From 16cefcc55e10c67a5d4deda299540b4b174880d0 Mon Sep 17 00:00:00 2001
From: Andrey Pokhilko <apc4@ya.ru>
Date: Mon, 21 Feb 2022 15:03:32 +0300
Subject: [PATCH] Figure out decimal pattern

---
 agent/pkg/oas/tree.go | 63 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 51 insertions(+), 12 deletions(-)

diff --git a/agent/pkg/oas/tree.go b/agent/pkg/oas/tree.go
index 81ed6d778..f2e464bee 100644
--- a/agent/pkg/oas/tree.go
+++ b/agent/pkg/oas/tree.go
@@ -1,7 +1,9 @@
 package oas
 
 import (
+	"encoding/json"
 	"net/url"
+	"regexp"
 	"strconv"
 	"strings"
 
@@ -50,7 +52,7 @@ func (n *Node) getOrSet(path NodePath, existingPathObj *openapi.PathObj) (node *
 	}
 
 	if node == nil {
-		node = n.searchInParams(paramObj, chunkIsGibberish)
+		node = n.searchInParams(paramObj, pathChunk, chunkIsGibberish)
 	}
 
 	// still no node found, should create it
@@ -76,6 +78,10 @@ func (n *Node) getOrSet(path NodePath, existingPathObj *openapi.PathObj) (node *
 		if err != nil {
 			logger.Log.Warningf("Failed to add example to a parameter: %s", err)
 		}
+
+		if len(*exmp) > 1 && node.pathParam.Schema.Pattern == nil { // is it enough to decide on 2 samples?
+			node.pathParam.Schema.Pattern = getPatternFromExamples(exmp)
+		}
 	}
 
 	// TODO: eat up trailing slash, in a smart way: node.pathObj!=nil && path[1]==""
@@ -88,6 +94,34 @@ func (n *Node) getOrSet(path NodePath, existingPathObj *openapi.PathObj) (node *
 	return node
 }
 
+func getPatternFromExamples(exmp *openapi.Examples) *openapi.Regexp {
+	allInts := true
+	for _, example := range *exmp {
+		exampleObj, err := example.ResolveExample(exampleResolver)
+		if err != nil {
+			continue
+		}
+
+		var value string
+		err = json.Unmarshal(exampleObj.Value, &value)
+		if err != nil {
+			logger.Log.Warningf("Failed decoding parameter example into string: %s", err)
+			continue
+		}
+
+		if _, err := strconv.Atoi(value); err != nil {
+			allInts = false
+		}
+	}
+
+	if allInts {
+		re := new(openapi.Regexp)
+		re.Regexp = regexp.MustCompile("\\d+")
+		return re
+	}
+	return nil
+}
+
 func (n *Node) createParam() *openapi.ParameterObj {
 	name := "param"
 
@@ -118,20 +152,25 @@ func (n *Node) createParam() *openapi.ParameterObj {
 	return newParam
 }
 
-func (n *Node) searchInParams(paramObj *openapi.ParameterObj, chunkIsGibberish bool) *Node {
-	// look among params
+func (n *Node) searchInParams(paramObj *openapi.ParameterObj, chunk string, chunkIsGibberish bool) *Node {
 	if paramObj != nil || chunkIsGibberish {
-		for _, subnode := range n.children {
-			if subnode.constant != nil {
-				continue
-			}
+		logger.Log.Debugf("")
+	}
 
-			// TODO: check the regex pattern of param? for exceptions etc
+	// look among params
+	for _, subnode := range n.children {
+		if subnode.constant != nil {
+			continue
+		}
 
-			if paramObj != nil {
-				// TODO: mergeParam(subnode.pathParam, paramObj)
-				return subnode
-			} else {
+		if chunkIsGibberish {
+			return subnode
+		} else if paramObj != nil {
+			// TODO: mergeParam(subnode.pathParam, paramObj)
+			return subnode
+		} else if subnode.pathParam.Schema.Pattern != nil {
+			// TODO: and not in exceptions
+			if subnode.pathParam.Schema.Pattern.Match([]byte(chunk)) {
 				return subnode
 			}
 		}