Replace fixed DSL fields with parameterized metric expressions

app/analysis_migration.py

@@ -0,0 +1,69 @@
+"""One-time rewrite of saved queries to parameterized metric expressions."""
+
+import re
+
+import click
+
+from .extensions import db
+from .models import SavedAnalysis, User
+from .stats import parse_query, query_text
+
+
+def rewrite(query):
+    threshold = '10'
+    lines = []
+    for line in query.splitlines():
+        match = re.fullmatch(r'\s*long run distance >= (\d+(?:\.\d+)?) km\s*', line)
+        if match:
+            threshold = match[1]
+        else:
+            lines.append(line)
+    daily = any(line.strip() in {'days', 'health'} for line in lines)
+    replacements = {
+        'days_since_run': 'days_since_run()',
+        'days_since_long_run': f'days_since_run(distance >= {threshold} km)',
+        **{f'best_{km}km': f'best_time({km} km)' for km in (1, 2, 5, 10)},
+        **{f'rolling_{days}d_distance': f'rolling_sum(distance, {days} days)' for days in (7, 28)},
+        **{f'rolling_{days}d_count': (f'rolling_sum(sessions, {days} days)' if daily
+                                    else f'rolling_count(distance, {days} days)') for days in (7, 28)},
+    }
+    pattern = re.compile(r'\b(' + '|'.join(replacements) + r')\b(?!\s*\()')
+    result = []
+    for line in lines:
+        if not line.lstrip().startswith('#'):
+            parts = re.split(r'("(?:[^"\\]|\\.)*")', line)
+            for index in range(0, len(parts), 2):
+                parts[index] = pattern.sub(lambda m: replacements[m[0]], parts[index])
+            line = ''.join(parts)
+        result.append(line)
+    return '\n'.join(result)
+
+
+def migrate(user):
+    changes = []
+    for row in db.session.scalars(db.select(SavedAnalysis).where(SavedAnalysis.owner_id == user.id)):
+        updated = rewrite(row.query)
+        if updated != row.query:
+            # Validate every replacement before modifying any persisted query.
+            canonical = query_text(parse_query({'query': updated}))
+            parse_query({'query': canonical})
+            changes.append((row, updated))
+    for row, updated in changes:
+        row.query = updated
+    db.session.commit()
+    return len(changes)
+
+
+def register_cli(app):
+    @app.cli.command('migrate-analysis-expressions')
+    @click.option('--email', required=True)
+    def migrate_queries(email):
+        user = db.session.scalar(db.select(User).filter_by(email=email.strip().lower()))
+        if not user:
+            raise click.ClickException('Account not found.')
+        try:
+            count = migrate(user)
+        except ValueError as error:
+            db.session.rollback()
+            raise click.ClickException(str(error)) from None
+        click.echo(f'Updated {count} saved analyses.')