"""Ядро сервиса: построение значений и создание документа."""
from __future__ import annotations

from . import config, store
from .render import render_certificate, russian_date


def base_url() -> str:
    if config.BASE_URL:
        return config.BASE_URL
    return f"http://{config.HOST}:{config.PORT}"


def build_values(template: dict, body: dict) -> dict:
    defaults = template.get("defaults") or {}
    title = (body.get("title") or defaults.get("title") or template.get("title") or "").strip()
    text = body.get("body")
    if text is None:
        text = defaults.get("body", "")
    fields = body.get("fields") or {}
    values = {
        "title": title,
        "fio": (body.get("fio") or "").strip(),
        "body": text or "",
        "date": (body.get("date") or "").strip() or russian_date(),
        "fields": fields,
    }
    # произвольные поля из fields доступны как {ключ}
    for k, v in fields.items():
        values.setdefault(str(k), v)
    return values


def cert_api(cert: dict, base: str) -> dict:
    token = cert.get("public_token")
    return {
        **cert,
        "url": f"{base}/c/{cert['seq']}",
        "page": f"{base}/c/{cert['seq']}",
        "png": f"{base}/c/{cert['seq']}.png",
        "pdf": f"{base}/c/{cert['seq']}.pdf",
        "public_url": f"{base}/s/{token}" if token else None,
        "public_png": f"{base}/s/{token}.png" if token else None,
        "public_pdf": f"{base}/s/{token}.pdf" if token else None,
    }


def create_certificate(template: dict, body: dict, base: str | None = None,
                       created_by: int | None = None) -> dict:
    """Создать документ: зарезервировать номер, отрендерить, сохранить пути."""
    base = base or base_url()
    values = build_values(template, body)
    cert = store.reserve_certificate(
        template=template["slug"], values=values, prefix=body.get("prefix"),
        number=body.get("number"),
        recipient_email=body.get("email") or body.get("recipient_email"),
        created_by=created_by,
    )
    seq = cert["seq"]
    values["number"] = cert["number"]

    out_png = config.OUTPUT_DIR / f"{seq:06d}.png"
    out_pdf = config.OUTPUT_DIR / f"{seq:06d}.pdf"
    try:
        render_certificate(template, values, out_png, out_pdf)
    except Exception:
        store.delete_certificate(seq)
        raise
    store.update_certificate_files(seq, str(out_png), str(out_pdf))
    return cert_api(store.get_certificate(seq), base)