#!/usr/bin/env python
#
# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2012 Yannick Brosseau <yannick.brosseau@gmail.com>

from __future__ import print_function
import sys
import getopt
import re
import os
import subprocess


class Usage(Exception):
    def __init__(self, msg):
        self.msg = msg


class HeaderFile:
    HEADER_TPL = """
#undef LTTNG_UST_TRACEPOINT_PROVIDER
#define LTTNG_UST_TRACEPOINT_PROVIDER {providerName}

#undef LTTNG_UST_TRACEPOINT_INCLUDE
#define LTTNG_UST_TRACEPOINT_INCLUDE "./{headerFilename}"

#if !defined({includeGuard}) || defined(LTTNG_UST_TRACEPOINT_HEADER_MULTI_READ)
#define {includeGuard}

#include <lttng/tracepoint.h>

"""
    FOOTER_TPL = """
#endif /* {includeGuard} */

#include <lttng/tracepoint-event.h>
"""

    def __init__(self, filename, template):
        self.outputFilename = filename
        self.template = template

    def write(self):
        outputFile = open(self.outputFilename, "w")
        # Include guard macro will be created by uppercasing the filename and
        # replacing all non alphanumeric characters with '_'
        includeGuard = re.sub('[^0-9a-zA-Z]', '_', self.outputFilename.upper())

        outputFile.write(HeaderFile.HEADER_TPL.format(providerName=self.template.domain,
                                           includeGuard=includeGuard,
                                           headerFilename=self.outputFilename))
        outputFile.write(self.template.text)
        outputFile.write(HeaderFile.FOOTER_TPL.format(includeGuard=includeGuard))
        outputFile.close()


class CFile:
    FILE_TPL = """
#define LTTNG_UST_TRACEPOINT_CREATE_PROBES
/*
 * The header containing our LTTNG_UST_TRACEPOINT_EVENTs.
 */
#define LTTNG_UST_TRACEPOINT_DEFINE
#include "{headerFilename}"
"""

    def __init__(self, filename, template):
        self.outputFilename = filename
        self.template = template

    def write(self):
        outputFile = open(self.outputFilename, "w")

        headerFilename = self.outputFilename
        if headerFilename.endswith(".c"):
            headerFilename = headerFilename[:-2] + ".h"

        outputFile.write(CFile.FILE_TPL.format(
                                           headerFilename=headerFilename))
        outputFile.close()


class ObjFile:
    def __init__(self, filename, template):
        self.outputFilename = filename
        self.template = template

    def _detectCC(self):
        cc = ""
        if 'CC' in os.environ:
            cc = os.environ['CC']
            try:
                subprocess.call(cc.split(),
                                stdout=subprocess.PIPE,
                                stderr=subprocess.PIPE)
            except OSError as msg:
                print("Invalid CC environment variable")
                cc = ""

        else:
            # Try c first, if that fails try gcc
            try:
                useCC = True
                subprocess.call("cc",
                                stdout=subprocess.PIPE,
                                stderr=subprocess.PIPE)
            except OSError as msg:
                useCC = False
            if useCC:
                cc = "cc"

            else:
                try:
                    useGCC = True
                    subprocess.call("gcc",
                                    stdout=subprocess.PIPE,
                                    stderr=subprocess.PIPE)
                except OSError as msg:
                    useGCC = False
                if useGCC:
                    cc = "gcc"
        return cc

    def write(self):
        cFilename = self.outputFilename
        if cFilename.endswith(".o"):
            cFilename = cFilename[:-2] + ".c"

        cc = self._detectCC()
        if cc == "":
            raise RuntimeError("No C Compiler detected")
        if 'CPPFLAGS' in os.environ:
            cppflags = " " + os.environ['CPPFLAGS']
        else:
            cppflags = ""
        if 'CFLAGS' in os.environ:
            cflags = " " + os.environ['CFLAGS']
        else:
            cflags = ""

        command = cc + " -c" + cppflags + cflags + " -I. -o " + self.outputFilename + " " + cFilename
        if verbose:
            print("Compile command: " + command)
        subprocess.call(command.split())


class TemplateFile:
    def __init__(self, filename):
        self.domain = ""
        self.inputFilename = filename
        self.parseTemplate()

    def parseTemplate(self):
        f = open(self.inputFilename, "r")

        self.text = f.read()

