"""Shared Jinja2 environment with custom filters for the dashboard.
Imported by both routers/pages.py and routers/api.py so the filters are
registered exactly once."""
from __future__ import annotations

import time
from pathlib import Path

from fastapi.templating import Jinja2Templates
from markupsafe import Markup, escape

from app import branding
from app.config import get_settings
from app.services.glossary import wrap_glossary


# Cache-busting token for static assets. Computed once at import time
# (i.e. process startup), so every container restart yields a fresh
# value and browsers refetch CSS/JS instead of serving stale cache.
# Templates append `?v={{ ASSET_VERSION }}` to every static URL.
ASSET_VERSION = str(int(time.time()))


TEMPLATE_DIR = Path(__file__).resolve().parent / "templates"


def _fmt_price(v: float | None) -> str:
    """Format a price in a way that's readable in dense terminal tables.
    Avoids scientific notation for large round numbers (FTSE 25,962, not 2.596e+04)
    and keeps enough precision for FX rates like 0.8725 EUR/GBP."""
    if v is None:
        return "—"
    av = abs(v)
    if av >= 1000:
        return f"{v:,.2f}"
    if av >= 10:
        return f"{v:.2f}"
    if av >= 1:
        return f"{v:.4f}"
    return f"{v:.4f}"


def _fmt_signed(v: float | None, decimals: int = 2) -> str:
    if v is None:
        return "—"
    return f"{v:+,.{decimals}f}"


def _fmt_money(v: float | None) -> str:
    if v is None:
        return "—"
    return f"{v:,.2f}"


def _glossary_filter(value, tone: str | None = None):
    """Wrap glossary terms in NOVICE-mode AI content. Returns Markup so
    Jinja won't re-escape the inserted <span> tags. Plain-text inputs are
    HTML-escaped first; already-Markup inputs (e.g. log.content_html) are
    treated as HTML and passed through wrap_glossary unchanged."""
    if value is None:
        return Markup("")
    if isinstance(value, Markup):
        html = str(value)
    else:
        html = str(escape(value))
    if (tone or "").upper() != "NOVICE":
        return Markup(html)
    return Markup(wrap_glossary(html, tone=tone))


templates = Jinja2Templates(directory=str(TEMPLATE_DIR))
templates.env.filters["price"] = _fmt_price
templates.env.filters["signed"] = _fmt_signed
templates.env.filters["money"] = _fmt_money
templates.env.filters["glossary"] = _glossary_filter

# Brand globals — every template that prints a product name should pull
# from these so a future rename is a one-liner in `app/branding.py`.
templates.env.globals["BRAND_NAME"] = branding.BRAND_NAME
templates.env.globals["BRAND_SHORT"] = branding.BRAND_SHORT
templates.env.globals["SITE_URL"] = branding.SITE_URL
templates.env.globals["APP_URL"] = branding.APP_URL
templates.env.globals["TAGLINE"] = branding.TAGLINE
templates.env.globals["LEGAL_OPERATOR"] = branding.LEGAL_OPERATOR
templates.env.globals["OPERATOR_EMAIL"] = branding.OPERATOR_EMAIL
templates.env.globals["OPERATOR_JURISDICTION"] = branding.OPERATOR_JURISDICTION
templates.env.globals["BETA_MODE"] = get_settings().BETA_MODE
templates.env.globals["ASSET_VERSION"] = ASSET_VERSION