diff --git a/gen_enum_str.py b/gen_enum_str.py
index e9332ce..f6458f5 100755
--- a/gen_enum_str.py
+++ b/gen_enum_str.py
@@ -1,6 +1,6 @@
 #!/bin/python3
 """
-A python script to generate to_string functions for all enumerations in a cpp file.
+A python script to generate toString functions for all enumerations in a cpp file.
 Copyright  ©  2022  Matthias  Quintern.
 This software comes with no warranty.
 This software is licensed under the GPL3
@@ -10,40 +10,280 @@ from sys import argv, exit
 import re
 
 
-filetypes = [".hpp", ".cpp", ".tpp"]
+# search in header files for enums 
+header_filetypes = [".hpp"]
+# definition are written to source file having the same name as the header
+source_filetype = ".cpp"
 
 def error(s):
     print(s)
     exit(1)
 
 
-def getEnumStrF(name: str, enum: dict, spaces: int):
-    s = " " * spaces
-    s += f"const std::map<{name}, std::string> {name}ToStringMap" + " {  // generated by gen_enum_str.py\n"
-    for name_, val in enum.items():
-        s += " " * (spaces + 4)
-        s += "{ " + name_ + ", \"" + name_ + "\" },\n"
-    s += " " * spaces + "};\n"
-    s += " " * spaces + "const std::string& to_string(" + name + " v) { return " + f"{name}ToStringMap.at(v);" + " };  // generated by gen_enum_str.py\n\n"
-    return s
+class Enum:
+    # settings
+    include_docstrings = True
+    """
+    include a doxygen docstring before the declarations
+    """
+    docstring_include_generated = True
+    """
+    include a list of the enum values in @details
+    """
+    docstring_include_names = True
+    """
+    throw exceptions on invalid arguments
+    if false:
+        toString: return empty string
+        fromString: return the last enum value
+    """
+    throw_exceptions = True
+    # generate fromString for string_view
+    string_view = True
+    def __init__(self, startLine:int, name:str, numbers:list[int], names:list[str], namespace:str=""):
+        self.startLine = startLine
+        self.name = name
+        self.numbers = numbers
+        self.names = names
+        self.namespace = namespace
+
+    def is_range(self) -> tuple[bool, int, int]:
+        """
+        check if the enum is a continous range
+        returns: bool, min, max
+        """
+        sorted_numbers = self.numbers.copy()
+        sorted_numbers.sort()
+        if sorted_numbers == range(sorted_numbers[0], sorted_numbers[-1]+1, 1):
+            return True, sorted_numbers[0], sorted_numbers[-1]
+        else:
+            return False, -1, -1
+
+    def get_name(self):
+        if self.namespace:
+            return self.namespace + "::" + self.name
+        else:
+            return self.name
+
+    def get_struct_name(self) -> str:
+        return "EnumStringConversion_" + self.name
+
+    def get_names_for_doc(self, qoutes="") -> str:
+        """
+        returns all names in quotes, separated with a ,
+        """
+        s = ""
+        for name in self.names:
+            s += qoutes + name + qoutes + ", "
+        if len(s) > 2: return s[:-1]
+        else: return s
+
+    def get_dec_toString(self) -> str:
+        """
+        return the declaration for the toString method
+        """
+        s = ""
+        if Enum.include_docstrings:
+            s += "/**\n"
+            s += f' * @brief Convert @ref {self.get_name()} "an enumeration value" to std::string\n'
+            s += f' * @details\n'
+            if Enum.docstring_include_generated:
+                s += f' *  This function was generated by gen_enum_str.py\\n\n'
+                if Enum.throw_exceptions:
+                    s += f' *  Throws gz::InvalidArgument if v is invalid.\n'
+                    s += f' * @throws gz::InvalidArgument if v is invalid.\n'
+                else:
+                    s += f' * Returns an empty string if v is invalid.\n'
+            s += f' */\n'
+        s += f"std::string toString(const {self.get_name()}& v);\n"
+        return s
+
+    def get_dec_fromString(self) -> str:
+        """
+        return the declaration(s) for the fromString method(s)
+        """
+        s = f"template<std::same_as<{self.get_name()}> T>\n"
+        s += f"{self.get_name()} fromString(const std::string& s);\n"
+
+        if Enum.string_view:
+            s += f"template<std::same_as<{self.get_name()}> T>\n"
