package resp

import (
	"encoding/json"
	"errors"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/gin-gonic/gin"
)

func setupRouter() *gin.Engine {
	gin.SetMode(gin.TestMode)
	r := gin.New()
	return r
}

func decode(t *testing.T, w *httptest.ResponseRecorder) map[string]any {
	t.Helper()
	var m map[string]any
	if err := json.Unmarshal(w.Body.Bytes(), &m); err != nil {
		t.Fatalf("response not json: %v (%s)", err, w.Body.String())
	}
	return m
}

func TestFailEnvelope(t *testing.T) {
	r := setupRouter()
	r.GET("/x", func(c *gin.Context) { BadRequest(c, "参数不合法") })

	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/x", nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want 400", w.Code)
	}
	m := decode(t, w)
	if m["detail"] != "参数不合法" {
		t.Fatalf("detail = %v", m["detail"])
	}
}

func TestInternalErrSanitizes(t *testing.T) {
	r := setupRouter()
	dbErr := errors.New("SQL logic error: no such table: users (database is locked)")
	r.GET("/x", func(c *gin.Context) { InternalErr(c, dbErr) })

	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/x", nil)
	r.ServeHTTP(w, req)

	if w.Code != http.StatusInternalServerError {
		t.Fatalf("status = %d, want 500", w.Code)
	}
	m := decode(t, w)
	// 客户端不得看到 DB 错误原文
	if m["detail"] == dbErr.Error() {
		t.Fatalf("internal error leaked to client: %v", m["detail"])
	}
	if m["code"] != "internal" {
		t.Fatalf("code = %v, want internal", m["code"])
	}
}

func TestPageEnvelope(t *testing.T) {
	r := setupRouter()
	r.GET("/x", func(c *gin.Context) {
		Page(c, []string{"a", "b"}, 42, 2, 10)
	})

	w := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/x", nil)
	r.ServeHTTP(w, req)

	m := decode(t, w)
	if m["total"].(float64) != 42 || m["page"].(float64) != 2 || m["page_size"].(float64) != 10 {
		t.Fatalf("pagination envelope wrong: %v", m)
	}
	items, ok := m["items"].([]any)
	if !ok || len(items) != 2 {
		t.Fatalf("items wrong: %v", m["items"])
	}
}