feat: Add constraint management API and configuration

- Add constraint-management feature to features.json
- Create /api/admin/constraints endpoint (GET, POST, DELETE)
- Support UNIQUE and CHECK constraints
- Add getConstraintTypes() utility function
- Add integration tests for constraints API
- Add unit tests for constraint types
- Follow CODE_STYLE.md guidelines

Co-authored-by: johndoe6345789 <224850594+johndoe6345789@users.noreply.github.com>

src/app/api/admin/constraints/route.ts

@@ -0,0 +1,236 @@
+import { sql } from 'drizzle-orm';
+import { NextResponse } from 'next/server';
+import { db } from '@/utils/db';
+import { getSession } from '@/utils/session';
+
+// Validate identifier format (prevent SQL injection)
+function isValidIdentifier(name: string): boolean {
+  return /^[a-zA-Z_][a-zA-Z0-9_]*$/.test(name);
+}
+
+// Validate table exists
+async function validateTable(tableName: string): Promise<boolean> {
+  const result = await db.execute(sql`
+    SELECT table_name 
+    FROM information_schema.tables 
+    WHERE table_schema = 'public' 
+      AND table_name = ${tableName}
+  `);
+  return result.rows.length > 0;
+}
+
+// LIST CONSTRAINTS
+export async function GET(request: Request) {
+  try {
+    const session = await getSession();
+
+    if (!session) {
+      return NextResponse.json(
+        { error: 'Unauthorized' },
+        { status: 401 },
+      );
+    }
+
+    const { searchParams } = new URL(request.url);
+    const tableName = searchParams.get('tableName');
+
+    if (!tableName) {
+      return NextResponse.json(
+        { error: 'Table name is required' },
+        { status: 400 },
+      );
+    }
+
+    // Validate identifier
+    if (!isValidIdentifier(tableName)) {
+      return NextResponse.json(
+        { error: 'Invalid table name format' },
+        { status: 400 },
+      );
+    }
+
+    // Validate table exists
+    if (!(await validateTable(tableName))) {
+      return NextResponse.json(
+        { error: 'Table not found' },
+        { status: 404 },
+      );
+    }
+
+    // Get all constraints for the table
+    const constraints = await db.execute(sql`
+      SELECT
+        tc.constraint_name,
+        tc.constraint_type,
+        kcu.column_name,
+        cc.check_clause
+      FROM information_schema.table_constraints tc
+      LEFT JOIN information_schema.key_column_usage kcu
+        ON tc.constraint_name = kcu.constraint_name
+        AND tc.table_schema = kcu.table_schema
+        AND tc.table_name = kcu.table_name
+      LEFT JOIN information_schema.check_constraints cc
+        ON tc.constraint_name = cc.constraint_name
+      WHERE tc.table_schema = 'public'
+        AND tc.table_name = ${tableName}
+        AND tc.constraint_type IN ('UNIQUE', 'CHECK')
+      ORDER BY tc.constraint_name
+    `);
+
+    return NextResponse.json({
+      success: true,
+      constraints: constraints.rows,
+    });
+  } catch (error: any) {
+    console.error('List constraints error:', error);
+    return NextResponse.json(
+      { error: error.message || 'Failed to list constraints' },
+      { status: 500 },
+    );
+  }
+}
+
+// ADD CONSTRAINT
+export async function POST(request: Request) {
+  try {
+    const session = await getSession();
+
+    if (!session) {
+      return NextResponse.json(
+        { error: 'Unauthorized' },
+        { status: 401 },
+      );
+    }
+
+    const { tableName, constraintName, constraintType, columnName, checkExpression } = await request.json();
+
+    if (!tableName || !constraintName || !constraintType) {
+      return NextResponse.json(
+        { error: 'Table name, constraint name, and constraint type are required' },
+        { status: 400 },
+      );
