# Wir schreiben einen einfachen Task-Parser in Python, der Markdown-Dateien nach Task-Listeneinträgen durchsucht.
# Dafür nutzen wir den 'markdown' Parser und reguläre Ausdrücke.

import os
import re
from pathlib import Path

from dataclasses import dataclass
from sys import stdout
from typing import List, Optional
from datetime import datetime

import caldav
from icalendar import Todo
from dotenv import load_dotenv

load_dotenv()


@dataclass
class Task:
    file: str
    line_number: int
    raw_text: str
    text: str
    completed: bool
    due: Optional[datetime] = None
    start: Optional[datetime] = None
    scheduled: Optional[datetime] = None
    recurrence: Optional[str] = None
    priority: Optional[str] = None


def parse_task_line(line: str, file: str, line_number: int) -> Optional[Task]:
    task_pattern = re.compile(r"- \[([ +/\-?!<])\] (.+)")
    match = task_pattern.match(line)
    if not match:
        return None

    completed = match.group(1) == "x" or match.group(1) == "-"
    text = match.group(2)
    # Suche nach Metadaten im Text
    due = extract_date(text, r"📅 (\d{4}-\d{2}-\d{2})")
    if due is not None:
        due = due.replace(hour=23, minute=59, second=59)
    start = extract_date(text, r"🛫 (\d{4}-\d{2}-\d{2})")
    scheduled = extract_date(text, r"⏳ (\d{4}-\d{2}-\d{2})")
    if scheduled is not None:
        scheduled = scheduled.replace(hour=23, minute=59, second=59)
    recurrence = extract_text(text, r"🔁 ([^\s]+)")
    priority = extract_text(text, r"(‼|❗|➖|🔽)")
    clean = extract_text(text, r"([^📅🛫⏳🔁‼❗➖🔽🆔➕⛔]*)")

    if due is not None and scheduled is not None:
        if due < scheduled:
            due = scheduled
    return Task(
        file=file,
        line_number=line_number,
        raw_text=line.strip(),
        text=clean or text.strip(),
        completed=completed,
        due=due,
        start=start,
        scheduled=scheduled,
        recurrence=recurrence,
        priority=priority,
    )


def extract_date(text: str, pattern: str) -> Optional[datetime]:
    match = re.search(pattern, text)
    if match:
        try:
            return datetime.strptime(match.group(1), "%Y-%m-%d")
        except ValueError:
            return None
    return None


def extract_text(text: str, pattern: str) -> Optional[str]:
    match = re.search(pattern, text)
    if match:
        return match.group(1)
    return None


def parse_tasks_from_vault(vault_path: str) -> List[Task]:
    tasks = []
    for md_file in Path(vault_path).rglob("*.md"):
        with open(md_file, "r", encoding="utf-8") as f:
            for i, line in enumerate(f):
                task = parse_task_line(line, str(md_file), i + 1)
                if task:
                    tasks.append(task)
    return tasks


# Für die Demonstration verwenden wir ein Testverzeichnis
tasks = parse_tasks_from_vault(os.getenv("OBSIDIAN_VAULT_PATH", "."))

# Verbindung zur Nextcloud herstellen
client = caldav.DAVClient(
    url=os.getenv("NEXTCLOUD_URL"),
    username=os.getenv("NEXTCLOUD_USER"),
    password=os.getenv("NEXTCLOUD_PASSWORD"),
)

# Hole das erste verfügbare Kalender-Objekt (für Aufgaben, nicht Termine!)
principal = client.principal()
task_calendars = [c for c in principal.calendars() if "nicole" == str(c.name).lower()]

print(f"Found task calendars: {task_calendars}")

calendar = task_calendars[0]

## delete all created todos
for todo in calendar.todos():
    ical = todo.vobject_instance
    todoitem = ical.contents["vtodo"][0].contents

    if "x-obsidian-task-id" in todoitem:
        print(f"deleting {todoitem['summary']}")
        todo.delete()

# create new todos

for t in tasks:
    if not t.completed and t.scheduled is not None:
        print(f"adding on {t.scheduled.date().isoformat()}: {t.text}")
        stdout.flush()
        todo = Todo()
        todo.add("summary", t.text)
        todo.add("created", datetime.now())
        todo.add("description", "Generated by ObsidianSyncScript")
        todo.add("X-OBSIDIAN-TASK-ID", f"{t.file}:{t.line_number}")
        if t.scheduled:
            todo.add("due", t.scheduled)
        if t.start:
            todo.add("dtstart", t.start)
        if t.due:
            todo.add("comment", f"due {t.due}")
        # if t.priority:
        #    todo.add('priority', convert_priority(t.priority))

        try:
            calendar.add_todo(todo.to_ical().decode("utf-8"))
        except Exception as e:
            print(e)