import codecs
from codecs import BOM_UTF8
import os
import re
import shlex
import sys
import tempfile

import tkinter.filedialog as tkFileDialog
import tkinter.messagebox as tkMessageBox
from tkinter.simpledialog import askstring

import idlelib
from idlelib.config import idleConf

if idlelib.testing:  # Set True by test.test_idle to avoid setlocale.
    encoding = 'utf-8'
    errors = 'surrogateescape'
else:
    # Try setting the locale, so that we can find out
    # what encoding to use
    try:
        import locale
        locale.setlocale(locale.LC_CTYPE, "")
    except (ImportError, locale.Error):
        pass

    if sys.platform == 'win32':
        encoding = 'utf-8'
        errors = 'surrogateescape'
    else:
        try:
            # Different things can fail here: the locale module may not be
            # loaded, it may not offer nl_langinfo, or CODESET, or the
            # resulting codeset may be unknown to Python. We ignore all
            # these problems, falling back to ASCII
            locale_encoding = locale.nl_langinfo(locale.CODESET)
            if locale_encoding:
                codecs.lookup(locale_encoding)
        except (NameError, AttributeError, LookupError):
            # Try getdefaultlocale: it parses environment variables,
            # which may give a clue. Unfortunately, getdefaultlocale has
            # bugs that can cause ValueError.
            try:
                locale_encoding = locale.getdefaultlocale()[1]
                if locale_encoding:
                    codecs.lookup(locale_encoding)
            except (ValueError, LookupError):
                pass

        if locale_encoding:
            encoding = locale_encoding.lower()
            errors = 'strict'
        else:
            # POSIX locale or macOS
            encoding = 'ascii'
            errors = 'surrogateescape'
        # Encoding is used in multiple files; locale_encoding nowhere.
        # The only use of 'encoding' below is in _decode as initial value
        # of deprecated block asking user for encoding.
        # Perhaps use elsewhere should be reviewed.

coding_re = re.compile(r'^[ \t\f]*#.*?coding[:=][ \t]*([-\w.]+)', re.ASCII)
blank_re = re.compile(r'^[ \t\f]*(?:[#\r\n]|$)', re.ASCII)

def coding_spec(data):
    """Return the encoding declaration according to PEP 263.

    When checking encoded data, only the first two lines should be passed
    in to avoid a UnicodeDecodeError if the rest of the data is not unicode.
    The first two lines would contain the encoding specification.

    Raise a LookupError if the encoding is declared but unknown.
    """
    if isinstance(data, bytes):
        # This encoding might be wrong. However, the coding
        # spec must be ASCII-only, so any non-ASCII characters
        # around here will be ignored. Decoding to Latin-1 should
        # never fail (except for memory outage)
        lines = data.decode('iso-8859-1')
    else:
        lines = data
    # consider only the first two lines
    if '\n' in lines:
        lst = lines.split('\n', 2)[:2]
    elif '\r' in lines:
        lst = lines.split('\r', 2)[:2]
    else:
        lst = [lines]
    for line in lst:
        match = coding_re.match(line)
        if match is not None:
            break
        if not blank_re.match(line):
            return None
    else:
        return None
    name = match.group(1)
    try:
        codecs.lookup(name)
    except LookupError:
        # The standard encoding error does not indicate the encoding
        raise LookupError("Unknown encoding: "+name)
    return name


class IOBinding:
# One instance per editor Window so methods know which to save, close.
# Open returns focus to self.editwin if aborted.
# EditorWindow.open_module, others, belong here.

    def __init__(self, editwin):
        self.editwin = editwin
        self.text = editwin.text
        self.__id_open = self.text.bind("<<open-window-from-file>>", self.open)
        self.__id_save = self.text.bind("<<save-window>>", self.save)
        self.__id_saveas = self.text.bind("<<save-window-as-file>>",
                                          self.save_as)
        self.__id_savecopy = self.text.bind("<<save-copy-of-window-as-file>>",
                                            self.save_a_copy)
        self.fileencoding = None
        self.__id_print = self.text.bind("<<print-window>>", self.print_window)

    def close(self):
        # Undo command bindings
        self.text.unbind("<<open-window-from-file>>", self.__id_open)
        self.text.unbind("<<save-window>>", self.__id_save)
        self.text.unbind("<<save-window-as-file>>",self.__id_saveas)
        self.text.unbind("<<save-copy-of-window-as-file>>", self.__id_savecopy)
        self.text.unbind("<<print-window>>", self.__id_print)
        # Break cycles
        self.editwin = None
        self.text = None
        self.filename_change_hook = None

