+        <div className="mt-4 space-y-4" data-testid="drop-preview">
+
+          {/* Per-subject matched files */}
+          {statusRows.map(({ animal, status }) => {
+            const files = dropped.matched.get(animal.id) ?? [];
+            if (files.length === 0) return null;
+            return (
+              <div key={animal.id} className="bg-white border border-gray-200 rounded-xl p-4">
+                <div className="flex items-center justify-between mb-2">
+                  <span className="text-sm font-semibold text-gray-800">
+                    {animal.animal_name}
+                    {animal.animal_id_string && (
+                      <span className="ml-1.5 text-xs font-normal text-gray-400">{animal.animal_id_string}</span>
+                    )}
+                  </span>
+                  <span className="text-xs text-gray-400">{files.length} file{files.length !== 1 ? 's' : ''}</span>
+                </div>
+                <div className="divide-y divide-gray-50">
+                  {files.map((f, i) => (
+                    <FileRow key={f.name + i} file={f} onRemove={() => removeMatchedFile(animal.id, i)} />
+                  ))}
+                </div>
+              </div>
+            );
+          })}
+
+          {/* Subjects with no matched files */}
+          {statusRows.some(({ animal }) => (dropped.matched.get(animal.id) ?? []).length === 0) && (
+            <div className="bg-amber-50 border border-amber-100 rounded-xl p-4">
+              <p className="text-xs font-semibold text-amber-700 mb-1">No files matched for:</p>
+              {statusRows
+                .filter(({ animal }) => (dropped.matched.get(animal.id) ?? []).length === 0)
+                .map(({ animal }) => (
+                  <span key={animal.id} className="inline-block text-xs text-amber-600 bg-amber-100 rounded px-2 py-0.5 mr-1 mb-1 font-mono">
+                    {animal.animal_id_string || animal.animal_name}
+                  </span>
+                ))}
+            </div>
+          )}
+
+          {/* Unmatched files */}
+          {dropped.unmatched.length > 0 && (
+            <div className="bg-gray-50 border border-dashed border-gray-200 rounded-xl p-4">
+              <p className="text-xs font-semibold text-gray-500 mb-2">
+                Unmatched ({dropped.unmatched.length}) — no subject ID found in filename
+              </p>
+              <div className="divide-y divide-gray-100">
+                {dropped.unmatched.map((f, i) => (
+                  <FileRow key={f.name + i} file={f} onRemove={() => removeUnmatched(i)} />
+                ))}
+              </div>
+            </div>
+          )}
+
+          {saveError && (
+            <p className="text-xs text-red-500 px-1">{saveError}</p>
+          )}
+
+          {/* Action row */}
+          <div className="flex items-center gap-3 pt-1">
+            {hasMatchedDropped && (
+              <button
+                type="button"
+                onClick={save}
+                disabled={saving}
+                data-testid="save-btn"
+                className="px-4 py-2 rounded-lg text-sm font-medium bg-blue-600 text-white hover:bg-blue-700 disabled:opacity-50 transition-colors"
+              >
+                {saving ? 'Saving…' : `Register ${totalDropped} file${totalDropped !== 1 ? 's' : ''}`}
+              </button>
+            )}
+            <button
+              type="button"
+              onClick={() => { setDropped(null); setSaveError(null); }}
+              className="text-sm text-gray-400 hover:text-gray-600"
+            >
+              Clear
+            </button>
+          </div>
+        </div>
+      )}
+
+      {/* Saved files */}
+      {hasSaved && (
