import os
import tempfile
import locale
import sys
from exc import WorblehatException

stdout_encoding = locale.getpreferredencoding()
file_encoding = 'utf-8'

output = sys.stdout

# def write_tmpfile(pfix, content, encoding='utf8'):
#     file = tempfile.NamedTemporaryFile(prefix=pfix+'-', dir='/tmp', delete=False)
#     file.write(content.encode(encoding))
#     name = file.name
#     file.close()
#     return name

def open_tmpfile(prefix):
    global output
    if output != sys.stdout:
        raise WorblehatException('open_tmpfile: Already writing to a file')
    tmpfile = tempfile.NamedTemporaryFile(prefix='worblehat-%s-' % prefix,
                                          dir='/tmp',
                                          delete=False)
    output = tmpfile
    return tmpfile.name

def close_tmpfile():
    global output
    if output == sys.stdout:
        raise WorblehatException('close_tmpfile: No file open')
    output.close()
    output = sys.stdout
    
def output_encoding():
    if output == sys.stdout:
        return stdout_encoding
    else:
        return file_encoding

def encoding_comment():
    return '# -*- coding: %s -*-\n' % file_encoding

def write(data):
    if type(data) == unicode:
        data = data.encode(output_encoding())
    output.write(data)

def write_stderr(data):
    if type(data) == unicode:
        data = data.encode(output_encoding())
    sys.stderr.write(data)

debugging = True
def debug(msg):
    if debugging:
        write_stderr('DEBUG: %s\n' % msg)

def tmpfile_name():
    if output == sys.stdout:
        raise WorblehatException('tmpfile_name: No file open')
    return output.name

class tmpfile:
    def __init__(self, prefix):
        self.prefix = prefix
    def __enter__(self):
        open_tmpfile(self.prefix)
    def __exit__(self, exc_type, exc, traceback):
        close_tmpfile()

def run_editor(filename):
    if os.path.exists(filename):
        os.system("%s %s || /usr/bin/env vi %s" %
                  (os.getenv("EDITOR"), filename, filename))
    else:
        exit("Error: %s: File does not exist!" % filename)