From 42b38863761f8258781406469505f0ac1c27ac54 Mon Sep 17 00:00:00 2001
From: Chris Xiong <chirs241097@gmail.com>
Date: Tue, 12 Feb 2019 23:51:08 +0800
Subject: New feature: thumbnail generation!

---
 README.rst                |  1 +
 generator/postrenderer.js | 76 +++++++++++++++++++++++++++++++++++------------
 generator/scanner.js      | 10 ++-----
 generator/util.js         | 19 ++++++++++++
 4 files changed, 80 insertions(+), 26 deletions(-)
 create mode 100644 generator/util.js

diff --git a/README.rst b/README.rst
index 9a165cb..feee8fc 100644
--- a/README.rst
+++ b/README.rst
@@ -17,6 +17,7 @@ Dependencies:
  - jsdom
  - aes-js
  - scrypt-js
+ - Imagemagick >7.x (for thumbnail generation)
 
 Usage:
 
diff --git a/generator/postrenderer.js b/generator/postrenderer.js
index e387691..f3cf46b 100644
--- a/generator/postrenderer.js
+++ b/generator/postrenderer.js
@@ -12,6 +12,11 @@ const scrypt=require('scrypt-js');
 const btoa=require('btoa');
 const sha256=require('./sha256').sha256;
 const spawn=require('child_process').spawn;
+const util=require('./util');
+
+const THUMB_IMAGE_URL='//filestorage.chrisoft.org/blog/img/';
+const THUMB_LOCAL_DIR='../content/img/';
+
 let template_file='';
 let tmplcont='';
 let tocid;
@@ -43,26 +48,58 @@ function _dfs(doc,el,le,p)
 }
 function footnoter(doc)
 {
-	var footnotes=doc.body.getElementsByTagName("footnote");
-	let starting=doc.getElementById("notediv").children.length;
+	var footnotes=doc.body.getElementsByTagName('footnote');
+	let starting=doc.getElementById('notediv').children.length;
 	for(var i=0;i<footnotes.length;++i)
 	{
 		var s=footnotes[i].innerHTML;
-		footnotes[i].innerHTML="";
-		var a=doc.createElement("a");
-		a.setAttribute("id","n"+(starting+i+1));
-		a.setAttribute("href","#note"+(starting+i+1));
-		a.setAttribute("class","note");
-		a.innerHTML="["+(starting+i+1)+"]";
+		footnotes[i].innerHTML='';
+		var a=doc.createElement('a');
+		a.setAttribute('id',`n${(starting+i+1)}`);
+		a.setAttribute('href',`#note${(starting+i+1)}`);
+		a.setAttribute('class','note');
+		a.innerHTML=`[${(starting+i+1)}]`;
 		footnotes[i].parentNode.insertBefore(a,footnotes[i]);
-		var span=doc.createElement("span");
-		span.setAttribute("class","TText");
-		span.innerHTML="<a id=\"note"+(starting+i+1)+"\" href=\"#n"+(starting+i+1)+"\">["+(starting+i+1)+"]</a>: "+s+"<br>";
-		doc.getElementById("notediv").appendChild(span);
+		var span=doc.createElement('span');
+		span.setAttribute('class','TText');
+		span.innerHTML=`<a id="note${(starting+i+1)}" href="#n${(starting+i+1)}">[${(starting+i+1)}]</a>: ${s}<br>`;
+		doc.getElementById('notediv').appendChild(span);
 	}
 	starting+=footnotes.length;
 	while(footnotes.length)footnotes[0].remove();
 }
+function gen_thumb(doc,el)
+{
+	const a=doc.createElement('a');
+	const im=doc.createElement('img');
+	const srcfn=el.innerHTML;
+	let w=el.hasAttribute('width')?Number(el.getAttribute('width')):-1;
+	let h=el.hasAttribute('height')?Number(el.getAttribute('height')):-1;
+	let p=el.hasAttribute('scale')?Number(el.getAttribute('scale')):-1;
+	if(el.hasAttribute('iw'))
+	im.style.width=el.getAttribute('iw');
+	if(el.hasAttribute('ih'))
+	im.style.height=el.getAttribute('ih');
+	if(p>0)w=h=-1;
+	if(w>0||h>0)
+	{
+		if(w<=0)w=h;
+		else if(h<=0)h=w;
+	}
+	const dstfn=`ssbsthumb_${p>0?'s'+p.toFixed(2):w+'x'+h}_${srcfn}`
+	const srcf=path.join(THUMB_LOCAL_DIR,srcfn);
+	const dstf=path.join(THUMB_LOCAL_DIR,dstfn);
+	if(!util.mtime_cmp(srcf,dstf))
+	{
+		const m=spawn('magick',[srcf,'-resize',p>0?(p*100).toFixed()+'%':w+'x'+h,dstf]);
+		m.stdout.on('data',(d)=>{console.log(`IMout:${d}`);});
+		m.stderr.on('data',(d)=>{console.log(`IMerr:${d}`);});
+	}
+	a.setAttribute('href',THUMB_IMAGE_URL+srcfn);
+	im.src=THUMB_IMAGE_URL+dstfn;
+	a.appendChild(im);
+	el.parentNode.replaceChild(a,el);
+}
 async function encrypt(doc)
 {
 	let enid=0;
@@ -128,6 +165,14 @@ async function _render(inf,outf,np,pp)
 	}
 	else
 	trd.getElementById('article').innerHTML=contsplit.join('\n');
+	
+	//async images
+	trd.getElementById('article').querySelectorAll('img').forEach(
+		(i)=>{if(!i.getAttribute('decoding'))i.setAttribute('decoding','async');}
+	);
+
+	//thumbnails generation
+	trd.getElementById('article').querySelectorAll('thumb').forEach((el)=>{gen_thumb(trd,el);});
 
