"""
A custom transform using external command
"""

from os import popen3
from Products.PortalTransforms.interfaces import ITransform
from Products.PortalTransforms.libtransforms.commandtransform import commandtransform
from Products.PortalTransforms.utils import log
from zope.interface import implementer

import os.path


@implementer(ITransform)
class ExternalCommandTransform(commandtransform):
    """Custom external command

    transform content by launching an external command

    the command should take the content in an input file (designed by '%s' in
    the command line parameters) and return output on stdout.
    Input and output mime types must be set correctly !
    """

    __name__ = "command_transform"

    def __init__(self, name=None, input_extension=None, **kwargs):
        self.config = {
            "binary_path": "",
            "command_line": "",
            "inputs": ("text/plain",),
            "output": "text/plain",
        }
        self.config_metadata = {
            "binary_path": (
                "string",
                "Binary path",
                "Path of the executable on the server.",
            ),
            "command_line": (
                "string",
                "Command line",
                """Additional command line option.
There should be at least the input file (designed by "%(input)s").
The transformation\'s result must be printed on stdout.
""",
            ),
            "inputs": ("list", "Inputs", "Input(s) MIME type. Change with care."),
            "output": ("string", "Output", "Output MIME type. Change with care."),
        }
        self.config.update(kwargs)
        commandtransform.__init__(
            self, name=name, binary=self.config["binary_path"], **kwargs
        )

        # use the full binary path
        self.config.update({"binary_path": self.binary})
        self.input_extension = input_extension

    def __getattr__(self, attr):
        if attr == "inputs":
            return self.config["inputs"]
        if attr == "output":
            return self.config["output"]
        raise AttributeError(attr)

    def convert(self, data, cache, **kwargs):
        filename = kwargs.get("filename") or "unknown"
        if self.input_extension is not None:
            kwargs["filename"] = "unknown" + self.input_extension
        else:
            kwargs["filename"] = "unknown" + os.path.splitext(filename)[-1]
        tmpdir, fullname = self.initialize_tmpdir(data, **kwargs)

        data = self.invokeCommand(fullname)
        cache.setData(data)
        path, images = self.subObjects(tmpdir)
        objects = {}
        if images:
            self.fixImages(path, images, objects)
            cache.setSubObjects(objects)
        self.cleanDir(tmpdir)
        return cache

    def invokeCommand(self, input_name):
        command = "%(binary_path)s %(command_line)s" % self.config
        input, output, error = popen3(command % input_name)
        input.close()
        # first read stderr, else we may hang on stout
        # but, still hang my windows, so commented it :-(
        # error_data = error.read()
        error_data = 'error while running "%s"' % (command % input_name)
        error.close()
        data = output.read()
        output.close()
        if error_data and not data:
            data = error_data
        else:
            log(
                'Error while running "{}":\n {}'.format(
                    command % input_name, error_data
                )
            )
        return data


def register():
    return ExternalCommandTransform()
