package ttymididrv

import (
	"fmt"
	"sync"

	"github.com/tarm/serial"
)

type out struct {
	mu     sync.RWMutex
	driver *driver
	port   *serial.Port
	name   string
	baud   int
	closed bool
	number int
}

func (o *out) Open() (err error) {
	o.mu.RLock()
	if o.closed || o.port != nil {
		o.mu.RUnlock()
		return nil
	}
	o.mu.RUnlock()

	o.mu.Lock()
	defer o.mu.Unlock()

	c := &serial.Config{Name: o.name, Baud: o.baud}
	o.port, err = serial.OpenPort(c)
	if err != nil {
		return err
	}

	o.driver.mu.Lock()
	o.driver.opened = append(o.driver.opened, o)
	o.driver.mu.Unlock()

	return nil
}

func (o *out) Close() error {
	o.mu.RLock()
	if o.closed || o.port == nil {
		o.mu.RUnlock()
		return nil
	}
	o.mu.RUnlock()

	o.mu.Lock()
	o.closed = true
	o.mu.Unlock()

	return o.port.Close()
}

func (o *out) IsOpen() bool {
	o.mu.RLock()
	defer o.mu.RUnlock()
	return !o.closed && o.port != nil
}

func (o *out) Number() int {
	return o.number
}

func (o *out) String() string {
	return o.name
}

func (o *out) Underlying() interface{} {
	return o.port
}

func (o *out) Write(b []byte) (int, error) {
	_, err := o.port.Write(b)
	if err != nil {
		return 0, fmt.Errorf("could not write to port: %w", err)
	}
	return len(b), nil
}