    def get_saved(self):
        return self.editwin.get_saved()

    def set_saved(self, flag):
        self.editwin.set_saved(flag)

    def reset_undo(self):
        self.editwin.reset_undo()

    filename_change_hook = None

    def set_filename_change_hook(self, hook):
        self.filename_change_hook = hook

    filename = None
    dirname = None

    def set_filename(self, filename):
        if filename and os.path.isdir(filename):
            self.filename = None
            self.dirname = filename
        else:
            self.filename = filename
            self.dirname = None
            self.set_saved(1)
            if self.filename_change_hook:
                self.filename_change_hook()

    def open(self, event=None, editFile=None):
        flist = self.editwin.flist
        # Save in case parent window is closed (ie, during askopenfile()).
        if flist:
            if not editFile:
                filename = self.askopenfile()
            else:
                filename=editFile
            if filename:
                # If editFile is valid and already open, flist.open will
                # shift focus to its existing window.
                # If the current window exists and is a fresh unnamed,
                # unmodified editor window (not an interpreter shell),
                # pass self.loadfile to flist.open so it will load the file
                # in the current window (if the file is not already open)
                # instead of a new window.
                if (self.editwin and
                        not getattr(self.editwin, 'interp', None) and
                        not self.filename and
                        self.get_saved()):
                    flist.open(filename, self.loadfile)
                else:
                    flist.open(filename)
            else:
                if self.text:
                    self.text.focus_set()
            return "break"

        # Code for use outside IDLE:
        if self.get_saved():
            reply = self.maybesave()
            if reply == "cancel":
                self.text.focus_set()
                return "break"
        if not editFile:
            filename = self.askopenfile()
        else:
            filename=editFile
        if filename:
            self.loadfile(filename)
        else:
            self.text.focus_set()
        return "break"

    eol = r"(\r\n)|\n|\r"  # \r\n (Windows), \n (UNIX), or \r (Mac)
    eol_re = re.compile(eol)
    eol_convention = os.linesep  # default

    def loadfile(self, filename):
        try:
            # open the file in binary mode so that we can handle
            # end-of-line convention ourselves.
            with open(filename, 'rb') as f:
                two_lines = f.readline() + f.readline()
                f.seek(0)
                bytes = f.read()
        except OSError as msg:
            tkMessageBox.showerror("I/O Error", str(msg), parent=self.text)
            return False
        chars, converted = self._decode(two_lines, bytes)
        if chars is None:
            tkMessageBox.showerror("Decoding Error",
                                   "File %s\nFailed to Decode" % filename,
                                   parent=self.text)
            return False
        # We now convert all end-of-lines to '\n's
        firsteol = self.eol_re.search(chars)
        if firsteol:
            self.eol_convention = firsteol.group(0)
            chars = self.eol_re.sub(r"\n", chars)
        self.text.delete("1.0", "end")
        self.set_filename(None)
        self.text.insert("1.0", chars)
        self.reset_undo()
        self.set_filename(filename)
        if converted:
            # We need to save the conversion results first
            # before being able to execute the code
            self.set_saved(False)
        self.text.mark_set("insert", "1.0")
        self.text.yview("insert")
        self.updaterecentfileslist(filename)
        return True

    def _decode(self, two_lines, bytes):
        "Create a Unicode string."
        chars = None
        # Check presence of a UTF-8 signature first
        if bytes.startswith(BOM_UTF8):
            try:
                chars = bytes[3:].decode("utf-8")
            except UnicodeDecodeError:
                # has UTF-8 signature, but fails to decode...
                return None, False
            else:
                # Indicates that this file originally had a BOM
                self.fileencoding = 'BOM'
                return chars, False
        # Next look for coding specification
        try:
            enc = coding_spec(two_lines)
        except LookupError as name:
            tkMessageBox.showerror(
                title="Error loading the file",
                message="The encoding '%s' is not known to this Python "\
                "installation. The file may not display correctly" % name,
                parent = self.text)
            enc = None
        except UnicodeDecodeError:
            return None, False
        if enc:
            try:
                chars = str(bytes, enc)
                self.fileencoding = enc
                return chars, False
            except UnicodeDecodeError:
                pass
        # Try ascii:
        try:
            chars = str(bytes, 'ascii')
            self.fileencoding = None
            return chars, False
        except UnicodeDecodeError:
            pass
        # Try utf-8:
        try:
            chars = str(bytes, 'utf-8')
            self.fileencoding = 'utf-8'
            return chars, False
        except UnicodeDecodeError:
            pass
        # Finally, try the locale's encoding. This is deprecated;
        # the user should declare a non-ASCII encoding
        try:
            # Wait for the editor window to appear
            self.editwin.text.update()
            enc = askstring(
                "Specify file encoding",
                "The file's encoding is invalid for Python 3.x.\n"
                "IDLE will convert it to UTF-8.\n"
                "What is the current encoding of the file?",
                initialvalue = encoding,
                parent = self.editwin.text)

