"""Call-time switches for long-report rendering and same-chart reuse.

Values are read on every call so one process can measure the old path and the
new path back to back. The old path stays in place when a switch is off.
"""

from __future__ import annotations

import os

# Masked Windows A/B on 2026-10-14: render shortcuts byte-identical, less memory,
# end-to-end -20–23%, short of the 35% gate then set, so the path stayed off.
# Linux A/B on 2026-10-28 (four fictional charts, PyJHora masked): byte-identical
# again, -19–26% (median 23%). The product owner chose to turn it on anyway
# (issue #121, option A); JYOTISH_REPORT_RENDER_FAST=0 restores the old path.
# Cache hits matched the miss bytes and returned in about 0.06s, under the 1.5s
# gate. A missing or unknown GITHUB_SHA still disables the cache at the call site.
RENDER_FAST_DEFAULT = True
REFERENCE_CACHE_DEFAULT = True

_ON = {"1", "true", "yes", "on"}


def _enabled(name: str, default: bool) -> bool:
    raw = os.environ.get(name)
    if raw is None or not raw.strip():
        return default
    return raw.strip().lower() in _ON


def report_render_fast_enabled() -> bool:
    """True when the equivalent render and hash shortcuts may run."""
    return _enabled("JYOTISH_REPORT_RENDER_FAST", RENDER_FAST_DEFAULT)


def report_reference_cache_enabled() -> bool:
    """True when a full_data markdown response may be reused from disk.

    A missing or ``unknown`` ``GITHUB_SHA`` still disables the cache at the
    call site. This function only reads the switch.
    """
    return _enabled("JYOTISH_REPORT_REFERENCE_CACHE", REFERENCE_CACHE_DEFAULT)