From db920336425eb994cba7cb7f1ec663f0efbd8e60 Mon Sep 17 00:00:00 2001
From: PhatPhuckDave <david.majdandzic@hotmail.com>
Date: Tue, 25 Mar 2025 18:28:28 +0100
Subject: [PATCH] Rework rounding and building lua script

To allow user script to specify what was modified where
---
 processor/json.go      | 54 +++++++++++++++---------------------------
 processor/processor.go | 23 ++++++++++++++++--
 2 files changed, 40 insertions(+), 37 deletions(-)

diff --git a/processor/json.go b/processor/json.go
index 60d267e..b72cc1e 100644
--- a/processor/json.go
+++ b/processor/json.go
@@ -7,7 +7,6 @@ import (
 	"modify/processor/jsonpath"
 	"os"
 	"path/filepath"
-	"strings"
 
 	lua "github.com/yuin/gopher-lua"
 )
@@ -68,6 +67,7 @@ func (p *JSONProcessor) ProcessContent(content string, pattern string, luaExpr s
 		return content, 0, 0, nil
 	}
 
+	modCount := 0
 	for _, node := range nodes {
 		log.Printf("Processing node at path: %s with value: %v", node.Path, node.Value)
 
@@ -85,10 +85,14 @@ func (p *JSONProcessor) ProcessContent(content string, pattern string, luaExpr s
 		}
 		log.Printf("Converted node value to Lua: %v", node.Value)
 
+		originalScript := luaExpr
+		fullScript := BuildLuaScript(luaExpr)
+		log.Printf("Original script: %q, Full script: %q", originalScript, fullScript)
+
 		// Execute Lua script
-		log.Printf("Executing Lua script: %s", luaExpr)
-		if err := L.DoString(luaExpr); err != nil {
-			return content, len(nodes), 0, fmt.Errorf("error executing Lua %s: %v", luaExpr, err)
+		log.Printf("Executing Lua script: %q", fullScript)
+		if err := L.DoString(fullScript); err != nil {
+			return content, len(nodes), 0, fmt.Errorf("error executing Lua %q: %v", fullScript, err)
 		}
 		log.Println("Lua script executed successfully.")
 
@@ -99,53 +103,33 @@ func (p *JSONProcessor) ProcessContent(content string, pattern string, luaExpr s
 		}
 		log.Printf("Retrieved modified value from Lua: %v", result)
 
+		modified := false
+		modified = L.GetGlobal("modified").String() == "true"
+		if !modified {
+			log.Printf("No changes made to node at path: %s", node.Path)
+			continue
+		}
+
 		// Apply the modification to the JSON data
 		err = p.updateJSONValue(jsonData, node.Path, result)
 		if err != nil {
 			return content, len(nodes), 0, fmt.Errorf("error updating JSON: %v", err)
 		}
 		log.Printf("Updated JSON at path: %s with new value: %v", node.Path, result)
+		modCount++
 	}
 
 	// Convert the modified JSON back to a string with same formatting
 	var jsonBytes []byte
-	if indent, err := detectJsonIndentation(content); err == nil && indent != "" {
-		// Use detected indentation for output formatting
-		jsonBytes, err = json.MarshalIndent(jsonData, "", indent)
-	} else {
-		// Fall back to standard 2-space indent
-		jsonBytes, err = json.MarshalIndent(jsonData, "", "  ")
+	jsonBytes, err = json.MarshalIndent(jsonData, "", "  ")
+	if err != nil {
+		return content, len(nodes), 0, fmt.Errorf("error marshalling JSON: %v", err)
 	}
 
 	// We changed all the nodes trust me bro
 	return string(jsonBytes), len(nodes), len(nodes), nil
 }
 
-// detectJsonIndentation tries to determine the indentation used in the original JSON
-func detectJsonIndentation(content string) (string, error) {
-	lines := strings.Split(content, "\n")
-	if len(lines) < 2 {
-		return "", fmt.Errorf("not enough lines to detect indentation")
-	}
-
-	// Look for the first indented line
-	for i := 1; i < len(lines); i++ {
-		line := lines[i]
-		trimmed := strings.TrimSpace(line)
-		if trimmed == "" {
-			continue
-		}
-
-		// Calculate leading whitespace
-		indent := line[:len(line)-len(trimmed)]
-		if len(indent) > 0 {
-			return indent, nil
-		}
-	}
-
-	return "", fmt.Errorf("no indentation detected")
-}
-
 // / 	Selects from the root node
 // // 	Selects nodes in the document from the current node that match the selection no matter where they are
 // . 	Selects the current node
diff --git a/processor/processor.go b/processor/processor.go
index e268a63..9afd8ab 100644
--- a/processor/processor.go
+++ b/processor/processor.go
@@ -129,7 +129,10 @@ func InitLuaHelpers(L *lua.LState) error {
 -- Custom Lua helpers for math operations
 function min(a, b) return math.min(a, b) end
 function max(a, b) return math.max(a, b) end
-function round(x) return math.floor(x + 0.5) end
+function round(x, n) 
+	if n == nil then n = 0 end
+	return math.floor(x * 10^n + 0.5) / 10^n 
+end
 function floor(x) return math.floor(x) end
 function ceil(x) return math.ceil(x) end
 function upper(s) return string.upper(s) end
@@ -149,6 +152,8 @@ end
 function is_number(str)
     return tonumber(str) ~= nil
 end
+
+modified = false
 `
 	if err := L.DoString(helperScript); err != nil {
 		return fmt.Errorf("error loading helper functions: %v", err)
@@ -187,7 +192,21 @@ func BuildLuaScript(luaExpr string) string {
 		luaExpr = "v1 = " + luaExpr
 	}
 
-	return luaExpr
+	// This allows the user to specify whether or not they modified a value
+	// If they do nothing we assume they did modify (no return at all)
+	// If they return before our return then they themselves specify what they did
+	// If nothing is returned lua assumes nil
+	// So we can say our value was modified if the return value is either nil or true
+	// If the return value is false then the user wants to keep the original
+	fullScript := fmt.Sprintf(`
+		function run()
+			%s
+		end
+		local res = run()
+		modified = res == nil or res
+	`, luaExpr)
+
+	return fullScript
 }
 
 // Max returns the maximum of two integers