import os, re
from lxml import etree

from xmlclass import GenerateParserFromXSD

from CodeFileTreeNode import CodeFile
from PythonEditor import PythonEditor

class PythonFileCTNMixin(CodeFile):

    CODEFILE_NAME = "PyFile"
    SECTIONS_NAMES = [
        "globals",
        "init",
        "cleanup",
        "start",
        "stop"]
    EditorType = PythonEditor

    def __init__(self):
        CodeFile.__init__(self)

        filepath = self.PythonFileName()

        if os.path.isfile(filepath):
            PythonParser = GenerateParserFromXSD(
                os.path.join(os.path.dirname(__file__), "py_ext_xsd.xsd"))

            xmlfile = open(filepath, 'r')
            pythonfile_xml = xmlfile.read()
            xmlfile.close()

            pythonfile_xml = pythonfile_xml.replace(
                'xmlns="http://www.w3.org/2001/XMLSchema"',
                'xmlns:xhtml="http://www.w3.org/1999/xhtml"')
            for cre, repl in [
                (re.compile("(?<!<xhtml:p>)(?:<!\[CDATA\[)"), "<xhtml:p><![CDATA["),
                (re.compile("(?:]]>)(?!</xhtml:p>)"), "]]></xhtml:p>")]:
                pythonfile_xml = cre.sub(repl, pythonfile_xml)

            try:
                python_code, error = PythonParser.LoadXMLString(pythonfile_xml)
                if error is None:
                    self.CodeFile.globals.setanyText(python_code.getanyText())
                    os.remove(filepath)
                    self.CreateCodeFileBuffer(False)
                    self.OnCTNSave()
            except Exception, exc:
                error = unicode(exc)

            if error is not None:
                self.GetCTRoot().logger.write_error(
                    _("Couldn't import old %s file.") % self.CTNName())

    def CodeFileName(self):
        return os.path.join(self.CTNPath(), "pyfile.xml")

    def PythonFileName(self):
        return os.path.join(self.CTNPath(), "py_ext.xml")

    PreSectionsTexts = {}
    PostSectionsTexts = {}
    def GetSection(self,section):
        return self.PreSectionsTexts.get(section,"") + "\n" + \
               getattr(self.CodeFile, section).getanyText() + "\n" + \
               self.PostSectionsTexts.get(section,"")


    def CTNGenerate_C(self, buildpath, locations):
        # location string for that CTN
        location_str = "_".join(map(lambda x:str(x),
                                self.GetCurrentLocation()))
        configname = self.GetCTRoot().GetProjectConfigNames()[0]


        # python side PLC global variables access stub
        globalstubs = "\n".join(["""\
_%(name)s_ctype, _%(name)s_unpack, _%(name)s_pack = \\
    TypeTranslator["%(IECtype)s"]
_PySafeGetPLCGlob_%(name)s = PLCBinary.__SafeGetPLCGlob_%(name)s
_PySafeGetPLCGlob_%(name)s.restype = None
_PySafeGetPLCGlob_%(name)s.argtypes = [ctypes.POINTER(_%(name)s_ctype)]
_PySafeSetPLCGlob_%(name)s = PLCBinary.__SafeSetPLCGlob_%(name)s
_PySafeSetPLCGlob_%(name)s.restype = None
_PySafeSetPLCGlob_%(name)s.argtypes = [ctypes.POINTER(_%(name)s_ctype)]
_PySafePLCGlobals.append(("%(name)s","%(IECtype)s"))
""" % { "name": variable.getname(),
        "configname": configname.upper(),
        "uppername": variable.getname().upper(),
        "IECtype": variable.gettype()}
            for variable in self.CodeFile.variables.variable])

        # Runtime calls (start, stop, init, and cleanup)
        rtcalls = ""
        for section in self.SECTIONS_NAMES:
            if section != "globals":
                rtcalls += "def _runtime_%s_%s():\n" % (location_str, section)
                sectiontext = self.GetSection(section).strip()
                if sectiontext:
                    rtcalls += '    ' + \
                        sectiontext.replace('\n', '\n    ')+"\n\n"
                else:
                    rtcalls += "    pass\n\n"

        globalsection = self.GetSection("globals")

        pyextname = self.CTNName()