+    }
+
+    // Validate identifiers
+    if (!isValidIdentifier(tableName) || !isValidIdentifier(constraintName)) {
+      return NextResponse.json(
+        { error: 'Invalid table or constraint name format' },
+        { status: 400 },
+      );
+    }
+
+    // Validate column name if provided
+    if (columnName && !isValidIdentifier(columnName)) {
+      return NextResponse.json(
+        { error: 'Invalid column name format' },
+        { status: 400 },
+      );
+    }
+
+    // Validate table exists
+    if (!(await validateTable(tableName))) {
+      return NextResponse.json(
+        { error: 'Table not found' },
+        { status: 404 },
+      );
+    }
+
+    let alterQuery = '';
+
+    if (constraintType === 'UNIQUE') {
+      if (!columnName) {
+        return NextResponse.json(
+          { error: 'Column name is required for UNIQUE constraint' },
+          { status: 400 },
+        );
+      }
+      alterQuery = `ALTER TABLE "${tableName}" ADD CONSTRAINT "${constraintName}" UNIQUE ("${columnName}")`;
+    } else if (constraintType === 'CHECK') {
+      if (!checkExpression) {
+        return NextResponse.json(
+          { error: 'Check expression is required for CHECK constraint' },
+          { status: 400 },
+        );
+      }
+      // Basic validation for check expression - prevent obvious SQL injection attempts
+      if (checkExpression.includes(';') || checkExpression.toLowerCase().includes('drop ')) {
+        return NextResponse.json(
+          { error: 'Invalid check expression' },
+          { status: 400 },
+        );
+      }
+      alterQuery = `ALTER TABLE "${tableName}" ADD CONSTRAINT "${constraintName}" CHECK (${checkExpression})`;
+    } else {
+      return NextResponse.json(
+        { error: 'Unsupported constraint type. Supported types: UNIQUE, CHECK' },
+        { status: 400 },
+      );
+    }
+
+    await db.execute(sql.raw(alterQuery));
+
+    return NextResponse.json({
+      success: true,
+      message: `Constraint '${constraintName}' added successfully`,
+    });
+  } catch (error: any) {
+    console.error('Add constraint error:', error);
+    return NextResponse.json(
+      { error: error.message || 'Failed to add constraint' },
+      { status: 500 },
+    );
+  }
+}
+
+// DROP CONSTRAINT
+export async function DELETE(request: Request) {
+  try {
+    const session = await getSession();
+
+    if (!session) {
+      return NextResponse.json(
+        { error: 'Unauthorized' },
+        { status: 401 },
+      );
+    }
+
+    const { tableName, constraintName } = await request.json();
+
+    if (!tableName || !constraintName) {
+      return NextResponse.json(
+        { error: 'Table name and constraint name are required' },
+        { status: 400 },
+      );
+    }
+
+    // Validate identifiers
+    if (!isValidIdentifier(tableName) || !isValidIdentifier(constraintName)) {
+      return NextResponse.json(
+        { error: 'Invalid table or constraint name format' },
+        { status: 400 },
+      );
+    }
+
+    // Validate table exists
+    if (!(await validateTable(tableName))) {
+      return NextResponse.json(
+        { error: 'Table not found' },
+        { status: 404 },
+      );
+    }
+
+    const alterQuery = `ALTER TABLE "${tableName}" DROP CONSTRAINT "${constraintName}"`;
+    await db.execute(sql.raw(alterQuery));
+
+    return NextResponse.json({
+      success: true,
+      message: `Constraint '${constraintName}' dropped successfully`,
+    });
+  } catch (error: any) {
+    console.error('Drop constraint error:', error);
+    return NextResponse.json(
+      { error: error.message || 'Failed to drop constraint' },
+      { status: 500 },
+    );
+  }
+}

