From 198e5b8897ff40d95dd7d251b93e0e90742c10b2 Mon Sep 17 00:00:00 2001
From: "Sascha L. Teichmann" <sascha.teichmann@intevation.de>
Date: Thu, 30 Jun 2022 11:58:36 +0200
Subject: [PATCH] write dynamic categories into feed categories document.

---
 cmd/csaf_provider/actions.go | 24 ++++++++++++++++++-
 cmd/csaf_provider/rolie.go   | 46 ++++++++++++++++++++++++++++++++++++
 csaf/rolie.go                | 40 +++++++++++++++++++++++++------
 util/json.go                 | 20 ++++++++++++++++
 4 files changed, 122 insertions(+), 8 deletions(-)

diff --git a/cmd/csaf_provider/actions.go b/cmd/csaf_provider/actions.go
index ec621c0..486cfd7 100644
--- a/cmd/csaf_provider/actions.go
+++ b/cmd/csaf_provider/actions.go
@@ -14,6 +14,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -182,11 +183,24 @@ func (c *controller) upload(r *http.Request) (interface{}, error) {
 		}
 	}
 
-	ex, err := csaf.NewAdvisorySummary(util.NewPathEval(), content)
+	// Extract informations from the document.
+	pe := util.NewPathEval()
+
+	ex, err := csaf.NewAdvisorySummary(pe, content)
 	if err != nil {
 		return nil, err
 	}
 
+	// Check if we have to search for dynamic categories.
+	var dynamicCategories []string
+	if catExprs := c.cfg.DynamicCategories(); len(catExprs) > 0 {
+		var err error
+		if dynamicCategories, err = pe.Strings(catExprs, true, content); err != nil {
+			// XXX: Should we die here?
+			log.Printf("eval of dynamic catecory expressions failed: %v\n", err)
+		}
+	}
+
 	t, err := c.tlpParam(r)
 	if err != nil {
 		return nil, err
@@ -217,6 +231,14 @@ func (c *controller) upload(r *http.Request) (interface{}, error) {
 				return err
 			}
 
+			// if we have found dynamic categories merge them into
+			// the existing once.
+			if len(dynamicCategories) > 0 {
+				if err := c.mergeCategories(folder, t, dynamicCategories); err != nil {
+					return err
+				}
+			}
+
 			// Create yearly subfolder
 			year := strconv.Itoa(ex.InitialReleaseDate.Year())
 
diff --git a/cmd/csaf_provider/rolie.go b/cmd/csaf_provider/rolie.go
index e260de9..2334699 100644
--- a/cmd/csaf_provider/rolie.go
+++ b/cmd/csaf_provider/rolie.go
@@ -19,6 +19,52 @@ import (
 	"github.com/csaf-poc/csaf_distribution/util"
 )
 
+// mergeCategories merges the given categories into the old ones.
+func (c *controller) mergeCategories(
+	folder string,
+	t tlp,
+	categories []string,
+) error {
+	ts := string(t)
+	catName := "category-" + ts + ".json"
+	catPath := filepath.Join(folder, catName)
+
+	catDoc, err := loadCategoryDocument(catPath)
+	if err != nil {
+		return err
+	}
+
+	var changed bool
+
+	if catDoc == nil {
+		catDoc = csaf.NewROLIECategoryDocument(categories...)
+		changed = true
+	} else {
+		changed = catDoc.Merge(categories...)
+	}
+
+	if changed {
+		if err := util.WriteToFile(catPath, catDoc); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// loadROLIEFeed loads a ROLIE feed from file if its exists.
+// Returns nil if the file does not exists.
+func loadCategoryDocument(path string) (*csaf.ROLIECategoryDocument, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil
+		}
+		return nil, err
+	}
+	defer f.Close()
+	return csaf.LoadROLIECategoryDocument(f)
+}
+
 // extendROLIE adds a new entry to the ROLIE feed for a given advisory.
 func (c *controller) extendROLIE(
 	folder string,
diff --git a/csaf/rolie.go b/csaf/rolie.go
index 84dc3de..6b9d4ef 100644
--- a/csaf/rolie.go
+++ b/csaf/rolie.go
@@ -82,15 +82,41 @@ type ROLIECategoryDocument struct {
 // NewROLIECategoryDocument creates a new ROLIE category document from a list
 // of categories.
 func NewROLIECategoryDocument(categories ...string) *ROLIECategoryDocument {
-	cats := make([]ROLIECategory, len(categories))
-	for i, cat := range categories {
-		cats[i] = ROLIECategory{Term: cat}
+	rcd := &ROLIECategoryDocument{}
+	rcd.Merge(categories...)
+	return rcd
+}
+
+// Merge merges the given categories into the existing ones.
+// The results indicates if there were changes.
+func (rcd *ROLIECategoryDocument) Merge(categories ...string) bool {
+	index := make(map[string]bool)
+	for i := range rcd.Categories.Category {
+		index[rcd.Categories.Category[i].Term] = true
 	}
-	return &ROLIECategoryDocument{
-		Categories: ROLIECategories{
-			Category: cats,
-		},
+
+	oldLen := len(index)
+
+	for _, cat := range categories {
+		if index[cat] {
+			continue
+		}
+		index[cat] = true
+		rcd.Categories.Category = append(
+			rcd.Categories.Category, ROLIECategory{Term: cat})
 	}
+
+	if len(index) == oldLen {
+		// No new categories
+		return false
+	}
+
+	// Re-establish order.
+	sort.Slice(rcd.Categories.Category, func(i, j int) bool {
+		return rcd.Categories.Category[i].Term < rcd.Categories.Category[j].Term
+	})
+
+	return true
 }
 
 // LoadROLIECategoryDocument loads a ROLIE category document from a reader.
diff --git a/util/json.go b/util/json.go
index 45878c0..bd53f64 100644
--- a/util/json.go
+++ b/util/json.go
@@ -146,3 +146,23 @@ func (pe *PathEval) Match(matcher []PathEvalMatcher, doc interface{}) error {
 	}
 	return nil
 }
+
+// Strings searches the given document for the given set of expressions
+// and returns the corresponding strings. The optional flag indicates
+// if the expression evaluation have to succseed or not.
+func (pe *PathEval) Strings(
+	exprs []string,
+	optional bool,
+	doc interface{},
+) ([]string, error) {
+	results := make([]string, 0, len(exprs))
+	var result string
+	matcher := StringMatcher(&result)
+	for _, expr := range exprs {
+		if err := pe.Extract(expr, matcher, optional, doc); err != nil {
+			return nil, err
+		}
+		results = append(results, result)
+	}
+	return results, nil
+}