+            s += f"{self.get_name()} fromString(const std::string_view& sv);\n"
+
+        if Enum.include_docstrings:
+            s += "/**\n"
+            s += f' * @brief Convert a std::string to @ref {self.get_name()} "an enumeration value"\n'
+            s += f' * @details\n'
+            if Enum.docstring_include_generated:
+                s += f' *  This function was generated by gen_enum_str.py\\n\n'
+                if Enum.throw_exceptions:
+                    s += f' *  Throws gz::InvalidArgument if s is invalid.\n'
+                    s += f' * @throws gz::InvalidArgument if s is invalid.\n'
+                else:
+                    s += f' * Returns {self.get_name()}::{self.names[-1]} if s is invalid.\n'
+                if Enum.docstring_include_names:
+                    s += f' * @param v one of: {self.get_names_for_doc()}\n'
+            s += f' */\n'
+        s += f"template<> {self.get_name()} fromString<{self.get_name()}>(const std::string& s);\n"
+
+        if Enum.string_view:
+            if Enum.include_docstrings:
+                s += '/// @brief Convert a std::string_view to @ref {self.get_name()} "an enumeration value"\n'
+            s += f"template<> {self.get_name()} fromString<{self.get_name()}>(const std::string_view& sv);\n"
+        return s
+
+    def get_def_struct(self) -> str:
+        """
+        return the definition of the EnumStringConversion struct
+        """
+        s = ""
+        s += f"// Holds maps used by fromString and toString for conversion of {self.name} values\n"
+        s += f"struct {self.get_struct_name()}" + " {\n"
+        s += f"    static gz::util::unordered_string_map<{self.get_name()}> name2type;\n"
+        s += f"    static std::map<{self.get_name()}, std::string> type2name;\n"
+        s += "};  // generated by gen_enum_str\n\n"
+
+        # name2type
+        s += f"gz::util::unordered_string_map<{self.get_name()}> {self.get_struct_name()}::name2type " + "{\n"
+        for i in range(len(self.names)):
+            # { "ENUM_VAL", namespace::ENUM_NAME::ENUM_VAL },
+            s += '\t{ "' + self.names[i] + '", ' + self.get_name() + "::" + self.names[i] + " },\n"
+        s += "};  // generated by gen_enum_str\n\n"
+
+        # type2name
+        s += f"std::map<{self.get_name()}, std::string> {self.get_struct_name()}::type2name " + "{\n"
+        for i in range(len(self.names)):
+            # { namespace::ENUM_NAME::ENUM_VAL, "ENUM_VAL", },
+            s += '\t{ ' + self.get_name() + "::" + self.names[i] + ', "' + self.names[i] + '" },\n'
+        s += "};  // generated by gen_enum_str\n\n"
+        return s
+
+    def get_def_toString(self) -> str:
+        s = ""
+        s += f"std::string toString(const {self.get_name()}& v) " + "{\n"
+        s += f"\tif ({self.get_struct_name()}::type2name.contains(v)) " + "{\n"
+        s += f"\t\treturn {self.get_struct_name()}::type2name.at(v);\n"
+        s +=  "\t}\n"
+        s +=  "\telse {\n"
+        if Enum.throw_exceptions:
+            s += f'\t\tthrow gz::InvalidArgument("InvalidArgument: \'" + std::to_string(static_cast<int>(v)) + "\'", "toString({self.name})");\n'
+        else:
+            s += f'\t\treturn "";\n'
+        s +=  "\t}\n"
+        s +=  "}  // generated by gen_enum_str\n\n"
+        return s
+
+    def get_def_fromString(self) -> str:
+        s = ""
+        # string_view
+        s += f"template<> {self.get_name()} fromString<{self.get_name()}>(const std::string_view& sv) " + "{\n"
+        s += f"\tif ({self.get_struct_name()}::name2type.contains(sv)) " + "{\n"
+        s += f"\t\treturn {self.get_struct_name()}::name2type.find(sv)->second;\n"
+        s +=  "\t}\n"
+        s +=  "\telse {\n"
+        if Enum.throw_exceptions:
+            s += f'\t\tthrow gz::InvalidArgument("InvalidArgument: \'" + std::string(sv) + "\'", "fromString<{self.name}>");\n'
+        else:
+            s += f'\t\treturn {self.get_name()}::{self.names[-1]};\n'
+        s +=  "\t}\n"
+        s +=  "}  // generated by gen_enum_str\n\n"
+        # string
+        s += f"template<> {self.get_name()} fromString<{self.get_name()}>(const std::string& s) " + "{\n"
+        s += f"\treturn fromString<{self.get_name()}>(std::string_view(s));\n"
+        s +=  "}  // generated by gen_enum_str\n\n"
+        return s
 
