Add selected profile overlays

profile.go

@@ -0,0 +1,179 @@
+package configkit
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/ConfigKit/internal/document"
+	yamladapter "gitea.maximumdirect.net/eric/ConfigKit/internal/yaml"
+)
+
+func activeProfile(name string) bool {
+	return name != "" && name != "default"
+}
+
+func validProfileName(name string) bool {
+	if !activeProfile(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 loadProfileDocument(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}
+	}
+	profilePath := filepath.Join(rootPath, "profiles", name+".yml")
+	canonical, err := canonicalExistingPath(profilePath)
+	if err != nil {
+		code := CodeProfileInvalid
+		message := "selected profile could not be resolved"
+		if errors.Is(err, fs.ErrNotExist) {
+			code, message = CodeProfileMissing, "selected profile does not exist"
+		} else if errors.Is(err, fs.ErrPermission) {
+			code, message = CodeImportPermission, "selected profile cannot be accessed"
+		}
+		return nil, cloneSourceInfos(sources), []Diagnostic{importDiagnostic(code, message, nil)}
+	}
+	if !containedPath(rootPath, canonical) {
+		return nil, cloneSourceInfos(sources), []Diagnostic{importDiagnostic(CodeProfileOutsideRoot, "selected profile resolves outside the configuration root", nil)}
+	}
+	for _, existing := range sources {
+		if existing.Path != "" && existing.Path == canonical {
+			return nil, cloneSourceInfos(sources), []Diagnostic{importDiagnostic(CodeProfileRepeated, "selected profile is already present in the base source graph", nil)}
+		}
+	}
+	if len(sources)+1 > limits.sources {
+		return nil, cloneSourceInfos(sources), []Diagnostic{importDiagnostic(CodeProfileLimitExceeded, "selected profile 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 profile", Location{})
+		value.Primary = nil
+		return nil, cloneSourceInfos(sources), []Diagnostic{value}
+	}
+	relative, err := filepath.Rel(rootPath, canonical)
+	if err != nil || filepath.IsAbs(relative) || relative == ".." || strings.HasPrefix(relative, ".."+string(filepath.Separator)) {
+		_ = root.Close()
+		return nil, cloneSourceInfos(sources), []Diagnostic{importDiagnostic(CodeProfileOutsideRoot, "selected profile could not be addressed inside the configuration root", nil)}
+	}
+
+	sourceID := "source-" + strconv.Itoa(len(sources)+1)
+	profileLocation := &Location{SourceID: sourceID}
+	profileSource := SourceInfo{ID: sourceID, Label: filepath.ToSlash(filepath.Join("profiles", name+".yml")), Path: canonical, Layer: LayerProfile}
+	sources = append(cloneSourceInfos(sources), profileSource)
+	data, diagnostic := readProfileFile(root, relative, sourceID, limits.bytes-base.inputBytes)
+	if diagnostic != nil {
+		_ = root.Close()
+		return nil, sources, []Diagnostic{*diagnostic}
+	}
+	profileRoot, issues := yamladapter.Parse(bytes.NewReader(data), sourceID, yamladapter.Limits{Depth: maxDocumentDepth, Nodes: maxDocumentNodes})
+	if len(issues) != 0 {
+		_ = root.Close()
+		return nil, sources, importParseDiagnostics(sourceID, issues)
+	}
+	nodeCount := countInputNodes(profileRoot)
+	if base.inputNodes+nodeCount > limits.nodes {
+		_ = root.Close()
+		return nil, sources, []Diagnostic{importDiagnostic(CodeProfileLimitExceeded, "selected profile exceeds the aggregate node limit", profileLocation)}
+	}
+	if diagnostics := profileDirectiveDiagnostics(profileRoot, Path{}); len(diagnostics) != 0 {
+		_ = root.Close()
+		return nil, sources, diagnostics
+	}
+	if versionNode := fragmentVersionClaim(profileRoot, rule); versionNode != nil {
+		location := publicLocation(versionNode.Location)
+		_ = root.Close()
+		return nil, sources, []Diagnostic{{
+			Code: CodeProfileVersion, Severity: SeverityError, Path: rule.Path.clone(),
+			Message: "profiles cannot contribute to or replace the schema-version path", Primary: &location,
+		}}
+	}
+	if err := root.Close(); err != nil {
+		return nil, sources, []Diagnostic{importDiagnostic(CodeImportRead, "configuration root could not be closed after reading the selected profile", nil)}
+	}
+
+	profiled, diagnostics := overlayDocuments(base, profileRoot)
+	if profiled != nil {
+		profiled.inputBytes = base.inputBytes + int64(len(data))
+		profiled.inputNodes = base.inputNodes + nodeCount
+	}
+	return profiled, sources, diagnostics
+}
+
+func readProfileFile(root *os.Root, relative, sourceID string, remaining int64) ([]byte, *Diagnostic) {
+	limit := min(int64(maxSourceBytes), remaining)
+	if limit < 0 {
+		limit = 0
+	}
+	file, err := root.Open(relative)
+	if err != nil {
+		value := classifySourceError(err, sourceID)
+		return nil, &value
+	}
+	defer func() { _ = file.Close() }()
+	info, err := file.Stat()
+	if err != nil {
+		value := classifySourceError(err, sourceID)
+		return nil, &value
+	}
+	if !info.Mode().IsRegular() {
+		value := sourceDiagnostic(CodeSourceNotRegular, sourceID, "source is not a regular file")
+		return nil, &value
+	}
+	if info.Size() > limit {
+		value := importDiagnostic(CodeProfileLimitExceeded, "selected profile exceeds a source or aggregate byte limit", &Location{SourceID: sourceID})
+		return nil, &value
+	}
+	data, err := io.ReadAll(io.LimitReader(file, limit+1))
+	if err != nil {
+		value := classifySourceError(err, sourceID)
+		return nil, &value
+	}
+	if int64(len(data)) > limit {
+		value := importDiagnostic(CodeProfileLimitExceeded, "selected profile exceeds a source or aggregate byte limit", &Location{SourceID: sourceID})
+		return nil, &value
+	}
+	return data, nil
+}
+
+func profileDirectiveDiagnostics(node *document.Node, current Path) []Diagnostic {
+	if node.Kind == document.Mapping {
+		for _, entry := range node.Mapping {
+			childPath := current.Key(entry.Key)
+			if entry.Key == "_configkit" {
+				location := publicLocation(entry.KeyLocation)
+				return []Diagnostic{{
+					Code: CodeProfileDirective, Severity: SeverityError, Path: childPath,
+					Message: "profiles cannot contain configuration directives", Primary: &location,
+				}}
+			}
+			if diagnostics := profileDirectiveDiagnostics(entry.Value, childPath); len(diagnostics) != 0 {
+				return diagnostics
+			}
+		}
+	} else if node.Kind == document.Sequence {
+		for index, child := range node.Sequence {
+			if diagnostics := profileDirectiveDiagnostics(child, current.Index(index)); len(diagnostics) != 0 {
+				return diagnostics
+			}
+		}
+	}
+	return nil
+}