 	//Encryption
 	await encrypt(trd);
@@ -144,13 +189,6 @@ async function _render(inf,outf,np,pp)
 	
 	//Footnotes
 	footnoter(trd);
-	
-	//async images
-	//TODO: Actually compress the images using imagemagick
-	//(by introducing a new tag e.g. <thumb> ?)
-	trd.getElementById('article').querySelectorAll('img').forEach(
-		(i)=>{if(!i.getAttribute('decoding'))i.setAttribute('decoding','async');}
-	);
 
 	//Tag list
 	const tgs=meta[2].split(',');
diff --git a/generator/scanner.js b/generator/scanner.js
index 87b3f2f..52744a4 100644
--- a/generator/scanner.js
+++ b/generator/scanner.js
@@ -6,6 +6,7 @@ module.exports={
 };
 const fs=require('fs');
 const path=require('path');
+const util=require('./util');
 const list=[];
 const tags=[];
 function _scan(s,dst)
@@ -22,11 +23,6 @@ function _scan(s,dst)
 		if(i.endsWith('.txt'))
 		{
 			const cont=fs.readFileSync(path.join(s,i),'utf8');
-			const smodt=fs.statSync(path.join(s,i)).mtimeMs;
-			let dmodt=0;
-			try{
-				dmodt=fs.statSync(path.join(pdst,i.substring(0,i.length-4)+'.html')).mtimeMs;
-			}catch(e){};
 			contsplit=cont.split('\n');
 			if(contsplit.length<4)continue;
 			if(contsplit[1].indexOf('WIP')!=-1)continue;
@@ -35,8 +31,8 @@ function _scan(s,dst)
 				title:contsplit[0].trim(),
 				date:contsplit[1].trim(),
 				tags:contsplit[2].trim(),
-				mdate:smodt,
-				needsupdate:dmodt<smodt
+				mdate:fs.statSync(path.join(s,i)).mtimeMs,
+				needsupdate:!util.mtime_cmp(path.join(s,i),path.join(pdst,i.substring(0,i.length-4)+'.html'))
 			});
 			
 		}
diff --git a/generator/util.js b/generator/util.js
new file mode 100644
index 0000000..e9b5c78
--- /dev/null
+++ b/generator/util.js
@@ -0,0 +1,19 @@
+//Copyright Chris Xiong 2019
+//License: Expat (MIT)
+module.exports={
+	mtime_cmp:function(a,b){return _mtime_cmp(a,b);}
+};
+const fs=require('fs');
+
+/*Returns true when file b exists and has a mtime no earlier than file a,
+ *false otherwise.
+ */
+function _mtime_cmp(a,b)
+{
+	const mtimea=fs.statSync(a).mtimeMs;
+	let mtimeb=0;
+	try{
+		mtimeb=fs.statSync(b).mtimeMs;
+	}catch(e){return false};
+	return mtimeb>=mtimea;
+}
-- 
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