# tool to generate the modules.md content
#

import os, json, sys, time, fnmatch, re, importlib

PATH_GENERATED_OBJ = "KSR.lua"

class ModuleObjGenerator(object):

    # Contains the output until it should be written to disk
    object_string = ""

    def execute(self, data):
        # Validate that we got some methods back. 155 is an arbitrary large number.
        if len(data) < 1:
            print("ERR: Invalid data")
            exit()

        functions_parsed = self.parse_function_list(data)
        self.output_obj(functions_parsed)

        print ("File created successfully at: " + PATH_GENERATED_OBJ)

    def parse_function_list(self, functions):
        data = {}

        for elem in functions:
            module = elem["module"]

            # TODO: What about the hdr, pv, x sub-module?
            if module == "":
                module = "_core"

            if module not in data:
                data[module] = []

            data[module].append({"name": elem["name"], "return": elem["ret"], "params": elem["params"]})

        return data

    def output_obj(self, data):

        for key in sorted(data):
            methods = data[key]
            # Sort the functions by name alphabetically
            methods = sorted(methods, key = lambda k: k['name'])
            self.object_module_content(key, methods)
        
        self.obj_write()

        return True

    def object_module_content(self, module, methods):
        if module == "_core":
            module_prefix = ""
        else:
            module_prefix = module + "."

        for value in methods:
            self.object_string += "local function KSR." + module_prefix + value["name"]

            # Sanitize the return values
            if value["return"] == "none":
                return_value = ""
            elif value["return"] == "void":
                return_value = ""
            elif value["return"] == "xval":
                return_value = " \"\""
            elif value["return"] == "int":
                return_value = " 1"
            elif value["return"] == "bool":
                return_value = " true"
            else:
                return_value = " nil"

            # Sanitize the parameter values
            if value["params"] == "none":
                params_value = ""
            else:
                params_value = value["params"]

            # Generate the output string for the file
            self.object_string += "(" + params_value + ")\n"
            self.object_string += "\treturn" + return_value + ";\n"
            self.object_string += "end\n\n"


        return True

    def obj_write(self):
        f = open(PATH_GENERATED_OBJ, "w")
        f.write("local KSR = {};\n\n")
        f.write(self.object_string)
        f.write("return KSR;\n")
        f.close()
        return True

    def read_file_to_string(self, filename):
        path = self.PATH_MODULES_DOCS + filename
        if os.path.isfile(path):
            with open(path, 'r') as myfile:
                return myfile.read() + "\n"
        return ""


class KemiFileExportParser(object):
    # These functions are created by a macro so makes the parsing somewhat tricky,
    # for now they are statically defined
    macro_functions = {
        "t_set_auto_inv_100": "int state",
        "t_set_disable_6xx": "int state",
        "t_set_disable_failover": "int state",
        "t_set_no_e2e_cancel_reason": "int state",
        "t_set_disable_internal_reply": "int state"
    }

    # These files export the KEMI functions in a special way so we map them manually
    # TODO: Discuss with @miconda if core/HDR/pv/x should be added as well or not
    special_exports = [
        {"filename": "kemi.c", "export": "_sr_kemi_core", "folder": "/src/core/"},
        {"filename": "kemi.c", "export": "_sr_kemi_hdr", "folder": "/src/core/"},
        {"filename": "kemi.c", "export": "_sr_kemi_pv", "folder": "/src/core/"},
        #{"filename": "app_lua_mod.c", "export": "sr_kemi_app_lua_rpc_exports", "folder": "/modules/app_lua/"}
    ]

    def generate_kemi_export_list(self, source_path):
        files = self.list_c_files_in_directory(source_path)
        lists = []

        for file in files:
            with open(file, 'r', encoding='utf-8', errors='ignore') as f:
                lines = f.readlines()

            export_name = self.find_c_file_kemi_export(file, lines)
            if export_name:
                export_functions = self.extract_c_file_kemi_export_lines(file, lines, export_name)
                lists = lists + export_functions
                print ("Found ", len(export_functions), "functions", "Total:", len(lists))

        # Handle some special files separately
        for elem in self.special_exports:
            file = source_path + elem["folder"] + elem["filename"]
            with open(file) as f:
                lines = f.readlines()
            lists = lists + self.extract_c_file_kemi_export_lines(file, lines, elem["export"])

        return lists

    def find_c_file_kemi_export(self, filename, lines):
        param = None

        for line in lines:
            if line.find("sr_kemi_modules_add") >= 0:
                line = line.lstrip(" ")
                line = line.lstrip("\t")
                if line.find("sr_kemi_modules_add") == 0:
                    param = line[line.find("(") + 1:line.find(")")]
                    print ("INFO: ---- Found export", filename, param)
                    break
                else:
                    if line != "int sr_kemi_modules_add(sr_kemi_t *klist)\n":
                        print ("ERR: Possible error at line: ", filename, line)
                        exit()

        return param

    def extract_c_file_kemi_export_lines(self, filename, lines, export_name):
        list_functions = []
        find_start = True

        for line in lines:
            if find_start and line.find("static sr_kemi_t " + export_name + "[]") >= 0:
                find_start = False
            elif not find_start:
                if line.find("};") >= 0:
                    break
                line = line.lstrip(" \t")
                line = line.rstrip()
                list_functions.append(line)

        if len(list_functions) < 1:
            print ("ERR: Couldn't parse file for exported functions: ", export_name)
            exit()

        parsed_list = self.parse_kemi_export_c_lines(filename, list_functions)

        return parsed_list

    def parse_kemi_export_c_lines(self, filename, lines):
        elements = []
        function_lines = []
        temp_function = ""

