refactor: remove duplicated code, unify includes.

src/css.js

@@ -1,6 +1,4 @@
-import path from 'path';
-
-import { handleTemplateFile } from './transforms/template-data.js';
+import { handleIncludes } from './includes.js';
 
 const INCLUDE_REGEX = /@import [\"\']([\w:\/\\\.\-]+?\.css)[\"\'](?:\s*layer\s*\((\w+)\))?;/g;
 
@@ -10,21 +8,22 @@ export default (config) => {
   config.addExtension('css', {
     outputFileExtension: 'css',
     compile: async function (inputContent, inputPath) {
-      let parsed = path.parse(inputPath);
-
       return async (data) => {
-        const includes = new Map();
-        const matches = inputContent.matchAll(INCLUDE_REGEX);
-        for (const [, file, layer] of matches) {
-          const tpl = await handleTemplateFile(config, data, path.join(parsed.dir, file));
-          if (layer) {
-            includes.set(file, tpl ? `@layer ${layer} {\n${tpl.content}\n}` : `@import url("${file}") layer(${layer});`);
-            continue;
+        return await handleIncludes(
+          inputContent, inputPath,
+          config, data, null, INCLUDE_REGEX, 
+          (context, _, file, layer) => {
+            const include = context.includes.get(file);
+            if (!include || !include.content) {
+              return `@import url("${file}")${layer ?` layer(${layer});`:``};`;
+            }
+            if (! layer) {
+              return include.content;
+            }
+            return `@layer ${layer} {\n${tpl.content}\n}`;
           }
-          includes.set(file, tpl ? tpl.content : `@import url("${file}");`);
-        }
-        return inputContent.replace(INCLUDE_REGEX, (_, file) => includes.get(file)) 
-      };
+        );
+      }
     },
   });
 };

src/html.js

@@ -1,5 +1,4 @@
-import path from 'path';
-import { handleTemplateFile } from './transforms/template-data.js';
+import { handleIncludes } from './includes.js';
 
 const INCLUDE_REGEX = /<html-include[\s\r\n]*src="([\w\-\.]+?)"[\s\r\n]*\/?>/g;
 
@@ -9,24 +8,12 @@ export default (config) => {
   config.addExtension('html', {
     outputFileExtension: 'html',
     compile: async function (inputContent, inputPath) {
-
-      let parsed = path.parse(inputPath);
-
       return async (data) => {
-        const includes = new Map();
-        let content = inputContent;
-        const matches = Array.from(content.matchAll(INCLUDE_REGEX));
-        if (matches.length > 0) {
-          for (const [, file] of matches) {
-            const include = await handleTemplateFile(config, data, path.join(config.dir.includes, file));
-            includes.set(file, include ? include.content : `<!-- html-include src="${file}" -->`);
-          }
-          content = content.replace(INCLUDE_REGEX, (_, file) => {
-            return includes.get(file)
-          });
-        }
-        return content;
-      };
+        return await handleIncludes(
+          inputContent, inputPath, 
+          config, data, config.dir.includes, 
+          INCLUDE_REGEX);
+      }
     },
   });
 };

src/includes.js

@@ -0,0 +1,47 @@
+import path from 'node:path';
+import { handleTemplateFile } from './transforms/template-data.js';
+
+/**
+ * Language-agnostic include method to handle includes in sissi
+ * @param {string} inputContent the content
+ * @param {string} inputPath the full path to the file processed
+ * @param {SissiConfig} config the configuration
+ * @param {any} data the data object
+ * @param {string} includePath the include path to be used. If nullish, it's relative to the inputPath
+ * @param {Regexp} regex the regular expression to match include directives
+ * @param {(context, ...args: string[]) => string} replaceFunction the callback function of the string.replace 
+ * @returns {string} the contents with the includes resolved
+ */
+export async function handleIncludes(
+  content, inputPath, config, data, includePath, regex, replaceFunction) {
+  const includes = new Map();
+  let parsed = path.parse(inputPath);
+  const matches = Array.from(content.matchAll(regex));
+  for (const [, file] of matches) {
+    if (includes.has(file)) {
+      continue;
+    }
+    const _dependants = data?._dependants instanceof Array ? data._dependants.slice(0) : [inputPath];
+    const includeFile = path.join(includePath ?? parsed.dir, file);
+    if (_dependants.includes(includeFile)) {
+      console.warn(`Skipping Circular include detected in ${inputPath}: ${includeFile}`);
+      continue;
+    }
+    _dependants.push(file);
+    const include = await handleTemplateFile(config, {_dependants, ...(data ?? {})}, includeFile);
+    includes.set(file, include);
+  }
+
+  const defaultReplaceFunction = (context, _, file) => {
+    return context.includes.get(file)?.content ?? `<!-- missing include: ${file} -->`;
+  };
+
+  const replaceContext = {
+    inputPath,
+    includes,
+  };
+
+  return content.replace(regex, 
+    (...args) => (replaceFunction ?? defaultReplaceFunction)(replaceContext, ...args)
+  );
+}

src/md.js

@@ -1,6 +1,4 @@
-import path from 'path';
-
-import { handleTemplateFile } from './transforms/template-data.js';
+import { handleIncludes } from './includes.js';
 import { markdown } from './transforms/markdown.js';
 
 const INCLUDE_REGEX = /<html-include[\s\r\n]*src="([\w\.]+)"[\s\r\n]*\/?>/g;
@@ -13,16 +11,10 @@ export default (config) => {
     compile: async function (inputContent, inputPath) {
 
       return async (data) => {
-        const includes = new Map();
-        const content = markdown(inputContent);
-        const matches = content.matchAll(INCLUDE_REGEX);
-        for (const [, file] of matches) {
-          const include = await handleTemplateFile(config, data, path.join(config.dir.includes, file));
-          includes.set(file, include ? include.content : `<!-- html-include src="${file}" -->`);
-        }   
-        return content.replace(INCLUDE_REGEX, (_, file) => {
-          return includes.get(file)
-        });
+        return await handleIncludes(
+          markdown(inputContent), inputPath, 
+          config, data, config.dir.includes, 
+          INCLUDE_REGEX);
       };
     },
   });