Working initial version

src/formex_viewer/server.py

@@ -0,0 +1,82 @@
+import lxml.etree as ET
+from fastapi import FastAPI, Response
+from fastapi.middleware.cors import CORSMiddleware
+
+from formex_viewer.formex4 import FormexArticleConverter
+from formex_viewer.main import (
+    CellarClient,
+    CellarIdentifier,
+    ContentType,
+    Language,
+    SystemName,
+)
+
+origins = [
+    "http://localhost:5173",
+]
+app = FastAPI()
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=origins,
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+type CacheKey = tuple[str, Language]
+
+CACHE: dict[CacheKey, str] = {}
+
+
+def _get_fmx4_data(celex_id: str, language: Language) -> str:
+    """
+    Fetch the FMX4 data from the server.
+    """
+
+    if (celex_id, language) in CACHE:
+        return CACHE[(celex_id, language)]
+
+    client = CellarClient(language)
+    cellar_id = CellarIdentifier(
+        system_name=SystemName.CELEX,
+        system_id=celex_id,
+    )
+    fmx4_data = client.publication_text(cellar_id, ContentType.ZIP_FMX4)
+
+    CACHE[(celex_id, language)] = fmx4_data
+
+    return fmx4_data
+
+
+@app.get("/{celex_id}/articles")
+def article_ids(celex_id: str, language: Language = Language.ENG):
+    """
+    Fetch the article IDs from the server.
+    """
+    fmx4_data = _get_fmx4_data(celex_id, language)
+    xml = ET.fromstring(fmx4_data.encode("utf-8"))
+
+    article_xpath = "//ARTICLE/@IDENTIFIER"
+    article_ids = xml.xpath(article_xpath)
+    article_ids = [int(article_id.lstrip("0")) for article_id in article_ids]
+    article_ids.sort()
+    return article_ids
+
+
+@app.get("/{celex_id}/articles/{article_id}/{language}")
+def article(celex_id: str, article_id: int, language: Language = Language.ENG):
+    """
+    Fetch an article from the server.
+    """
+    fmx4_data = _get_fmx4_data(celex_id, language)
+    xml = ET.fromstring(fmx4_data.encode("utf-8"))
+
+    article_xpath = "//ARTICLE"
+    articles = xml.xpath(article_xpath)
+    for article in articles:
+        num = article.get("IDENTIFIER").lstrip("0")
+        if num == str(article_id):
+            return Response(
+                FormexArticleConverter().convert_article(article),
+                media_type="text/html",
+            )