+        <div className="mt-6 space-y-3" data-testid="saved-files">
+          <p className="text-xs font-semibold text-gray-500 uppercase tracking-wide">
+            Registered files ({totalSaved})
+          </p>
+          {statusRows.map(({ animal, status }) => {
+            const files = savedByStatus[status.id] ?? [];
+            if (files.length === 0) return null;
+            return (
+              <div key={animal.id} className="bg-white border border-gray-200 rounded-xl p-4">
+                <div className="flex items-center justify-between mb-2">
+                  <span className="text-sm font-semibold text-gray-800">
+                    {animal.animal_name}
+                    {animal.animal_id_string && (
+                      <span className="ml-1.5 text-xs font-normal text-gray-400">{animal.animal_id_string}</span>
+                    )}
+                  </span>
+                  <span className="text-xs text-gray-400">{files.length} file{files.length !== 1 ? 's' : ''}</span>
+                </div>
+                <div className="divide-y divide-gray-50">
+                  {files.map((f) => (
+                    <SavedFileRow
+                      key={f.id}
+                      file={f}
+                      onDelete={() => deleteFile(f.id, status.id)}
+                      deleting={deletingId === f.id}
+                    />
+                  ))}
+                </div>
+              </div>
+            );
+          })}
+        </div>
+      )}
+    </div>
+  );
+}
@@ -10,6 +10,7 @@ import Button from '../components/ui/Button';
 import Modal from '../components/ui/Modal';
 import DailyStatusForm from '../components/DailyStatusForm';
 import Alert from '../components/ui/Alert';
+import FileDropZone from '../components/FileDropZone';

 const BUILTIN_KEYS_SET = new Set(['experiment_description', 'vitals', 'treatment', 'notes']);

@@ -367,6 +368,9 @@ export default function ExperimentDayView() {
        </div>
      )}

+      {/* Session file drop zone */}
+      <FileDropZone rows={rows} date={date} />
+
      {/* Edit modal (full row) */}
      {editStatus && (
        <Modal
@@ -0,0 +1,301 @@
+import React from 'react';
+import { render, screen, fireEvent, waitFor, act } from '@testing-library/react';
+import FileDropZone from '../src/components/FileDropZone';
+import { sessionFilesApi } from '../src/api/client';
+
+jest.mock('../src/api/client', () => ({
+  sessionFilesApi: {
+    list:   jest.fn(),
+    create: jest.fn(),
+    delete: jest.fn(),
+  },
+}));
+
+// ── Fixtures ───────────────────────────────────────────────────────────────────
+
+const DATE = '2026-04-23';
+
+const ANIMALS = [
+  { id: 'a1', animal_name: 'Rat 2852', animal_id_string: '2852' },
+  { id: 'a2', animal_name: 'Rat 3076', animal_id_string: '3076' },
+  { id: 'a3', animal_name: 'Rat 3077', animal_id_string: '3077' },
+];
+
+const STATUS_A1 = { id: 's-a1', animal_id: 'a1', date: `${DATE}T00:00:00.000Z` };
+const STATUS_A2 = { id: 's-a2', animal_id: 'a2', date: `${DATE}T00:00:00.000Z` };
+const STATUS_A3 = { id: 's-a3', animal_id: 'a3', date: `${DATE}T00:00:00.000Z` };
+
+const ROWS = [
+  { animal: ANIMALS[0], status: STATUS_A1 },
+  { animal: ANIMALS[1], status: STATUS_A2 },
+  { animal: ANIMALS[2], status: STATUS_A3 },
+];
+
+function makeFile(name, size = 1024, type = '') {
+  return new File(['x'], name, { type, lastModified: Date.now() });
+}
+
+function makeSavedFile(id, statusId, filename, fileSize = '10240') {
+  return { id, daily_status_id: statusId, filename, file_size: fileSize, file_type: 'CSV', last_modified: null, created_at: new Date().toISOString() };
+}
+
+function dropFiles(files) {
+  const zone = screen.getByTestId('drop-zone');
