#!/usr/bin/env python
from __future__ import print_function

COPYRIGHT = """\
Copyright (C) 2011-2012 OpenStack LLC.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied.

See the License for the specific language governing permissions and
limitations under the License."""

import sys
import urllib
import json

from distutils.version import StrictVersion
if sys.version < '3':
    from urlparse import urlparse
    import ConfigParser
else:
    from urllib.parse import urlparse
    import configparser as ConfigParser

import datetime
import os
import sys
import time
import re
import shlex
import subprocess

version = "1.18"

VERBOSE = False
UPDATE = False
CONFIGDIR = os.path.expanduser("~/.config/git-review")
GLOBAL_CONFIG = "/etc/git-review/git-review.conf"
PYPI_URL = "http://pypi.python.org/pypi/git-review/json"
PYPI_CACHE_TIME = 60 * 60 * 24  # 24 hours

_branch_name = None
_has_color = None


class colors:
    yellow = '\033[33m'
    green = '\033[92m'
    red = '\033[91m'
    reset = '\033[0m'


def run_command(cmd, status=False, env={}):
    if VERBOSE:
        print(datetime.datetime.now(), "Running:", cmd)
    cmd_list = shlex.split(str(cmd))
    newenv = os.environ
    newenv.update(env)
    p = subprocess.Popen(cmd_list, stdout=subprocess.PIPE,
                         stderr=subprocess.STDOUT, env=newenv)
    (out, nothing) = p.communicate()
    out = out.decode('utf-8')
    if status:
        return (p.returncode, out.strip())
    return out.strip()


def run_command_status(cmd, env={}):
    return run_command(cmd, True, env)


def update_latest_version(version_file_path):
    """ Cache the latest version of git-review for the upgrade check. """

    if not os.path.exists(CONFIGDIR):
        os.makedirs(CONFIGDIR)

    if os.path.exists(version_file_path) and not UPDATE:
        if (time.time() - os.path.getmtime(version_file_path)) < 28800:
            return

    latest_version = version
    try:
        latest_version = json.load(urllib.urlopen(PYPI_URL))['info']['version']
    except:
        pass

    with open(version_file_path, "w") as version_file:
        version_file.write(latest_version)


def latest_is_newer():
    """ Check if there is a new version of git-review. """

    # Skip version check if distro package turns it off
    if os.path.exists(GLOBAL_CONFIG):
        config = dict(check=False)
        configParser = ConfigParser.ConfigParser(config)
        configParser.read(GLOBAL_CONFIG)
        if not configParser.getboolean("updates", "check"):
            return False

    version_file_path = os.path.join(CONFIGDIR, "latest-version")
    update_latest_version(version_file_path)

    latest_version = None
    with open(version_file_path, "r") as version_file:
        latest_version = StrictVersion(version_file.read())
    if latest_version > StrictVersion(version):
        return True
    return False


def get_hooks_target_file():
    top_dir = run_command('git rev-parse --git-dir')
    hooks_dir = os.path.join(top_dir, "hooks")
    return os.path.join(hooks_dir, "commit-msg")


def set_hooks_commit_msg(remote, target_file):
    """ Install the commit message hook if needed. """

    # Create the hooks directory if it's not there already
    hooks_dir = os.path.dirname(target_file)
    if not os.path.isdir(hooks_dir):
        os.mkdir(hooks_dir)

    (hostname, username, port, project_name) = \
        parse_git_show(remote, "Push")

    if not os.path.exists(target_file) or UPDATE:
        if VERBOSE:
            print("Fetching commit hook from: scp://%s:%s" % (hostname, port))
        scp_cmd = "scp "
        if port is not None:
            scp_cmd += "-P%s " % port
        if username is None:
            scp_cmd += hostname
        else:
            scp_cmd += "%s@%s" % (username, hostname)
        scp_cmd += ":hooks/commit-msg %s" % target_file
        (status, scp_output) = run_command_status(scp_cmd)
        if status != 0:
            print("Problems encountered installing commit-msg hook")
            print(scp_output)
            return False

    if not os.access(target_file, os.X_OK):
        os.chmod(target_file, os.path.stat.S_IREAD | os.path.stat.S_IEXEC)

