#!/usr/bin/python2
# -*- coding: utf-8 -*-

from __future__ import print_function
import re
import argparse
from abc import abstractmethod
import os
from shutil import copyfile
import subprocess

import jwutils
from jwutils.log import *

_exts_h     = set([ '.h', '.H', '.hxx', '.HXX'])
_exts_cpp   = set([ '.cpp', '.CPP', '.c', '.C', '.cxx', '.CXX' ])
_exts_h_cpp = _exts_h | _exts_cpp

class Cmd(jwutils.Cmd):

    def __init__(self, name, help):
        self.replacements = None
        super(Cmd, self).__init__(name, help=help)

    @staticmethod
    def _replace_pattern(line, src, target):
        return line.replace(src, target)

    @staticmethod
    def _replace_cpp_symbol(data, src, target):
	stopc  = "^a-zA-Z0-9_"
	stopa  = "(^|[" + stopc + "])"
	stope  = "([" + stopc + "]|$)"
        f = stopa + src + stope
        t = "\\1" + target + "\\2"
        done = False
        try:
            while True:
                #slog(WARNING, "replacing", f, "by", t)
                r = re.sub(f, t, data, flags=re.MULTILINE)
                if r == data:
                    break
                data = r
        except:
            slog(ERR, "failed to replace", f, "by", t, "in", data)
            return data
        #if r != data:
        #    slog(NOTICE, "  replaced ", f, "->", t)
        #    slog(NOTICE, "  resulted in ", data, "->", r)
        return r

    def _replace_in_file(self, path, replacements, func=None, backup='rep'):
        if func is None:
            func = self._replace_pattern
        tmp = path + '.' + backup
        changed = False
        with open(path) as infile, open(tmp, 'w') as outfile:
            data = infile.read()
            for src, target in replacements.iteritems():
                odata = data
                #data = data.replace(src, target)
                data = func(data, src, target)
                if data != odata:
                    #slog(NOTICE, "changed", odata, "to", data, "in", path)
                    changed = True
            outfile.write(data)
        if not changed:
            return False

        if backup is None:
            os.rename(tmp, path)
        else:
            copyfile(tmp, path)
        return True

    def _replace_in_string(self, string, replacements, func=None):
        r = ""
        if func is None:
            func = self._replace_pattern
        for line in iter(string.splitlines()):
            for src, target in replacements.iteritems():
                line = func(line, src, target)
                r = r + line
        return r

    def _add_namespace_to_header(self, data, ns_new):
        lines = data.splitlines()
        old = None
        ns_cur = []
        for line in iter(lines):
            match = re.sub('^ *namespace[ \t]*([^ ]+)[ \t]*{.*', '\\1', line)
            if match != line:
                #ns_cur = match(blah, bl
                raise Exception("Name space addition is not yet implemented")
            classname = re.sub('^ *#[ \t]*ifndef[\t ]+([^ ]+)($|[ \t/;])', '\\1', line)

    def _fix_multiple_inclusion_preventer(self, prefix, path):
        dir, name = os.path.split(path)
        if len(name) == 0:
            return False
        trunc, ext = os.path.splitext(name)
        if ext not in _exts_h:
            return False
        tok = re.sub('([A-Z])', '_\\1', name)
        tok = re.sub('\.', '_', tok)
        mip = prefix + '_' + tok
        mip = re.sub('__', '_', mip)
        mip = mip.upper()
        # find first old mip
        with open(path, 'r') as f:
            data = f.read()
        lines = data.splitlines()
        old = None
        for line in iter(lines):
            old = re.sub('^ *#[ \t]*ifndef[\t ]+([^ ]+)($|[ \t/;])', '\\1', line)
            if old == line:
                continue
            #slog(NOTICE, "found MIP", old, "in", line)
            break
        if old is None:
            # TODO: add anyway at beginning and end
            raise Exception('No multiple inclusion preventer found in', path, ', not implemented')
        data = ''
        level = 0
        for line in iter(lines):
            if re.match('^ *#[ \t]*if.?def[\t ]', line):
                level += 1
                if re.match('^ *#[ \t]*ifndef[\t ]+' + old + '($|[ \t/;])', line):
                    data += '#ifndef ' + mip + '\n'
                    continue
            elif re.match('^ *#[ \t]*define[\t ]+' + old + '($|[ \t/;])', line):
                data += '#define ' + mip + '\n'
                continue
            elif re.match('^ *#[ \t]*endif($|[ \t/;])', line):
                level -= 1
                if level == 0:
                    data += '#endif /* ' + mip + ' */' + '\n'
                    continue
            data += line + '\n'
        tmp = path + '.mip'
        with open(tmp, 'w') as f:
            f.write(data)
        os.rename(tmp, path)

    def add_parser(self, parsers):
        p = super(Cmd, self).add_parser(parsers)
        p.add_argument("--regex", help="Specify regular expression by input file", default=None)
        p.add_argument("--replace-patterns-from", help="File with patterns to replace, side by side, divided by '->'", default=None)
        p.add_argument('-r', "--root", help="Point in file system from which to start search", default='.')
        p.add_argument("--backup", help="Backup extension", default='rep')
        p.add_argument('-g', '--git', help="Use git mv for renaming files", action='store_true', default=False)
        return p

    def _init(self, args):
        if args.replace_patterns_from is not None:
	    self.replacements = dict()
            with open(args.replace_patterns_from) as infile:
                for line in infile:
                    s = re.split('->', line)
                    self.replacements[s[0]] = s[1].rstrip('\n')
	    #slog(NOTICE, "replacements =", self.replacements)