+  fireEvent.dragEnter(zone, { dataTransfer: { files } });
+  fireEvent.dragOver(zone, { dataTransfer: { files } });
+  fireEvent.drop(zone, { dataTransfer: { files } });
+}
+
+beforeEach(() => {
+  jest.clearAllMocks();
+  sessionFilesApi.list.mockResolvedValue([]);
+  sessionFilesApi.create.mockResolvedValue([]);
+  sessionFilesApi.delete.mockResolvedValue();
+});
+
+// ── Rendering ──────────────────────────────────────────────────────────────────
+
+describe('rendering', () => {
+  it('renders the drop zone', () => {
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    expect(screen.getByTestId('drop-zone')).toBeInTheDocument();
+    expect(screen.getByText(/drag.*drop session files/i)).toBeInTheDocument();
+  });
+
+  it('shows naming convention hint using first animal id', () => {
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    expect(screen.getByText(/2026-04-23_2852/)).toBeInTheDocument();
+  });
+
+  it('loads saved files on mount for each status', async () => {
+    sessionFilesApi.list.mockResolvedValue([]);
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    await waitFor(() => {
+      expect(sessionFilesApi.list).toHaveBeenCalledWith('s-a1');
+      expect(sessionFilesApi.list).toHaveBeenCalledWith('s-a2');
+      expect(sessionFilesApi.list).toHaveBeenCalledWith('s-a3');
+    });
+  });
+
+  it('shows saved files loaded from the API', async () => {
+    sessionFilesApi.list.mockImplementation((id) =>
+      id === 's-a1'
+        ? Promise.resolve([makeSavedFile('f1', 's-a1', `${DATE}_2852_trials.csv`)])
+        : Promise.resolve([])
+    );
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    await waitFor(() =>
+      expect(screen.getByText(`${DATE}_2852_trials.csv`)).toBeInTheDocument()
+    );
+    expect(screen.getByTestId('saved-files')).toBeInTheDocument();
+  });
+});
+
+// ── Drag state ─────────────────────────────────────────────────────────────────
+
+describe('drag interaction', () => {
+  it('highlights drop zone on dragenter', () => {
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    const zone = screen.getByTestId('drop-zone');
+    fireEvent.dragEnter(zone, { dataTransfer: { files: [] } });
+    expect(zone.className).toMatch(/border-blue-400/);
+    expect(screen.getByText(/release to register/i)).toBeInTheDocument();
+  });
+
+  it('removes highlight on dragleave', () => {
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    const zone = screen.getByTestId('drop-zone');
+    fireEvent.dragEnter(zone, { dataTransfer: { files: [] } });
+    fireEvent.dragLeave(zone, { dataTransfer: { files: [] } });
+    expect(zone.className).not.toMatch(/border-blue-400/);
+  });
+});
+
+// ── File matching ──────────────────────────────────────────────────────────────
+
+describe('filename-to-subject matching', () => {
+  it('matches files containing the animal_id_string to the correct subject', async () => {
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    dropFiles([
+      makeFile(`${DATE}_2852_ephys_raw.bin`, 10_000_000_000),
+      makeFile(`${DATE}_3076_trials.csv`, 10_000_000),
+    ]);
+    await waitFor(() => screen.getByTestId('drop-preview'));
+    expect(screen.getByText(/Rat 2852/)).toBeInTheDocument();
+    expect(screen.getByText(/Rat 3076/)).toBeInTheDocument();
+    expect(screen.getByText(`${DATE}_2852_ephys_raw.bin`)).toBeInTheDocument();
+    expect(screen.getByText(`${DATE}_3076_trials.csv`)).toBeInTheDocument();
+  });
+
+  it('shows unmatched section for files with no subject ID in name', async () => {
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    dropFiles([makeFile('unknown_file.csv', 1024)]);
+    await waitFor(() => screen.getByTestId('drop-preview'));
+    expect(screen.getByText(/unmatched/i)).toBeInTheDocument();