    return True


def test_remote(username, hostname, port, project):
    """ Tests that a possible gerrit remote works """

    if username is None:
        ssh_cmd = "ssh -x -p%s %s gerrit ls-projects"
        cmd = ssh_cmd % (port, hostname)
    else:
        ssh_cmd = "ssh -x -p%s %s@%s gerrit ls-projects"
        cmd = ssh_cmd % (port, username, hostname)
    (status, ssh_output) = run_command_status(cmd)
    if status == 0:
        if VERBOSE:
            print("%s@%s:%s worked." % (username, hostname, port))
        return True
    else:
        if VERBOSE:
            print("%s@%s:%s did not work." % (username, hostname, port))
        return False


def make_remote_url(username, hostname, port, project):
    """ Builds a gerrit remote URL """
    if username is None:
        return "ssh://%s:%s/%s" % (hostname, port, project)
    else:
        return "ssh://%s@%s:%s/%s" % (username, hostname, port, project)


def add_remote(hostname, port, project, remote):
    """ Adds a gerrit remote. """
    asked_for_username = False

    username = os.getenv("USERNAME")
    if not username:
        username = run_command('git config --get gitreview.username')
    if not username:
        username = os.getenv("USER")
    if port is None:
        port = 29418

    remote_url = make_remote_url(username, hostname, port, project)
    if VERBOSE:
        print("No remote set, testing %s" % remote_url)
    if not test_remote(username, hostname, port, project):
        print("Could not connect to gerrit.")
        username = raw_input("Enter your gerrit username: ")
        remote_url = make_remote_url(username, hostname, port, project)
        print("Trying again with %s" % remote_url)
        if not test_remote(username, hostname, port, project):
            raise Exception("Could not connect to gerrit at %s" % remote_url)
        asked_for_username = True

    print("Creating a git remote called \"%s\" that maps to:" % remote)
    print("\t%s" % remote_url)
    cmd = "git remote add -f %s %s" % (remote, remote_url)
    (status, remote_output) = run_command_status(cmd)

    if status != 0:
        raise Exception("Error running %s" % cmd)

    if asked_for_username:
        print()
        print("This repository is now set up for use with git-review.")
        print("You can set the default username for future repositories with:")
        print('  git config --global --add gitreview.username "%s"' % username)
        print()


def parse_git_show(remote, verb):
    fetch_url = ""
    for line in run_command("git remote show -n %s" % remote).split("\n"):
        if line.strip().startswith("%s" % verb):
            fetch_url = line.split()[2]

    parsed_url = urlparse(fetch_url)
    project_name = parsed_url.path.lstrip("/")
    if project_name.endswith(".git"):
        project_name = project_name[:-4]

    hostname = parsed_url.netloc
    username = None
    port = parsed_url.port

    if VERBOSE:
        print("Found origin %s URL:" % verb, fetch_url)

    # Workaround bug in urlparse on OSX
    if parsed_url.scheme == "ssh" and parsed_url.path[:2] == "//":
        hostname = parsed_url.path[2:].split("/")[0]

    if "@" in hostname:
        (username, hostname) = hostname.split("@")
    if ":" in hostname:
        (hostname, port) = hostname.split(":")

    # Is origin an ssh location? Let's pull more info
    if parsed_url.scheme == "ssh" and port == None:
        port = 22

    return (hostname, username, str(port), project_name)


def git_config_get_value(section, option):
    cmd = "git config --get %s.%s" % (section, option)
    return run_command(cmd).strip()


def check_color_support():
    global _has_color
    if _has_color is None:
        test_command = "git log --color=never --oneline HEAD^1..HEAD"
        (status, output) = run_command_status(test_command)
        if status == 0:
            _has_color = True
        else:
            _has_color = False
    return _has_color


