import os
import subprocess
import tempfile

import yaml

from .color import colored

try:
    import pybtex
    import pybtex.database
    import pybtex.database.input
    import pybtex.database.input.bibtex
    import pybtex.database.input.bibtexml
    import pybtex.database.input.bibyaml
    import pybtex.database.output
    import pybtex.database.output.bibtex
    import pybtex.database.output.bibtexml
    import pybtex.database.output.bibyaml

except ImportError:
    print(colored('error', 'error')
            + ': you need to install Pybtex; try running \'pip install'
            'pybtex\' or \'easy_install pybtex\'')


_papersdir = None

BIB_EXTENSIONS = ['.bib', '.bibyaml', '.bibml', '.yaml']
FORMATS = {'bib': pybtex.database.input.bibtex,
           'xml': pybtex.database.input.bibtexml,
           'yml': pybtex.database.input.bibyaml,
           'yaml': pybtex.database.input.bibyaml,
           'bibyaml': pybtex.database.input.bibyaml}


def clean_path(path):
    return os.path.abspath(os.path.expanduser(path))


def find_papersdir():
    """Find .papers directory in this directory and the parent directories"""
    global _papersdir
    if _papersdir is None:
        curdir = os.path.abspath('')
        while curdir != '':
            curdir_path = os.path.join(clean_path(curdir), '.papers')
            if (os.path.exists(curdir_path) and os.path.isdir(curdir_path)):
                _papersdir = curdir + '/.papers'
                curdir = ''
            if curdir == '/':
                curdir = '~'
            elif curdir == '~':
                curdir = ''
            else:
                curdir = os.path.split(curdir)[0]
        if _papersdir is None:
            print (colored('error', 'error')
                    + ': no papers repo found in this directory or in '
                    'any parent directory.')
            exit(-1)
    return _papersdir


def name_from_path(fullpdfpath, verbose=False):
    name, ext = os.path.splitext(os.path.split(fullpdfpath)[1])
    if verbose:
        if ext != '.pdf' and ext != '.ps':
            print(colored('warning', 'yellow')
                    + '{: extension {ext} not recognized'.format(
                        ext=colored(ext, 'cyan')))
    return name, ext


def check_file(filepath):
    if not os.path.exists(filepath):
        print(colored('error', 'error') +
                ': {} does not exists'.format(
               colored(filepath, 'filepath')))
        exit(-1)
    if not os.path.isfile(filepath):
        print(colored('error', 'error')
                + ': {} is not a file'.format(
                    colored(filepath, 'filepath')))
        exit(-1)


# yaml I/O

def write_yamlfile(filepath, datamap):
    try:
        with open(filepath, 'w') as f:
            yaml.dump(datamap, f)
    except IOError:
        print(colored('error', 'error')
                + ': impossible to read file {}'.format(
                    colored(filepath, 'filepath')))
        exit(-1)


def read_yamlfile(filepath):
    check_file(filepath)
    try:
        with open(filepath, 'r') as f:
            return yaml.load(f)
    except IOError:
        print(colored('error', 'error')
                + ': impossible to read file {}'.format(
                    colored(filepath, 'filepath')))
        exit(-1)


def load_bibdata(filename, filepath):
    return load_externalbibfile(filepath)


def save_bibdata(bib_data, filepath):
    with open(filepath, 'w') as f:
        parser = pybtex.database.output.bibyaml.Writer()
        parser.write_stream(bib_data, f)


def save_meta(meta_data, filepath):
    write_yamlfile(filepath, meta_data)


def load_meta(filepath):
    return read_yamlfile(filepath)


# specific to bibliography data

def load_externalbibfile(fullbibpath):
    check_file(fullbibpath)

    filename, ext = os.path.splitext(os.path.split(fullbibpath)[1])
    if ext[1:] in FORMATS.keys():
        with open(fullbibpath) as f:
            return parse_bibdata(f, ext[1:])
    else:
        print(colored('error', 'error')
                + ': {} not recognized format for bibliography'.format(
                    colored(ext, 'cyan')))
        exit(-1)


def parse_bibdata(content, format_):
    """Parse bib data from string.

    :content: stream
    :param format_: (bib|xml|yml)
    """
    parser = FORMATS[format_].Parser()
    return parser.parse_stream(content)


def editor_input(editor, initial=""):
    """Use an editor to get input"""
    with tempfile.NamedTemporaryFile(suffix=".tmp", delete=False) as temp_file:
        tfile_name = temp_file.name
        temp_file.write(initial)
        temp_file.flush()
        subprocess.call([editor, tfile_name])
    with open(tfile_name) as temp_file:
        content = temp_file.read()
        os.remove(tfile_name)
    return content