        PyFileContent = """\
#!/usr/bin/env python
# -*- coding: utf-8 -*-
## Code generated by Beremiz python mixin confnode
##

## Code for PLC global variable access
from targets.typemapping import TypeTranslator
import ctypes
_PyExtName = "%(pyextname)s"
_PySafePLCGlobals = []
%(globalstubs)s

## User code in "global" scope
%(globalsection)s

## Beremiz python runtime calls
%(rtcalls)s

""" % locals()

        # write generated content to python file
        runtimefile_path = os.path.join(buildpath,
            "runtime_%s.py"%location_str)
        runtimefile = open(runtimefile_path, 'w')
        runtimefile.write(PyFileContent.encode('utf-8'))
        runtimefile.close()

        # C code for safe global variables access

        vardecfmt = """\
extern  __IEC_%(IECtype)s_t %(configname)s__%(uppername)s;
IEC_%(IECtype)s __%(name)s_rbuffer = __INIT_%(IECtype)s;
IEC_%(IECtype)s __%(name)s_wbuffer;
long __%(name)s_rlock = 0;
long __%(name)s_wlock = 0;
int __%(name)s_wbuffer_written = 0;
void __SafeGetPLCGlob_%(name)s(IEC_%(IECtype)s *pvalue){
    while(AtomicCompareExchange(&__%(name)s_rlock, 0, 1));
    *pvalue = __%(name)s_rbuffer;
    AtomicCompareExchange((long*)&__%(name)s_rlock, 1, 0);
}
void __SafeSetPLCGlob_%(name)s(IEC_%(IECtype)s *value){
    while(AtomicCompareExchange(&__%(name)s_wlock, 0, 1));
    __%(name)s_wbuffer = *value;
    __%(name)s_wbuffer_written = 1;
    AtomicCompareExchange((long*)&__%(name)s_wlock, 1, 0);
}

"""
        varretfmt = """\
    if(!AtomicCompareExchange(&__%(name)s_wlock, 0, 1)){
        if(__%(name)s_wbuffer_written == 1){
            %(configname)s__%(uppername)s.value = __%(name)s_wbuffer;
            __%(name)s_wbuffer_written = 0;
        }
        AtomicCompareExchange((long*)&__%(name)s_wlock, 1, 0);
    }
"""
        varpubfmt = """\
    if(!AtomicCompareExchange(&__%(name)s_rlock, 0, 1)){
        __%(name)s_rbuffer = %(configname)s__%(uppername)s.value;
        AtomicCompareExchange((long*)&__%(name)s_rlock, 1, 0);
    }
"""

        var_str = map("\n".join, zip(*[
            map(lambda f : f % varinfo,
                (vardecfmt, varretfmt, varpubfmt))
                for varinfo in map(lambda variable : {
                    "name": variable.getname(),
                    "configname": configname.upper(),
                    "uppername": variable.getname().upper(),
                    "IECtype": variable.gettype()},
                    self.CodeFile.variables.variable)]))
        if len(var_str) > 0:
            vardec, varret, varpub = var_str
        else:
            vardec = varret = varpub = ""

        PyCFileContent = """\
/*
 * Code generated by Beremiz py_ext confnode
 * for safe global variables access
 */
#include "iec_types_all.h"
#include "beremiz.h"

/* User variables reference */
%(vardec)s

/* Beremiz confnode functions */
int __init_%(location_str)s(int argc,char **argv){
    return 0;
}

void __cleanup_%(location_str)s(void){
}

void __retrieve_%(location_str)s(void){
%(varret)s
}

void __publish_%(location_str)s(void){
%(varpub)s
}
""" % locals()

        Gen_PyCfile_path = os.path.join(buildpath, "PyCFile_%s.c"%location_str)
        pycfile = open(Gen_PyCfile_path,'w')
        pycfile.write(PyCFileContent)
        pycfile.close()

        matiec_flags = '"-I%s"'%os.path.abspath(
            self.GetCTRoot().GetIECLibPath())

        return ([(Gen_PyCfile_path, matiec_flags)],
                "",
                True,
                ("runtime_%s.py"%location_str, file(runtimefile_path,"rb")))