        # Remove # comments (from input and output file) but keep
        # #include in the output file
        removeComments = re.compile("#[^include].*$", flags=re.MULTILINE)
        self.text = removeComments.sub("", self.text)
        # Remove #include directive from the parsed text
        removePreprocess = re.compile("#.*$", flags=re.MULTILINE)
        noPreprocess = removePreprocess.sub("", self.text)
        # Remove // comments
        removeLineComment = re.compile("\/\/.*$", flags=re.MULTILINE)
        nolinecomment = removeLineComment.sub("", noPreprocess)
        # Remove all spaces and lines
        cleantext = re.sub("\s*", "", nolinecomment)
        # Remove multine C style comments
        nocomment = re.sub("/\*.*?\*/", "", cleantext)
        entries = re.split("^LTTNG_UST_TRACEPOINT_.*?", nocomment)

        for entry in entries:
            if entry != '':
                decomp = re.findall("(\w*?)\((\w*?),(\w*?),", entry)
                typea = decomp[0][0]
                domain = decomp[0][1]
                name = decomp[0][2]

                if self.domain == "":
                    self.domain = domain
                else:
                    if self.domain != domain:
                        print("Warning: different domain provided (%s,%s)" % (self.domain, domain))


verbose = False

usage = """
 lttng-gen-tp - Generate the LTTng-UST header and source based on a simple template

 usage: lttng-gen-tp TEMPLATE_FILE [-o OUTPUT_FILE][-o OUTPUT_FILE]

 If no OUTPUT_FILE is given, the .h and .c file will be generated.
 (The basename of the template file with be used for the generated file.
  for example sample.tp will generate sample.h, sample.c and sample.o)

 When using the -o option, the OUTPUT_FILE must end with either .h, .c or .o
 The -o option can be repeated multiple times.

 The template file must contains LTTNG_UST_TRACEPOINT_EVENT and LTTNG_UST_TRACEPOINT_LOGLEVEL
 as per defined in the lttng/tracepoint.h file.
 See the lttng-ust(3) man page for more details on the format.
"""


def main(argv=None):
    if argv is None:
        argv = sys.argv

    try:
        try:
            opts, args = getopt.gnu_getopt(argv[1:], "ho:av", ["help", "verbose"])
        except getopt.error as msg:
            raise Usage(msg)

    except Usage as err:
        print(err.msg, file=sys.stderr)
        print("for help use --help", file=sys.stderr)
        return 2

    outputNames = []
    for o, a in opts:
        if o in ("-h", "--help"):
            print(usage)
            return(0)
        if o in ("-o", ""):
            outputNames.append(a)
        if o in ("-a", ""):
            all = True
        if o in ("-v", "--verbose"):
            global verbose
            verbose = True
    try:
        if len(args) == 0:
            raise Usage("No template file given")

    except Usage as err:
        print(err.msg, file=sys.stderr)
        print("for help use --help", file=sys.stderr)
        return 2

    doCFile = None
    doHeader = None
    doObj = None
    headerFilename = None
    cFilename = None
    objFilename = None

    if len(outputNames) > 0:
        if len(args) > 1:
            print("Cannot process more than one input if you specify an output")
            return(3)

        for outputName in outputNames:
            if outputName[-2:] == ".h":
                doHeader = True
                headerFilename = outputName
            elif outputName[-2:] == ".c":
                doCFile = True
                cFilename = outputName
            elif outputName[-2:] == ".o":
                doObj = True
                objFilename = outputName
            else:
                print("output file type unsupported")
                return(4)
    else:
        doHeader = True
        doCFile = True
        doObj = True

    # process arguments
    for arg in args:
        if arg[-3:] != ".tp":
                print(arg + " does not end in .tp. Skipping.")
                continue

        tpl = None
        try:
            tpl = TemplateFile(arg)
        except IOError as args:
            print("Cannot read input file " + args.filename + " " + args.strerror)
            return -1
        try:
            if doHeader:
                if headerFilename:
                    curFilename = headerFilename
                else:
                    curFilename = re.sub("\.tp$", ".h", arg)
                doth = HeaderFile(curFilename, tpl)
                doth.write()
            if doCFile:
                if cFilename:
                    curFilename = cFilename
                else:
                    curFilename = re.sub("\.tp$", ".c", arg)
                dotc = CFile(curFilename, tpl)
                dotc.write()
            if doObj:
                if objFilename:
                    curFilename = objFilename
                else:
                    curFilename = re.sub("\.tp$", ".o", arg)
                dotobj = ObjFile(curFilename, tpl)
                dotobj.write()
        except IOError as args:
            print("Cannot write output file " + args.filename + " " + args.strerror)
            return -1


if __name__ == "__main__":
    sys.exit(main())