def get_config():
    """Get the configuration options set in the .gitremote file, if present."""
    """Returns a hashmap with hostname, port, project and defaultbranch."""
    """If there is no .gitremote file, default values will be used."""
    config = dict(hostname=False, port='29418', project=False,
                  defaultbranch='master', defaultremote="gerrit",
                  defaultrebase="1")
    top_dir = run_command('git rev-parse --show-toplevel')
    target_file = os.path.join(top_dir, ".gitreview")
    if os.path.exists(target_file):
        configParser = ConfigParser.ConfigParser(config)
        configParser.read(target_file)
        config['hostname'] = configParser.get("gerrit", "host")
        config['port'] = configParser.get("gerrit", "port")
        config['project'] = configParser.get("gerrit", "project")
        config['defaultbranch'] = configParser.get("gerrit", "defaultbranch")
        if configParser.has_option("gerrit", "defaultremote"):
            config['defaultremote'] = configParser.get("gerrit",
                                                       "defaultremote")
        if configParser.has_option("gerrit", "defaultrebase"):
            config['defaultrebase'] = configParser.getboolean("gerrit",
                                                              "defaultrebase")
    return config


def update_remote(remote):
    cmd = "git remote update %s" % remote
    (status, output) = run_command_status(cmd)
    if VERBOSE:
        print(output)
    if status != 0:
        print("Problem running '%s'" % cmd)
        if not VERBOSE:
            print(output)
        return False
    return True


def check_remote(branch, remote, hostname, port, project):
    """Check that a Gerrit Git remote repo exists, if not, set one."""

    has_color = check_color_support()
    if has_color:
        color_never = "--color=never"
    else:
        color_never = ""

    if remote in run_command("git remote").split("\n"):

        remotes = run_command("git branch -a %s" % color_never).split("\n")
        for current_remote in remotes:
            if current_remote.strip() == "remotes/%s/%s" % (remote, branch) \
                and not UPDATE:
                return
        # We have the remote, but aren't set up to fetch. Fix it
        if VERBOSE:
            print("Setting up gerrit branch tracking for better rebasing")
        update_remote(remote)
        return

    if hostname == False or port == False or project == False:
        # This means there was no .gitreview file
        print("No '.gitreview' file found in this repository.")
        print("We don't know where your gerrit is. Please manually create ")
        print("a remote named gerrit and try again.")
        sys.exit(1)

    # Gerrit remote not present, try to add it
    try:
        add_remote(hostname, port, project, remote)
    except:
        print(sys.exc_info()[2])
        print("We don't know where your gerrit is. Please manually create ")
        print("a remote named \"%s\" and try again." % remote)
        raise


def rebase_changes(branch, remote):

    remote_branch = "remotes/%s/%s" % (remote, branch)

    if not update_remote(remote):
        return False

    cmd = "git rebase -i %s" % remote_branch
    (status, output) = run_command_status(cmd, env=dict(GIT_EDITOR='true'))
    if status != 0:
        print("Errors running %s" % cmd)
        print(output)
        return False
    return True


def get_branch_name(target_branch):
    global _branch_name
    if _branch_name is not None:
        return _branch_name
    _branch_name = None
    has_color = check_color_support()
    if has_color:
        color_never = "--color=never"
    else:
        color_never = ""
    for branch in run_command("git branch %s" % color_never).split("\n"):
        if branch.startswith('*'):
            _branch_name = branch.split()[1].strip()
    if _branch_name == "(no":
        _branch_name = target_branch
    return _branch_name


def assert_one_change(remote, branch, yes, have_hook):
    update_remote(remote)
    branch_name = get_branch_name(branch)
    has_color = check_color_support()
    if has_color:
        color = git_config_get_value("color", "ui").lower()
        if(color == "" or color == "true"):
            color = "auto"
        elif color == "false":
            color = "never"
        elif color == "auto":
            # Python is not a tty, we have to force colors
            color = "always"
        use_color = "--color=%s" % color
    else:
        use_color = ""
    cmd = "git log %s --decorate --oneline %s --not remotes/%s/%s" % \
              (use_color, branch_name, remote, branch)
    (status, output) = run_command_status(cmd)
    if status != 0:
        print("Had trouble running %s" % cmd)
        print(output)
        sys.exit(1)
    output_lines = len(output.split("\n"))
    if output_lines == 1 and not have_hook:
        print("Your change was committed before the commit hook was installed")
        print("Amending the commit to add a gerrit change id")
        run_command("git commit --amend", env=dict(GIT_EDITOR='true'))
    elif output_lines == 0:
        print("No changes between HEAD and %s/%s." % (remote, branch))
        print("Submitting for review would be pointless.")
        sys.exit(1)
    elif output_lines > 1:
        if not yes:
            print("You have more than one commit"
                    " that you are about to submit.")
            print("The outstanding commits are:\n\n%s\n" % output)
            print("Is this really what you meant to do?")
            yes_no = raw_input("Type 'yes' to confirm: ")
            if yes_no.lower().strip() != "yes":
                print("Aborting.")
                print("Please rebase/squash your changes and try again")
                sys.exit(1)


