🖼️ added images support

- Should investigate how to resize the image from .md specs

lib/remark-copy-images.ts

@@ -0,0 +1,146 @@
+import { visit } from 'unist-util-visit'
+import fs from 'fs/promises'
+import path from 'path'
+import { Node } from 'unist'
+
+interface ImageNode extends Node {
+  type: 'image'
+  url: string
+  alt?: string
+  title?: string
+}
+
+interface Options {
+  contentDir: string
+  publicDir: string
+  currentSlug: string
+}
+
+function isRelativePath(url: string): boolean {
+  // Matches: ./, ../, or bare filenames without protocol/absolute path
+  return (
+    url.startsWith('./') || url.startsWith('../') || (!url.startsWith('/') && !url.includes('://'))
+  )
+}
+
+function stripQueryParams(url: string): string {
+  return url.split('?')[0]
+}
+
+// In-memory cache to prevent duplicate copies across parallel compilations
+const copiedFiles = new Set<string>()
+
+async function copyAndRewritePath(node: ImageNode, options: Options): Promise<void> {
+  const { contentDir, publicDir, currentSlug } = options
+
+  const urlWithoutParams = stripQueryParams(node.url)
+  const slugParts = currentSlug.split('/')
+  const contentPostDir = path.join(process.cwd(), contentDir, ...slugParts.slice(0, -1))
+
+  const sourcePath = path.resolve(contentPostDir, urlWithoutParams)
+
+  if (sourcePath.includes('..') && !sourcePath.startsWith(path.join(process.cwd(), contentDir))) {
+    throw new Error(`Invalid image path: ${node.url} (path traversal detected)`)
+  }
+
+  const relativeToContent = path.relative(path.join(process.cwd(), contentDir), sourcePath)
+  const destPath = path.join(process.cwd(), publicDir, relativeToContent)
+
+  try {
+    await fs.access(sourcePath)
+  } catch {
+    throw new Error(
+      `Image not found: ${sourcePath}\nReferenced in: ${currentSlug}\nURL: ${node.url}`
+    )
+  }
+
+  const destDir = path.dirname(destPath)
+  await fs.mkdir(destDir, { recursive: true })
+
+  // Deduplication: check cache first
+  const cacheKey = `${sourcePath}:${destPath}`
+  if (copiedFiles.has(cacheKey)) {
+    // Already copied, just rewrite URL
+    const publicUrl =
+      '/' + path.relative(path.join(process.cwd(), 'public'), destPath).replace(/\\/g, '/')
+    const queryParams = node.url.includes('?') ? '?' + node.url.split('?')[1] : ''
+    node.url = publicUrl + queryParams
+    return
+  }
+
+  // Check if destination exists with matching size
+  try {
+    const [sourceStat, destStat] = await Promise.all([
+      fs.stat(sourcePath),
+      fs.stat(destPath).catch(() => null),
+    ])
+
+    if (destStat && sourceStat.size === destStat.size) {
+      // File already exists and matches, skip copy
+      copiedFiles.add(cacheKey)
+      const publicUrl =
+        '/' + path.relative(path.join(process.cwd(), 'public'), destPath).replace(/\\/g, '/')
+      const queryParams = node.url.includes('?') ? '?' + node.url.split('?')[1] : ''
+      node.url = publicUrl + queryParams
+      return
+    }
+  } catch (error) {
+    // Stat failed, proceed with copy
+  }
+
+  // Attempt copy with EBUSY retry logic
+  try {
+    await fs.copyFile(sourcePath, destPath)
+    copiedFiles.add(cacheKey)
+  } catch (error: unknown) {
+    const err = error as NodeJS.ErrnoException
+    if (err.code === 'EBUSY') {
+      // Race condition: another process is copying this file
+      // Wait briefly and check if file now exists
+      await new Promise(resolve => setTimeout(resolve, 100))
+
+      try {
+        await fs.access(destPath)
+        // File exists now, verify integrity
+        const [sourceStat, destStat] = await Promise.all([fs.stat(sourcePath), fs.stat(destPath)])
+
+        if (sourceStat.size === destStat.size) {
+          // Successfully copied by another process
+          copiedFiles.add(cacheKey)
+        } else {
+          // File corrupted, retry once
+          await fs.copyFile(sourcePath, destPath)
+          copiedFiles.add(cacheKey)
+        }
+      } catch {
+        // File still doesn't exist, retry copy
+        await fs.copyFile(sourcePath, destPath)
+        copiedFiles.add(cacheKey)
+      }
+    } else {
+      // Unknown error, rethrow
+      throw error
+    }
+  }
+
+  const publicUrl =
+    '/' + path.relative(path.join(process.cwd(), 'public'), destPath).replace(/\\/g, '/')
+
+  const queryParams = node.url.includes('?') ? '?' + node.url.split('?')[1] : ''
+  node.url = publicUrl + queryParams
+}
+
+export function remarkCopyImages(options: Options) {
+  return async (tree: Node) => {
+    const promises: Promise<void>[] = []
+
+    visit(tree, 'image', (node: Node) => {
+      const imageNode = node as ImageNode
+      if (isRelativePath(imageNode.url)) {
+        promises.push(copyAndRewritePath(imageNode, options))
+      }
+    })
+
+    await Promise.all(promises)
+  }
+}