# Webhooks for external integrations.
import re
from functools import partial
from six.moves import zip
from typing import Any, Callable, Dict, List, Optional, Text
from django.http import HttpRequest, HttpResponse
from django.utils.translation import ugettext as _
from zerver.lib.actions import check_send_stream_message
from zerver.lib.response import json_success, json_error
from zerver.decorator import REQ, has_request_variables, api_key_only_webhook_view
from zerver.models import UserProfile
from zerver.lib.webhooks.git import get_push_commits_event_message, SUBJECT_WITH_BRANCH_TEMPLATE,\
    get_force_push_commits_event_message, get_remove_branch_event_message, get_pull_request_event_message,\
    SUBJECT_WITH_PR_OR_ISSUE_INFO_TEMPLATE, get_issue_event_message, get_commits_comment_action_message,\
    get_push_tag_event_message


BITBUCKET_SUBJECT_TEMPLATE = '{repository_name}'
USER_PART = 'User {display_name}(login: {username})'

BITBUCKET_FORK_BODY = USER_PART + ' forked the repository into [{fork_name}]({fork_url}).'
BITBUCKET_COMMIT_STATUS_CHANGED_BODY = '[System {key}]({system_url}) changed status of {commit_info} to {status}.'


PULL_REQUEST_SUPPORTED_ACTIONS = [
    'approved',
    'unapproved',
    'created',
    'updated',
    'rejected',
    'fulfilled',
    'comment_created',
    'comment_updated',
    'comment_deleted',
]

class UnknownTriggerType(Exception):
    pass


@api_key_only_webhook_view('Bitbucket2')
@has_request_variables
def api_bitbucket2_webhook(request, user_profile, payload=REQ(argument_type='body'),
                           stream=REQ(default='bitbucket'), branches=REQ(default=None)):
    # type: (HttpRequest, UserProfile, Dict[str, Any], str, Optional[Text]) -> HttpResponse
    type = get_type(request, payload)
    if type != 'push':
        subject = get_subject_based_on_type(payload, type)
        body = get_body_based_on_type(type)(payload)
        check_send_stream_message(user_profile, request.client,
                                  stream, subject, body)
    else:
        branch = get_branch_name_for_push_event(payload)
        if branch and branches:
            if branches.find(branch) == -1:
                return json_success()
        subjects = get_push_subjects(payload)
        bodies_list = get_push_bodies(payload)
        for body, subject in zip(bodies_list, subjects):
            check_send_stream_message(user_profile, request.client,
                                      stream, subject, body)
    return json_success()

def get_subject_for_branch_specified_events(payload, branch_name=None):
    # type: (Dict[str, Any], Optional[Text]) -> Text
    return SUBJECT_WITH_BRANCH_TEMPLATE.format(
        repo=get_repository_name(payload['repository']),
        branch=get_branch_name_for_push_event(payload) if branch_name is None else branch_name
    )

def get_push_subjects(payload):
    # type: (Dict[str, Any]) -> List[str]
    subjects_list = []
    for change in payload['push']['changes']:
        potential_tag = (change['new'] or change['old'] or {}).get('type')
        if potential_tag == 'tag':
            subjects_list.append(str(get_subject(payload)))
        else:
            if change.get('new'):
                branch_name = change['new']['name']
            else:
                branch_name = change['old']['name']
            subjects_list.append(str(get_subject_for_branch_specified_events(payload, branch_name)))
    return subjects_list

def get_subject(payload):
    # type: (Dict[str, Any]) -> str
    assert(payload['repository'] is not None)
    return BITBUCKET_SUBJECT_TEMPLATE.format(repository_name=get_repository_name(payload['repository']))

def get_subject_based_on_type(payload, type):
    # type: (Dict[str, Any], str) -> Text
    if type.startswith('pull_request'):
        return SUBJECT_WITH_PR_OR_ISSUE_INFO_TEMPLATE.format(
            repo=get_repository_name(payload['repository']),
            type='PR',
            id=payload['pullrequest']['id'],
            title=payload['pullrequest']['title']
        )
    if type.startswith('issue'):
        return SUBJECT_WITH_PR_OR_ISSUE_INFO_TEMPLATE.format(
            repo=get_repository_name(payload['repository']),
            type='Issue',
            id=payload['issue']['id'],
            title=payload['issue']['title']
        )
    return get_subject(payload)