        # We look for str_init which would be the start of each exported function
        for line in lines:
            if line.find("str_init") >= 0:
                if temp_function != "":
                    function_lines.append(temp_function)
                    temp_function = ""
            temp_function += line

        if temp_function != "":
            function_lines.append(temp_function)

        # Now we parse each exported function to extract its declaration
        for func in function_lines:
            function_lines_split = func.split(",{")

            if len(function_lines_split) < 2:
                print ("ERR: Incorrect function line", func)
                exit()

            declarations = function_lines_split[0].split(",")
            params = function_lines_split[1]

            # Extract the content from the definitions
            val_module = declarations[0]
            val_module = val_module[val_module.find('("') + 2:val_module.find('")')]
            val_function = declarations[1]
            val_function = val_function[val_function.find('("') + 2:val_function.find('")')]

            if declarations[2] == "SR_KEMIP_INT":
                val_return = "int"
            elif declarations[2] == "SR_KEMIP_STR":
                val_return = "string"
            elif declarations[2] == "SR_KEMIP_NONE":
                val_return = "void"
            elif declarations[2] == "SR_KEMIP_BOOL":
                val_return = "bool"
            elif declarations[2] == "SR_KEMIP_XVAL":
                val_return = "xval"
            else:
                print("ERR: Invalid return value", declarations[2], func)
                exit()

            val_c_function = declarations[3].strip()

            # Count how many parameters the KEMI C function expects
            val_params = []
            itr = 0
            for val in params.rstrip("},").split(","):
                itr += 1
                # KEMI function has a maximum of 6 params
                if itr > 6:
                    break
                pm = val.strip()
                if pm == "SR_KEMIP_INT":
                    val_params.append("int")
                elif pm == "SR_KEMIP_STR":
                    val_params.append("str")
                elif pm == "SR_KEMIP_NONE":
                    continue
                else:
                    print("Invalid return value", declarations[2], func)
                    exit()

            if itr != 6:
                print("ERR: Couldn't iterate the params: ", params)
                exit()

            param_string = self.find_c_function_params(filename, val_c_function, val_return)
            param_string = self.prettify_params_list(val_function, param_string, val_params)

            elements.append({"module": val_module, "name": val_function, "ret": val_return, "params": param_string})

        return elements

    def prettify_params_list(self, function_name, function_declaration, kemi_types):
        # Validate the quantity and types of declaration vs export
        if function_declaration == "" and len(kemi_types) == 0:
            return ""

        params = function_declaration.split(",")

        if params[0].find("sip_msg_t") >= 0 or params[0].find("struct sip_msg") >= 0:
            params.pop(0)

        if len(params) != len(kemi_types):
            print("ERR: Mismatching quantity of params. Declaration for", function_name, ":", function_declaration, "KEMI:", kemi_types)
            exit()

        for declared, type in zip(params, kemi_types):
            declared = declared.replace("*", "")
            declared = declared.strip().split(" ")[0]
            if declared != type:
                print("ERR: Mismatching type of params for", function_name, ":", function_declaration, " | ", kemi_types, " | Declared: ", declared, " Type: ", type)
                exit()

        param_string = ""

        for param in params:
            param = param.strip()
            param = param.replace("*", "")
            if param[:3] == "str" or param[:3] == "int":
                temp = param.split(" ")
                param = "p_" + temp[1]
            param_string += param + ", "

        # Clean up the presentation of the params
        param_string = param_string.rstrip(", ")
        return param_string

    def find_c_function_params(self, filename, function_name, return_type):
        # First we try with the same file to find the declaration
        param_string = self.search_file_for_function_declaration(filename, function_name, return_type)
        # If we couldn't find it, let's try all files in the same folder as the first file
        if param_string:
            return param_string
        else:
            files = self.list_c_files_in_directory(os.path.dirname(filename))
            for file in files:
                param_string = self.search_file_for_function_declaration(file, function_name, return_type)
                if param_string:
                    return param_string

        if function_name in self.macro_functions:
            return self.macro_functions[function_name]

        print("ERR: Couldn't find the function declaration", filename, function_name, return_type)
        exit()

    def search_file_for_function_declaration(self, filename, function_name, return_type):
        # print "Searching file", filename, "for", function_name
        with open(filename, 'r', encoding='utf-8', errors='ignore') as f:
            lines = f.readlines()

        param_string = None
        found = False
        temp_string = ""
        return_match = return_type

        # KEMI has some magic where most functions actually return INTs but KEMI maps them to void/bool
        if return_type == "void" or return_type == "bool":
            return_match = "int"

        if return_type == "xval":
            return_match = "sr_kemi_xval_t([ \t])*\*"

        # Look for declarations in format:    static? return_type function_name(
        r = re.compile("^(?:static )?" + return_match + "[ \t]*(" + function_name + ")[ \t]*\(")
        for line in lines:
            m = r.match(line)
            if m:
                found = True
            if found:
                temp_string += line
                if line.find("{") >= 0:
                    param_string = temp_string[temp_string.find('(') + 1:temp_string.find(')')]
                    break

        return param_string

    def list_c_files_in_directory(self, path):
        matches = []
        for root, dirnames, filenames in os.walk(path):
            for filename in fnmatch.filter(filenames, '*.c'):
                matches.append(os.path.join(root, filename))
        return matches


if __name__ == "__main__":
    try:
        if not os.path.isdir(sys.argv[1]):
            raise Exception('Not a valid directory')
    except:
        print("Please provide the path to the Kamailio src folder as the first argument")
        exit()

    print("Parsing the source")
    parser = KemiFileExportParser()
    data = parser.generate_kemi_export_list(sys.argv[1].rstrip("/"))
    fgen = ModuleObjGenerator()
    fgen.execute(data)
    print("Done")