package pool_test

import (
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/yaoapp/yao/agent/robot/pool"
	"github.com/yaoapp/yao/agent/robot/types"
)

// ==================== Priority Queue Basic Tests ====================

// TestQueueNewPriorityQueue tests queue creation
func TestQueueNewPriorityQueue(t *testing.T) {
	t.Run("create with positive size", func(t *testing.T) {
		pq := pool.NewPriorityQueue(100)
		assert.NotNil(t, pq)
		assert.Equal(t, 0, pq.Size())
		assert.False(t, pq.IsFull())
	})

	t.Run("create with zero size (unlimited)", func(t *testing.T) {
		pq := pool.NewPriorityQueue(0)
		assert.NotNil(t, pq)
		assert.False(t, pq.IsFull()) // never full when maxSize=0
	})
}

// TestQueueEnqueueDequeue tests basic enqueue and dequeue
func TestQueueEnqueueDequeue(t *testing.T) {
	pq := pool.NewPriorityQueue(100)
	robot := createTestRobot("robot_1", "team_1", 5, 10, 5)
	ctx := createTestContext()

	t.Run("enqueue single item", func(t *testing.T) {
		item := &pool.QueueItem{
			Robot:   robot,
			Ctx:     ctx,
			Trigger: types.TriggerClock,
			Data:    "test_data",
		}
		ok := pq.Enqueue(item)
		assert.True(t, ok)
		assert.Equal(t, 1, pq.Size())
	})

	t.Run("dequeue single item", func(t *testing.T) {
		item := pq.Dequeue()
		assert.NotNil(t, item)
		assert.Equal(t, "robot_1", item.Robot.MemberID)
		assert.Equal(t, "test_data", item.Data)
		assert.Equal(t, 0, pq.Size())
	})

	t.Run("dequeue from empty queue", func(t *testing.T) {
		item := pq.Dequeue()
		assert.Nil(t, item)
	})
}

// TestQueueSize tests Size method
func TestQueueSize(t *testing.T) {
	pq := pool.NewPriorityQueue(100)
	robot := createTestRobot("robot_1", "team_1", 5, 10, 5)

	assert.Equal(t, 0, pq.Size())

	// Add 5 items
	for i := 0; i < 5; i++ {
		pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
	}
	assert.Equal(t, 5, pq.Size())

	// Remove 2 items
	pq.Dequeue()
	pq.Dequeue()
	assert.Equal(t, 3, pq.Size())
}

// ==================== Global Queue Limit Tests ====================

// TestQueueGlobalLimit tests global queue size limit
func TestQueueGlobalLimit(t *testing.T) {
	pq := pool.NewPriorityQueue(5) // max 5 items

	// Create different robots to avoid per-robot limit
	for i := 0; i < 10; i++ {
		robot := createTestRobot("robot_"+string(rune('A'+i)), "team_1", 5, 10, 5)
		item := &pool.QueueItem{Robot: robot, Trigger: types.TriggerClock}
		ok := pq.Enqueue(item)

		if i < 5 {
			assert.True(t, ok, "Should accept item %d", i)
		} else {
			assert.False(t, ok, "Should reject item %d (queue full)", i)
		}
	}

	assert.Equal(t, 5, pq.Size())
	assert.True(t, pq.IsFull())
}

// TestQueueUnlimitedSize tests queue with no size limit (maxSize=0)
func TestQueueUnlimitedSize(t *testing.T) {
	pq := pool.NewPriorityQueue(0) // unlimited

	// Add many items
	for i := 0; i < 100; i++ {
		robot := createTestRobot("robot_"+string(rune('A'+i%26)), "team_1", 5, 1000, 5)
		item := &pool.QueueItem{Robot: robot, Trigger: types.TriggerClock}
		ok := pq.Enqueue(item)
		assert.True(t, ok)
	}

	assert.Equal(t, 100, pq.Size())
	assert.False(t, pq.IsFull()) // never full
}

// ==================== Per-Robot Queue Limit Tests ====================

// TestQueuePerRobotLimit tests per-robot queue limit (Quota.Queue)
func TestQueuePerRobotLimit(t *testing.T) {
	pq := pool.NewPriorityQueue(100) // large global limit

	// Robot with Queue=3
	robot := createTestRobot("robot_limited", "team_1", 5, 3, 5)

