package com.ankurm.customvalidation;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.webmvc.test.autoconfigure.AutoConfigureMockMvc;
import org.springframework.test.web.servlet.MockMvc;

import static org.assertj.core.api.Assertions.assertThat;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

/**
 * What the default in {@link ValidationScenariosTest#recordBasedSpamMessageRejectedButWithNoErrorBodyByDefault}
 * does not do: emit a structured error body for a validation failure that has no BindingResult to
 * carry it. That structured body exists, but it is opt-in behind
 * {@code spring.mvc.problemdetails.enabled=true} -- unrelated to Bean Validation 3.1 itself, and
 * a property that already existed in Boot 3, but worth verifying directly rather than assuming it
 * changes the earlier empty-body result, because it does not touch content negotiation, only
 * whether a body is produced at all.
 */
@SpringBootTest(properties = "spring.mvc.problemdetails.enabled=true")
@AutoConfigureMockMvc
class ProblemDetailsEnabledTest {

    @Autowired
    MockMvc mockMvc;

    @Test
    void recordValidationFailureNowGetsAProblemDetailBody() throws Exception {
        var result = mockMvc.perform(post("/contact-record")
                        .contentType("application/json")
                        .content("{\"email\":\"spammy@email.com\",\"message\":\"This is spam.\"}"))
                .andExpect(status().isBadRequest())
                .andReturn();

        String body = result.getResponse().getContentAsString();
        // A real body now exists -- progress over the empty one -- but it is a GENERIC
        // ProblemDetail with no mention of "spam" or which field failed. Spring's default
        // MethodArgumentNotValidException -> ProblemDetail mapping does not populate per-field
        // messages for you; that needs a custom @ExceptionHandler (or ResponseEntityExceptionHandler
        // override) that reads bindingResult.getFieldErrors() into the ProblemDetail's properties.
        assertThat(body).isNotEmpty();
        assertThat(body).doesNotContain("spam");
        assertThat(body).contains("\"status\":400");

        Transcript.write("07-problemdetails-enabled-record-rejected.txt",
                "# application.yaml: spring.mvc.problemdetails.enabled: true (opt-in; unrelated to Bean\n"
                        + "# Validation 3.1 itself -- this property already existed in Boot 3)\n\n"
                        + "$ curl -s -X POST localhost:8080/contact-record \\\n"
                        + "     -H 'Content-Type: application/json' \\\n"
                        + "     -d '{\"email\":\"spammy@email.com\",\"message\":\"This is spam.\"}'\n\n"
                        + "HTTP status: " + result.getResponse().getStatus() + "\n"
                        + "Content-Type: " + result.getResponse().getContentType() + "\n"
                        + "Body: " + body + "\n"
                        + "\n# Progress over the empty body, but notice what is MISSING: no mention of \"spam\", no field\n"
                        + "# name. Boot's default MethodArgumentNotValidException -> ProblemDetail mapping fills in\n"
                        + "# only the generic RFC 9457 fields (title, status, detail=\"Invalid request content.\").\n"
                        + "# Per-field messages -- what the class-based /contact endpoint hand-rolls from\n"
                        + "# bindingResult.getFieldErrors() -- need a custom @ExceptionHandler that does the same\n"
                        + "# thing into the ProblemDetail's own \"properties\" map. Turning the property on is not,\n"
                        + "# by itself, a drop-in replacement for BindingResult-based error reporting.\n");
    }
}