package mock

import (
	"fmt"
	"math/rand"
	"sync"
	"time"

	"visiona-local/server/internal/driver"
)

var mockLabels = []string{"person", "car", "bicycle", "dog", "cat", "chair", "bottle", "phone"}

type MockDriver struct {
	info        driver.DeviceInfo
	connected   bool
	inferring   bool
	modelLoaded string
	mu          sync.Mutex
}

func NewMockDriver(info driver.DeviceInfo) *MockDriver {
	return &MockDriver{info: info}
}

func Factory(id string, index int) driver.DeviceDriver {
	info := driver.DeviceInfo{
		ID:          id,
		Name:        fmt.Sprintf("Kneron KL720 (Mock #%d)", index+1),
		Type:        "kneron_kl720",
		Port:        fmt.Sprintf("/dev/ttyMOCK%d", index),
		Status:      driver.StatusDetected,
		FirmwareVer: "2.2.0-mock",
	}
	return NewMockDriver(info)
}

func (d *MockDriver) Info() driver.DeviceInfo {
	d.mu.Lock()
	defer d.mu.Unlock()
	return d.info
}

func (d *MockDriver) Connect() error {
	d.mu.Lock()
	defer d.mu.Unlock()
	time.Sleep(200 * time.Millisecond)
	d.connected = true
	d.info.Status = driver.StatusConnected
	return nil
}

func (d *MockDriver) Disconnect() error {
	d.mu.Lock()
	defer d.mu.Unlock()
	d.connected = false
	d.inferring = false
	d.info.Status = driver.StatusDisconnected
	return nil
}

func (d *MockDriver) IsConnected() bool {
	d.mu.Lock()
	defer d.mu.Unlock()
	return d.connected
}

func (d *MockDriver) Flash(modelPath string, progressCh chan<- driver.FlashProgress) error {
	d.mu.Lock()
	d.info.Status = driver.StatusFlashing
	d.mu.Unlock()

	type stage struct {
		name     string
		duration time.Duration
		startPct int
		endPct   int
	}

	stages := []stage{
		{"preparing", 1 * time.Second, 0, 10},
		{"transferring", 6 * time.Second, 10, 80},
		{"verifying", 2 * time.Second, 80, 95},
		{"rebooting", 1 * time.Second, 95, 99},
	}

	for _, s := range stages {
		steps := (s.endPct - s.startPct) / 5
		if steps < 1 {
			steps = 1
		}
		interval := s.duration / time.Duration(steps)
		for i := 0; i <= steps; i++ {
			pct := s.startPct + (s.endPct-s.startPct)*i/steps
			progressCh <- driver.FlashProgress{
				Percent: pct,
				Stage:   s.name,
				Message: fmt.Sprintf("%s... %d%%", s.name, pct),
			}
			time.Sleep(interval)
		}
	}

	d.mu.Lock()
	d.modelLoaded = modelPath
	d.info.FlashedModel = modelPath
	d.info.Status = driver.StatusConnected
	d.mu.Unlock()

	progressCh <- driver.FlashProgress{Percent: 100, Stage: "done", Message: "Flash complete"}

	return nil
}

func (d *MockDriver) StartInference() error {
	d.mu.Lock()
	defer d.mu.Unlock()
	d.inferring = true
	d.info.Status = driver.StatusInferencing
	return nil
}

func (d *MockDriver) StopInference() error {
	d.mu.Lock()
	defer d.mu.Unlock()
	d.inferring = false
	d.info.Status = driver.StatusConnected
	return nil
}

func (d *MockDriver) ReadInference() (*driver.InferenceResult, error) {
	return d.RunInference(nil)
}

func (d *MockDriver) RunInference(imageData []byte) (*driver.InferenceResult, error) {
	time.Sleep(30 * time.Millisecond)

	numDetections := rand.Intn(3) + 1
	detections := make([]driver.DetectionResult, numDetections)
	for i := 0; i < numDetections; i++ {
		w := 0.1 + rand.Float64()*0.3
		h := 0.1 + rand.Float64()*0.3
		detections[i] = driver.DetectionResult{
			Label:      mockLabels[rand.Intn(len(mockLabels))],
			Confidence: 0.3 + rand.Float64()*0.7,
			BBox: driver.BBox{
				X:      rand.Float64() * (1 - w),
				Y:      rand.Float64() * (1 - h),
				Width:  w,
				Height: h,
			},
		}
	}

	classifications := []driver.ClassResult{
		{Label: "person", Confidence: 0.5 + rand.Float64()*0.5},
		{Label: "car", Confidence: rand.Float64() * 0.5},
		{Label: "dog", Confidence: rand.Float64() * 0.3},
		{Label: "cat", Confidence: rand.Float64() * 0.2},
		{Label: "bicycle", Confidence: rand.Float64() * 0.15},
	}

	return &driver.InferenceResult{
		TaskType:        "detection",
		Timestamp:       time.Now().UnixMilli(),
		LatencyMs:       20 + rand.Float64()*30,
		Detections:      detections,
		Classifications: classifications,
	}, nil
}

func (d *MockDriver) GetModelInfo() (*driver.ModelInfo, error) {
	d.mu.Lock()
	defer d.mu.Unlock()
	if d.modelLoaded == "" {
		return nil, fmt.Errorf("no model loaded")
	}
	return &driver.ModelInfo{
		ID:       d.modelLoaded,
		Name:     d.modelLoaded,
		LoadedAt: time.Now(),
	}, nil
}