# -*- coding: utf-8 -*-
# Copyright (C) 2012 Anaconda, Inc
# SPDX-License-Identifier: BSD-3-Clause
"""
Functions related to core conda functionality that relates to pip

NOTE: This modules used to in conda, as conda/pip.py
"""
from __future__ import absolute_import, print_function

import json
from logging import getLogger
import os
import re
import sys

from .exceptions import CondaEnvException
from conda.gateways.subprocess import any_subprocess
from conda.exports import on_win
from conda.base.context import context


log = getLogger(__name__)


def pip_subprocess(args, prefix, cwd):
    if on_win:
        python_path = os.path.join(prefix, 'python.exe')
    else:
        python_path = os.path.join(prefix, 'bin', 'python')
    run_args = [python_path, '-m', 'pip'] + args
    stdout, stderr, rc = any_subprocess(run_args, prefix, cwd=cwd)
    if not context.quiet and not context.json:
        print("Ran pip subprocess with arguments:")
        print(run_args)
        print("Pip subprocess output:")
        print(stdout)
    if rc != 0:
        print("Pip subprocess error:", file=sys.stderr)
        print(stderr, file=sys.stderr)
        raise CondaEnvException("Pip failed")

    # This will modify (break) Context. We have a context stack but need to verify it works
    # stdout, stderr, rc = run_command(Commands.RUN, *run_args, stdout=None, stderr=None)
    return stdout, stderr


def get_pip_installed_packages(stdout):
    """Return the list of pip packages installed based on the command output"""
    m = re.search(r"Successfully installed\ (.*)", stdout)
    if m:
        return m.group(1).strip().split()
    else:
        return None


def get_pip_version(prefix):
    stdout, stderr = pip_subprocess(['-V'], prefix)
    pip_version = re.search(r"pip\ (\d+\.\d+\.\d+)", stdout)
    if not pip_version:
        raise CondaEnvException("Failed to find pip version string in output")
    else:
        pip_version = pip_version.group(1)
    return pip_version


class PipPackage(dict):
    def __str__(self):
        if 'path' in self:
            return '%s (%s)-%s-<pip>' % (self['name'], self['path'], self['version'])
        return '%s-%s-<pip>' % (self['name'], self['version'])


def installed(prefix, output=True):
    pip_version = get_pip_version(prefix)
    pip_major_version = int(pip_version.split('.', 1)[0])

    env = os.environ.copy()
    args = ['list']

    if pip_major_version >= 9:
        args += ['--format', 'json']
    else:
        env[str('PIP_FORMAT')] = str('legacy')

    try:
        pip_stdout, stderr = pip_subprocess(args, prefix=prefix, env=env)
    except Exception:
        # Any error should just be ignored
        if output:
            print("# Warning: subprocess call to pip failed", file=sys.stderr)
        return

    if pip_major_version >= 9:
        pkgs = json.loads(pip_stdout)

        # For every package in pipinst that is not already represented
        # in installed append a fake name to installed with 'pip'
        # as the build string
        for kwargs in pkgs:
            kwargs['name'] = kwargs['name'].lower()
            if ', ' in kwargs['version']:
                # Packages installed with setup.py develop will include a path in
                # the version. They should be included here, even if they are
                # installed with conda, as they are preferred over the conda
                # version. We still include the conda version, though, because it
                # is still installed.

                version, path = kwargs['version'].split(', ', 1)
                # We do this because the code below uses rsplit('-', 2)
                version = version.replace('-', ' ')
                kwargs['version'] = version
                kwargs['path'] = path
            yield PipPackage(**kwargs)
    else:
        # For every package in pipinst that is not already represented
        # in installed append a fake name to installed with 'pip'
        # as the build string
        pat = re.compile(r'([\w.-]+)\s+\((.+)\)')
        for line in pip_stdout.splitlines():
            line = line.strip()
            if not line:
                continue
            m = pat.match(line)
            if m is None:
                if output:
                    print('Could not extract name and version from: %r' % line, file=sys.stderr)
                continue
            name, version = m.groups()
            name = name.lower()
            kwargs = {
                'name': name,
                'version': version,
            }
            if ', ' in version:
                # Packages installed with setup.py develop will include a path in
                # the version. They should be included here, even if they are
                # installed with conda, as they are preferred over the conda
                # version. We still include the conda version, though, because it
                # is still installed.

                version, path = version.split(', ')
                # We do this because the code below uses rsplit('-', 2)
                version = version.replace('-', ' ')
                kwargs.update({
                    'path': path,
                    'version': version,
                })
            yield PipPackage(**kwargs)


# canonicalize_{regex,name} inherited from packaging/utils.py
# Used under BSD license
_canonicalize_regex = re.compile(r"[-_.]+")


def _canonicalize_name(name):
    # This is taken from PEP 503.
    return _canonicalize_regex.sub("-", name).lower()


def add_pip_installed(prefix, installed_pkgs, json=None, output=True):
    # Defer to json for backwards compatibility
    if isinstance(json, bool):
        output = not json

    # TODO Refactor so installed is a real list of objects/dicts
    #      instead of strings allowing for direct comparison
    # split :: to get rid of channel info

    # canonicalize names for pip comparison
    # because pip normalizes `foo_bar` to `foo-bar`
    conda_names = {_canonicalize_name(rec.name) for rec in installed_pkgs}
    for pip_pkg in installed(prefix, output=output):
        pip_name = _canonicalize_name(pip_pkg['name'])
        if pip_name in conda_names and 'path' not in pip_pkg:
            continue
        installed_pkgs.add(str(pip_pkg))