+    expect(screen.getByText('unknown_file.csv')).toBeInTheDocument();
+  });
+
+  it('does not match a partial numeric overlap (2852 should not match 28520)', async () => {
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    dropFiles([makeFile('session_28520_data.csv', 1024)]);
+    await waitFor(() => screen.getByTestId('drop-preview'));
+    expect(screen.getByText(/unmatched/i)).toBeInTheDocument();
+  });
+
+  it('shows warning for subjects with no matched files', async () => {
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    // Only drop file for 2852 — 3076 and 3077 get no match
+    dropFiles([makeFile(`${DATE}_2852_trials.csv`, 1024)]);
+    await waitFor(() => screen.getByTestId('drop-preview'));
+    expect(screen.getByText(/no files matched/i)).toBeInTheDocument();
+    expect(screen.getByText('3076')).toBeInTheDocument();
+    expect(screen.getByText('3077')).toBeInTheDocument();
+  });
+
+  it('matches all four files per subject correctly', async () => {
+    render(<FileDropZone rows={[{ animal: ANIMALS[0], status: STATUS_A1 }]} date={DATE} />);
+    dropFiles([
+      makeFile(`${DATE}_2852_ephys_raw.bin`,    10_000_000_000),
+      makeFile(`${DATE}_2852_kilosort.h5`,       10_000_000_000),
+      makeFile(`${DATE}_2852_trials.csv`,            10_000_000),
+      makeFile(`${DATE}_2852_behavior_log.csv`,       10_000_000),
+    ]);
+    await waitFor(() => screen.getByTestId('drop-preview'));
+    // Save button label is the authoritative "all 4 matched" signal
+    expect(screen.getByTestId('save-btn')).toHaveTextContent('Register 4 files');
+  });
+
+  it('handles multiple subjects with 4 files each simultaneously', async () => {
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    dropFiles([
+      makeFile(`${DATE}_2852_ephys_raw.bin`,    10_000_000_000),
+      makeFile(`${DATE}_2852_kilosort.h5`,       10_000_000_000),
+      makeFile(`${DATE}_2852_trials.csv`,            10_000_000),
+      makeFile(`${DATE}_2852_behavior_log.csv`,       10_000_000),
+      makeFile(`${DATE}_3076_ephys_raw.bin`,    10_000_000_000),
+      makeFile(`${DATE}_3076_kilosort.h5`,       10_000_000_000),
+      makeFile(`${DATE}_3076_trials.csv`,            10_000_000),
+      makeFile(`${DATE}_3076_behavior_log.csv`,       10_000_000),
+    ]);
+    await waitFor(() => screen.getByTestId('drop-preview'));
+    const saveBtn = screen.getByTestId('save-btn');
+    expect(saveBtn.textContent).toMatch(/8 files/);
+  });
+});
+
+// ── Remove before saving ───────────────────────────────────────────────────────
+
+describe('remove files before saving', () => {
+  it('removes a matched file when ✕ is clicked', async () => {
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    dropFiles([makeFile(`${DATE}_2852_trials.csv`, 1024)]);
+    await waitFor(() => screen.getByText(`${DATE}_2852_trials.csv`));
+    fireEvent.click(screen.getAllByText('✕')[0]);
+    await waitFor(() =>
+      expect(screen.queryByText(`${DATE}_2852_trials.csv`)).not.toBeInTheDocument()
+    );
+  });
+});
+
+// ── Saving ─────────────────────────────────────────────────────────────────────
+
+describe('saving metadata', () => {
+  it('calls sessionFilesApi.create with correct payload for each subject', async () => {
+    const file = makeFile(`${DATE}_2852_trials.csv`); // size = 1 byte (content 'x')
+    const savedFile = makeSavedFile('f1', 's-a1', file.name, String(file.size));
+    sessionFilesApi.create.mockResolvedValue([savedFile]);
+
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    dropFiles([file]);
+    await waitFor(() => screen.getByTestId('save-btn'));
+    fireEvent.click(screen.getByTestId('save-btn'));
+
+    await waitFor(() =>