	// Try to add 10 items for same robot
	successCount := 0
	for i := 0; i < 10; i++ {
		item := &pool.QueueItem{Robot: robot, Trigger: types.TriggerClock}
		if pq.Enqueue(item) {
			successCount++
		}
	}

	// Should only accept Queue(3) items
	assert.Equal(t, 3, successCount)
	assert.Equal(t, 3, pq.Size())
	assert.Equal(t, 3, pq.RobotQueuedCount("robot_limited"))
}

// TestQueueMultipleRobotsIndependentLimits tests that each robot has independent queue limit
func TestQueueMultipleRobotsIndependentLimits(t *testing.T) {
	pq := pool.NewPriorityQueue(100)

	// Robot A: Queue=2
	robotA := createTestRobot("robot_A", "team_1", 5, 2, 5)
	// Robot B: Queue=3
	robotB := createTestRobot("robot_B", "team_1", 5, 3, 5)

	// Add items for Robot A
	for i := 0; i < 5; i++ {
		pq.Enqueue(&pool.QueueItem{Robot: robotA, Trigger: types.TriggerClock})
	}
	assert.Equal(t, 2, pq.RobotQueuedCount("robot_A"))

	// Add items for Robot B
	for i := 0; i < 5; i++ {
		pq.Enqueue(&pool.QueueItem{Robot: robotB, Trigger: types.TriggerClock})
	}
	assert.Equal(t, 3, pq.RobotQueuedCount("robot_B"))

	// Total in queue
	assert.Equal(t, 5, pq.Size())
}

// TestQueueRobotCountAfterDequeue tests robot count decrements after dequeue
func TestQueueRobotCountAfterDequeue(t *testing.T) {
	pq := pool.NewPriorityQueue(100)
	robot := createTestRobot("robot_1", "team_1", 5, 10, 5)

	// Add 3 items
	for i := 0; i < 3; i++ {
		pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
	}
	assert.Equal(t, 3, pq.RobotQueuedCount("robot_1"))

	// Dequeue 2
	pq.Dequeue()
	assert.Equal(t, 2, pq.RobotQueuedCount("robot_1"))
	pq.Dequeue()
	assert.Equal(t, 1, pq.RobotQueuedCount("robot_1"))

	// Dequeue last
	pq.Dequeue()
	assert.Equal(t, 0, pq.RobotQueuedCount("robot_1"))
}

// TestQueueNilRobot tests handling of nil robot
func TestQueueNilRobot(t *testing.T) {
	pq := pool.NewPriorityQueue(100)

	// Item with nil robot should still be enqueued
	item := &pool.QueueItem{
		Robot:   nil,
		Trigger: types.TriggerClock,
	}
	ok := pq.Enqueue(item)
	assert.True(t, ok)
	assert.Equal(t, 1, pq.Size())

	// Dequeue should work
	dequeued := pq.Dequeue()
	assert.NotNil(t, dequeued)
	assert.Nil(t, dequeued.Robot)
}

// TestQueueDefaultRobotQueueLimit tests default queue limit when Quota is nil
func TestQueueDefaultRobotQueueLimit(t *testing.T) {
	pq := pool.NewPriorityQueue(100)

	// Robot without Config
	robot := &types.Robot{
		MemberID: "robot_no_config",
		TeamID:   "team_1",
	}

	// Should use default queue limit (10)
	successCount := 0
	for i := 0; i < 15; i++ {
		item := &pool.QueueItem{Robot: robot, Trigger: types.TriggerClock}
		if pq.Enqueue(item) {
			successCount++
		}
	}

	assert.Equal(t, 10, successCount) // default queue limit
}

// ==================== Priority Tests ====================

// TestQueuePriorityByRobotPriority tests sorting by robot priority
func TestQueuePriorityByRobotPriority(t *testing.T) {
	pq := pool.NewPriorityQueue(100)

	// Add robots with different priorities (low to high)
	robotLow := createTestRobot("robot_low", "team_1", 5, 10, 1)
	robotMed := createTestRobot("robot_med", "team_1", 5, 10, 5)
	robotHigh := createTestRobot("robot_high", "team_1", 5, 10, 10)

	// Add in low-to-high order
	pq.Enqueue(&pool.QueueItem{Robot: robotLow, Trigger: types.TriggerClock})
	pq.Enqueue(&pool.QueueItem{Robot: robotMed, Trigger: types.TriggerClock})
	pq.Enqueue(&pool.QueueItem{Robot: robotHigh, Trigger: types.TriggerClock})

