feat(05-02): exa-search research integration

backend/src/routes/exerciseResearch.js

@@ -0,0 +1,81 @@
+const express = require('express');
+
+const normalizeQuery = (exerciseName, body) => {
+  if (body && typeof body.query === 'string' && body.query.trim()) {
+    return body.query.trim();
+  }
+
+  if (body && typeof body.name === 'string' && body.name.trim()) {
+    return body.name.trim();
+  }
+
+  return `${exerciseName} exercise`;
+};
+
+const createExerciseResearchRouter = ({ pool, exaSearch }) => {
+  if (!pool || typeof pool.query !== 'function') {
+    throw new Error('Pool with query function is required');
+  }
+  if (!exaSearch || typeof exaSearch !== 'function') {
+    throw new Error('exaSearch function is required');
+  }
+
+  const router = express.Router();
+
+  router.post('/:id/research', async (req, res) => {
+    try {
+      const exerciseId = Number.parseInt(req.params.id, 10);
+      if (!Number.isInteger(exerciseId)) {
+        return res.status(400).json({ error: 'Exercise id must be an integer' });
+      }
+
+      const exerciseResult = await pool.query(
+        'SELECT id, name, description, muscle_groups, difficulty, equipment_needed FROM exercises WHERE id = $1',
+        [exerciseId]
+      );
+
+      if (!exerciseResult.rows.length) {
+        return res.status(404).json({ error: 'Exercise not found' });
+      }
+
+      const exercise = exerciseResult.rows[0];
+      const query = normalizeQuery(exercise.name, req.body);
+      const requestedResults = req.body?.num_results;
+      const numResults = Number.isInteger(requestedResults) && requestedResults > 0
+        ? Math.min(requestedResults, 10)
+        : 5;
+
+      const { summary, results } = await exaSearch({ query, numResults });
+
+      let researchRecord = null;
+      try {
+        const insertResult = await pool.query(
+          `INSERT INTO research_results (exercise_id, query, summary, results, provider)
+           VALUES ($1, $2, $3, $4, $5)
+           RETURNING id, created_at`,
+          [exerciseId, query, summary, JSON.stringify(results), 'exa']
+        );
+        researchRecord = insertResult.rows[0] || null;
+      } catch (err) {
+        console.warn('Failed to store research results:', err.message);
+      }
+
+      res.json({
+        exercise,
+        query,
+        summary,
+        results,
+        stored: researchRecord
+      });
+    } catch (err) {
+      console.error('Error running exercise research:', err);
+      res.status(500).json({ error: 'Failed to fetch research' });
+    }
+  });
+
+  return router;
+};
+
+module.exports = {
+  createExerciseResearchRouter
+};