Source code for conda_tasks.template

"""Jinja2 template rendering for task commands and paths."""

from __future__ import annotations

from functools import lru_cache
from typing import TYPE_CHECKING

from .context import build_template_context

if TYPE_CHECKING:
    from pathlib import Path


@lru_cache(maxsize=1)
def _get_jinja_env():
    """Create and cache a Jinja2 Environment (singleton)."""
    from jinja2 import Environment, StrictUndefined

    return Environment(undefined=StrictUndefined)




def render(
    template_str: str,
    manifest_path: Path | None = None,
    task_args: dict[str, str] | None = None,
    extra_context: dict[str, object] | None = None,
) -> str:
    """Render a Jinja2 template string with the conda-tasks context.

    If *template_str* contains no template markers it is returned as-is
    (fast path that avoids Jinja2 import entirely).
    """
    if "{{" not in template_str and "{%" not in template_str:
        return template_str

    env = _get_jinja_env()
    ctx = build_template_context(manifest_path=manifest_path, task_args=task_args)
    if extra_context:
        ctx.update(extra_context)
    tpl = env.from_string(template_str)
    return tpl.render(ctx)





def render_list(
    items: list[str],
    manifest_path: Path | None = None,
    task_args: dict[str, str] | None = None,
) -> list[str]:
    """Render each string in *items* through the template engine."""
    return [render(s, manifest_path=manifest_path, task_args=task_args) for s in items]