import re
from datetime import datetime, timezone
from typing import Sequence

from .models import CaptureRequest


def normalize_tags(tags: Sequence[str]) -> list[str]:
    seen: set[str] = set()
    result: list[str] = []
    for raw in tags:
        tag = raw.strip().lower()
        tag = tag.lstrip("#")
        tag = tag.replace(" ", "_")
        tag = re.sub(r"[^a-z0-9_]", "", tag)
        if tag and tag not in seen:
            seen.add(tag)
            result.append(tag)
    return result


def _org_tags(tags: list[str]) -> str:
    if not tags:
        return ""
    return " :" + ":".join(tags) + ":"


def _created_stamp(created_at: str) -> str:
    """Parse ISO-8601 datetime and format as org inactive timestamp."""
    try:
        dt = datetime.fromisoformat(created_at)
    except ValueError:
        dt = datetime.now(timezone.utc)
    day_abbr = dt.strftime("%a").lower()
    return f"[{dt.strftime('%Y-%m-%d')} {day_abbr} {dt.strftime('%H:%M')}]"


def _property_drawer(created_stamp: str, source: str, capture_id: str) -> str:
    return (
        ":PROPERTIES:\n"
        f":CREATED: {created_stamp}\n"
        f":SOURCE: {source}\n"
        f":ID: {capture_id}\n"
        ":END:"
    )


def format_capture(capture: CaptureRequest) -> str:
    tags = normalize_tags(capture.tags)
    tag_str = _org_tags(tags)
    created_stamp = _created_stamp(capture.created_at)
    drawer = _property_drawer(created_stamp, capture.device, capture.id)

    if capture.kind == "todo":
        heading = f"* TODO {capture.body}{tag_str}"
        return f"{heading}\n{drawer}\n"

    # note
    lines = capture.body.split("\n")
    first_line = lines[0].rstrip()
    is_multiline = len(lines) > 1 and any(l.strip() for l in lines[1:])

    if is_multiline:
        heading = f"* note: {first_line}{tag_str}"
        return f"{heading}\n{drawer}\n\n{capture.body}\n"
    else:
        heading = f"* note{tag_str}"
        return f"{heading}\n{drawer}\n\n{capture.body}\n"