    # overriding
    def run(self, args):
        self._init(args)
        slog(NOTICE, "running")
        files = []
        if args.regex is not None:
            for root, dirs, names in os.walk(args.root):
                for name in names:
                    if re.match(args.regex, name):
                        files.append((root, name))
            self.process(args, files)

    @abstractmethod
    def process(self, args, files):
        pass


class CmdReplacePatterns(Cmd):

    def __init__(self):
        super(CmdReplacePatterns, self).__init__("replace-patterns", "Replace patterns in files")

    def process(self, args, files):
        for dir, name in files:
            if self.replacements is not None:
                path = dir + '/' + name
                self._replace_in_file(path, self.replacements, func=self._replace_pattern)

class CmdReplaceCppSymbols(Cmd):

    def __init__(self):
        super(CmdReplaceCppSymbols, self).__init__("replace-cpp-symbols", "Replace C++ symbols in files")

    def add_parser(self, parsers):
        p = super(CmdReplaceCppSymbols, self).add_parser(parsers)
        p.add_argument('-F', '--rename-files', help="Rename source files, too", action='store_true', default=False)
        p.add_argument('-P', '--mip-prefix', help="Prefix to multiple-inclusion preventer", default='')
        return p

    # overriding
    def run(self, args):
        if args.regex is not None:
            return super(CmdReplaceCppSymbols, self).run(args)
        self._init(args)
        slog(NOTICE, "running")
        files = []
        exts = _exts_h_cpp | set([ '.sh', '.py' ])
        for root, dirs, names in os.walk(args.root):
            for name in names:
                trunc, ext = os.path.splitext(name)
                if ext in exts:
                    files.append((root, name))
        self.process(args, files)

    # overriding
    def _init(self, args):
        r = super(CmdReplaceCppSymbols, self)._init(args)
        self.file_truncs = set()
	if self.replacements is not None:
            for patt in self.replacements:
                self.file_truncs.add(patt.lower())
        return r

    def process(self, args, files):
        for dir, name in files:
            path = dir + '/' + name
            if self.replacements is not None:
                self._replace_in_file(path, self.replacements, func=self._replace_cpp_symbol)
        if args.rename_files:
            for dir, name in files:
                trunc, ext = os.path.splitext(name)
                if not ext in _exts_h_cpp:
                    continue
                if not trunc.lower() in self.file_truncs:
                    continue
                for patt, repl in self.replacements.iteritems():
                    if patt == trunc:
                        path     = dir + '/' + name
                        new_path = dir + '/' + repl + ext
                        assert(new_path != path)
                        slog(NOTICE, "renaming", path, "->", new_path)
                        if args.git:
                            subprocess.call(['git', 'mv', path, new_path])
                        else:
                            os.rename(path, new_path)
                        self._fix_multiple_inclusion_preventer(args.mip_prefix, new_path)

class CmdAddCppNamespace(Cmd):

    def __init__(self):
        super(CmdAddCppNamespace, self).__init__("add-cpp-namespace", "Enclose C++ classes in namespace")

    def add_parser(self, parsers):
        p = super(CmdAddCppNamespace, self).add_parser(parsers)
        p.add_argument('-n', '--namespace', help="Namespace", default=None)
        p.add_argument('-p', '--package', help="Package", default=None)
        return p

    # overriding
    def run(self, args):
        if args.regex is not None:
            return super(CmdAddCppNamespace, self).run(args)
        self._init(args)
        slog(NOTICE, "running")
        files = []
        exts = _exts_h_cpp | set([ '.sh', '.py' ])
        for root, dirs, names in os.walk(args.root):
            for name in names:
                trunc, ext = os.path.splitext(name)
                if ext in exts:
                    files.append((root, name))
        self.process(args, files)

    # overriding
    def _init(self, args):
        r = super(CmdAddCppNamespace, self)._init(args)
        self.file_truncs = set()
	if self.replacements is not None:
            for patt in self.replacements:
                self.file_truncs.add(patt.lower())
        return r

    def process(self, args, files):
        if args.namespace:
            for dir, name in files:
                path = dir + '/' + name
                with open(path) as infile:
                    data = odata = infile.read()
                trunc, ext = os.path.splitext(name)
                if ext in _exts_h:
                    data = self._add_namespace_to_header(data, namespace)
                elif ext in _exts_cpp:
                    data = self._add_using_namespace(data, namespace)
                #elif: Not sure what this was meant to do
                #    continue
                if data == odata:
                    continue
                tmp = path + '.' + ('rep' if args.backup is None else args.backup)
                with open(tmp, 'w') as outfile:
                    outfile.write(data)

jwutils.run_sub_commands('process text files')