#!/usr/bin/python

# Copyright (c) 2017 Red Hat
#
# This module is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This software is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this software.  If not, see <http://www.gnu.org/licenses/>.
from __future__ import absolute_import, division, print_function
__metaclass__ = type

DOCUMENTATION = '''
---
module: tox_install_sibling_packages
short_description: Install packages needed by tox that have local git versions
author: Monty Taylor (@mordred)
description:
  - Looks for git repositories that zuul has placed on the system that provide
    python packages needed by package tox is testing. If if finds any, it will
    install them into the tox virtualenv so that subsequent runs of tox will
    use the provided git versions.
requirements:
  - "python >= 3.5"
options:
  tox_envlist:
    description:
      - The tox environment to operate in.
    required: true
    type: str
  project_dir:
    description:
      - The directory in which the project we care about is in.
    required: true
    type: str
  projects:
    description:
      - A list of project dicts that zuul knows about
    required: true
    type: list
'''

try:
    import configparser
except ImportError:
    import ConfigParser as configparser

import pkg_resources as prAPI
import os
import subprocess
import tempfile
import traceback

from ansible.module_utils.basic import AnsibleModule

log = list()


def get_sibling_python_packages(projects, tox_python):
    '''Finds all python packages that zuul has cloned.

    If someone does a require_project: and then runs a tox job, it can be
    assumed that what they want to do is to test the two together.
    '''
    packages = {}

    for project in projects:
        root = project['src_dir']
        package_name = None
        setup_cfg = os.path.join(root, 'setup.cfg')
        found_python = False
        if os.path.exists(setup_cfg):
            found_python = True
            c = configparser.ConfigParser()
            c.read(setup_cfg)
            try:
                package_name = c.get('metadata', 'name')
                packages[package_name] = root
            except Exception:
                # Some things have a setup.cfg, but don't keep
                # metadata in it; fall back to setup.py below
                log.append(
                    "[metadata] name not found in %s, skipping" % setup_cfg)
        if not package_name and os.path.exists(os.path.join(root, 'setup.py')):
            found_python = True
            # It's a python package but doesn't use pbr, so we need to run
            # python setup.py --name to get setup.py to tell us what the
            # package name is.
            package_name = subprocess.check_output(
                [os.path.abspath(tox_python), 'setup.py', '--name'],
                cwd=os.path.abspath(root)).decode('utf-8')
            if package_name:
                package_name = package_name.strip()
                packages[package_name] = root
        if found_python and not package_name:
            log.append(
                "Could not find package name for {root}".format(
                    root=root))
    return packages


def get_installed_packages(tox_python):
    # We use the output of pip freeze here as that is pip's stable public
    # interface.
    frozen_pkgs = subprocess.check_output(
        [tox_python, '-m', 'pip', '-qqq', 'freeze']
    ).decode('utf-8')
    # Matches strings of the form:
    # 1. '<package_name>==<version>'
    # 2. '# Editable Git install with no remote (<package_name>==<version>)'
    # both results: <package_name>
    return [x[x.find('(') + 1:].split('==')[0]
            for x in frozen_pkgs.split('\n') if '==' in x]


def write_new_constraints_file(constraints, packages):
    with tempfile.NamedTemporaryFile(mode='w', delete=False) \
            as constraints_file:
        constraints_lines = open(constraints, 'r').read().split('\n')
        for line in constraints_lines:
            package_name = line.split('===')[0]
            if package_name in packages:
                continue
            constraints_file.write(line)
            constraints_file.write('\n')
        return constraints_file.name


def _get_package_root(name, sibling_packages):
    '''
    Returns a package root from the sibling packages dict.

    If name is not found in sibling_packages, tries again using the 'filename'
    form of the name returned by the setuptools package resource API.

    :param name: package name
    :param sibling_packages: dict of python packages that zuul has cloned
    :returns: the package root (str)
    :raises: KeyError
    '''
    try:
        pkg_root = sibling_packages[name]
    except KeyError:
        pkg_root = sibling_packages[prAPI.to_filename(name)]

    return pkg_root


def main():
    module = AnsibleModule(
        argument_spec=dict(
            tox_envlist=dict(required=True, type='str'),
            tox_constraints_file=dict(type='str'),
            project_dir=dict(required=True, type='str'),
            projects=dict(required=True, type='list'),
        )
    )
    envlist = module.params['tox_envlist']
    constraints = module.params.get('tox_constraints_file')
    project_dir = module.params['project_dir']
    projects = module.params['projects']

    if not os.path.exists(os.path.join(project_dir, 'setup.cfg')):
        module.exit_json(changed=False, msg="No setup.cfg, no action needed")
    if constraints and not os.path.exists(constraints):
        module.fail_json(msg="Constraints file {constraints} was not found")

