# coding: utf-8
"""Utilities for installing Javascript extensions for the notebook"""

# Copyright (c) Jupyter Development Team.
# Distributed under the terms of the Modified BSD License.

from __future__ import print_function

import importlib
import json
import os
import os.path as osp
import shutil
import sys
from os.path import basename, join as pjoin, normpath
import subprocess
import sys

from jupyter_core.paths import (
    jupyter_data_dir, SYSTEM_JUPYTER_PATH, ENV_JUPYTER_PATH,
)
from jupyter_core.utils import ensure_dir_exists
from ipython_genutils.py3compat import cast_unicode_py2
from jupyterlab_server.config import get_federated_extensions

from .commands import _test_overlap


DEPRECATED_ARGUMENT = object()

HERE = osp.abspath(osp.dirname(__file__))


#------------------------------------------------------------------------------
# Public API
#------------------------------------------------------------------------------

def develop_labextension(path, symlink=True, overwrite=False,
                        user=False, labextensions_dir=None,
                        destination=None,
                        logger=None, sys_prefix=False
                        ):
    """Install a prebuilt extension for JupyterLab

    Stages files and/or directories into the labextensions directory.
    By default, this compares modification time, and only stages files that need updating.
    If `overwrite` is specified, matching files are purged before proceeding.

    Parameters
    ----------

    path : path to file, directory, zip or tarball archive, or URL to install
        By default, the file will be installed with its base name, so '/path/to/foo'
        will install to 'labextensions/foo'. See the destination argument below to change this.
        Archives (zip or tarballs) will be extracted into the labextensions directory.
    user : bool [default: False]
        Whether to install to the user's labextensions directory.
        Otherwise do a system-wide install (e.g. /usr/local/share/jupyter/labextensions).
    overwrite : bool [default: False]
        If True, always install the files, regardless of what may already be installed.
    symlink : bool [default: True]
        If True, create a symlink in labextensions, rather than copying files.
        Windows support for symlinks requires a permission bit which only admin users
        have by default, so don't rely on it.
    labextensions_dir : str [optional]
        Specify absolute path of labextensions directory explicitly.
    destination : str [optional]
        name the labextension is installed to.  For example, if destination is 'foo', then
        the source file will be installed to 'labextensions/foo', regardless of the source name.
    logger : Jupyter logger [optional]
        Logger instance to use
    """
    # the actual path to which we eventually installed
    full_dest = None

    labext = _get_labextension_dir(user=user, sys_prefix=sys_prefix, labextensions_dir=labextensions_dir)
    # make sure labextensions dir exists
    ensure_dir_exists(labext)

    if isinstance(path, (list, tuple)):
        raise TypeError("path must be a string pointing to a single extension to install; call this function multiple times to install multiple extensions")

    path = cast_unicode_py2(path)

    if not destination:
        destination = basename(normpath(path))
    destination = cast_unicode_py2(destination)

    full_dest = normpath(pjoin(labext, destination))
    if overwrite and os.path.lexists(full_dest):
        if logger:
            logger.info("Removing: %s" % full_dest)
        if os.path.isdir(full_dest) and not os.path.islink(full_dest):
            shutil.rmtree(full_dest)
        else:
            os.remove(full_dest)

    # Make sure the parent directory exists
    os.makedirs(os.path.dirname(full_dest), exist_ok=True)

    if symlink:
        path = os.path.abspath(path)
        if not os.path.exists(full_dest):
            if logger:
                logger.info("Symlinking: %s -> %s" % (full_dest, path))
            os.symlink(path, full_dest)
        elif not os.path.islink(full_dest):
            raise ValueError("%s exists and is not a symlink" % full_dest)

    elif os.path.isdir(path):
        path = pjoin(os.path.abspath(path), '') # end in path separator
        for parent, dirs, files in os.walk(path):
            dest_dir = pjoin(full_dest, parent[len(path):])
            if not os.path.exists(dest_dir):
                if logger:
                    logger.info("Making directory: %s" % dest_dir)
                os.makedirs(dest_dir)
            for file_name in files:
                src = pjoin(parent, file_name)
                dest_file = pjoin(dest_dir, file_name)
                _maybe_copy(src, dest_file, logger=logger)
    else:
        src = path
        _maybe_copy(src, full_dest, logger=logger)

    return full_dest


def develop_labextension_py(module, user=False, sys_prefix=False, overwrite=True, symlink=True, labextensions_dir=None, logger=None):
    """Develop a labextension bundled in a Python package.

    Returns a list of installed/updated directories.