            if enc:
                chars = str(bytes, enc)
                self.fileencoding = None
            return chars, True
        except (UnicodeDecodeError, LookupError):
            pass
        return None, False  # None on failure

    def maybesave(self):
        if self.get_saved():
            return "yes"
        message = "Do you want to save %s before closing?" % (
            self.filename or "this untitled document")
        confirm = tkMessageBox.askyesnocancel(
                  title="Save On Close",
                  message=message,
                  default=tkMessageBox.YES,
                  parent=self.text)
        if confirm:
            reply = "yes"
            self.save(None)
            if not self.get_saved():
                reply = "cancel"
        elif confirm is None:
            reply = "cancel"
        else:
            reply = "no"
        self.text.focus_set()
        return reply

    def save(self, event):
        if not self.filename:
            self.save_as(event)
        else:
            if self.writefile(self.filename):
                self.set_saved(True)
                try:
                    self.editwin.store_file_breaks()
                except AttributeError:  # may be a PyShell
                    pass
        self.text.focus_set()
        return "break"

    def save_as(self, event):
        filename = self.asksavefile()
        if filename:
            if self.writefile(filename):
                self.set_filename(filename)
                self.set_saved(1)
                try:
                    self.editwin.store_file_breaks()
                except AttributeError:
                    pass
        self.text.focus_set()
        self.updaterecentfileslist(filename)
        return "break"

    def save_a_copy(self, event):
        filename = self.asksavefile()
        if filename:
            self.writefile(filename)
        self.text.focus_set()
        self.updaterecentfileslist(filename)
        return "break"

    def writefile(self, filename):
        self.fixlastline()
        text = self.text.get("1.0", "end-1c")
        if self.eol_convention != "\n":
            text = text.replace("\n", self.eol_convention)
        chars = self.encode(text)
        try:
            with open(filename, "wb") as f:
                f.write(chars)
                f.flush()
                os.fsync(f.fileno())
            return True
        except OSError as msg:
            tkMessageBox.showerror("I/O Error", str(msg),
                                   parent=self.text)
            return False

    def encode(self, chars):
        if isinstance(chars, bytes):
            # This is either plain ASCII, or Tk was returning mixed-encoding
            # text to us. Don't try to guess further.
            return chars
        # Preserve a BOM that might have been present on opening
        if self.fileencoding == 'BOM':
            return BOM_UTF8 + chars.encode("utf-8")
        # See whether there is anything non-ASCII in it.
        # If not, no need to figure out the encoding.
        try:
            return chars.encode('ascii')
        except UnicodeError:
            pass
        # Check if there is an encoding declared
        try:
            # a string, let coding_spec slice it to the first two lines
            enc = coding_spec(chars)
            failed = None
        except LookupError as msg:
            failed = msg
            enc = None
        else:
            if not enc:
                # PEP 3120: default source encoding is UTF-8
                enc = 'utf-8'
        if enc:
            try:
                return chars.encode(enc)
            except UnicodeError:
                failed = "Invalid encoding '%s'" % enc
        tkMessageBox.showerror(
            "I/O Error",
            "%s.\nSaving as UTF-8" % failed,
            parent = self.text)
        # Fallback: save as UTF-8, with BOM - ignoring the incorrect
        # declared encoding
        return BOM_UTF8 + chars.encode("utf-8")

    def fixlastline(self):
        c = self.text.get("end-2c")
        if c != '\n':
            self.text.insert("end-1c", "\n")