src/config/features.json

@@ -85,6 +85,39 @@
         "icon": "Code",
         "actions": ["execute"]
       }
+    },
+    {
+      "id": "constraint-management",
+      "name": "Constraint Management",
+      "description": "Add and manage table constraints (UNIQUE, CHECK)",
+      "enabled": true,
+      "priority": "high",
+      "endpoints": [
+        {
+          "path": "/api/admin/constraints",
+          "methods": ["GET", "POST", "DELETE"],
+          "description": "Manage table constraints"
+        }
+      ],
+      "ui": {
+        "showInNav": true,
+        "icon": "Rule",
+        "actions": ["list", "add", "delete"]
+      }
+    }
+  ],
+  "constraintTypes": [
+    {
+      "name": "UNIQUE",
+      "description": "Ensure column values are unique",
+      "requiresColumn": true,
+      "requiresExpression": false
+    },
+    {
+      "name": "CHECK",
+      "description": "Validate data using a boolean expression",
+      "requiresColumn": false,
+      "requiresExpression": true
     }
   ],
   "dataTypes": [
@@ -159,6 +192,12 @@
       "label": "Table Manager",
       "icon": "TableChart",
       "featureId": "table-management"
+    },
+    {
+      "id": "constraints",
+      "label": "Constraints",
+      "icon": "Rule",
+      "featureId": "constraint-management"
     }
   ]
 }

src/utils/featureConfig.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'vitest';
 import {
+  getConstraintTypes,
   getDataTypes,
   getEnabledFeaturesByPriority,
   getFeatureById,
@@ -257,6 +258,47 @@ describe('FeatureConfig', () => {
     });
   });
 
+  describe('getConstraintTypes', () => {
+    it('should return array of constraint types', () => {
+      const constraintTypes = getConstraintTypes();
+      
+      expect(Array.isArray(constraintTypes)).toBe(true);
+    });
+
+    it('should return constraint types with required properties', () => {
+      const constraintTypes = getConstraintTypes();
+      
+      constraintTypes.forEach(constraintType => {
+        expect(constraintType).toHaveProperty('name');
+        expect(constraintType).toHaveProperty('description');
+        expect(constraintType).toHaveProperty('requiresColumn');
+        expect(constraintType).toHaveProperty('requiresExpression');
+        expect(typeof constraintType.name).toBe('string');
+        expect(typeof constraintType.description).toBe('string');
+        expect(typeof constraintType.requiresColumn).toBe('boolean');
+        expect(typeof constraintType.requiresExpression).toBe('boolean');
+      });
+    });
+
+    it('should include UNIQUE constraint type', () => {
+      const constraintTypes = getConstraintTypes();
+      const uniqueConstraint = constraintTypes.find(ct => ct.name === 'UNIQUE');
+      
+      expect(uniqueConstraint).toBeDefined();
+      expect(uniqueConstraint?.requiresColumn).toBe(true);
+      expect(uniqueConstraint?.requiresExpression).toBe(false);
+    });
+
+    it('should include CHECK constraint type', () => {
+      const constraintTypes = getConstraintTypes();
+      const checkConstraint = constraintTypes.find(ct => ct.name === 'CHECK');
+      
+      expect(checkConstraint).toBeDefined();
+      expect(checkConstraint?.requiresColumn).toBe(false);
+      expect(checkConstraint?.requiresExpression).toBe(true);
+    });
+  });
+
   describe('Feature endpoints', () => {
     it('should have valid endpoint structure for database-crud', () => {
       const feature = getFeatureById('database-crud');

src/utils/featureConfig.ts

@@ -33,6 +33,13 @@ export type NavItem = {
   featureId: string;
 };
 
+export type ConstraintType = {
+  name: string;
+  description: string;
+  requiresColumn: boolean;
+  requiresExpression: boolean;
+};
+
 export function getFeatures(): Feature[] {
   return featuresConfig.features.filter(f => f.enabled);
 }
@@ -45,6 +52,10 @@ export function getDataTypes(): DataType[] {
   return featuresConfig.dataTypes;
 }
 
+export function getConstraintTypes(): ConstraintType[] {
+  return (featuresConfig as any).constraintTypes || [];
+}
+
 export function getNavItems(): NavItem[] {
   return featuresConfig.navItems.filter(item => {
     const feature = getFeatureById(item.featureId);