+      expect(sessionFilesApi.create).toHaveBeenCalledWith(
+        's-a1',
+        expect.arrayContaining([
+          expect.objectContaining({
+            filename:  `${DATE}_2852_trials.csv`,
+            file_size: file.size,
+            file_type: 'CSV',
+          }),
+        ])
+      )
+    );
+  });
+
+  it('does not call create for subjects with no matched files', async () => {
+    sessionFilesApi.create.mockResolvedValue([]);
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    // Only 2852 gets a file
+    dropFiles([makeFile(`${DATE}_2852_trials.csv`, 1024)]);
+    await waitFor(() => screen.getByTestId('save-btn'));
+    fireEvent.click(screen.getByTestId('save-btn'));
+
+    await waitFor(() => expect(sessionFilesApi.create).toHaveBeenCalledTimes(1));
+    expect(sessionFilesApi.create).toHaveBeenCalledWith('s-a1', expect.any(Array));
+  });
+
+  it('stores correct file_type classification from extension', async () => {
+    sessionFilesApi.create.mockResolvedValue([]);
+    render(<FileDropZone rows={[{ animal: ANIMALS[0], status: STATUS_A1 }]} date={DATE} />);
+    dropFiles([
+      makeFile(`${DATE}_2852_ephys.bin`,  10_000_000_000),
+      makeFile(`${DATE}_2852_spikes.h5`,  10_000_000_000),
+      makeFile(`${DATE}_2852_trials.csv`,     10_000_000),
+      makeFile(`${DATE}_2852_log.csv`,        10_000_000),
+    ]);
+    await waitFor(() => screen.getByTestId('save-btn'));
+    fireEvent.click(screen.getByTestId('save-btn'));
+
+    await waitFor(() => expect(sessionFilesApi.create).toHaveBeenCalled());
+    const [, files] = sessionFilesApi.create.mock.calls[0];
+    expect(files.find((f) => f.filename.endsWith('.bin')).file_type).toBe('Binary');
+    expect(files.find((f) => f.filename.endsWith('.h5')).file_type).toBe('HDF5');
+    expect(files.filter((f) => f.filename.endsWith('.csv'))).toHaveLength(2);
+    files.filter((f) => f.filename.endsWith('.csv')).forEach((f) => {
+      expect(f.file_type).toBe('CSV');
+    });
+  });
+
+  it('clears the drop preview after a successful save', async () => {
+    sessionFilesApi.create.mockResolvedValue([makeSavedFile('f1', 's-a1', `${DATE}_2852_trials.csv`)]);
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    dropFiles([makeFile(`${DATE}_2852_trials.csv`, 1024)]);
+    await waitFor(() => screen.getByTestId('save-btn'));
+    fireEvent.click(screen.getByTestId('save-btn'));
+    await waitFor(() =>
+      expect(screen.queryByTestId('drop-preview')).not.toBeInTheDocument()
+    );
+  });
+
+  it('shows an error message when create fails', async () => {
+    sessionFilesApi.create.mockRejectedValue({ message: 'Server error' });
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    dropFiles([makeFile(`${DATE}_2852_trials.csv`, 1024)]);
+    await waitFor(() => screen.getByTestId('save-btn'));
+    fireEvent.click(screen.getByTestId('save-btn'));
+    await waitFor(() => screen.getByText(/server error/i));
+  });
+});
+
+// ── Deleting saved files ───────────────────────────────────────────────────────
+
+describe('deleting saved files', () => {
+  it('removes a saved file when its ✕ is clicked', async () => {
+    sessionFilesApi.list.mockImplementation((id) =>
+      id === 's-a1'
+        ? Promise.resolve([makeSavedFile('f1', 's-a1', `${DATE}_2852_trials.csv`)])
+        : Promise.resolve([])
+    );
+    render(<FileDropZone rows={ROWS} date={DATE} />);
+    await waitFor(() => screen.getByText(`${DATE}_2852_trials.csv`));
+    fireEvent.click(screen.getAllByText('✕')[0]);
+    await waitFor(() =>
+      expect(sessionFilesApi.delete).toHaveBeenCalledWith('f1')
+    );
+    await waitFor(() =>
+      expect(screen.queryByText(`${DATE}_2852_trials.csv`)).not.toBeInTheDocument()
+    );
+  });
+});