"""
Walk all files in a directory, checking whether any TODOs are linked to a
resolved JIRA ticket, and labeling those JIRA tickets.
"""

#!/usr/bin/env python3

import argparse
import os
import re
import sys

import structlog
from jira import JIRAError
from structlog.stdlib import LoggerFactory

# Get relative imports to work when the package is not installed on the PYTHONPATH.
if __name__ == "__main__" and __package__ is None:
    sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from buildscripts.client.jiraclient import JiraAuth, JiraClient

structlog.configure(logger_factory=LoggerFactory())
LOG = structlog.getLogger(__name__)
JIRA_SERVER = "https://jira.mongodb.org"


def find_todos(search_file, jira, file_name):
    """Iterate through a file, finding TODOs with resolved tickets and creating new tickets."""
    for i, line in enumerate(search_file):
        if "todo" in line.lower():
            issue_key = get_issue_key_from_line(line)
            if issue_key:
                LOG.info("\n")
                LOG.info("=== Found Issue Key ===")
                LOG.info(line.lstrip().rstrip())
                LOG.info(f"{JIRA_SERVER}/browse/{issue_key}")
                LOG.info(f"Found in {file_name} on line {i+1}")

                # It is possible the referenced ticket in the code was deleted, so we need to
                # handle the possibility that searching for it will return nothing.
                try:
                    issue = jira.issue(issue_key)
                except JIRAError:
                    LOG.warn(f"{issue_key} not found in Jira.  Skipping.")
                    continue

                status = str(issue.fields.status)
                if status not in ["Resolved", "Closed"]:
                    LOG.info(f"{issue_key} is not resolved.  Skipping.")
                    continue

                if todo_ticket_exists(jira, issue):
                    LOG.info(f"Autogenerated ticket linked to {issue_key} already exists.")
                    continue

                create_todo_ticket(jira, issue)


def todo_ticket_exists(jira, resolved_issue):
    """Check if we have already created a ticket for this resolved issue"""
    jql = (
        "labels = autogen-todo AND resolution is empty AND issueFunction in"
        f" linkedIssuesOf('key={resolved_issue.key}')"
    )
    results = jira.search_issues(jql, maxResults=1000)
    if not results or results.total == 0:
        return False
    return True


def create_todo_ticket(jira, resolved_issue):
    """Given a resolved ticket, create a new ticket for that work and link to the resolved ticket."""
    key = resolved_issue.key
    assignee = get_assignable_user(resolved_issue)
    assigned_team = resolved_issue.fields.customfield_12751
    # Derive Team from Resolved ticket
    team = assigned_team[0].value if assigned_team else "Server Triage"

    issue_dict = {
        "project": {"key": "SERVER"},
        "issuetype": {"name": "Task"},
        "summary": "Complete TODO listed in " + key,
        "assignee": {"name": assignee},
        "description": construct_description(key),
        "labels": ["autogen-todo"],
        "customfield_12751": [{"value": team}],
    }

    if "REP" in key:
        issue_dict["project"] = {"key": "REP"}

    # It's possible for us to try and create a ticket with an illegal assignee (most commonly
    # a former employee) so for now we default to hard assigning these to Joe to reassign.
    # This situation should be very infrequent.
    try:
        new_issue = jira.create_issue(fields=issue_dict)
    except JIRAError:
        issue_dict["assignee"]["name"] = "joseph.kanaan@mongodb.com"
        new_issue = jira.create_issue(fields=issue_dict)
    jira.create_issue_link(
        type="Related", inwardIssue=resolved_issue.key, outwardIssue=new_issue.key
    )


def construct_description(key):
    repo = "10gen/mongosync" if "REP" in key else "10gen/mongo"
    return (
        "There is a TODO in the codebase referencing a resolved ticket which is"
        " assigned to you.\n\nPlease follow this link to see the lines of code"
        " referencing this resolved"
        f" ticket:\nhttps://github.com/{repo}/search?q={key}&type=Code\n\nThe next"
        " steps for this ticket are to either remove the outdated TODO or follow the"
        " steps in the TODO if it is correct. If the latter, please update the summary"
        " and description of this ticket to represent the work you're actually doing."
    )


def get_assignable_user(ticket):
    """If the original ticket is assigned to an existing employee, return the assignee"""
    assignee = None
    if ticket.fields.assignee:
        assignee = ticket.fields.assignee.name
    return assignee


def get_issue_key_from_line(line):
    """Given a string of text, find and return any issue keys from relevent projects."""
    match = re.search(
        "(BUILD|SERVER|WT|SPM|TOOLS|TIG|PERF|BF|REP|BACKPORT|WRITING|STAR)-[0-9]+",
        line,
        re.IGNORECASE,
    )
    if match:
        return match.group(0)


def main():
    """Execute main function."""
    argparser = argparse.ArgumentParser(description="")
    argparser.add_argument("--env", "-e", help="Jira environment {stg, prod}", required=False)
    argparser.add_argument("--path", "-p", help="File path to walk", required=True)
    args = vars(argparser.parse_args())

    jira = JiraClient(JIRA_SERVER, JiraAuth(), dry_run=False)

    for root, _, files in os.walk(args["path"]):
        for file_name in files:
            # ignore .git/
            if ".git" in root:
                continue
            try:
                with open(os.path.join(root, file_name), "r") as search_file:
                    find_todos(search_file, jira._jira, file_name)
                    search_file.close()
            except UnicodeDecodeError:
                continue


if __name__ == "__main__":
    main()