package handler_test

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

	"lyra/internal/handler"
	"lyra/internal/model"

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

type fakeCategoryModel struct {
	categories []*model.Category
	err        error
	calls      int
	gotCtx     context.Context
}

func (f *fakeCategoryModel) FindAll(ctx context.Context) ([]*model.Category, error) {
	f.calls++
	f.gotCtx = ctx
	return f.categories, f.err
}

func serveHello(t *testing.T, fake *fakeCategoryModel, req *http.Request) *httptest.ResponseRecorder {
	t.Helper()
	gin.SetMode(gin.TestMode)
	engine := gin.New()
	engine.GET("/test", handler.NewTestHandler(fake).Hello())
	recorder := httptest.NewRecorder()
	engine.ServeHTTP(recorder, req)
	return recorder
}

func newHelloRequest() *http.Request {
	return httptest.NewRequest(http.MethodGet, "/test", nil)
}

func TestHelloMapsCategoriesToResponse(t *testing.T) {
	fake := &fakeCategoryModel{categories: []*model.Category{
		{ID: 1, Slug: "go-basics", Title: "Go 基础", Sort: 1},
		{ID: 2, Slug: "sql-practice", Title: "SQL 练习", Sort: 2},
	}}

	recorder := serveHello(t, fake, newHelloRequest())

	if fake.calls != 1 {
		t.Fatalf("模型调用次数 = %d, want 1", fake.calls)
	}
	if recorder.Code != http.StatusOK {
		t.Fatalf("status = %d, want %d", recorder.Code, http.StatusOK)
	}
	want := `{"success":true,"data":[{"id":1,"slug":"go-basics","title":"Go 基础","sort":1},{"id":2,"slug":"sql-practice","title":"SQL 练习","sort":2}]}`
	if got := recorder.Body.String(); got != want {
		t.Fatalf("body = %q, want %q", got, want)
	}
}

func TestHelloReturnsEmptyArrayForNoCategories(t *testing.T) {
	tests := []struct {
		name       string
		categories []*model.Category
	}{
		{name: "空切片", categories: []*model.Category{}},
		{name: "nil结果", categories: nil},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			fake := &fakeCategoryModel{categories: tt.categories}

			recorder := serveHello(t, fake, newHelloRequest())

			if fake.calls != 1 {
				t.Fatalf("模型调用次数 = %d, want 1", fake.calls)
			}
			if recorder.Code != http.StatusOK {
				t.Fatalf("status = %d, want %d", recorder.Code, http.StatusOK)
			}
			want := `{"success":true,"data":[]}`
			if got := recorder.Body.String(); got != want {
				t.Fatalf("body = %q, want %q", got, want)
			}
		})
	}
}

func TestHelloReturnsInternalErrorOnModelFailure(t *testing.T) {
	modelErr := errors.New("数据库连接被拒绝: 10.0.0.8:5432")
	fake := &fakeCategoryModel{err: modelErr}

	recorder := serveHello(t, fake, newHelloRequest())

	if fake.calls != 1 {
		t.Fatalf("模型调用次数 = %d, want 1", fake.calls)
	}
	if recorder.Code != http.StatusInternalServerError {
		t.Fatalf("status = %d, want %d", recorder.Code, http.StatusInternalServerError)
	}
	want := `{"success":false,"error":{"code":10002,"message":"获取分类列表失败"}}`
	if got := recorder.Body.String(); got != want {
		t.Fatalf("body = %q, want %q", got, want)
	}
	if strings.Contains(recorder.Body.String(), modelErr.Error()) {
		t.Fatalf("响应泄漏了内部错误信息: %q", recorder.Body.String())
	}
}

type contextKey struct{}

func TestHelloPassesRequestContextToModel(t *testing.T) {
	fake := &fakeCategoryModel{categories: []*model.Category{}}
	reqCtx := context.WithValue(context.Background(), contextKey{}, "req-42")
	req := newHelloRequest().WithContext(reqCtx)

	serveHello(t, fake, req)

	if fake.gotCtx != reqCtx {
		t.Fatalf("模型收到非请求 context: %v", fake.gotCtx)
	}
	if got, _ := fake.gotCtx.Value(contextKey{}).(string); got != "req-42" {
		t.Fatalf("context 值 = %q, want %q", got, "req-42")
	}
}