def get_type(request, payload):
    # type: (HttpRequest, Dict[str, Any]) -> str
    event_key = request.META.get("HTTP_X_EVENT_KEY")
    if payload.get('push'):
        return 'push'
    elif payload.get('fork'):
        return 'fork'
    elif payload.get('comment') and payload.get('commit'):
        return 'commit_comment'
    elif payload.get('commit_status'):
        return 'change_commit_status'
    elif payload.get('issue'):
        if payload.get('changes'):
            return "issue_updated"
        if payload.get('comment'):
            return 'issue_commented'
        return "issue_created"
    elif payload.get('pullrequest'):
        pull_request_template = 'pull_request_{}'
        action = re.match('pullrequest:(?P<action>.*)$', event_key)
        if action:
            action = action.group('action')
            if action in PULL_REQUEST_SUPPORTED_ACTIONS:
                return pull_request_template.format(action)
    raise UnknownTriggerType("We don't support {} event type".format(event_key))

def get_body_based_on_type(type):
    # type: (str) -> Callable[[Dict[str, Any]], Text]
    fn = GET_SINGLE_MESSAGE_BODY_DEPENDING_ON_TYPE_MAPPER.get(type)
    assert callable(fn)  # type parameter should be pre-checked, so not None
    return fn

def get_push_bodies(payload):
    # type: (Dict[str, Any]) -> List[Text]
    messages_list = []
    for change in payload['push']['changes']:
        potential_tag = (change['new'] or change['old'] or {}).get('type')
        if potential_tag == 'tag':
            messages_list.append(get_push_tag_body(payload, change))
        elif change.get('closed'):
            messages_list.append(get_remove_branch_push_body(payload, change))
        elif change.get('forced'):
            messages_list.append(get_force_push_body(payload, change))
        else:
            messages_list.append(get_normal_push_body(payload, change))
    return messages_list

def get_remove_branch_push_body(payload, change):
    # type: (Dict[str, Any], Dict[str, Any]) -> Text
    return get_remove_branch_event_message(
        get_user_username(payload),
        change['old']['name'],
    )

def get_force_push_body(payload, change):
    # type: (Dict[str, Any], Dict[str, Any]) -> Text
    return get_force_push_commits_event_message(
        get_user_username(payload),
        change['links']['html']['href'],
        change['new']['name'],
        change['new']['target']['hash']
    )

def get_commit_author_name(commit):
    # type: (Dict[str, Any]) -> Text
    if commit['author'].get('user'):
        return commit['author']['user'].get('username')
    return commit['author']['raw'].split()[0]

def get_normal_push_body(payload, change):
    # type: (Dict[str, Any], Dict[str, Any]) -> Text
    commits_data = [{
        'name': get_commit_author_name(commit),
        'sha': commit.get('hash'),
        'url': commit.get('links').get('html').get('href'),
        'message': commit.get('message'),
    } for commit in change['commits']]

    return get_push_commits_event_message(
        get_user_username(payload),
        change['links']['html']['href'],
        change['new']['name'],
        commits_data,
        is_truncated=change['truncated']
    )

def get_fork_body(payload):
    # type: (Dict[str, Any]) -> str
    return BITBUCKET_FORK_BODY.format(
        display_name=get_user_display_name(payload),
        username=get_user_username(payload),
        fork_name=get_repository_full_name(payload['fork']),
        fork_url=get_repository_url(payload['fork'])
    )

def get_commit_comment_body(payload):
    # type: (Dict[str, Any]) -> Text
    comment = payload['comment']
    action = u'[commented]({})'.format(comment['links']['html']['href'])
    return get_commits_comment_action_message(
        get_user_username(payload),
        action,
        comment['commit']['links']['html']['href'],
        comment['commit']['hash'],
        comment['content']['raw'],
    )

def get_commit_status_changed_body(payload):
    # type: (Dict[str, Any]) -> str
    commit_id = re.match('.*/commit/(?P<commit_id>[A-Za-z0-9]*$)', payload['commit_status']['links']['commit']['href'])
    if commit_id:
        commit_info = "{}/{}".format(get_repository_url(payload['repository']), commit_id.group('commit_id'))
    else:
        commit_info = 'commit'

    return BITBUCKET_COMMIT_STATUS_CHANGED_BODY.format(
        key=payload['commit_status']['key'],
        system_url=payload['commit_status']['url'],
        commit_info=commit_info,
        status=payload['commit_status']['state']
    )

def get_issue_commented_body(payload):
    # type: (Dict[str, Any]) -> Text
    action = '[commented]({}) on'.format(payload['comment']['links']['html']['href'])
    return get_issue_action_body(payload, action)

def get_issue_action_body(payload, action):
    # type: (Dict[str, Any], str) -> Text
    issue = payload['issue']
    assignee = None
    message = None
    if action == 'created':
        if issue['assignee']:
            assignee = issue['assignee'].get('username')
        message = issue['content']['raw']

    return get_issue_event_message(
        get_user_username(payload),
        action,
        issue['links']['html']['href'],
        issue['id'],
        message,
        assignee
    )