def get_topic(target_branch):

    branch_name = get_branch_name(target_branch)

    branch_parts = branch_name.split("/")
    if len(branch_parts) >= 3 and branch_parts[0] == "review":
        return "/".join(branch_parts[2:])

    log_output = run_command("git log HEAD^1..HEAD")
    bug_re = r'\b([Bb]ug|[Ll][Pp])\s*[#:]?\s*(\d+)'

    match = re.search(bug_re, log_output)
    if match is not None:
        return "bug/%s" % match.group(2)

    bp_re = r'\b([Bb]lue[Pp]rint|[Bb][Pp])\s*[#:]?\s*([0-9a-zA-Z-_]+)'
    match = re.search(bp_re, log_output)
    if match is not None:
        return "bp/%s" % match.group(2)

    return branch_name


class Hacker:
    def __init__(self, username, name, email):
        self.username = username
        self.name = name
        self.email = email

    @classmethod
    def parse(cls, h):
        if not h:
            return None
        return cls(h.get('username'), h.get('name'), h.get('email'))


class Approval:
    CodeReviewed, Approved, Submitted, Verified = range(4)

    type_map = {
        'CRVW': CodeReviewed,
        'APRV': Approved,
        'SUBM': Submitted,
        'VRIF': Verified,
        }

    def __init__(self, type, value):
        self.type = type
        self.value = value

    @classmethod
    def parse(cls, a):
        return cls(cls.type_map[a['type']], int(a['value']))


class PatchSet:
    def __init__(self, revision, ref, approvals):
        self.revision = revision
        self.ref = ref
        self.approvals = approvals

    def _score(self, approval_type):
        values = [a.value for a in self.approvals if a.type == approval_type]
        if not values:
            return 0
        return max(values) if all(v > 0 for v in values) else min(values)

    @property
    def code_review_score(self):
        return self._score(Approval.CodeReviewed)

    @property
    def verified_score(self):
        return self._score(Approval.Verified)

    @property
    def approved_score(self):
        return self._score(Approval.Approved)

    @classmethod
    def parse(cls, ps):
        if not ps:
            return None
        return cls(ps.get('revision'), ps.get('ref'),
                   [Approval.parse(a) for a in ps.get('approvals', [])])


class Review:
    def __init__(self, id, number, subject, topic, owner, patchset):
        self.id = id
        self.number = number
        self.subject = subject
        self.topic = topic
        self.owner = owner
        self.patchset = patchset

    @property
    def shortid(self):
        return self.id[0:9]

    @classmethod
    def parse(cls, r):
        if not r:
            return None
        return cls(r['id'],
                   int(r['number']),
                   r['subject'],
                   r.get('topic'),
                   Hacker.parse(r.get('owner')),
                   PatchSet.parse(r.get('currentPatchSet')))


def run_ssh_query(remote, *args):
    (hostname, username, port, project_name) = parse_git_show(remote, "Push")

    ssh_cmds = ["ssh", "-x"]
    if port is not None:
        ssh_cmds.extend(["-p", port])
    if username is not None:
        ssh_cmds.extend(["-l", username])
    ssh_cmds.append(hostname)
    ssh_cmds.extend(["gerrit", "query", "--format=JSON"])
    ssh_cmds.extend(args)

    (status, output) = run_command_status(" ".join(ssh_cmds))

    if status != 0:
        print("Could not fetch review information from gerrit")
        print(output)
        return (status, None)

    def reviews(output):
        for line in output.split("\n"):
            # Warnings from ssh wind up in this output
            if line[0] != "{":
                print(line)
                continue

            review_json = json.loads(line)
            if 'type' not in review_json:
                yield Review.parse(review_json)

    if VERBOSE:
        print("== output ==\n" + output + "\n== output end ==")

    return (0, reviews(output))


def list_reviews(remote, branch):
    project_name = parse_git_show(remote, "Push")[-1]

