convert_yaml_to_json.go

package main

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

// convertYamlToJSON converts assignment.yml or assignment.yaml files to JSON format.
// It does this by simply wrapping the YAML content with { } and validating the result is valid JSON.
// If successful, it writes the content to assignment.json and deletes the original YAML file.
func convertYamlToJSON(args []string) {
	yamlFiles, err := findAssignmentYamlFiles(gitRoot)
	if err != nil {
		exitErr(err, "Error finding YAML files")
	}
	if len(yamlFiles) == 0 {
		fmt.Println("No assignment.yml or assignment.yaml files found.")
		return
	}

	for _, yamlFile := range yamlFiles {
		if err := convertSingleFile(yamlFile); err != nil {
			fmt.Printf("Error converting %s: %s\n", yamlFile, err)
			continue
		}
		fmt.Printf("Successfully converted %s to assignment.json\n", yamlFile)
	}
}

// findAssignmentYamlFiles finds all assignment.yml and assignment.yaml files in the given directory and its subdirectories
func findAssignmentYamlFiles(path string) ([]string, error) {
	var yamlFiles []string
	err := filepath.WalkDir(path, func(filePath string, dirEntry os.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if dirEntry.IsDir() {
			return nil
		}
		filename := dirEntry.Name()
		if filename == "assignment.yml" || filename == "assignment.yaml" {
			yamlFiles = append(yamlFiles, filePath)
		}
		return nil
	})
	return yamlFiles, err
}

// convertSingleFile converts a YAML file to JSON.
func convertSingleFile(yamlFilePath string) error {
	content, err := os.ReadFile(yamlFilePath)
	if err != nil {
		return fmt.Errorf("failed to read YAML file: %w", err)
	}
	contentStr := strings.TrimSpace(string(content))
	if contentStr == "" {
		return fmt.Errorf("empty YAML file")
	}
	jsonContent := convertYamlKeysToJSON(contentStr)

	// Validate that the result is valid JSON without reordering
	var jsonObj json.RawMessage
	if err := json.Unmarshal([]byte(jsonContent), &jsonObj); err != nil {
		return fmt.Errorf("resulting content is not valid JSON: %w", err)
	}
	jsonContentBytes := []byte(jsonContent)

	dir := filepath.Dir(yamlFilePath)
	jsonFilePath := filepath.Join(dir, "assignment.json")
	if err := os.WriteFile(jsonFilePath, jsonContentBytes, 0o644); err != nil {
		return fmt.Errorf("failed to write JSON file: %w", err)
	}

	if err := os.Remove(yamlFilePath); err != nil {
		return fmt.Errorf("failed to delete original YAML file: %w", err)
	}
	return nil
}

// convertYamlKeysToJSON converts YAML key-value pairs to JSON format by adding quotes around keys
func convertYamlKeysToJSON(yamlContent string) string {
	var jsonLines []string
	for line := range strings.Lines(yamlContent) {
		key, val, found := strings.Cut(line, ":")
		if found {
			jsonLines = append(jsonLines, fmt.Sprintf(`  "%s": %s`, key, strings.TrimSpace(val)))
		} else {
			// skip lines that do not match key-value pairs
			fmt.Printf("Skipping line: %s\n", line)
			continue
		}
	}
	// Join with commas and newlines for proper JSON format
	return "{\n" + strings.Join(jsonLines, ",\n") + "\n}"
}