populate the by_tag, by_uri and by_section maps

omicron/ssg/site.py

@@ -1,7 +1,12 @@
 import logging
 from typing import Any
 
-from omicron.ssg.content import Content, create_content, CONTENT_EXTENSIONS
+from omicron.ssg.content import (
+    Content,
+    create_content,
+    CONTENT_EXTENSIONS,
+    ContentError,
+)
 from pathlib import Path
 import yaml
 from jinja2 import Environment, FileSystemLoader
@@ -18,9 +23,9 @@ class Site:
     def __init__(self, site: Path):
         self.site_path = site.absolute()
         self.content: list[Content] = []
-        self.by_tag: dict[str, list[Content]]
-        self.by_uri: dict[str, Content]
-        self.by_section: dict[str, Content]
+        self.by_tag: dict[str, list[Content]] = {}
+        self.by_uri: dict[str, Content] = {}
+        self.by_section: dict[str, list[Content]] = {}
 
         config = self.read_config()
         self.name: str = config["name"]
@@ -47,12 +52,36 @@ class Site:
             raise ConfigError(f"template '{template}' not found at {path}")
         return path
 
+    def add_by_section(self, content: Content) -> None:
+        if content.section not in self.by_section:
+            self.by_section[content.section] = []
+        self.by_section[content.section].append(content)
+
+    def add_by_tag(self, content: Content) -> None:
+        for tag in content.tags:
+            if tag not in self.by_tag:
+                self.by_tag[tag] = []
+            self.by_tag[tag].append(content)
+
+    def add_by_uri(self, content: Content) -> None:
+        if content.uri in self.by_uri:
+            conflict = self.by_uri[content.uri]
+            raise ContentError(
+                f"the file at '{content.source}' maps to the same uri as the "
+                f"file at '{conflict.source}'"
+            )
+        self.by_uri[content.uri] = content
+
     def discover(self) -> None:
         log.info("Discovering content...")
         content_path = self.site_path / "content"
         for file in content_path.rglob("*"):
             if file.is_file() and file.suffix in CONTENT_EXTENSIONS:
-                self.content.append(create_content(file))
+                content = create_content(file)
+                self.add_by_uri(content)
+                self.add_by_section(content)
+                self.add_by_tag(content)
+                self.content.append(content)
         log.info("Discovered %d content items", len(self.content))
 
     def build(self):