    See develop_labextension for parameter information."""
    m, labexts = _get_labextension_metadata(module)
    base_path = os.path.split(m.__file__)[0]

    full_dests = []

    for labext in labexts:
        src = os.path.join(base_path, labext['src'])
        dest = labext['dest']
        if logger:
            logger.info("Installing %s -> %s" % (src, dest))

        if not os.path.exists(src):
            build_labextension(base_path, logger=logger)

        full_dest = develop_labextension(
            src, overwrite=overwrite, symlink=symlink,
            user=user, sys_prefix=sys_prefix, labextensions_dir=labextensions_dir,
            destination=dest, logger=logger
            )
        full_dests.append(full_dest)

    return full_dests


def build_labextension(path, logger=None, development=False, static_url=None, source_map = False, core_path=None):
    """Build a labextension in the given path"""
    if core_path is None:
        core_path = osp.join(HERE, 'staging')
    ext_path = osp.abspath(path)

    if logger:
        logger.info('Building extension in %s' % path)

    builder = _ensure_builder(ext_path, core_path)

    arguments = ['node', builder, '--core-path', core_path,  ext_path]
    if static_url is not None:
        arguments.extend(['--static-url', static_url])
    if development:
        arguments.append('--development')
    if source_map:
        arguments.append('--source-map')

    subprocess.check_call(arguments, cwd=ext_path)


def watch_labextension(path, labextensions_path, logger=None, development=False, source_map=False, core_path=None):
    """Watch a labextension in a given path"""
    if core_path is None:
        core_path = osp.join(HERE, 'staging')
    ext_path = osp.abspath(path)

    if logger:
        logger.info('Building extension in %s' % path)

    # Check to see if we need to create a symlink
    federated_extensions = get_federated_extensions(labextensions_path)

    with open(pjoin(ext_path, 'package.json')) as fid:
        ext_data = json.load(fid)

    if ext_data['name'] not in federated_extensions:
        develop_labextension_py(ext_path, sys_prefix=True)
    else:
        full_dest = pjoin(federated_extensions[ext_data['name']]['ext_dir'], ext_data['name'])
        output_dir = pjoin(ext_path, ext_data['jupyterlab'].get('outputDir', 'static'))
        if not osp.islink(full_dest):
            shutil.rmtree(full_dest)
            os.symlink(output_dir, full_dest)

    builder = _ensure_builder(ext_path, core_path)
    arguments = ['node', builder, '--core-path', core_path,  '--watch', ext_path]
    if development:
        arguments.append('--development')
    if source_map:
        arguments.append('--source-map')

    subprocess.check_call(arguments, cwd=ext_path)


#------------------------------------------------------------------------------
# Private API
#------------------------------------------------------------------------------


def _ensure_builder(ext_path, core_path):
    """Ensure that we can build the extension and return the builder script path
    """
    # Test for compatible dependency on @jupyterlab/builder
    with open(osp.join(core_path, 'package.json')) as fid:
        core_data = json.load(fid)
    with open(osp.join(ext_path, 'package.json')) as fid:
        ext_data = json.load(fid)
    depVersion1 = core_data['devDependencies']['@jupyterlab/builder']
    depVersion2 = ext_data.get('devDependencies', dict()).get('@jupyterlab/builder')
    depVersion2 = depVersion2 or ext_data.get('dependencies', dict()).get('@jupyterlab/builder')
    if depVersion2 is None:
        raise ValueError('Extensions require a devDependency on @jupyterlab/builder@%s' % depVersion1)

    # if we have installed from disk (version is a path), assume we know what
    # we are doing and do not check versions.
    if '/' in depVersion2:
        with open(osp.join(ext_path, depVersion2, 'package.json')) as fid:
            depVersion2 = json.load(fid).get('version')
    overlap = _test_overlap(depVersion1, depVersion2, drop_prerelease1=True, drop_prerelease2=True)
    if not overlap:
        raise ValueError('Extensions require a devDependency on @jupyterlab/builder@%s, you have a dependency on %s' % (depVersion1, depVersion2))
    if not osp.exists(osp.join(ext_path, 'node_modules')):
        subprocess.check_call(['jlpm'], cwd=ext_path)

    # Find @jupyterlab/builder using node module resolution
    # We cannot use a script because the script path is a shell script on Windows
    target = ext_path
    while not osp.exists(osp.join(target, 'node_modules', '@jupyterlab', 'builder')):
        if osp.dirname(target) == target:
            raise ValueError('Could not find @jupyterlab/builder')
        target = osp.dirname(target)

    return osp.join(target, 'node_modules', '@jupyterlab', 'builder', 'lib', 'build-labextension.js')


def _should_copy(src, dest, logger=None):
    """Should a file be copied, if it doesn't exist, or is newer?

    Returns whether the file needs to be updated.