 
-def process_file(inputfile: str, outputfile: str):
-    print("process_file:", inputfile)
-    if not path.isfile(inputfile): error("File does not exist:" + inputfile)
 
-    with open(inputfile, "r") as file:
+def append_enums_to_files(header_file:str, source_file:str, enums: list[Enum], interactive:bool=False):
+    """
+    put declaration at the end of the source
+    put definition at the end of the header
+    """
+    if len(enums) == 0:
+        return
+
+    print("append_enums_to_files:", header_file, source_file)
+    if not path.isfile(header_file): error("File does not exist:" + header_file)
+    if not path.isfile(source_file):
+        print("Creating source_file: " + source_file)
+        with open(source_file, "w") as file:
+            file.write(f'// generated by gen_enum_str\n#include "{header_file}"\n\n#include <gz-util/util/string.hpp>\n\n')
+
+    with open(header_file, "r") as file:
+        header = file.read()
+    with open(source_file, "r") as file:
+        source = file.read()
+
+    # delete everything between the two comments
+    comment_gen_begin = "// ENUM - STRING CONVERSION BEGIN\n"
+    comment_gen_end = "// ENUM - STRING CONVERSION END\n"
+
+    gen_begin = header.find(comment_gen_begin)
+    gen_end = header.find(comment_gen_end)
+    if gen_begin > 0 and gen_end > gen_begin:
+        header = header[:gen_begin - 1] + header[gen_end + len(comment_gen_end):]
+
+    gen_begin = source.find(comment_gen_begin)
+    gen_end = source.find(comment_gen_end)
+    if gen_begin > 0 and gen_end > gen_begin:
+        source = source[:gen_begin - 1] + source[gen_end + len(comment_gen_end):]
+
+    header += "\n" + comment_gen_begin
+    header += "// do not write your own code between these comment blocks - it will be overwritten when you run gen_enum_str.py again\n"
+    source += "\n" + comment_gen_begin
+    source += "// do not write your own code between these comment blocks - it will be overwritten when you run gen_enum_str.py again\n"
+    for enum in enums:
+        if interactive:
+            answer = input(f"Generate conversion for: {header_file}:{enum.startLine} - enum {enum.name}? (y/n): ")
+            if answer not in "yY":
+                continue
+        header += f"//\n// {enum.name}\n//\n"
+        header += enum.get_dec_toString()
+        header += enum.get_dec_fromString() + "\n"
+
+        source += f"//\n// {enum.name}\n//\n"
+        source += enum.get_def_struct()
+        source += enum.get_def_toString()
+        source += enum.get_def_fromString()
+    header += "\n" + comment_gen_end
+    source += "\n" + comment_gen_end
+
+
+    with open(header_file, "w") as file:
+        file.write(header)
+    with open(source_file, "w") as file:
+        file.write(source)
+
+
+
+def get_enums(headerfile: str) -> list[Enum]:
+    """
+    find enums in headerfile
+    namespaces are not properly supported, the script can not detect when a namespace is closed.
+    so it only works when you dont open namespaces in namespaces
+    """
+    # print("get_enums:", headerfile)
+    if not path.isfile(headerfile): error("File does not exist:" + headerfile)
+
+    with open(headerfile, "r") as file:
         lines = file.readlines()
 