def get_pull_request_action_body(payload, action):
    # type: (Dict[str, Any], str) -> Text
    pull_request = payload['pullrequest']
    return get_pull_request_event_message(
        get_user_username(payload),
        action,
        get_pull_request_url(pull_request),
        pull_request.get('id')
    )

def get_pull_request_created_or_updated_body(payload, action):
    # type: (Dict[str, Any], str) -> Text
    pull_request = payload['pullrequest']
    assignee = None
    if pull_request.get('reviewers'):
        assignee = pull_request.get('reviewers')[0]['username']

    return get_pull_request_event_message(
        get_user_username(payload),
        action,
        get_pull_request_url(pull_request),
        pull_request.get('id'),
        target_branch=pull_request['source']['branch']['name'],
        base_branch=pull_request['destination']['branch']['name'],
        message=pull_request['description'],
        assignee=assignee
    )

def get_pull_request_comment_created_action_body(payload):
    # type: (Dict[str, Any]) -> Text
    action = '[commented]({})'.format(payload['comment']['links']['html']['href'])
    return get_pull_request_comment_action_body(payload, action)

def get_pull_request_deleted_or_updated_comment_action_body(payload, action):
    # type: (Dict[str, Any], Text) -> Text
    action = "{} a [comment]({})".format(action, payload['comment']['links']['html']['href'])
    return get_pull_request_comment_action_body(payload, action)

def get_pull_request_comment_action_body(payload, action):
    # type: (Dict[str, Any], str) -> Text
    action += ' on'
    return get_pull_request_event_message(
        get_user_username(payload),
        action,
        payload['pullrequest']['links']['html']['href'],
        payload['pullrequest']['id'],
        message=payload['comment']['content']['raw']
    )

def get_push_tag_body(payload, change):
    # type: (Dict[str, Any], Dict[str, Any]) -> Text
    if change.get('created'):
        tag = change['new']
        action = 'pushed'  # type: Optional[Text]
    elif change.get('closed'):
        tag = change['old']
        action = 'removed'
    else:
        tag = change['new']
        action = None
    return get_push_tag_event_message(
        get_user_username(payload),
        tag.get('name'),
        tag_url=tag['links']['html'].get('href'),
        action=action
    )

def get_pull_request_title(pullrequest_payload):
    # type: (Dict[str, Any]) -> str
    return pullrequest_payload['title']

def get_pull_request_url(pullrequest_payload):
    # type: (Dict[str, Any]) -> str
    return pullrequest_payload['links']['html']['href']

def get_repository_url(repository_payload):
    # type: (Dict[str, Any]) -> str
    return repository_payload['links']['html']['href']

def get_repository_name(repository_payload):
    # type: (Dict[str, Any]) -> str
    return repository_payload['name']

def get_repository_full_name(repository_payload):
    # type: (Dict[str, Any]) -> str
    return repository_payload['full_name']

def get_user_display_name(payload):
    # type: (Dict[str, Any]) -> str
    return payload['actor']['display_name']

def get_user_username(payload):
    # type: (Dict[str, Any]) -> str
    return payload['actor']['username']

def get_branch_name_for_push_event(payload):
    # type: (Dict[str, Any]) -> Optional[str]
    change = payload['push']['changes'][-1]
    potential_tag = (change['new'] or change['old'] or {}).get('type')
    if potential_tag == 'tag':
        return None
    else:
        return (change['new'] or change['old']).get('name')

GET_SINGLE_MESSAGE_BODY_DEPENDING_ON_TYPE_MAPPER = {
    'fork': get_fork_body,
    'commit_comment': get_commit_comment_body,
    'change_commit_status': get_commit_status_changed_body,
    'issue_updated': partial(get_issue_action_body, action='updated'),
    'issue_created': partial(get_issue_action_body, action='created'),
    'issue_commented': get_issue_commented_body,
    'pull_request_created': partial(get_pull_request_created_or_updated_body, action='created'),
    'pull_request_updated': partial(get_pull_request_created_or_updated_body, action='updated'),
    'pull_request_approved': partial(get_pull_request_action_body, action='approved'),
    'pull_request_unapproved': partial(get_pull_request_action_body, action='unapproved'),
    'pull_request_fulfilled': partial(get_pull_request_action_body, action='merged'),
    'pull_request_rejected': partial(get_pull_request_action_body, action='rejected'),
    'pull_request_comment_created': get_pull_request_comment_created_action_body,
    'pull_request_comment_updated': partial(get_pull_request_deleted_or_updated_comment_action_body, action='updated'),
    'pull_request_comment_deleted': partial(get_pull_request_deleted_or_updated_comment_action_body, action='deleted')
}