    # Who are we?
    try:
        c = configparser.ConfigParser()
        c.read(os.path.join(project_dir, 'setup.cfg'))
        package_name = c.get('metadata', 'name')
    except Exception:
        module.exit_json(
            changed=False, msg="No name in setup.cfg, skipping siblings")

    envdir = '{project_dir}/.tox/{envlist}'.format(
        project_dir=project_dir, envlist=envlist)
    if not os.path.exists(envdir):
        module.exit_json(
            changed=False, msg="envdir does not exist, skipping siblings")

    tox_python = '{envdir}/bin/python'.format(envdir=envdir)
    # Write a log file into the .tox dir so that it'll get picked up
    # Name it with envlist as a prefix so that fetch-tox-output will properly
    # get it in a multi-env scenario
    log_dir = '{envdir}/log'.format(envdir=envdir)
    log_file = '{log_dir}/{envlist}-siblings.txt'.format(
        log_dir=log_dir, envlist=envlist)

    log.append(
        "Processing siblings for {name} from {project_dir}".format(
            name=package_name,
            project_dir=project_dir))

    changed = False

    try:
        sibling_python_packages = get_sibling_python_packages(
            projects, tox_python)
        for name, root in sibling_python_packages.items():
            log.append("Sibling {name} at {root}".format(name=name, root=root))
        found_sibling_packages = []
        for dep_name in get_installed_packages(tox_python):
            log.append(
                "Found {name} python package installed".format(
                    name=dep_name))
            if (dep_name == package_name or
                prAPI.to_filename(dep_name) == package_name):
                # We don't need to re-process ourself. We've filtered ourselves
                # from the source dir list, but let's be sure nothing is weird.
                log.append(
                    "Skipping {name} because it's us".format(
                        name=dep_name))
                continue
            if dep_name in sibling_python_packages:
                log.append(
                    "Package {name} on system in {root}".format(
                        name=dep_name,
                        root=sibling_python_packages[dep_name]))
                changed = True
                found_sibling_packages.append(dep_name)
            elif prAPI.to_filename(dep_name) in sibling_python_packages:
                real_name = prAPI.to_filename(dep_name)
                log.append(
                    "Package {name} ({pkg_name}) on system in {root}".format(
                        name=dep_name,
                        pkg_name=real_name,
                        root=sibling_python_packages[real_name]))
                changed = True
                # need to use dep_name here for later constraint file rewrite
                found_sibling_packages.append(dep_name)

        if constraints:
            constraints_file = write_new_constraints_file(
                constraints, found_sibling_packages)

        for sibling_package in found_sibling_packages:
            log.append("Uninstalling {name}".format(name=sibling_package))
            uninstall_output = subprocess.check_output(
                [tox_python, '-m',
                 'pip', 'uninstall', '-y', sibling_package],
                stderr=subprocess.STDOUT)
            log.extend(uninstall_output.decode('utf-8').split('\n'))

            args = [tox_python, '-m', 'pip', 'install']
            if constraints:
                args.extend(['-c', constraints_file])

            pkg_root = _get_package_root(sibling_package,
                                         sibling_python_packages)
            log.append(
                "Installing {name} from {root} for deps".format(
                    name=sibling_package,
                    root=pkg_root))
            args.append(pkg_root)

            install_output = subprocess.check_output(args)
            log.extend(install_output.decode('utf-8').split('\n'))

        for sibling_package in found_sibling_packages:
            pkg_root = _get_package_root(sibling_package,
                                         sibling_python_packages)
            log.append(
                "Installing {name} from {root}".format(
                    name=sibling_package,
                    root=pkg_root))

            install_output = subprocess.check_output(
                [tox_python, '-m', 'pip', 'install', '--no-deps',
                 pkg_root])
            log.extend(install_output.decode('utf-8').split('\n'))
    except Exception as e:
        tb = traceback.format_exc()
        log.append(str(e))
        log.append(tb)
        module.fail_json(msg=str(e), log="\n".join(log))
    finally:
        log_text = "\n".join(log)
        module.append_to_file(log_file, log_text)
    module.exit_json(changed=changed, msg=log_text)


if __name__ == '__main__':
    main()