     # FIND ENUMS
     enums_start = []
     enums_stop = []
+    enums_namespace = []
+    current_namespace = ""
     in_enum = False
     for i in range(len(lines)):
+        match = re.match(r" *namespace ([a-zA-Z0-9_:]+) +{.*", lines[i])
+        if match:
+            current_namespace = match.groups()[0]
+
         if re.match(r" *enum [a-zA-Z0-9_-]+ {.*", lines[i]) and not "gen_enum_str.py" in lines[i]:
             if in_enum: error("process_file: could not find end of enum starting at line " + str(enums_start.pop()))
             in_enum = True
             enums_start.append(i)
+            enums_namespace.append(current_namespace)
 
         if in_enum:
             if re.match(r" *[^/*]?.*}.*", lines[i]):
@@ -84,84 +324,149 @@ def process_file(inputfile: str, outputfile: str):
                 var_end = len(m.group())
             enum[m.group()[0:var_end]] = enum_val
             enum_val += 1
-        print("enum:", enum_names[i], enum)
+        # print("enum:", enum_names[i], enum)
         enum_dicts.append(enum)
-
-    for i in reversed(range(len(enum_names))):
-        lines.insert(enums_stop[i] + 1, getEnumStrF(enum_names[i], enum_dicts[i], spaces[i]))
-        lines[enums_start[i]] = lines[enums_start[i]].strip("\n") + "  // processed by gen_enum_str.py\n"
-
-    with open(outputfile, "w") as file:
-        file.writelines(lines)
+    enums = []
+    for i in range(len(enum_names)):
+        enums.append(Enum(enums_start[i], enum_names[i], list(enum_dicts[i].values()), list(enum_dicts[i].keys()), enums_namespace[i]))
+    return enums
 
 
-def process_path(path_):
-    if path.isfile(path_) and path.splitext(path_)[-1] in filetypes:
-        process_file(path_, path_)
+# def process_file(inputfile: str, outputfile: str):
+#     print("process_file:", inputfile)
+#     if not path.isfile(inputfile): error("File does not exist:" + inputfile)
 
-    elif path.isdir(path_):
-        for p in listdir(path_):
-            if path.isfile(p) and path.splitext(p)[-1] in filetypes:
-                process_file(p, p)
-            elif path.isdir(p):
-                chdir(p)
-                process_path(p)
-                chdir("..")
-    else:
-        print("Invalid path:", path_)
+#     with open(inputfile, "r") as file:
+#         lines = file.readlines()
+
+#     # FIND ENUMS
+#     enums_start = []
+#     enums_stop = []
+#     in_enum = False
+#     for i in range(len(lines)):
+#         if re.match(r" *enum [a-zA-Z0-9_-]+ {.*", lines[i]) and not "gen_enum_str.py" in lines[i]:
+#             if in_enum: error("process_file: could not find end of enum starting at line " + str(enums_start.pop()))
+#             in_enum = True
+#             enums_start.append(i)
+
+#         if in_enum:
+#             if re.match(r" *[^/*]?.*}.*", lines[i]):
+#                 enums_stop.append(i)
+#                 in_enum = False
+#     if len(enums_start) != len(enums_stop): error("process_file: could not find end of enum starting at line " + str(enums_start.pop()))
+
+#     # create a single string with the enum
+#     enums = []
+#     for i in range(len(enums_start)):
+#         enums.append("")
+#         j = enums_start[i]
+#         while j <= enums_stop[i]:
+#             enums[i] += lines[j]
+#             j += 1
+
+#     # get name and vars
+#     enum_names = []
+#     enum_dicts = []
+#     spaces = []
+#     var = "[a-zA-Z0-9_-]+"
+#     enumvar = "(" + var + r"(=*-?\d+)?)"
+#     restring = "enum (" + var + "){(" + enumvar + ",)*" + enumvar + ",?}"
+#     for i in range(len(enums)):
+#         enums[i] = enums[i].replace("\n", "").replace("enum ", "enumü").replace(" ", "").replace("enumü", "enum ")
+#         match = re.match(restring, enums[i])
+#         if not match: error("Invalid enum at line " + str(enums_start[i]))
+
+#         spaces.append(lines[enums_start[i]].find("e"))
+#         enum_names.append(match.groups()[0])
+#         enum_val = 0
+#         enum = {}
+#         for m in re.finditer(enumvar, enums[i][len("enum " + enum_names[i]):]):
+#             if "=" in m.group():
+#                 enum_val = int(m.group()[m.group().find("=")+1:])
+#                 var_end = m.group().find("=")
+#             else:
+#                 var_end = len(m.group())
+#             enum[m.group()[0:var_end]] = enum_val
+#             enum_val += 1
+#         print("enum:", enum_names[i], enum)
+#         enum_dicts.append(enum)
+
+#     for i in reversed(range(len(enum_names))):
+#         lines.insert(enums_stop[i] + 1, getEnumStrF(enum_names[i], enum_dicts[i], spaces[i]))
+#         lines[enums_start[i]] = lines[enums_start[i]].strip("\n") + "  // processed by gen_enum_str.py\n"
+
+#     with open(outputfile, "w") as file:
+#         file.writelines(lines)
+
+
+def process_path(path_, interactive:bool=False, recurse:bool=False):
+    # print("Processing path:", path_)
+    if path.isfile(path_) and path.splitext(path_)[-1] in header_filetypes:
+        enums = get_enums(path_)
+        append_enums_to_files(path_, path_.split('.')[0] + source_filetype, enums, interactive)
+    elif recurse:
+        if path.isdir(path_):
+            for p in listdir(path_):
+                process_path(path_ + "/" + p, interactive, recurse)
 
