package push

import (
	"context"
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// fakeServer 接收推送请求并保存;返回 status 由调用方控制。
type fakeServer struct {
	mu       sync.Mutex
	requests []Payload
	status   int
}

func (f *fakeServer) handler() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		body, _ := io.ReadAll(r.Body)
		_ = r.Body.Close()
		var p Payload
		_ = json.Unmarshal(body, &p)
		f.mu.Lock()
		f.requests = append(f.requests, p)
		status := f.status
		f.mu.Unlock()
		w.WriteHeader(status)
		_, _ = w.Write([]byte(`{"errcode":0}`))
	}
}

func (f *fakeServer) last() Payload {
	f.mu.Lock()
	defer f.mu.Unlock()
	if len(f.requests) == 0 {
		return Payload{}
	}
	return f.requests[len(f.requests)-1]
}

func (f *fakeServer) count() int {
	f.mu.Lock()
	defer f.mu.Unlock()
	return len(f.requests)
}

// TestUniPushClient_SendHappy 验证:成功路径下请求体含正确字段。
func TestUniPushClient_SendHappy(t *testing.T) {
	srv := &fakeServer{status: http.StatusOK}
	ts := httptest.NewServer(srv.handler())
	defer ts.Close()

	c := NewUniPushClient(ts.URL, 2*time.Second, nil)
	err := c.Send(context.Background(), Payload{
		CIDs:    []string{"cid-a", "cid-b"},
		Title:   "你好",
		Content: "有新消息",
		Data:    map[string]interface{}{"notification_id": int64(42), "type": "like"},
	})
	require.NoError(t, err)
	assert.Equal(t, 1, srv.count())

	got := srv.last()
	assert.ElementsMatch(t, []string{"cid-a", "cid-b"}, got.CIDs)
	assert.Equal(t, "你好", got.Title)
	assert.Equal(t, "有新消息", got.Content)
	assert.NotEmpty(t, got.RequestID, "request_id 应自动生成")
	assert.EqualValues(t, 42, got.Data["notification_id"])
	assert.Equal(t, "like", got.Data["type"])
}

// TestUniPushClient_SendNonSuccess 验证:非 2xx 返回 error。
func TestUniPushClient_SendNonSuccess(t *testing.T) {
	srv := &fakeServer{status: http.StatusBadRequest}
	ts := httptest.NewServer(srv.handler())
	defer ts.Close()

	c := NewUniPushClient(ts.URL, 2*time.Second, nil)
	err := c.Send(context.Background(), Payload{
		CIDs: []string{"cid-a"}, Title: "x", Content: "y",
	})
	require.Error(t, err)
	assert.Contains(t, err.Error(), "status=400")
}

// TestUniPushClient_EmptyCIDs 验证:cids 为空直接跳过(不发送 HTTP 请求)。
func TestUniPushClient_EmptyCIDs(t *testing.T) {
	srv := &fakeServer{status: http.StatusOK}
	ts := httptest.NewServer(srv.handler())
	defer ts.Close()

	c := NewUniPushClient(ts.URL, 2*time.Second, nil)
	err := c.Send(context.Background(), Payload{Title: "x", Content: "y"})
	require.NoError(t, err)
	assert.Equal(t, 0, srv.count(), "cids 为空时不应发请求")
}

// TestUniPushClient_EmptyURL 验证:URL 为空时返回 error。
func TestUniPushClient_EmptyURL(t *testing.T) {
	c := NewUniPushClient("", 2*time.Second, nil)
	err := c.Send(context.Background(), Payload{CIDs: []string{"cid-a"}, Title: "x", Content: "y"})
	require.Error(t, err)
	assert.Contains(t, err.Error(), "not initialized")
}

// TestUniPushClient_Timeout 验证:超时场景下返回 error。
func TestUniPushClient_Timeout(t *testing.T) {
	slow := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		time.Sleep(300 * time.Millisecond)
		w.WriteHeader(http.StatusOK)
	}))
	defer slow.Close()

	c := NewUniPushClient(slow.URL, 50*time.Millisecond, nil)
	err := c.Send(context.Background(), Payload{CIDs: []string{"cid-a"}, Title: "x", Content: "y"})
	require.Error(t, err)
	assert.True(t, strings.Contains(err.Error(), "timeout") ||
		strings.Contains(err.Error(), "context deadline") ||
		strings.Contains(err.Error(), "Client.Timeout"),
		"expected timeout error, got: %v", err)
}

// TestUniPushClient_RequestIDGenerated 验证:未传 request_id 时自动生成。
func TestUniPushClient_RequestIDGenerated(t *testing.T) {
	srv := &fakeServer{status: http.StatusOK}
	ts := httptest.NewServer(srv.handler())
	defer ts.Close()

	c := NewUniPushClient(ts.URL, 2*time.Second, nil)
	_ = c.Send(context.Background(), Payload{CIDs: []string{"x"}, Title: "t", Content: "c"})
	got := srv.last()
	assert.True(t, strings.HasPrefix(got.RequestID, ""), "request_id 应存在")
	assert.Greater(t, len(got.RequestID), 5)
}

// TestNoopPusher 验证:NoopPusher.Send 不报错也不发请求。
func TestNoopPusher(t *testing.T) {
	var p Pusher = NoopPusher{}
	assert.NoError(t, p.Send(context.Background(), Payload{CIDs: []string{"x"}}))
}