package ble

import (
	"ble_simulator/internal/device"
	"ble_simulator/internal/tui"

	"tinygo.org/x/bluetooth"
)

// SetupService configures the GATT service with command and notify characteristics
func SetupService(adapter *bluetooth.Adapter, state *device.DeviceState, logger *tui.LogBuffer) (*bluetooth.Characteristic, error) {
	var notifyChar bluetooth.Characteristic

	err := adapter.AddService(&bluetooth.Service{
		UUID: ServiceUUID,
		Characteristics: []bluetooth.CharacteristicConfig{
			{
				UUID: CommandCharUUID,
				Flags: bluetooth.CharacteristicWritePermission |
					bluetooth.CharacteristicWriteWithoutResponsePermission,
				WriteEvent: func(client bluetooth.Connection, offset int, value []byte) {
					cmd := string(value)
					logger.RX("Command: %s", cmd)

					response := state.ProcessCommand(cmd)
					logger.TX("Response: %s", response)

					// Non-blocking write in goroutine to avoid blocking the BLE stack
					go func() {
						_, err := notifyChar.Write([]byte(response + "\n"))
						if err != nil {
							logger.Err("Failed to send response: %v", err)
						}
					}()
				},
			},
			{
				UUID: NotifyCharUUID,
				Flags: bluetooth.CharacteristicReadPermission |
					bluetooth.CharacteristicNotifyPermission,
				Handle: &notifyChar,
			},
		},
	})

	if err != nil {
		return nil, err
	}

	return &notifyChar, nil
}