From 2e9138b55c56fa799d1005dec0c0dd3c4202f55a Mon Sep 17 00:00:00 2001
From: Trial97 <alexandru.tripon@itsyscom.com>
Date: Fri, 9 Aug 2019 17:31:48 +0300
Subject: [PATCH] Updated config error handling

---
 config/config_json.go |  28 ++++++--
 config/rjreader.go    | 148 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 172 insertions(+), 4 deletions(-)

diff --git a/config/config_json.go b/config/config_json.go
index fe0d4cdf2..e0d383a5b 100644
--- a/config/config_json.go
+++ b/config/config_json.go
@@ -86,8 +86,18 @@ func NewCgrJsonCfgFromFile(fpath string) (*CgrJsonCfg, error) {
 	if err != nil {
 		return nil, err
 	}
-	defer cfgFile.Close()
-	return NewCgrJsonCfgFromReader(cfgFile)
+	cfg, err := NewCgrJsonCfgFromReader(cfgFile)
+	cfgFile.Close()
+	if err != nil {
+		// for a better error message
+		cfgFile, oerr := os.Open(fpath)
+		if oerr != nil {
+			return cfg, oerr
+		}
+		defer cfgFile.Close()
+		return cfg, HandleJSONError(cfgFile, err)
+	}
+	return cfg, nil
 }
 
 // Loads the config out of http request
@@ -99,8 +109,18 @@ func NewCgrJsonCfgFromHttp(fpath string) (*CgrJsonCfg, error) {
 	if err != nil {
 		return nil, utils.ErrPathNotReachable(fpath)
 	}
-	defer cfgReq.Body.Close()
-	return NewCgrJsonCfgFromReader(cfgReq.Body)
+	cfg, err := NewCgrJsonCfgFromReader(cfgReq.Body)
+	cfgReq.Body.Close()
+	if err != nil {
+		// for a better error message
+		cfgReq, rerr := myClient.Get(fpath)
+		if rerr != nil {
+			return nil, utils.ErrPathNotReachable(fpath)
+		}
+		defer cfgReq.Body.Close()
+		return cfg, HandleJSONError(cfgReq.Body, err)
+	}
+	return cfg, nil
 }
 
 // Main object holding the loaded config as section raw messages
diff --git a/config/rjreader.go b/config/rjreader.go
index 28bc36574..804db8d4a 100644
--- a/config/rjreader.go
+++ b/config/rjreader.go
@@ -20,12 +20,16 @@ package config
 
 import (
 	"bufio"
+	"encoding/json"
+	"fmt"
 	"io"
 	"os"
 
 	"github.com/cgrates/cgrates/utils"
 )
 
+// NewRawJSONReader returns a raw JSON reader
+
 // NewRawJSONReader returns a raw JSON reader
 func NewRawJSONReader(r io.Reader) io.Reader {
 	return &EnvReader{
@@ -331,3 +335,147 @@ func (b *EnvReader) Read(p []byte) (n int, err error) {
 	}
 	return len(p), nil
 }
+
+// warning: needs to read file again
+func HandleJSONError(reader io.Reader, err error) error {
+	var offset int64
+	switch realErr := err.(type) {
+	case nil:
+		return nil
+	case *json.InvalidUTF8Error, *json.UnmarshalFieldError: // deprecated
+		return err
+	case *json.InvalidUnmarshalError: // e.g. nil parameter
+		return err
+	case *json.SyntaxError:
+		offset = realErr.Offset
+	case *json.UnmarshalTypeError:
+		offset = realErr.Offset
+	default:
+		fmt.Printf("%T", err)
+		return err
+	}
+
+	var line int64 = 1 // start line counting from 1
+	var character int64
+	var lastChar byte
+	if offset == 0 {
+		return fmt.Errorf("%s at line %v around position %v", err.Error(), line, character)
+	}
+	br := bufio.NewReader(reader)
+
+	var i int64 = 0
+	readString := func() error {
+		for i < offset {
+			b, rerr := br.ReadByte()
+			if rerr != nil {
+				return rerr
+			}
+			i++
+			if isNewLine(b) {
+				line++
+				character = 0
+			} else {
+				character++
+			}
+			if b == '"' {
+				return nil
+			}
+		}
+		return nil
+	}
+	readLineComment := func() error {
+		for i < offset {
+			b, rerr := br.ReadByte()
+			if rerr != nil {
+				return rerr
+			}
+			if isNewLine(b) {
+				line++
+				character = 0
+				return nil
+			}
+			character++
+		}
+		return nil
+	}
+
+	readComment := func() error {
+		for i < offset {
+			b, rerr := br.ReadByte()
+			if rerr != nil {
+				return rerr
+			}
+			if isNewLine(b) {
+				line++
+				character = 0
+			} else {
+				character++
+			}
+			if b == '*' {
+				b, rerr := br.ReadByte()
+				if rerr != nil {
+					return rerr
+				}
+				if b == '/' {
+					character++
+					return nil
+				}
+				rerr = br.UnreadByte()
+				if rerr != nil {
+					return rerr
+				}
+			}
+		}
+		return nil
+	}
+
+	for i < offset { // handle the parsing
+		b, rerr := br.ReadByte()
+		if rerr != nil {
+			break
+		}
+		character++
+		if isNewLine(b) {
+			line++
+			character = 0
+		}
+		if (b == ']' || b == '}') && lastChar == ',' {
+			i-- //ignore ',' if is followed by ] or }
+		}
+		if !isWhiteSpace(b) {
+			i++
+			lastChar = b
+		}
+		if b == '"' { // read "" value
+			rerr := readString()
+			if rerr != nil {
+				break
+			}
+		}
+		if b == '/' {
+			b, rerr := br.ReadByte()
+			if rerr != nil {
+				break
+			}
+			if b == '/' { // read //
+				i--
+				rerr := readLineComment()
+				if rerr != nil {
+					break
+				}
+			} else if b == '*' { // read /*
+				i--
+				rerr := readComment()
+				if rerr != nil {
+					break
+				}
+			} else {
+				rerr := br.UnreadByte()
+				if rerr != nil {
+					break
+				}
+			}
+		}
+	}
+	return fmt.Errorf("%s around line %v and position %v", err.Error(), line, character)
+}