import os
import tw
from tw.api import Widget, JSLink, CSSLink, Link
from tw.core.resources import registry, working_set, Requirement
from defaults import __DEFAULT_LINK_IS_EXTERNAL__, __YUI_URL_BASE__, __YUI_VERSION__, __DEFAULT_SUFFIX__

class YUILinkMixin(Link):
    params = {'basename': '(string) basename for the given file.  if you want yuitest-min.js, the base is yuitest/yuitest',
              'suffix': '(string) "", min, beta-min, or beta.  Default is "min"',
              'version': '(string) select the yui version you would like to use. Default version is: '+__YUI_VERSION__,
              'external': '(boolean) default:False True if you would like to grab the file from YAHOO! instead of locally',
              'yui_url_base':'The base url for fetching the YUI library externally',
    }

    version = __YUI_VERSION__
    external = __DEFAULT_LINK_IS_EXTERNAL__
    yui_url_base = __YUI_URL_BASE__
    modname = "tw.yui"
    extension = 'js'
    default_suffix = __DEFAULT_SUFFIX__
    _suffix = ''

    def __init__(self, *args, **kw):
        super(Link, self).__init__(*args, **kw)
        if not self.is_external:
            modname = self.modname or self.__module__
            self.webdir, self.dirname, self.link = registry.register(
                modname, self.filename
                )
        if 'suffix' in kw:
            self.suffix = kw['suffix']
        else:
            self.suffix = self.default_suffix

    def _get_suffix(self):
        if self._suffix == '':
            return ''
        return '-'+self._suffix

    def _set_suffix(self, value):
        self._suffix = value

    suffix = property(_get_suffix, _set_suffix)

    @property
    def external_link(self):
        link = '/'.join((self.yui_url_base, self.version, 'build', self.basename+self.suffix+'.'+self.extension))
        #xxx:check for existance of this resource and choose -min -min-beta -debug or no suffix as alternatives.
        return link

    def _get_link(self):
        if self.is_external:
            return self.external_link
        return tw.framework.url(self._link or '')

    def _set_link(self, link):
        self._link = link

    link = property(_get_link, _set_link)

    def abspath(self, filename):
        return os.sep.join((os.path.dirname(__file__), filename))

    def try_filename(self, filename):
        abspath = self.abspath(filename)
        if os.path.exists(abspath):
            return filename
        return False

    @property
    def filename(self):
        #make basename windows/qnix compat
        basename = self.basename.replace('/', os.sep)
        basename = self.basename.replace('\\', os.sep)

        basename = os.sep.join(('static', self.version, 'build', basename))
        #try the default
        filename =  basename+self.suffix+'.'+self.extension
        if self.try_filename(filename):
            return filename

        #try '' if the default suffix is min
        if self.default_suffix == '':
            filename =  basename+self.suffix+'.'+self.extension
            if self.try_filename(filename):
                return filename

        #try min if the default suffix is ''
        if self.default_suffix == 'min':
            filename =  basename+'.'+self.extension
            if self.try_filename(filename):
                return filename

        #try debug
        filename =  basename+'-debug'+'.'+self.extension
        if self.try_filename(filename):
            return filename

        #try beta-min
        filename =  basename+'-beta-min'+'.'+self.extension
        if self.try_filename(filename):
            return filename

        #try beta
        filename =  basename+'-beta'+'.'+self.extension
        if self.try_filename(filename):
            return filename

        #try beta-debug
        filename =  basename+'-beta-debug'+'.'+self.extension
        if self.try_filename(filename):
            return filename
        return None

    @property
    def is_external(self):
        return self.external


class YUIJSLink(JSLink, YUILinkMixin):
    pass

class YUICSSLink(YUILinkMixin, CSSLink):
    extension = 'css'