    (status, reviews) = run_ssh_query(remote,
                                      "--current-patch-set",
                                      "status:open",
                                      "project:" + project_name,
                                      "branch:" + branch)
    if status != 0:
        return status

    count = 0
    try:
        for r in reviews:
            change = "%s(%d)" % (r.shortid, r.number)
            owner = r.owner.username
            if check_color_support():
                change = colors.yellow + change + colors.reset
                owner = colors.yellow + owner + colors.reset

            def format_score(prefix, value, neg=True):
                score = prefix + "="
                score += ("%-2d" if neg else "%d") % (value,)
                if value and check_color_support():
                    color = colors.green if value > 0 else colors.red
                    score = color + score + colors.reset
                return score

            rscore = format_score("R", r.patchset.code_review_score)
            vscore = format_score("V", r.patchset.verified_score)
            ascore = format_score("A", r.patchset.approved_score, neg=False)

            print("%s [%s %s %s]  %s  (%s)" %
                  (change, rscore, vscore, ascore, r.subject, owner))
            count += 1
    except:
        print("Could not parse json query response:", sys.exc_info()[1])
        return 1

    print("Found %d items for review" % count)
    return 0


def download_review(review, masterbranch, remote):
    (status, reviews) = run_ssh_query(remote,
                                      "--current-patch-set",
                                      "change:%s" % review)
    if status != 0:
        print("Could not fetch review information from gerrit")
        print(output)
        return status

    try:
        r = reviews.next()
    except StopIteration:
        print("Could not find a gerrit review with id: %s" % review)
        return 1
    except:
        print("Could not parse json query response:", sys.exc_info()[1])
        return 1

    topic = r.topic
    if not topic or topic == masterbranch:
        topic = review

    author = re.sub('\W+', '_', r.owner.name.lower())
    branch_name = "review/%s/%s" % (author, topic)
    revision = r.patchset.revision
    refspec = r.patchset.ref

    print("Downloading %s from gerrit into %s" % (refspec, branch_name))
    (status, output) = run_command_status("git fetch %s %s"
        % (remote, refspec))
    if status != 0:
        print(output)
        return status

    checkout_cmd = "git checkout -b %s FETCH_HEAD" % branch_name
    (status, output) = run_command_status(checkout_cmd)
    if status != 0:
        if re.search("already exists\.?", output):
            print("Branch already exists - reusing")
            checkout_cmd = "git checkout %s" % branch_name
            (status, output) = run_command_status(checkout_cmd)
            if status != 0:
                print(output)
                return status
            reset_cmd = "git reset --hard FETCH_HEAD"
            (status, output) = run_command_status(reset_cmd)
            if status != 0:
                print(output)
                return status
        else:
            print(output)
            return status

    print("Switched to branch '%s'" % branch_name)
    return 0


def finish_branch(target_branch):
    local_branch = get_branch_name(target_branch)
    if VERBOSE:
        print("Switching back to %s and deleting %s" % (target_branch,
                                                        local_branch))
    checkout_cmd = "git checkout %s" % target_branch
    (status, output) = run_command_status(checkout_cmd)
    if status != 0:
        print(output)
        return status
    print("Switched to branch '%s'" % target_branch)
    close_cmd = "git branch -D %s" % local_branch
    (status, output) = run_command_status(close_cmd)
    if status != 0:
        print(output)
        return status
    print("Deleted branch '%s'" % local_branch)
    return 0


def do_submit(options, config):
    branch = options.branch
    remote = options.remote
    yes = options.yes
    status = 0

    check_remote(branch, remote,
                 config['hostname'], config['port'], config['project'])

    if options.download is not None:
        return download_review(options.download, branch, remote)
    elif options.list:
        return list_reviews(remote, branch)

    topic = options.topic
    if topic is None:
        topic = get_topic(branch)
    if VERBOSE:
        print("Found topic '%s' from parsing changes." % topic)

    hook_file = get_hooks_target_file()

    have_hook = os.path.exists(hook_file) and os.access(hook_file, os.X_OK)

    if not have_hook:
        if not set_hooks_commit_msg(remote, hook_file):
            return 1

