"""vCard 3.0 erzeugen - das Format, das iOS beim Antippen zuverlaessig oeffnet."""
from datetime import datetime

_ESCAPES = (("\\", "\\\\"), (";", "\\;"), (",", "\\,"), ("\n", "\\n"))


def _escape(value) -> str:
    text = str(value)
    for char, replacement in _ESCAPES:
        text = text.replace(char, replacement)
    return text


def _line(name: str, value) -> list:
    return [name + ":" + _escape(value)] if value else []


def _display_name(card: dict) -> str:
    joined = " ".join(filter(None, (card.get("first_name"), card.get("last_name"))))
    return joined or card.get("company") or "Unbenannt"


def _note(card: dict) -> str:
    parts = []
    if card.get("notes"):
        parts.append(card["notes"])

    stamp = card.get("captured_at") or card.get("created_at")
    scanned = ""
    if stamp:
        try:
            when = datetime.fromisoformat(stamp).strftime("%d.%m.%Y um %H:%M")
            scanned = "Gescannt am " + when
        except ValueError:
            scanned = "Gescannt am " + str(stamp)
    if card.get("place"):
        scanned = (scanned + " in " if scanned else "Gescannt in ") + card["place"]
    if scanned:
        parts.append(scanned)
    return "\n".join(parts)


def build(card: dict) -> str:
    lines = ["BEGIN:VCARD", "VERSION:3.0"]
    lines.append(
        "N:{};{};;;".format(
            _escape(card.get("last_name") or ""), _escape(card.get("first_name") or "")
        )
    )
    lines.append("FN:" + _escape(_display_name(card)))
    lines += _line("ORG", card.get("company"))
    lines += _line("TITLE", card.get("job_title"))
    if card.get("email"):
        lines.append("EMAIL;TYPE=INTERNET,WORK:" + _escape(card["email"]))
    if card.get("phone"):
        lines.append("TEL;TYPE=WORK,VOICE:" + _escape(card["phone"]))
    if card.get("mobile"):
        lines.append("TEL;TYPE=CELL:" + _escape(card["mobile"]))
    if card.get("fax"):
        lines.append("TEL;TYPE=WORK,FAX:" + _escape(card["fax"]))
    if card.get("website"):
        lines.append("URL:" + _escape(card["website"]))
    if any(card.get(k) for k in ("street", "postal_code", "city", "country")):
        lines.append(
            "ADR;TYPE=WORK:;;{};{};;{};{}".format(
                _escape(card.get("street") or ""),
                _escape(card.get("city") or ""),
                _escape(card.get("postal_code") or ""),
                _escape(card.get("country") or ""),
            )
        )
    if card.get("lat") is not None and card.get("lon") is not None:
        lines.append("GEO:{};{}".format(card["lat"], card["lon"]))
    note = _note(card)
    if note:
        lines.append("NOTE:" + _escape(note))
    lines.append("END:VCARD")
    return "\r\n".join(lines) + "\r\n"


def filename(card: dict) -> str:
    base = _display_name(card).replace(" ", "-")
    safe = "".join(c for c in base if c.isalnum() or c in "-_")
    return (safe or "kontakt") + ".vcf"