Move initialization code closer to the appropriate structs. (#17)

Reviewed-on: #17
Co-authored-by: Anna Rose Wiggins <annabunches@gmail.com>
Co-committed-by: Anna Rose Wiggins <annabunches@gmail.com>

internal/configparser/configparser.go

@@ -0,0 +1,67 @@
+package configparser
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"git.annabunches.net/annabunches/joyful/internal/logger"
+	"github.com/goccy/go-yaml"
+)
+
+func ParseConfig(directory string) (*Config, error) {
+	config := new(Config)
+
+	configFiles, err := getConfigFilePaths(directory)
+	if err != nil {
+		return nil, err
+	}
+
+	// Open each yaml file and add its contents to the global config
+	for _, filePath := range configFiles {
+		data, err := os.ReadFile(filePath)
+		if err != nil {
+			logger.LogError(err, "Error while opening config file")
+			continue
+		}
+
+		newConfig := Config{}
+		err = yaml.Unmarshal(data, &newConfig)
+		logger.LogIfError(err, "Error parsing YAML")
+		config.Rules = append(config.Rules, newConfig.Rules...)
+		config.Devices = append(config.Devices, newConfig.Devices...)
+		config.Modes = append(config.Modes, newConfig.Modes...)
+	}
+
+	if len(config.Devices) == 0 {
+		return nil, errors.New("Found no devices in configuration. Please add configuration at " + directory)
+	}
+
+	return config, nil
+}
+
+func getConfigFilePaths(directory string) ([]string, error) {
+	paths := make([]string, 0)
+
+	dirEntries, err := os.ReadDir(directory)
+	if err != nil {
+		err = os.Mkdir(directory, 0755)
+		if err != nil {
+			return nil, errors.New("failed to create config directory at " + directory)
+		} else {
+			return nil, errors.New("no config files found at " + directory)
+		}
+	}
+
+	for _, file := range dirEntries {
+		name := strings.ToLower(file.Name())
+		if file.IsDir() || !(strings.HasSuffix(name, ".yaml") || strings.HasSuffix(name, ".yml")) {
+			continue
+		}
+
+		paths = append(paths, filepath.Join(directory, file.Name()))
+	}
+
+	return paths, nil
+}