    if not options.setup:
        if options.rebase:
            if not rebase_changes(branch, remote):
                return 1
        assert_one_change(remote, branch, yes, have_hook)

        ref = "publish"

        if options.draft:
            ref = "drafts"
        elif options.compatible:
            ref = "for"

        cmd = "git push %s HEAD:refs/%s/%s/%s" % (remote, ref, branch,
                                                  topic)
        if options.dry:
            print("Please use the following command " \
                  "to send your commits to review:\n")
            print("\t%s\n" % cmd)
        else:
            (status, output) = run_command_status(cmd)
            print(output)

    if options.finish and not options.dry and status == 0:
        status = finish_branch(branch)

    return status


def default_to_submit(argv):
    COMMON_ARGS = ["-h", "--help",
                   "--verbose", "-u", "--update",
                   "--version", "-v",  "--license"]
    ACTIONS = ["submit"]

    i = 0
    while i < len(argv) and argv[i] in COMMON_ARGS:
        i += 1

    if not (i < len(argv) and argv[i] in ACTIONS):
        argv.insert(i, "submit")

    return argv


def print_exit_message(status):

    if latest_is_newer():
        print("""
***********************************************************
A new version of git-review is available on PyPI. Please
update your copy with:

  pip install -U git-review

to ensure proper behavior with gerrit. Thanks!
***********************************************************
""")
    sys.exit(status)


def main():

    config = get_config()

    usage = "git review [submit] [OPTIONS] ... [BRANCH]"

    import argparse
    parser = argparse.ArgumentParser(usage=usage, description=COPYRIGHT)
    parser.add_argument("-u", "--update", dest="update", action="store_true",
                        help="Force updates from remote locations")
    parser.add_argument("-v", "--verbose", dest="verbose", action="store_true",
                        help="Output more information about what's going on")
    parser.add_argument("--license", dest="license", action="store_true",
                        help="Print the license and exit")
    parser.add_argument("--version", action="version",
                        version='%s version %s' % \
                            (os.path.split(sys.argv[0])[-1], version))

    subparsers = parser.add_subparsers()

    sparser = subparsers.add_parser('submit')
    sparser.add_argument("-t", "--topic", dest="topic",
                         help="Topic to submit branch to")
    sparser.add_argument("-D", "--draft", dest="draft", action="store_true",
                         help="Submit review as a draft")
    sparser.add_argument("-c", "--compatible", dest="compatible",
                         action="store_true",
                         help="Push change to refs/for/* for compatibility "
                              "with Gerrit versions < 2.3. Ignored if "
                              "-D/--draft is used.")
    sparser.add_argument("-n", "--dry-run", dest="dry", action="store_true",
                         help="Don't actually submit the branch for review")
    sparser.add_argument("-r", "--remote", dest="remote",
                         help="git remote to use for gerrit")
    sparser.add_argument("-R", "--no-rebase", dest="rebase",
                         action="store_false",
                        help="Don't rebase changes before submitting.")
    sparser.add_argument("-d", "--download", dest="download",
                         help="Download the contents of an existing gerrit "
                              "review into a branch")
    sparser.add_argument("-s", "--setup", dest="setup", action="store_true",
                         help="Just run the repo setup commands but don't "
                              "submit anything")
    sparser.add_argument("-f", "--finish", dest="finish", action="store_true",
                         help="Close down this branch and switch back to "
                              "master on successful submission")
    sparser.add_argument("-l", "--list", dest="list", action="store_true",
                         help="list available reviews for the current project")
    sparser.add_argument("-y", "--yes", dest="yes", action="store_true",
                         help="Indicate that you do, in fact, understand if "
                              "you are submitting more than one patch")
    sparser.add_argument("branch", nargs="?", default=config['defaultbranch'])
    sparser.set_defaults(func=do_submit,
                         rebase=config['defaultrebase'],
                         remote=config['defaultremote'])

    argv = default_to_submit(sys.argv[1:])

    options = parser.parse_args(argv)

    if options.license:
        print(COPYRIGHT)
        sys.exit(0)

    global VERBOSE
    VERBOSE = options.verbose

    global UPDATE
    UPDATE = options.update

    print_exit_message(options.func(options, config))


if __name__ == "__main__":
    main()