housekeeping: Refactored API to separate packages

config/config.go

@@ -0,0 +1,207 @@
+package config
+
+import (
+	"fmt"
+	"os"
+
+	"git.datalore.sh/datalore/midi-hid/translation"
+
+	"github.com/goccy/go-yaml"
+	"github.com/bendahl/uinput"
+	"github.com/charmbracelet/log"
+)
+
+// Config is the root type of a config, consisting of an arbitrary number of controller configs.
+type Config struct {
+	Controller []ControllerConfig `yaml:"controller"`
+}
+
+// A ControllerConfig represents the data needed to later construct a Controller object.
+type ControllerConfig struct {
+	PortName string `yaml:"portName"`
+	VendorID uint16 `yaml:"vendorID"`
+	ProductID uint16 `yaml:"productID"`
+	Mappings []MappingConfig `yaml:"mappings"`
+}
+
+// A MappingConfig consists of all data possibly needed to construct a mapping, both button and control.
+type MappingConfig struct {
+	Comment string `yaml:"comment"`
+	Type MappingType `yaml:"type"`
+	MidiChannel uint8 `yaml:"midiChannel"`
+	MidiKey uint8 `yaml:"midiKey"`
+	MidiController uint8 `yaml:"midiController"`
+	Button ButtonName `yaml:"button"`
+	Axis AxisName `yaml:"axis"`
+	IsSigned bool `yaml:"isSigned"`
+	Deadzone float64 `yaml:"deadzone"`
+}
+
+type MappingType string
+type ButtonName string
+type AxisName string
+
+const (
+	ButtonMappingType MappingType = "button"
+	ControlMappingType MappingType = "control"
+	ButtonNorth ButtonName = "north"
+	ButtonEast ButtonName = "east"
+	ButtonSouth ButtonName = "south"
+	ButtonWest ButtonName = "west"
+	ButtonL1 ButtonName = "l1"
+	ButtonL2 ButtonName = "l2"
+	ButtonL3 ButtonName = "l3"
+	ButtonR1 ButtonName = "r1"
+	ButtonR2 ButtonName = "r2"
+	ButtonR3 ButtonName = "r3"
+	ButtonSelect ButtonName = "select"
+	ButtonStart ButtonName = "start"
+	ButtonDpadUp ButtonName = "dpad-up"
+	ButtonDpadDown ButtonName = "dpad-down"
+	ButtonDpadLeft ButtonName = "dpad-left"
+	ButtonDpadRight ButtonName = "dpad-right"
+	AxisLeftX AxisName = "left-x"
+	AxisLeftY AxisName = "left-y"
+	AxisRightX AxisName = "right-x"
+	AxisRightY AxisName = "right-y"
+)
+
+// ParseConfig takes the path to a config file and returns the parsed Config object,
+// or an error if thrown.
+func ParseConfig(path string) (Config, error) {
+	var config Config
+
+	buffer, err := os.ReadFile(os.ExpandEnv(path))
+	if err != nil {
+		return config, err
+	}
+
+	err = yaml.Unmarshal(buffer, &config)
+	if err != nil {
+		return config, err
+	}
+
+	return config, nil
+}
+
+// Construct iterates over all ControllerConfigs and constructs the Controller objects.
+// In case of a failure, it aborts and returns an error.
+func (config Config) Construct() (translation.ControllerList, error) {
+	var controllerList translation.ControllerList
+
+	for _, controllerConfig := range config.Controller {
+		actualController, err := controllerConfig.Construct()
+		if err != nil {
+			return nil, err
+		}
+
+		controllerList = append(controllerList, actualController)
+	}
+
+	return controllerList, nil
+}
+
+// Construct builds a Controller object and its corresponding mappings.
+// Aborts and returns an error if the midi port was not found or one of
+// the Mappings is invalid.
+func (cc ControllerConfig) Construct() (*translation.Controller, error) {
+	actualController, err := translation.NewController(cc.PortName, cc.VendorID, cc.ProductID)
+	if err != nil {
+		return actualController, err
+	}
+
+	for _, mappingConfig := range cc.Mappings {
+		actualMapping, err := mappingConfig.Construct()
+		if err != nil {
+			return nil, err
+		}
+
+		actualController.AddMapping(actualMapping)
+	}
+
+	return actualController, nil
+}
+
+// Construct builds the Mapping object. Returns an error if config is invalid.
+func (mc MappingConfig) Construct() (translation.Mapping, error) {
+	switch mc.Type {
+	case ButtonMappingType:
+		button, err := mc.Button.Construct()
+		if err != nil {
+			return translation.ButtonMapping{}, err
+		}
+
+		log.Debug("Parsed button mapping", "comment", mc.Comment, "midiChannel", mc.MidiChannel, "midiKey", mc.MidiKey, "button", button)
+
+		return translation.ButtonMapping{mc.Comment, mc.MidiChannel, mc.MidiKey, button}, nil
+	case ControlMappingType:
+		axis, err := mc.Axis.Construct()
+		if err != nil {
+			return translation.ControlMapping{}, err
+		}
+
+		log.Debug("Parsed control mapping", "comment", mc.Comment, "midiChannel", mc.MidiChannel, "midiController", mc.MidiController, "axis", axis, "isSigned", mc.IsSigned, "deadzone", mc.Deadzone)
+
+		return translation.ControlMapping{mc.Comment, mc.MidiChannel, mc.MidiController, axis, mc.IsSigned, mc.Deadzone}, nil
+	default:
+		return translation.ButtonMapping{}, fmt.Errorf("Invalid mapping type")
+	}
+}
+
+// Construct converts a ButtonName to its corresponding key code, or returns an error if the
+// name is unknown.
+func (bn ButtonName) Construct() (int, error) {
+	switch bn {
+	case ButtonNorth:
+		return uinput.ButtonNorth, nil
+	case ButtonEast:
+		return uinput.ButtonEast, nil
+	case ButtonSouth:
+		return uinput.ButtonSouth, nil
+	case ButtonWest:
+		return uinput.ButtonWest, nil
+	case ButtonL1:
+		return uinput.ButtonBumperLeft, nil
+	case ButtonL2:
+		return uinput.ButtonTriggerLeft, nil
+	case ButtonL3:
+		return uinput.ButtonThumbLeft, nil
+	case ButtonR1:
+		return uinput.ButtonBumperRight, nil
+	case ButtonR2:
+		return uinput.ButtonTriggerRight, nil
+	case ButtonR3:
+		return uinput.ButtonThumbRight, nil
+	case ButtonSelect:
+		return uinput.ButtonSelect, nil
+	case ButtonStart:
+		return uinput.ButtonStart, nil
+	case ButtonDpadUp:
+		return uinput.ButtonDpadUp, nil
+	case ButtonDpadDown:
+		return uinput.ButtonDpadDown, nil
+	case ButtonDpadLeft:
+		return uinput.ButtonDpadLeft, nil
+	case ButtonDpadRight:
+		return uinput.ButtonDpadRight, nil
+	default:
+		return -1, fmt.Errorf("Invalid button name \"%s\"", bn)
+	}
+}
+
+// Construct converts an AxisName into the internal representation for a ControllerAxis.
+// Returns an error if AxisName is invalid.
+func (an AxisName) Construct() (translation.ControllerAxis, error) {
+	switch an {
+	case AxisLeftX:
+		return translation.LeftX, nil
+	case AxisLeftY:
+		return translation.LeftY, nil
+	case AxisRightX:
+		return translation.RightX, nil
+	case AxisRightY:
+		return translation.RightY, nil
+	default:
+		return -1, fmt.Errorf("Invalid axis name \"%s\"", an)
+	}
+}