Refactor backend and frontend code for improved structure and functionality

backend/Dockerfile

@@ -35,4 +35,4 @@ COPY . .
 
 EXPOSE 8000
 
-CMD ["sh", "-c", "until mysqladmin ping -hdb -ucheatsheet_user -pcheatsheet_pass --silent; do sleep 2; done && python manage.py runserver 0.0.0.0:8000"]
+CMD ["sh", "-c", "until mysqladmin ping -hdb -ucheatsheet_user -pcheatsheet_pass --ssl=0 --silent; do sleep 2; done && python manage.py migrate && python manage.py runserver 0.0.0.0:8000"]

backend/api/latex_utils.py

@@ -0,0 +1,103 @@
+import subprocess
+import tempfile
+import os
+
+LATEX_HEADER = r"""\documentclass[fleqn]{article}
+\usepackage[margin=0.15in]{geometry}
+\usepackage{amsmath, amssymb}
+\usepackage{enumitem} 
+\usepackage{multicol}
+\usepackage{titlesec}
+
+\setlength{\mathindent}{0pt}
+\setlist[itemize]{noitemsep, topsep=0pt, leftmargin=*}
+\pagestyle{empty}
+
+\titlespacing*{\subsection}{0pt}{2pt}{1pt}
+\titlespacing*{\section}{0pt}{4pt}{2pt}
+
+\begin{document}
+\scriptsize
+"""
+
+LATEX_FOOTER = r"""
+\end{document}
+"""
+
+def build_latex_for_formulas(selected_formulas):
+    """
+    Given a list of selected formulas (each with class_name, category, name, latex),
+    build a complete LaTeX document.
+    """
+    body_lines = []
+
+    # Group formulas by class
+    by_class = {}
+    for formula in selected_formulas:
+        class_name = formula.get("class_name") or formula.get("class")
+        if class_name not in by_class:
+            by_class[class_name] = {}
+
+        category = formula.get("category")
+        if category not in by_class[class_name]:
+            by_class[class_name][category] = []
+
+        by_class[class_name][category].append(formula)
+
+    # Build LaTeX for each class
+    for class_name, categories in by_class.items():
+        body_lines.append("\\section*{" + class_name + "}")
+        body_lines.append("")
+
+        for category_name, formulas in categories.items():
+            body_lines.append("\\subsection*{" + category_name + "}")
+            body_lines.append("")
+            body_lines.append(r"\begin{flushleft}")
+
+            for formula in formulas:
+                name = formula.get("name", "")
+                latex = formula.get("latex", "")
+                body_lines.append("\\textbf{" + name + "}")
+                body_lines.append("\\[ " + latex + " \\]")
+                body_lines.append("\\\\[4pt]")
+
+            body_lines.append(r"\end{flushleft}")
+            body_lines.append("")
+
+    body = "\n".join(body_lines)
+    return LATEX_HEADER + body + LATEX_FOOTER
+
+def compile_latex_to_pdf(content):
+    """
+    Compiles LaTeX content to a PDF using Tectonic.
+    Returns the generated PDF as bytes or raises an Exception.
+    """
+    # Ensure document has proper structure
+    if r"\begin{document}" not in content:
+        content = LATEX_HEADER + content + LATEX_FOOTER
+
+    # Use a context manager so the temporary directory is always cleaned up
+    with tempfile.TemporaryDirectory() as tempdir:
+        tex_file_path = os.path.join(tempdir, "document.tex")
+        with open(tex_file_path, "w", encoding="utf-8") as f:
+            f.write(content)
+
+        try:
+            subprocess.run(
+                ["tectonic", tex_file_path],
+                cwd=tempdir,
+                capture_output=True,
+                text=True,
+                check=True,
+            )
+        except subprocess.CalledProcessError:
+            # Propagate the error; the temporary directory will still be cleaned up
+            raise
+
+        pdf_file_path = os.path.join(tempdir, "document.pdf")
+        if not os.path.exists(pdf_file_path):
+            raise FileNotFoundError("PDF not generated")
+
+        # Read and return the PDF bytes before the temporary directory is removed
+        with open(pdf_file_path, "rb") as pdf_file:
+            return pdf_file.read()

backend/api/urls.py

@@ -1,18 +1,19 @@
-from django.urls import path
+from django.urls import path, include
+from rest_framework.routers import DefaultRouter
 from . import views
 
+# Create a router and register our viewsets with it.
+router = DefaultRouter()
+router.register(r'templates', views.TemplateViewSet, basename='template')
+router.register(r'cheatsheets', views.CheatSheetViewSet, basename='cheatsheet')
+router.register(r'problems', views.PracticeProblemViewSet, basename='problem')
+
 urlpatterns = [
     path("health/", views.health_check, name="health-check"),
     path("classes/", views.get_classes, name="get-classes"),
     path("generate-sheet/", views.generate_sheet, name="generate-sheet"),
     path("compile/", views.compile_latex, name="compile-latex"),
 
-    # CRUD endpoints
-    path("templates/", views.template_list, name="template-list"),
-    path("templates/<int:pk>/", views.template_detail, name="template-detail"),
-    path("cheatsheets/", views.cheatsheet_list, name="cheatsheet-list"),
-    path("cheatsheets/from-template/", views.cheatsheet_from_template, name="cheatsheet-from-template"),
-    path("cheatsheets/<int:pk>/", views.cheatsheet_detail, name="cheatsheet-detail"),
-    path("problems/", views.problem_list, name="problem-list"),
-    path("problems/<int:pk>/", views.problem_detail, name="problem-detail"),
+    # Include the router URLs for CRUD operations
+    path('', include(router.urls)),
 ]