Rename selected configuration profiles to overlays

internal/engine/selected_overlay.go

@@ -0,0 +1,131 @@
+package engine
+
+import (
+	"bytes"
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	yamladapter "gitea.maximumdirect.net/eric/ConfigKit/internal/yaml"
+)
+
+func activeOverlay(name string) bool {
+	return name != "" && name != "default"
+}
+
+func validOverlayName(name string) bool {
+	if !activeOverlay(name) {
+		return true
+	}
+	for _, character := range name {
+		if (character >= 'a' && character <= 'z') ||
+			(character >= 'A' && character <= 'Z') ||
+			(character >= '0' && character <= '9') || character == '_' || character == '-' {
+			continue
+		}
+		return false
+	}
+	return true
+}
+
+func loadSelectedOverlayDocument(source Source, context *FilesystemContext, main parsedSource, base *composedDocument, sources []SourceInfo, name string, rule *VersionRule, limits importLimits) (*composedDocument, []SourceInfo, []Diagnostic) {
+	rootPath, _, _, diagnostic := importFilesystem(source, context, main)
+	if diagnostic != nil {
+		return nil, cloneSourceInfos(sources), []Diagnostic{*diagnostic}
+	}
+	overlayPath := filepath.Join(rootPath, "overlays", name+".yml")
+	canonical, err := canonicalExistingPath(overlayPath)
+	if err != nil {
+		code := CodeOverlayInvalid
+		message := "selected overlay could not be resolved"
+		if errors.Is(err, fs.ErrNotExist) {
+			code, message = CodeOverlayMissing, "selected overlay does not exist"
+		} else if errors.Is(err, fs.ErrPermission) {
+			code, message = CodeImportPermission, "selected overlay cannot be accessed"
+		}
+		return nil, cloneSourceInfos(sources), []Diagnostic{importDiagnostic(code, message, nil)}
+	}
+	if !containedPath(rootPath, canonical) {
+		return nil, cloneSourceInfos(sources), []Diagnostic{importDiagnostic(CodeOverlayOutsideRoot, "selected overlay resolves outside the configuration root", nil)}
+	}
+	for _, existing := range sources {
+		if existing.Path != "" && existing.Path == canonical {
+			return nil, cloneSourceInfos(sources), []Diagnostic{importDiagnostic(CodeOverlayRepeated, "selected overlay is already present in the base source graph", nil)}
+		}
+	}
+	if len(sources)+1 > limits.sources {
+		return nil, cloneSourceInfos(sources), []Diagnostic{importDiagnostic(CodeOverlayLimitExceeded, "selected overlay exceeds the source-count limit", nil)}
+	}
+
+	root, err := os.OpenRoot(rootPath)
+	if err != nil {
+		value := globFilesystemDiagnostic(err, "configuration root could not be opened for the selected overlay", Location{})
+		value.Primary = nil
+		return nil, cloneSourceInfos(sources), []Diagnostic{value}
+	}
+	rootClosed := false
+	defer func() {
+		if !rootClosed {
+			_ = root.Close()
+		}
+	}()
+	relative, err := filepath.Rel(rootPath, canonical)
+	if err != nil || filepath.IsAbs(relative) || relative == ".." || strings.HasPrefix(relative, ".."+string(filepath.Separator)) {
+		return nil, cloneSourceInfos(sources), []Diagnostic{importDiagnostic(CodeOverlayOutsideRoot, "selected overlay could not be addressed inside the configuration root", nil)}
+	}
+
+	sourceID := "source-" + strconv.Itoa(len(sources)+1)
+	overlayLocation := &Location{SourceID: sourceID}
+	overlaySource := SourceInfo{ID: sourceID, Label: filepath.ToSlash(filepath.Join("overlays", name+".yml")), Path: canonical, Layer: LayerOverlay}
+	sources = append(cloneSourceInfos(sources), overlaySource)
+	data, diagnostic := readOverlayFile(root, relative, sourceID, limits.bytes-base.inputBytes)
+	if diagnostic != nil {
+		return nil, sources, []Diagnostic{*diagnostic}
+	}
+	overlayRoot, issues := yamladapter.Parse(bytes.NewReader(data), sourceID, yamladapter.Limits{Depth: maxDocumentDepth, Nodes: maxDocumentNodes})
+	if len(issues) != 0 {
+		return nil, sources, parserDiagnostics(sourceID, issues)
+	}
+	nodeCount := countInputNodes(overlayRoot)
+	if base.inputNodes+nodeCount > limits.nodes {
+		return nil, sources, []Diagnostic{importDiagnostic(CodeOverlayLimitExceeded, "selected overlay exceeds the aggregate node limit", overlayLocation)}
+	}
+	if diagnostics := overlayDirectiveDiagnostics(overlayRoot, Path{}); len(diagnostics) != 0 {
+		return nil, sources, diagnostics
+	}
+	if versionNode := fragmentVersionClaim(overlayRoot, rule); versionNode != nil {
+		location := publicLocation(versionNode.Location)
+		return nil, sources, []Diagnostic{{
+			Code: CodeOverlayVersion, Severity: SeverityError, Path: rule.Path.clone(),
+			Message: "overlays cannot contribute to or replace the schema-version path", Primary: &location,
+		}}
+	}
+	closeErr := root.Close()
+	rootClosed = true
+	if closeErr != nil {
+		return nil, sources, []Diagnostic{importDiagnostic(CodeImportRead, "configuration root could not be closed after reading the selected overlay", nil)}
+	}
+
+	overlayd, diagnostics := overlayDocuments(base, overlayRoot)
+	if overlayd != nil {
+		overlayd.inputBytes = base.inputBytes + int64(len(data))
+		overlayd.inputNodes = base.inputNodes + nodeCount
+	}
+	return overlayd, sources, diagnostics
+}
+
+func readOverlayFile(root *os.Root, relative, sourceID string, remaining int64) ([]byte, *Diagnostic) {
+	limit := min(int64(maxSourceBytes), remaining)
+	if limit < 0 {
+		limit = 0
+	}
+	data, failure := readRegularFile(relative, root.Stat, root.Open, limit)
+	if failure != nil {
+		value := sourceReadDiagnostic(failure, sourceID, CodeOverlayLimitExceeded, "selected overlay exceeds a source or aggregate byte limit")
+		return nil, &value
+	}
+	return data, nil
+}