Merge pull request #3831 from hashicorp/refactor/9-arm-importer-trans…

…forms-and-sdk-models

`tools/importer-rest-api-specs`: splitting the `dataapigeneratorjson` package into transforms and stages

tools/importer-rest-api-specs/components/dataapigeneratorjson/filesystem.go

@@ -0,0 +1,123 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package dataapigeneratorjson
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/hashicorp/go-hclog"
+	"github.com/hashicorp/pandora/tools/data-api-sdk/v1/models"
+)
+
+var directoryPermissions = os.FileMode(0755)
+
+// filePath is a typealias to make it clearer what's being returned from this generationStage.
+// This represents the path to a file on disk
+type filePath = string
+
+// fileBody is a typealias to make it clearer what's being returned from this generationStage.
+type fileBody = []byte
+
+// fileSystem is an abstraction around a set of files within a working directory.
+// It's intended to allow a representation around the API Definitions working directory
+// containing a reference to both the files that _would_ be written (during saving/testing)
+// and that exist (when loading the API Definitions from disk).
+type fileSystem struct {
+	f map[filePath]fileBody
+}
+
+func newFileSystem() *fileSystem {
+	return &fileSystem{
+		f: map[filePath]fileBody{},
+	}
+}
+
+// stage stages the specified body at the specified path, ensuring that it's unique.
+// This doesn't persist the file to disk, which is handled in persistFileSystem.
+func (f *fileSystem) stage(path filePath, body any) error {
+	if _, existing := f.f[path]; existing {
+		return fmt.Errorf("a duplicate file exists at the path %q", path)
+	}
+
+	fileExtension := strings.ToLower(filepath.Ext(path))
+	if fileExtension == ".hcl" {
+		str, ok := body.(string)
+		if !ok {
+			return fmt.Errorf("`body` must be a string for an `*.hcl` file but got %T", body)
+		}
+
+		f.f[path] = []byte(str)
+		return nil
+	}
+
+	if fileExtension == ".json" {
+		bytes, err := json.MarshalIndent(body, "", "  ")
+		if err != nil {
+			return fmt.Errorf("marshalling file body for %q as json: %+v", path, err)
+		}
+
+		f.f[path] = bytes
+		return nil
+	}
+
+	return fmt.Errorf("internal-error: unexpected file extension %q for %q", fileExtension, path)
+}
+
+func persistFileSystem(workingDirectory string, dataType models.SourceDataType, serviceName string, input *fileSystem, logger hclog.Logger) error {
+	rootDir := filepath.Join(workingDirectory, string(dataType))
+
+	// Delete any existing directory with this service name
+	serviceDir := filepath.Join(rootDir, serviceName)
+	logger.Debug(fmt.Sprintf("Removing any existing Directory for Service %q", serviceName))
+	_ = os.RemoveAll(serviceDir)
+	if err := os.MkdirAll(serviceDir, directoryPermissions); err != nil {
+		return fmt.Errorf("recreating directory %q: %+v", serviceDir, err)
+	}
+
+	// pull out a list of directories
+	directories := uniqueDirectories(input.f)
+	logger.Debug(fmt.Sprintf("Creating directories for Service %q", serviceName))
+	for _, dir := range directories {
+		dirPath := filepath.Join(rootDir, dir)
+		if err := os.MkdirAll(dirPath, directoryPermissions); err != nil {
+			return fmt.Errorf("creating directory %q: %+v", dirPath, err)
+		}
+	}
+
+	// write the files
+	for filePath, fileBody := range input.f {
+		fileFullPath := filepath.Join(rootDir, filePath)
+		logger.Trace(fmt.Sprintf("Writing file %q", fileFullPath))
+		file, err := os.Create(fileFullPath)
+		if err != nil {
+			return fmt.Errorf("opening %q: %+v", fileFullPath, err)
+		}
+
+		_, _ = file.Write(fileBody)
+		_ = file.Close()
+	}
+
+	return nil
+}
+
+func uniqueDirectories(input map[filePath]fileBody) []string {
+	directories := make(map[string]struct{})
+	for path := range input {
+		dir := filepath.Dir(path)
+		directories[dir] = struct{}{}
+	}
+
+	out := make([]string, 0)
+	for k := range directories {
+		out = append(out, k)
+	}
+	sort.Strings(out)
+
+	return out
+}