    Parameters
    ----------

    src : string
        A path that should exist from which to copy a file
    src : string
        A path that might exist to which to copy a file
    logger : Jupyter logger [optional]
        Logger instance to use
    """
    if not os.path.exists(dest):
        return True
    if os.stat(src).st_mtime - os.stat(dest).st_mtime > 1e-6:
        # we add a fudge factor to work around a bug in python 2.x
        # that was fixed in python 3.x: https://bugs.python.org/issue12904
        if logger:
            logger.warn("Out of date: %s" % dest)
        return True
    if logger:
        logger.info("Up to date: %s" % dest)
    return False


def _maybe_copy(src, dest, logger=None):
    """Copy a file if it needs updating.

    Parameters
    ----------

    src : string
        A path that should exist from which to copy a file
    src : string
        A path that might exist to which to copy a file
    logger : Jupyter logger [optional]
        Logger instance to use
    """
    if _should_copy(src, dest, logger=logger):
        if logger:
            logger.info("Copying: %s -> %s" % (src, dest))
        shutil.copy2(src, dest)


def _get_labextension_dir(user=False, sys_prefix=False, prefix=None, labextensions_dir=None):
    """Return the labextension directory specified

    Parameters
    ----------

    user : bool [default: False]
        Get the user's .jupyter/labextensions directory
    sys_prefix : bool [default: False]
        Get sys.prefix, i.e. ~/.envs/my-env/share/jupyter/labextensions
    prefix : str [optional]
        Get custom prefix
    labextensions_dir : str [optional]
        Get what you put in
    """
    conflicting = [
        ('user', user),
        ('prefix', prefix),
        ('labextensions_dir', labextensions_dir),
        ('sys_prefix', sys_prefix),
    ]
    conflicting_set = ['{}={!r}'.format(n, v) for n, v in conflicting if v]
    if len(conflicting_set) > 1:
        raise ArgumentConflict(
            "cannot specify more than one of user, sys_prefix, prefix, or labextensions_dir, but got: {}"
            .format(', '.join(conflicting_set)))
    if user:
        labext = pjoin(jupyter_data_dir(), u'labextensions')
    elif sys_prefix:
        labext = pjoin(ENV_JUPYTER_PATH[0], u'labextensions')
    elif prefix:
        labext = pjoin(prefix, 'share', 'jupyter', 'labextensions')
    elif labextensions_dir:
        labext = labextensions_dir
    else:
        labext = pjoin(SYSTEM_JUPYTER_PATH[0], 'labextensions')
    return labext


def _get_labextension_metadata(module):
    """Get the list of labextension paths associated with a Python module.

    Returns a tuple of (the module path,             [{
        'src': 'mockextension',
        'dest': '_mockdestination'
    }])

    Parameters
    ----------

    module : str
        Importable Python module exposing the
        magic-named `_jupyter_labextension_paths` function
    """

    mod_path = osp.abspath(module)
    if not osp.exists(mod_path):
        raise FileNotFoundError('The path `{}` does not exist.'.format(mod_path))

    # Check if the path is a valid labextension
    try:
        m = importlib.import_module(module)
        if hasattr(m, '_jupyter_labextension_paths') :
            labexts = m._jupyter_labextension_paths()
            return m, labexts
        else :
            m = None

    except Exception:
        m = None

    # Try getting the package name from setup.py
    try:
        package = subprocess.check_output([sys.executable, 'setup.py', '--name'], cwd=mod_path).decode('utf8').strip()
    except subprocess.CalledProcessError:
        raise FileNotFoundError('The Python package `{}` is not a valid package, '
                'it is missing the `setup.py` file.'.format(module))

    # Make sure the package is installed
    import pkg_resources
    try:
        dist = pkg_resources.get_distribution(package)
    except pkg_resources.DistributionNotFound:
        subprocess.check_call([sys.executable, '-m', 'pip', 'install', '-e', mod_path])
        sys.path.insert(0, mod_path)

    # Importing module with the same name as package
    try:
        # Replace hyphens with underscores to match Python convention
        package = package.replace('-', '_')
        m = importlib.import_module(package)
        if hasattr(m, '_jupyter_labextension_paths') :
            return m, m._jupyter_labextension_paths()
    except Exception:
        m = None

    # Looking for modules in the package
    from setuptools import find_packages
    packages = find_packages(mod_path)

    # Looking for the labextension metadata
    for package in packages :
        try:
            m = importlib.import_module(package)
            if hasattr(m, '_jupyter_labextension_paths') :
                return m, m._jupyter_labextension_paths()
        except Exception:
            m = None

    raise ModuleNotFoundError('There is not a labextensions at {}'.format(module))
