[plomtask] / plomtask / http.py

"""Web server stuff."""
from typing import Any
from http.server import BaseHTTPRequestHandler
from http.server import HTTPServer
from urllib.parse import urlparse, parse_qs
from os.path import split as path_split
from jinja2 import Environment as JinjaEnv, FileSystemLoader as JinjaFSLoader
from plomtask.days import Day, todays_date
from plomtask.exceptions import HandledException, BadFormatException, \
        NotFoundException
from plomtask.db import DatabaseConnection, DatabaseFile
from plomtask.processes import Process

TEMPLATES_DIR = 'templates'


class TaskServer(HTTPServer):
    """Variant of HTTPServer that knows .jinja as Jinja Environment."""

    def __init__(self, db_file: DatabaseFile,
                 *args: Any, **kwargs: Any) -> None:
        super().__init__(*args, **kwargs)
        self.db = db_file
        self.jinja = JinjaEnv(loader=JinjaFSLoader(TEMPLATES_DIR))


class TaskHandler(BaseHTTPRequestHandler):
    """Handles single HTTP request."""
    server: TaskServer

    def do_GET(self) -> None:
        """Handle any GET request."""
        try:
            conn, site, params = self._init_handling()
            if 'calendar' == site:
                start = params.get('start', [''])[0]
                end = params.get('end', [''])[0]
                html = self.do_GET_calendar(conn, start, end)
            elif 'day' == site:
                date = params.get('date', [todays_date()])[0]
                html = self.do_GET_day(conn, date)
            elif 'process' == site:
                id_ = params.get('id', [None])[0]
                try:
                    id__ = int(id_) if id_ else None
                except ValueError as e:
                    raise BadFormatException(f'Bad ?id= value: {id_}') from e
                html = self.do_GET_process(conn, id__)
            elif 'processes' == site:
                html = self.do_GET_processes(conn)
            elif '' == site:
                self._redirect('/day')
                return
            else:
                raise NotFoundException(f'Unknown page: /{site}')
            conn.commit()
            conn.close()
            self._send_html(html)
        except HandledException as error:
            self._send_msg(error, code=error.http_code)

    def do_GET_calendar(self, conn: DatabaseConnection,
                        start: str, end: str) -> str:
        """Show Days."""
        days = Day.all(conn, date_range=(start, end), fill_gaps=True)
        return self.server.jinja.get_template('calendar.html').render(
                days=days, start=start, end=end)

    def do_GET_day(self, conn: DatabaseConnection, date: str) -> str:
        """Show single Day."""
        day = Day.by_date(conn, date, create=True)
        return self.server.jinja.get_template('day.html').render(day=day)

    def do_GET_process(self, conn: DatabaseConnection, id_: int | None) -> str:
        """Show process of id_."""
        return self.server.jinja.get_template('process.html').render(
                process=Process.by_id(conn, id_, create=True))

    def do_GET_processes(self, conn: DatabaseConnection) -> str:
        """Show all Processes."""
        return self.server.jinja.get_template('processes.html').render(
                processes=Process.all(conn))

    def do_POST(self) -> None:
        """Handle any POST request."""
        try:
            conn, site, params = self._init_handling()
            length = int(self.headers['content-length'])
            postvars = parse_qs(self.rfile.read(length).decode(),
                                keep_blank_values=True)
            if 'day' == site:
                date = params.get('date', [''])[0]
                self.do_POST_day(conn, date, postvars)
            elif 'process' == site:
                id_ = params.get('id', [''])[0]
                try:
                    id__ = int(id_) if id_ else None
                except ValueError as e:
                    raise BadFormatException(f'Bad ?id= value: {id_}') from e
                self.do_POST_process(conn, id__, postvars)
            conn.commit()
            conn.close()
            self._redirect('/')
        except HandledException as error:
            self._send_msg(error, code=error.http_code)

    def do_POST_day(self, conn: DatabaseConnection,
                    date: str, postvars: dict[str, list[str]]) -> None:
        """Update or insert Day of date and fields defined in postvars."""
        day = Day.by_date(conn, date, create=True)
        day.comment = postvars['comment'][0]
        day.save(conn)

    def do_POST_process(self, conn: DatabaseConnection, id_: int | None,
                        postvars: dict[str, list[str]]) -> None:
        """Update or insert Process of id_ and fields defined in postvars."""
        process = Process.by_id(conn, id_, create=True)
        process.title.set(postvars['title'][0])
        process.description.set(postvars['description'][0])
        effort = postvars['effort'][0]
        try:
            process.effort.set(float(effort))
        except ValueError as e:
            raise BadFormatException(f'Bad effort value: {effort}') from e
        process.save(conn)

    def _init_handling(self) -> \
            tuple[DatabaseConnection, str, dict[str, list[str]]]:
        conn = DatabaseConnection(self.server.db)
        parsed_url = urlparse(self.path)
        site = path_split(parsed_url.path)[1]
        params = parse_qs(parsed_url.query)
        return conn, site, params

    def _redirect(self, target: str) -> None:
        self.send_response(302)
        self.send_header('Location', target)
        self.end_headers()

    def _send_html(self, html: str, code: int = 200) -> None:
        """Send HTML as proper HTTP response."""
        self.send_response(code)
        self.end_headers()
        self.wfile.write(bytes(html, 'utf-8'))

    def _send_msg(self, msg: Exception, code: int = 400) -> None:
        """Send message in HTML formatting as HTTP response."""
        html = self.server.jinja.get_template('msg.html').render(msg=msg)
        self._send_html(html, code)