// Package task_test 包含对 task 包的单元测试
package task_test

import (
	"errors"
	"fmt"
	"sync"
	"sync/atomic"
	"testing"
	"time"

	"git.huangwc.com/pig/pig-farm-controller/internal/infra/config"
	"git.huangwc.com/pig/pig-farm-controller/internal/infra/logs"
	"git.huangwc.com/pig/pig-farm-controller/internal/infra/task"
	"github.com/stretchr/testify/assert"
)

// testLogger 是一个用于所有测试用例的静默 logger 实例。
var testLogger *logs.Logger

func init() {
	// 使用 "fatal" 级别来创建一个在测试期间不会产生任何输出的 logger。
	// 这避免了在运行 `go test` 时被日志淹没。
	cfg := config.LogConfig{Level: "fatal"}
	testLogger = logs.NewLogger(cfg)
}

// MockTask 用于测试的模拟任务
type MockTask struct {
	id       string
	priority int
	isDone   bool
	execute  func() error
	executed int32 // 使用原子操作来跟踪执行次数
}

// Execute 实现了 Task 接口，并确保每次调用都增加执行计数
func (m *MockTask) Execute() error {
	atomic.AddInt32(&m.executed, 1)
	if m.execute != nil {
		return m.execute()
	}
	return nil
}

func (m *MockTask) GetID() string {
	return m.id
}

func (m *MockTask) GetPriority() int {
	return m.priority
}

func (m *MockTask) IsDone() bool {
	return m.isDone
}

// ExecutedCount 返回任务被执行的次数
func (m *MockTask) ExecutedCount() int32 {
	return atomic.LoadInt32(&m.executed)
}

// --- Helper function for robust waiting ---
func waitForWaitGroup(t *testing.T, wg *sync.WaitGroup, timeout time.Duration) {
	waitChan := make(chan struct{})
	go func() {
		defer close(waitChan)
		wg.Wait()
	}()

	select {
	case <-waitChan:
		// Wait succeeded
	case <-time.After(timeout):
		t.Fatal("timed out waiting for tasks to complete")
	}
}

// --- TaskQueue Tests (No changes needed) ---

func TestNewTaskQueue(t *testing.T) {
	tq := task.NewTaskQueue(testLogger)
	assert.NotNil(t, tq, "新创建的任务队列不应为 nil")
	assert.Equal(t, 0, tq.GetTaskCount(), "新创建的任务队列应为空")
}

func TestTaskQueue_AddTask(t *testing.T) {
	tq := task.NewTaskQueue(testLogger)
	mockTask := &MockTask{id: "task1", priority: 1}

	tq.AddTask(mockTask)
	assert.Equal(t, 1, tq.GetTaskCount(), "添加任务后，队列中的任务数应为 1")
}

// ... (other TaskQueue tests remain the same)
func TestTaskQueue_GetNextTask(t *testing.T) {
	t.Run("从空队列获取任务", func(t *testing.T) {
		tq := task.NewTaskQueue(testLogger)
		nextTask := tq.GetNextTask()
		assert.Nil(t, nextTask, "从空队列中获取任务应返回 nil")
	})

	t.Run("按优先级获取任务", func(t *testing.T) {
		tq := task.NewTaskQueue(testLogger)
		task1 := &MockTask{id: "task1", priority: 10}
		task2 := &MockTask{id: "task2", priority: 1} // 优先级更高
		task3 := &MockTask{id: "task3", priority: 5}

		tq.AddTask(task1)
		tq.AddTask(task2)
		tq.AddTask(task3)

		assert.Equal(t, 3, tq.GetTaskCount(), "添加三个任务后，队列中的任务数应为 3")

		nextTask := tq.GetNextTask()
		assert.NotNil(t, nextTask)
		assert.Equal(t, "task2", nextTask.GetID(), "应首先获取优先级最高的任务 (task2)")

		nextTask = tq.GetNextTask()
		assert.NotNil(t, nextTask)
		assert.Equal(t, "task3", nextTask.GetID(), "应获取下一个优先级最高的任务 (task3)")

		nextTask = tq.GetNextTask()
		assert.NotNil(t, nextTask)
		assert.Equal(t, "task1", nextTask.GetID(), "应最后获取优先级最低的任务 (task1)")

		assert.Equal(t, 0, tq.GetTaskCount(), "获取所有任务后，队列应为空")
	})
}

func TestTaskQueue_Concurrency(t *testing.T) {
	tq := task.NewTaskQueue(testLogger)
	var wg sync.WaitGroup
	taskCount := 100

	wg.Add(taskCount)
	for i := 0; i < taskCount; i++ {
		go func(i int) {
			defer wg.Done()
			tq.AddTask(&MockTask{id: fmt.Sprintf("task-%d", i), priority: i})
		}(i)
	}
	wg.Wait()

	assert.Equal(t, taskCount, tq.GetTaskCount(), "并发添加任务后，队列中的任务数应为 %d", taskCount)

