grants/server/middleware/validate.ts

import type { Request, Response, NextFunction } from "express";
import { z } from "zod";

/**
 * Request validation middleware factory.
 * Validates req.body against a Zod schema.
 * Returns 400 with validation errors if invalid.
 */

export function validateBody<T extends z.ZodType>(schema: T) {
  return (req: Request, res: Response, next: NextFunction) => {
    const result = schema.safeParse(req.body);
    if (!result.success) {
      return res.status(400).json({
        ok: false,
        error: "Invalid request body",
        details: result.error.issues.map((e) => ({
          path: e.path.join("."),
          message: e.message,
        })),
      });
    }
    next();
  };
}

/**
 * Query parameter validation middleware factory.
 */
export function validateQuery<T extends z.ZodType>(schema: T) {
  return (req: Request, res: Response, next: NextFunction) => {
    const result = schema.safeParse(req.query);
    if (!result.success) {
      return res.status(400).json({
        ok: false,
        error: "Invalid query parameters",
        details: result.error.issues.map((e) => ({
          path: e.path.join("."),
          message: e.message,
        })),
      });
    }
    next();
  };
}