package httputil

import (
	"context"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"code.nochebuena.dev/einherjar/contracts/logging"
	"code.nochebuena.dev/einherjar/core/logz"
	"code.nochebuena.dev/einherjar/core/valid"
)

type tReq struct {
	Name string `json:"name" validate:"required"`
}
type tRes struct {
	ID string `json:"id"`
}

func discardLogger() logging.Logger { return logz.New(logz.Config{Writer: io.Discard}) }

// Default: Handle writes 200 with the JSON payload (regression — no opts).
func TestHandle_Default200(t *testing.T) {
	h := Handle(valid.New(), discardLogger(), func(context.Context, tReq) (tRes, error) {
		return tRes{ID: "x"}, nil
	})
	rec := httptest.NewRecorder()
	h(rec, httptest.NewRequest(http.MethodPost, "/", strings.NewReader(`{"name":"a"}`)))
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200", rec.Code)
	}
	if got := strings.TrimSpace(rec.Body.String()); got != `{"id":"x"}` {
		t.Errorf("body = %q, want {\"id\":\"x\"}", got)
	}
}

// WithStatus(201) makes a resource-creating Handle return 201 Created + the body.
func TestHandle_WithStatusCreated(t *testing.T) {
	h := Handle(valid.New(), discardLogger(), func(context.Context, tReq) (tRes, error) {
		return tRes{ID: "x"}, nil
	}, WithStatus(http.StatusCreated))
	rec := httptest.NewRecorder()
	h(rec, httptest.NewRequest(http.MethodPost, "/", strings.NewReader(`{"name":"a"}`)))
	if rec.Code != http.StatusCreated {
		t.Fatalf("status = %d, want 201", rec.Code)
	}
	if got := strings.TrimSpace(rec.Body.String()); got != `{"id":"x"}` {
		t.Errorf("body = %q, want the payload", got)
	}
}

func TestHandleNoBody_WithStatus(t *testing.T) {
	h := HandleNoBody(discardLogger(), func(context.Context) (tRes, error) {
		return tRes{ID: "y"}, nil
	}, WithStatus(http.StatusAccepted))
	rec := httptest.NewRecorder()
	h(rec, httptest.NewRequest(http.MethodGet, "/", nil))
	if rec.Code != http.StatusAccepted {
		t.Fatalf("status = %d, want 202", rec.Code)
	}
}

// Default: HandleEmpty writes 204 with no body.
func TestHandleEmpty_Default204(t *testing.T) {
	h := HandleEmpty(valid.New(), discardLogger(), func(context.Context, tReq) error { return nil })
	rec := httptest.NewRecorder()
	h(rec, httptest.NewRequest(http.MethodPost, "/", strings.NewReader(`{"name":"a"}`)))
	if rec.Code != http.StatusNoContent {
		t.Fatalf("status = %d, want 204", rec.Code)
	}
	if rec.Body.Len() != 0 {
		t.Errorf("expected empty body, got %q", rec.Body.String())
	}
}

// WithStatus on a body-less adapter changes the code but keeps the empty body.
func TestHandleEmpty_WithStatusAccepted_NoBody(t *testing.T) {
	h := HandleEmpty(valid.New(), discardLogger(), func(context.Context, tReq) error { return nil }, WithStatus(http.StatusAccepted))
	rec := httptest.NewRecorder()
	h(rec, httptest.NewRequest(http.MethodPost, "/", strings.NewReader(`{"name":"a"}`)))
	if rec.Code != http.StatusAccepted {
		t.Fatalf("status = %d, want 202", rec.Code)
	}
	if rec.Body.Len() != 0 {
		t.Errorf("expected empty body, got %q", rec.Body.String())
	}
}

// A non-2xx code is a wiring mistake: WithStatus panics at construction so the
// service fails to boot rather than emitting a wrong status at request time.
func TestWithStatus_PanicsOnNon2xx(t *testing.T) {
	for _, code := range []int{0, 100, 199, 300, 404, 500, 1000} {
		func() {
			defer func() {
				if recover() == nil {
					t.Errorf("WithStatus(%d) did not panic", code)
				}
			}()
			_ = WithStatus(code)
		}()
	}
}

func TestWithStatus_Allows2xx(t *testing.T) {
	for _, code := range []int{200, 201, 202, 204, 299} {
		func() {
			defer func() {
				if r := recover(); r != nil {
					t.Errorf("WithStatus(%d) panicked: %v", code, r)
				}
			}()
			_ = WithStatus(code)
		}()
	}
}