webstatement/app/Http/Requests/PrintStatementRequest.php

<?php

    namespace Modules\Webstatement\Http\Requests;

    use Illuminate\Foundation\Http\FormRequest;

    class PrintStatementRequest extends FormRequest
    {
        /**
         * Determine if the user is authorized to make this request.
         */
        public function authorize()
        : bool
        {
            return true;
        }

        /**
         * Get the validation rules that apply to the request.
         *
         * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array<mixed>|string>
         */
        public function rules()
        : array
        {
            $rules = [
                'branch_code'     => ['required', 'string', 'exists:branches,code'],
                'account_number'  => ['required', 'string'],
                'is_period_range' => ['sometimes', 'boolean'],
                'period_from'     => ['required', 'string', 'regex:/^\d{6}$/'], // YYYYMM format
            ];

            // If it's a period range, require period_to
            if ($this->input('is_period_range')) {
                $rules['period_to'] = [
                    'required',
                    'string',
                    'regex:/^\d{6}$/', // YYYYMM format
                    'gte:period_from' // period_to must be greater than or equal to period_from
                ];
            }

            return $rules;
        }

        /**
         * Get custom messages for validator errors.
         *
         * @return array
         */
        public function messages()
        : array
        {
            return [
                'branch_code.required'    => 'Branch code is required',
                'branch_code.exists'      => 'Selected branch does not exist',
                'account_number.required' => 'Account number is required',
                'period_from.required'    => 'Period is required',
                'period_from.regex'       => 'Period must be in YYYYMM format',
                'period_to.required'      => 'End period is required for period range',
                'period_to.regex'         => 'End period must be in YYYYMM format',
                'period_to.gte'           => 'End period must be after or equal to start period',
            ];
        }

        /**
         * Prepare the data for validation.
         *
         * @return void
         */
        protected function prepareForValidation()
        : void
        {
            // Convert is_period_range to boolean if it exists
            if ($this->has('is_period_range')) {
                $this->merge([
                    'is_period_range' => filter_var($this->is_period_range, FILTER_VALIDATE_BOOLEAN),
                ]);
            }
        }
    }