package hardware

import (
	"context"
	"fmt"
	"math/rand"
	"strings"
	"sync"

	"github.com/rs/zerolog/log"
	"github.com/wailsapp/wails/v2/pkg/runtime"
)

// OS2LFinder represents how the protocol is defined
type OS2LFinder struct {
	wg sync.WaitGroup
	mu sync.Mutex

	detected map[string]*OS2LPeripheral // The list of saved peripherals

	eventBus EventBus // The hardware event bus

	onArrival func(context.Context, Peripheral, bool) // When a peripheral arrives
	onRemoval func(context.Context, Peripheral)       // When a peripheral goes away
}

// NewOS2LFinder creates a new OS2L finder
func NewOS2LFinder(eventBus EventBus) *OS2LFinder {
	log.Trace().Str("file", "OS2LFinder").Msg("OS2L finder created")
	return &OS2LFinder{
		detected: make(map[string]*OS2LPeripheral),
		eventBus: eventBus,
	}
}

// Initialize initializes the finder
func (f *OS2LFinder) Initialize() error {
	// Subscribe to all OS2L peripherals that are added to the project
	f.eventBus.SubscribeType(f.GetName(), f)
	log.Trace().Str("file", "OS2LFinder").Msg("OS2L finder initialized")
	return nil
}

// OnArrival is the callback function when a new peripheral arrives
func (f *OS2LFinder) OnArrival(cb func(context.Context, Peripheral, bool)) {
	f.onArrival = cb
}

// OnRemoval i the callback when a peripheral goes away
func (f *OS2LFinder) OnRemoval(cb func(context.Context, Peripheral)) {
	f.onRemoval = cb
}

// Create creates a new peripheral, based on the peripheral information (manually created)
func (f *OS2LFinder) Create(ctx context.Context, peripheralInfo PeripheralInfo) error {
	// If the SerialNumber is empty, generate another one
	if peripheralInfo.SerialNumber == "" {
		peripheralInfo.SerialNumber = strings.ToUpper(fmt.Sprintf("%08x", rand.Intn(1<<32)))
	}

	// Create a new OS2L peripheral
	peripheral, err := NewOS2LPeripheral(peripheralInfo)
	if err != nil {
		return fmt.Errorf("unable to create the OS2L peripheral: %w", err)
	}

	// Set the event callback
	peripheral.SetEventCallback(func(event any) {
		runtime.EventsEmit(ctx, string(PeripheralEventEmitted), peripheralInfo.SerialNumber, event)
	})

	f.detected[peripheralInfo.SerialNumber] = peripheral

	if f.onArrival != nil {
		f.onArrival(ctx, peripheral, true) // Ask to register the peripheral in the project
	}
	return err
}

// Remove removes an existing peripheral (manually created)
func (f *OS2LFinder) Remove(ctx context.Context, peripheral Peripheral) error {
	if f.onRemoval != nil {
		f.onRemoval(ctx, peripheral)
	}
	delete(f.detected, peripheral.GetInfo().SerialNumber)
	return nil
}

// GetName returns the name of the driver
func (f *OS2LFinder) GetName() string {
	return "OS2L"
}

// Start starts the finder
func (f *OS2LFinder) Start(ctx context.Context) error {
	// No peripherals to scan here
	return nil
}

// WaitStop stops the finder
func (f *OS2LFinder) WaitStop() error {
	log.Trace().Str("file", "OS2LFinder").Msg("stopping the OS2L finder...")

	// Waiting internal tasks
	f.wg.Wait()

	log.Trace().Str("file", "OS2LFinder").Msg("OS2L finder stopped")
	return nil
}