    def print_window(self, event):
        confirm = tkMessageBox.askokcancel(
                  title="Print",
                  message="Print to Default Printer",
                  default=tkMessageBox.OK,
                  parent=self.text)
        if not confirm:
            self.text.focus_set()
            return "break"
        tempfilename = None
        saved = self.get_saved()
        if saved:
            filename = self.filename
        # shell undo is reset after every prompt, looks saved, probably isn't
        if not saved or filename is None:
            (tfd, tempfilename) = tempfile.mkstemp(prefix='IDLE_tmp_')
            filename = tempfilename
            os.close(tfd)
            if not self.writefile(tempfilename):
                os.unlink(tempfilename)
                return "break"
        platform = os.name
        printPlatform = True
        if platform == 'posix': #posix platform
            command = idleConf.GetOption('main','General',
                                         'print-command-posix')
            command = command + " 2>&1"
        elif platform == 'nt': #win32 platform
            command = idleConf.GetOption('main','General','print-command-win')
        else: #no printing for this platform
            printPlatform = False
        if printPlatform:  #we can try to print for this platform
            command = command % shlex.quote(filename)
            pipe = os.popen(command, "r")
            # things can get ugly on NT if there is no printer available.
            output = pipe.read().strip()
            status = pipe.close()
            if status:
                output = "Printing failed (exit status 0x%x)\n" % \
                         status + output
            if output:
                output = "Printing command: %s\n" % repr(command) + output
                tkMessageBox.showerror("Print status", output, parent=self.text)
        else:  #no printing for this platform
            message = "Printing is not enabled for this platform: %s" % platform
            tkMessageBox.showinfo("Print status", message, parent=self.text)
        if tempfilename:
            os.unlink(tempfilename)
        return "break"

    opendialog = None
    savedialog = None

    filetypes = (
        ("Python files", "*.py *.pyw", "TEXT"),
        ("Text files", "*.txt", "TEXT"),
        ("All files", "*"),
        )

    defaultextension = '.py' if sys.platform == 'darwin' else ''

    def askopenfile(self):
        dir, base = self.defaultfilename("open")
        if not self.opendialog:
            self.opendialog = tkFileDialog.Open(parent=self.text,
                                                filetypes=self.filetypes)
        filename = self.opendialog.show(initialdir=dir, initialfile=base)
        return filename

    def defaultfilename(self, mode="open"):
        if self.filename:
            return os.path.split(self.filename)
        elif self.dirname:
            return self.dirname, ""
        else:
            try:
                pwd = os.getcwd()
            except OSError:
                pwd = ""
            return pwd, ""

    def asksavefile(self):
        dir, base = self.defaultfilename("save")
        if not self.savedialog:
            self.savedialog = tkFileDialog.SaveAs(
                    parent=self.text,
                    filetypes=self.filetypes,
                    defaultextension=self.defaultextension)
        filename = self.savedialog.show(initialdir=dir, initialfile=base)
        return filename

    def updaterecentfileslist(self,filename):
        "Update recent file list on all editor windows"
        if self.editwin.flist:
            self.editwin.update_recent_files_list(filename)

def _io_binding(parent):  # htest #
    from tkinter import Toplevel, Text

    root = Toplevel(parent)
    root.title("Test IOBinding")
    x, y = map(int, parent.geometry().split('+')[1:])
    root.geometry("+%d+%d" % (x, y + 175))
    class MyEditWin:
        def __init__(self, text):
            self.text = text
            self.flist = None
            self.text.bind("<Control-o>", self.open)
            self.text.bind('<Control-p>', self.print)
            self.text.bind("<Control-s>", self.save)
            self.text.bind("<Alt-s>", self.saveas)
            self.text.bind('<Control-c>', self.savecopy)
        def get_saved(self): return 0
        def set_saved(self, flag): pass
        def reset_undo(self): pass
        def open(self, event):
            self.text.event_generate("<<open-window-from-file>>")
        def print(self, event):
            self.text.event_generate("<<print-window>>")
        def save(self, event):
            self.text.event_generate("<<save-window>>")
        def saveas(self, event):
            self.text.event_generate("<<save-window-as-file>>")
        def savecopy(self, event):
            self.text.event_generate("<<save-copy-of-window-as-file>>")

    text = Text(root)
    text.pack()
    text.focus_set()
    editwin = MyEditWin(text)
    IOBinding(editwin)

if __name__ == "__main__":
    from unittest import main
    main('idlelib.idle_test.test_iomenu', verbosity=2, exit=False)

    from idlelib.idle_test.htest import run
    run(_io_binding)