	wg.Add(taskCount)
	for i := 0; i < taskCount; i++ {
		go func() {
			defer wg.Done()
			task := tq.GetNextTask()
			assert.NotNil(t, task)
		}()
	}
	wg.Wait()

	assert.Equal(t, 0, tq.GetTaskCount(), "并发获取所有任务后，队列应为空")
}

// --- Executor Tests (Refactored for reliability) ---

func TestNewExecutor(t *testing.T) {
	executor := task.NewExecutor(5, testLogger)
	assert.NotNil(t, executor, "新创建的执行器不应为 nil")
}

func TestExecutor_StartStop(t *testing.T) {
	executor := task.NewExecutor(2, testLogger)
	executor.Start()
	// 确保立即停止不会导致死锁或竞争条件。
	executor.Stop()
}

// TestExecutor_SubmitAndExecuteTask 测试提交并执行单个任务 (已重构，更可靠)
func TestExecutor_SubmitAndExecuteTask(t *testing.T) {
	var wg sync.WaitGroup
	wg.Add(1)

	executor := task.NewExecutor(1, testLogger)
	mockTask := &MockTask{
		id:       "task1",
		priority: 1,
		execute: func() error {
			wg.Done() // 任务完成时通知 WaitGroup
			return nil
		},
	}

	executor.Start()
	executor.SubmitTask(mockTask)

	// 等待任务完成，设置一个合理的超时时间
	waitForWaitGroup(t, &wg, 2*time.Second)

	executor.Stop()

	assert.Equal(t, int32(1), mockTask.ExecutedCount(), "任务应该已被执行")
}

// TestExecutor_ExecuteMultipleTasks 测试执行多个任务 (已重构，更可靠)
func TestExecutor_ExecuteMultipleTasks(t *testing.T) {
	taskCount := 10
	var wg sync.WaitGroup
	wg.Add(taskCount)

	executor := task.NewExecutor(3, testLogger)
	mockTasks := make([]*MockTask, taskCount)
	for i := 0; i < taskCount; i++ {
		mockTasks[i] = &MockTask{
			id:       fmt.Sprintf("task-%d", i),
			priority: i,
			execute: func() error {
				wg.Done() // 每个任务完成时都通知 WaitGroup
				return nil
			},
		}
	}

	executor.Start()
	for _, task := range mockTasks {
		executor.SubmitTask(task)
	}

	// 等待所有任务完成
	waitForWaitGroup(t, &wg, 2*time.Second)

	executor.Stop()

	var totalExecuted int32
	for _, task := range mockTasks {
		totalExecuted += task.ExecutedCount()
	}

	assert.Equal(t, int32(taskCount), totalExecuted, "所有提交的任务都应该被执行")
}

// TestExecutor_TaskExecutionError 测试任务执行失败的场景 (已重构，更可靠)
func TestExecutor_TaskExecutionError(t *testing.T) {
	var wg sync.WaitGroup
	wg.Add(2) // 我们期望两个任务都被执行

	executor := task.NewExecutor(1, testLogger)
	errorTask := &MockTask{
		id:       "errorTask",
		priority: 1,
		execute: func() error {
			wg.Done()
			return errors.New("执行失败")
		},
	}

	successTask := &MockTask{
		id:       "successTask",
		priority: 2, // 后执行
		execute: func() error {
			wg.Done()
			return nil
		},
	}

	executor.Start()
	executor.SubmitTask(errorTask)
	executor.SubmitTask(successTask)

	waitForWaitGroup(t, &wg, 2*time.Second)
	executor.Stop()

	assert.Equal(t, int32(1), errorTask.ExecutedCount(), "失败的任务应该被执行一次")
	assert.Equal(t, int32(1), successTask.ExecutedCount(), "成功的任务也应该被执行")
}

// TestExecutor_StopWithPendingTasks 测试停止执行器时仍有待处理任务 (已重构，更可靠)
func TestExecutor_StopWithPendingTasks(t *testing.T) {
	executor := task.NewExecutor(1, testLogger)
	task1Started := make(chan struct{})

	task1 := &MockTask{
		id:       "task1",
		priority: 1,
		execute: func() error {
			close(task1Started)                // 发送信号，通知测试 task1 已开始执行
			time.Sleep(200 * time.Millisecond) // 模拟耗时操作
			return nil
		},
	}
	task2 := &MockTask{id: "task2", priority: 2}

	executor.Start()
	executor.SubmitTask(task1)
	executor.SubmitTask(task2)

	// 等待 task1 开始执行的信号，而不是依赖不确定的 sleep
	select {
	case <-task1Started:
		// task1 已开始，可以安全地停止执行器了
	case <-time.After(1 * time.Second):
		t.Fatal("timed out waiting for task1 to start")
	}

	executor.Stop()

	assert.Equal(t, int32(1), task1.ExecutedCount(), "task1 应该在停止前开始执行")
	assert.Equal(t, int32(0), task2.ExecutedCount(), "task2 不应该被执行，因为执行器已停止")
}