	// Dequeue should return high priority first
	item1 := pq.Dequeue()
	assert.Equal(t, "robot_high", item1.Robot.MemberID)

	item2 := pq.Dequeue()
	assert.Equal(t, "robot_med", item2.Robot.MemberID)

	item3 := pq.Dequeue()
	assert.Equal(t, "robot_low", item3.Robot.MemberID)
}

// TestQueuePriorityByTriggerType tests sorting by trigger type
func TestQueuePriorityByTriggerType(t *testing.T) {
	pq := pool.NewPriorityQueue(100)

	// Same robot, different trigger types
	robot := createTestRobot("robot_1", "team_1", 5, 10, 5)

	// Add in clock -> event -> human order
	pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
	pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerEvent})
	pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerHuman})

	// Dequeue should return human first (highest trigger priority)
	item1 := pq.Dequeue()
	assert.Equal(t, types.TriggerHuman, item1.Trigger)

	item2 := pq.Dequeue()
	assert.Equal(t, types.TriggerEvent, item2.Trigger)

	item3 := pq.Dequeue()
	assert.Equal(t, types.TriggerClock, item3.Trigger)
}

// TestQueuePriorityRobotOverTrigger tests that robot priority > trigger priority
func TestQueuePriorityRobotOverTrigger(t *testing.T) {
	pq := pool.NewPriorityQueue(100)

	// Low priority robot with human trigger
	robotLow := createTestRobot("robot_low", "team_1", 5, 10, 1)
	// High priority robot with clock trigger
	robotHigh := createTestRobot("robot_high", "team_1", 5, 10, 10)

	pq.Enqueue(&pool.QueueItem{Robot: robotLow, Trigger: types.TriggerHuman})
	pq.Enqueue(&pool.QueueItem{Robot: robotHigh, Trigger: types.TriggerClock})

	// Robot priority (10*1000=10000) > trigger priority (1*1000+10*100=2000)
	// So high priority robot should come first even with lower trigger type
	item1 := pq.Dequeue()
	assert.Equal(t, "robot_high", item1.Robot.MemberID)

	item2 := pq.Dequeue()
	assert.Equal(t, "robot_low", item2.Robot.MemberID)
}

// TestQueuePriorityByEnqueueTime tests FIFO for same priority
func TestQueuePriorityByEnqueueTime(t *testing.T) {
	pq := pool.NewPriorityQueue(100)

	// Same robot, same trigger type (same priority)
	robot := createTestRobot("robot_1", "team_1", 5, 10, 5)

	// Add items with slight delay to ensure different EnqueueTime
	pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock, Data: "first"})
	time.Sleep(1 * time.Millisecond)
	pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock, Data: "second"})
	time.Sleep(1 * time.Millisecond)
	pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock, Data: "third"})

	// Should dequeue in FIFO order (earlier EnqueueTime first)
	item1 := pq.Dequeue()
	assert.Equal(t, "first", item1.Data)

	item2 := pq.Dequeue()
	assert.Equal(t, "second", item2.Data)

	item3 := pq.Dequeue()
	assert.Equal(t, "third", item3.Data)
}

// ==================== Concurrency Tests ====================

// TestQueueConcurrentEnqueue tests concurrent enqueue operations
func TestQueueConcurrentEnqueue(t *testing.T) {
	pq := pool.NewPriorityQueue(1000)

	// Concurrently add items from multiple goroutines
	done := make(chan bool)
	for i := 0; i < 10; i++ {
		go func(id int) {
			robot := createTestRobot("robot_"+string(rune('A'+id)), "team_1", 5, 100, 5)
			for j := 0; j < 50; j++ {
				pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
			}
			done <- true
		}(i)
	}

	// Wait for all goroutines
	for i := 0; i < 10; i++ {
		<-done
	}

	// Should have 10 robots * 50 items = 500 items
	assert.Equal(t, 500, pq.Size())
}

// TestQueueConcurrentDequeue tests concurrent dequeue operations
func TestQueueConcurrentDequeue(t *testing.T) {
	pq := pool.NewPriorityQueue(1000)

	// Pre-fill queue
	for i := 0; i < 500; i++ {
		robot := createTestRobot("robot_"+string(rune('A'+i%10)), "team_1", 5, 100, 5)
		pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
	}

	// Concurrently dequeue from multiple goroutines
	dequeued := make(chan *pool.QueueItem, 500)
	done := make(chan bool)

	for i := 0; i < 10; i++ {
		go func() {
			for {
				item := pq.Dequeue()
				if item == nil {
					break
				}
				dequeued <- item
			}
			done <- true
		}()
	}