 
 
 
 def print_help():
-    """
-Synposis:       get_enum_str.py <Options>... <file>...
--o <path>       output: file to path. Only when 1 input file.
--h --help       help
--r              recurse: Recurse through the directory and process all cpp/hpp files. Implies -i
--i              in place: Edit the file in place
-"""
+    print("""
+Synposis:           get_enum_str.py <Options>... <file>...
+                    get_enum_str.py <Options>... -r <path>...
+-h --help           help
+-r                  recurse: Recurse through given paths process all files.
+-i                  interactive: prompt for every enumeration
+--no-docs           turn off docstring generation
+--docs-no-names     do not list names of enumeration values in docstring
+--docs-no-gen       do not put "generated by gen_enum_str" in docstring
+--no-throw          return empty string/last enum value if the argument for to/fromString is invalid.
+                    This would normaly throw gz::InvalidArgument
+                    This option does not make the functions noexcept!
+
+If the generated code produces errors:
+- check that necessary headers are included in the source file:
+  - gz-util/string.hpp
+  - gz-util/exceptions.hpp (unless you use --no-throw)
+- check the namespaces of the enumerations, the generated code should be in global namespace
+  nested namespace are not supported, you will have to correct that if you use them
+""")
 
 def missing_arg(arg):
     print("Missing argument for", arg)
     exit(1)
 
 if __name__ == "__main__":
-    output_file = None
     input_files = []
-    in_place = False
     recurse = False
+    interactive = False
     i = 1
     while i in range(1, len(argv)):
         if  argv[i] == "--help" or argv[i] == "-h":
             print_help()
             exit(0)
-        if argv[i] == "-o":
-            if len(argv) > i + 1: output_file = argv[i+1]
-            else: missing_arg(argv[i])
-            i += 1
         elif argv[i] == "-r":
             recurse = True
         elif argv[i] == "-i":
-            in_place = True
+            interactive = True
+        elif argv[i] == "--no-throw":
+            Enum.throw_exceptions = False
+        elif argv[i] == "--no-docs":
+            Enum.include_docstrings = False
+        elif argv[i] == "--docs-no-names":
+            Enum.docstring_include_names = False
+        elif argv[i] == "--docs-no-gen":
+            Enum.docstring_include_generated = False
         else:
             input_files.append(argv[i])
         i += 1
 
-    if output_file is None and not in_place and not recurse:
-        error("Missing output path or -i")
-    if output_file and (recurse or in_place or len(input_files) > 1):
-        error("Error: -o does not work with -r, -i or multiple input paths.")
     if len(input_files) == 0:
-        error("Missing input files.")
-    if in_place:
-        output_file = input_files[0]
-
-    if (recurse):
-        for f in input_files:
-            process_path(f)
-    else:
-        process_file(input_files[0], output_file)
+        error("Missing input files/paths.")
+    for f in input_files:
+        process_path(path.abspath(f), recurse=recurse, interactive=interactive)