Initial version of the E-Invoice solution of JR IT Services

jr_einvoice/render.py

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+from __future__ import annotations
+from pathlib import Path
+import subprocess
+import shutil
+
+from jinja2 import Environment, FileSystemLoader, select_autoescape
+
+from .models import Invoice
+from .calc import compute_totals
+from .types import RenderResult
+from .utils import money_fmt
+
+def render_html(inv: Invoice, template_path: Path) -> str:
+    env = Environment(
+        loader=FileSystemLoader(str(template_path.parent)),
+        autoescape=select_autoescape(["html", "xml"]),
+    )
+    env.globals["money"] = lambda x: money_fmt(x, inv.meta.currency)
+    tpl = env.get_template(template_path.name)
+
+    totals = compute_totals(inv)
+
+    items = []
+    for it in inv.items:
+        d = it.model_dump()
+        d["line_total_net"] = float(it.quantity) * float(it.unit_price_net)
+        items.append(type("Obj", (), d))
+
+    ctx = {
+        "meta": inv.meta.model_dump(),
+        "seller": inv.seller.model_dump(),
+        "buyer": inv.buyer.model_dump(),
+        "payment": inv.payment.model_dump(),
+        "items": items,
+        "totals": totals,
+    }
+    return tpl.render(**ctx)
+
+def _weasyprint_available() -> bool:
+    try:
+        import weasyprint  # noqa
+        return True
+    except Exception:
+        return False
+
+def render_pdf(html: str, out_pdf: Path, logger, prefer_weasyprint: bool = True, base_url: str | None = None) -> RenderResult:
+    out_pdf.parent.mkdir(parents=True, exist_ok=True)
+
+    if prefer_weasyprint and _weasyprint_available():
+        logger.info("Rendering PDF using WeasyPrint")
+        try:
+            from weasyprint import HTML  # type: ignore
+            HTML(string=html, base_url=base_url).write_pdf(str(out_pdf))
+            return RenderResult(ok=True, backend="weasyprint", path=out_pdf)
+        except Exception as e:
+            logger.exception("WeasyPrint rendering failed; trying wkhtmltopdf if available: %s", e)
+
+    wk = shutil.which("wkhtmltopdf")
+    if wk:
+        logger.info("Rendering PDF using wkhtmltopdf (%s)", wk)
+        tmp_html = out_pdf.with_suffix(".tmp.html")
+        tmp_html.write_text(html, encoding="utf-8")
+        try:
+            proc = subprocess.run(
+                [wk, "--quiet", "--enable-local-file-access", str(tmp_html), str(out_pdf)],
+                capture_output=True,
+                text=True,
+                check=False,
+            )
+            if proc.returncode != 0:
+                logger.error("wkhtmltopdf failed (rc=%s). stderr=%s", proc.returncode, proc.stderr.strip())
+                return RenderResult(ok=False, backend="wkhtmltopdf", path=None, error="wkhtmltopdf failed")
+            return RenderResult(ok=True, backend="wkhtmltopdf", path=out_pdf)
+        finally:
+            try:
+                tmp_html.unlink(missing_ok=True)
+            except Exception:
+                pass
+
+    return RenderResult(ok=False, backend="none", path=None, error="No PDF backend available (install weasyprint or wkhtmltopdf).")