	// Wait for all goroutines
	for i := 0; i < 10; i++ {
		<-done
	}
	close(dequeued)

	// Count dequeued items
	count := 0
	for range dequeued {
		count++
	}

	assert.Equal(t, 500, count)
	assert.Equal(t, 0, pq.Size())
}

// TestQueueConcurrentEnqueueDequeue tests concurrent enqueue and dequeue
func TestQueueConcurrentEnqueueDequeue(t *testing.T) {
	pq := pool.NewPriorityQueue(100)

	// Run for a short time with concurrent operations
	done := make(chan bool)

	// Enqueue goroutine
	go func() {
		for i := 0; i < 200; i++ {
			robot := createTestRobot("robot_"+string(rune('A'+i%10)), "team_1", 5, 50, 5)
			pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
			time.Sleep(1 * time.Millisecond)
		}
		done <- true
	}()

	// Dequeue goroutine
	dequeueCount := 0
	go func() {
		for i := 0; i < 200; i++ {
			if pq.Dequeue() != nil {
				dequeueCount++
			}
			time.Sleep(1 * time.Millisecond)
		}
		done <- true
	}()

	// Wait for both
	<-done
	<-done

	// Should have processed some items (exact count depends on timing)
	assert.GreaterOrEqual(t, dequeueCount, 1)
}

// ==================== Edge Cases ====================

// TestQueueIsFull tests IsFull method
func TestQueueIsFull(t *testing.T) {
	t.Run("not full initially", func(t *testing.T) {
		pq := pool.NewPriorityQueue(5)
		assert.False(t, pq.IsFull())
	})

	t.Run("full when at max", func(t *testing.T) {
		pq := pool.NewPriorityQueue(3)
		for i := 0; i < 3; i++ {
			robot := createTestRobot("robot_"+string(rune('A'+i)), "team_1", 5, 10, 5)
			pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
		}
		assert.True(t, pq.IsFull())
	})

	t.Run("not full after dequeue", func(t *testing.T) {
		pq := pool.NewPriorityQueue(3)
		for i := 0; i < 3; i++ {
			robot := createTestRobot("robot_"+string(rune('A'+i)), "team_1", 5, 10, 5)
			pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
		}
		pq.Dequeue()
		assert.False(t, pq.IsFull())
	})

	t.Run("never full when unlimited", func(t *testing.T) {
		pq := pool.NewPriorityQueue(0)
		for i := 0; i < 100; i++ {
			robot := createTestRobot("robot_"+string(rune('A'+i%26)), "team_1", 5, 1000, 5)
			pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
		}
		assert.False(t, pq.IsFull())
	})
}

// TestQueueRobotQueuedCount tests RobotQueuedCount method
func TestQueueRobotQueuedCount(t *testing.T) {
	pq := pool.NewPriorityQueue(100)

	t.Run("zero for unknown robot", func(t *testing.T) {
		assert.Equal(t, 0, pq.RobotQueuedCount("unknown_robot"))
	})

	t.Run("correct count for robot", func(t *testing.T) {
		robot := createTestRobot("robot_1", "team_1", 5, 10, 5)
		pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
		pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
		assert.Equal(t, 2, pq.RobotQueuedCount("robot_1"))
	})

	t.Run("zero after all dequeued", func(t *testing.T) {
		robot := createTestRobot("robot_2", "team_1", 5, 10, 5)
		pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
		pq.Dequeue()
		pq.Dequeue() // dequeue robot_1's items too
		pq.Dequeue()
		assert.Equal(t, 0, pq.RobotQueuedCount("robot_2"))
	})
}

// TestQueueEnqueueSetsEnqueueTime tests that EnqueueTime is set on enqueue
func TestQueueEnqueueSetsEnqueueTime(t *testing.T) {
	pq := pool.NewPriorityQueue(100)
	robot := createTestRobot("robot_1", "team_1", 5, 10, 5)

	before := time.Now()
	pq.Enqueue(&pool.QueueItem{Robot: robot, Trigger: types.TriggerClock})
	after := time.Now()

	item := pq.Dequeue()
	assert.True(t, item.EnqueueTime.After(before) || item.EnqueueTime.Equal(before))
	assert.True(t, item.EnqueueTime.Before(after) || item.EnqueueTime.Equal(after))
}