package hardware

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

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

// OS2LProvider represents how the protocol is defined
type OS2LProvider struct {
	wg sync.WaitGroup
	mu sync.Mutex

	detected map[string]*OS2LEndpoint // The list of saved endpoints

	onArrival func(context.Context, Endpoint) // When a endpoint arrives
	onRemoval func(context.Context, Endpoint) // When a endpoint goes away
}

// NewOS2LProvider creates a new OS2L provider
func NewOS2LProvider() *OS2LProvider {
	log.Trace().Str("file", "OS2LProvider").Msg("OS2L provider created")
	return &OS2LProvider{
		detected: make(map[string]*OS2LEndpoint),
	}
}

// Initialize initializes the provider
func (f *OS2LProvider) Initialize() error {
	log.Trace().Str("file", "OS2LProvider").Msg("OS2L provider initialized")
	return nil
}

// OnArrival is the callback function when a new endpoint arrives
func (f *OS2LProvider) OnArrival(cb func(context.Context, Endpoint)) {
	f.onArrival = cb
}

// OnRemoval if the callback when a endpoint goes away
func (f *OS2LProvider) OnRemoval(cb func(context.Context, Endpoint)) {
	f.onRemoval = cb
}

// Create creates a new endpoint, based on the endpoint information (manually created)
func (f *OS2LProvider) Create(ctx context.Context, endpointInfo EndpointInfo) (EndpointInfo, error) {
	// If the SerialNumber is empty, generate another one
	if endpointInfo.SerialNumber == "" {
		endpointInfo.SerialNumber = strings.ToUpper(fmt.Sprintf("%08x", rand.Intn(1<<32)))
	}

	// Create a new OS2L endpoint
	endpoint, err := NewOS2LEndpoint(endpointInfo)
	if err != nil {
		return EndpointInfo{}, fmt.Errorf("unable to create the OS2L endpoint: %w", err)
	}

	// Set the event callback
	endpoint.SetEventCallback(func(event any) {
		runtime.EventsEmit(ctx, string(EndpointEventEmitted), endpointInfo.SerialNumber, event)
	})

	f.detected[endpointInfo.SerialNumber] = endpoint

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

// Remove removes an existing endpoint (manually created)
func (f *OS2LProvider) Remove(ctx context.Context, endpoint Endpoint) error {
	if f.onRemoval != nil {
		f.onRemoval(ctx, endpoint)
	}
	delete(f.detected, endpoint.GetInfo().SerialNumber)
	return nil
}

// GetName returns the name of the driver
func (f *OS2LProvider) GetName() string {
	return "OS2L"
}

// Start starts the provider
func (f *OS2LProvider) Start(ctx context.Context) error {
	// No endpoints to scan here
	return nil
}

// WaitStop stops the provider
func (f *OS2LProvider) WaitStop() error {
	log.Trace().Str("file", "OS2LProvider").Msg("stopping the OS2L provider...")

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

	log.Trace().Str("file", "OS2LProvider").Msg("OS2L provider stopped")
	return nil
}