refactor a bit

index.js

@@ -5,46 +5,176 @@ const childProcess = require('child_process')
 const multer  = require('multer')
 const uuid = require('uuid')
 const fs = require ('fs')
-const app = express()
+const os = require('os')
+const path = require('path')
 
-const workDir = '/tmp/api'
 const port = 3000
 
+const workDir = '/tmp/makesweet-api'
 const upload = multer({ dest: workDir })
+const app = express()
 
 app.get('/', (req, res) => {
     res.send('Hello World!')
 })
 
-app.post('/make/:template', upload.any('images'), (req, res) => {
+app.post('/make/:template', upload.any('images'), handleErrors, (req, res) => {
     if (!req.files) {
-	return res.status(400).json({error: "i hunger for images..."})
+        throw new ApiError(400, 'i hunger for images...');
     }
-    const template = `templates/${req.params.template}.zip`
-    if (!fs.existsSync(template)) {
-	return res.status(404).json({error: "i seek the template everywhere, but it is not to be found. try 'heart-locket'"})
-    }
-    const path=`${workDir}/${uuid.v4()}.gif`
+    const textHtml = `${process.cwd()}/text.html`;
+    const output = `${workDir}/${uuid.v4()}.gif`;
+    const template = getTemplatePathFromName(req.params.template);
+    const generator = new Generator();
+    generator.useTemplate(template);
     try {
-        const cwd = process.cwd()
-	const command = ['run', '-v', `${workDir}:${workDir}`, '-v', `${cwd}:/share`, 'paulfitz/makesweet', '--zip', template, '--in']
-	for (const file of req.files) {
-	    command.push(file.path)
-	}
-	command.push('--gif', path)
-	console.log(command)
-	
-	const result = childProcess.execFileSync('docker', command).stdout
-	res.send(fs.readFileSync(path))
+        generator.addTexts(req.query.text, textHtml);
+        generator.addImages(req.files);
+        generator.setOutput(output);
+	res.send(generator.apply());
     } finally {
-	for (const file of req.files) {
-	    fs.unlinkSync(file.path)
-	}
-	fs.unlinkSync(path)
+        generator.clean();
     }
 })
 
+app.use(handleErrors)
+
 app.listen(port, () => {
     console.log(`Example app listening at http://localhost:${port}`)
 })
 
+function execSync(command) {
+    console.log("Executing: " + command);
+    childProcess.execSync(command, { stdio: 'inherit' });
+}
+
+function text2image(htmlTemplate, outputDir, prefix, txt, border) {
+    console.log("text2image:", txt);
+    const data = {
+        text: txt.replace(/[ \n\r\t]+\/\/[ \n\r\t]+/g, '\n').trim()
+    };
+    fs.writeFileSync(`${outputDir}/text.json`, JSON.stringify(data));
+    fs.copyFileSync(htmlTemplate, `${outputDir}/text.html`);
+    console.log("ready");
+    execSync(`wkhtmltoimage --enable-local-file-access  --transparent --width 3000 --window-status ready_to_print ${outputDir}/text.html ${outputDir}/${prefix}.png`);
+    console.log("123");
+    execSync(`convert ${outputDir}/${prefix}.png -trim  -bordercolor none -border ` + border + ` ${outputDir}/${prefix}2.png`);
+    console.log("234");
+    return `${outputDir}/${prefix}2.png`;
+}
+
+function getTemplatePathFromName(name) {
+    if (!name) {
+        throw new ApiError(400, 'i must have a template i cannot do anything without a template');
+    }
+    const nameStr = String(name);
+    if (!nameStr.match(/^[-a-zA-Z0-9]+$/)) {
+        throw new ApiError(400, 'is that really a template: ' + nameStr);
+    }
+    const template = `templates/${nameStr}.zip`
+    if (!fs.existsSync(template)) {
+        throw new ApiError(404, 'i seek the template everywhere, but it is not to be found.');
+    }
+    return template;
+}
+
+function handleErrors(err, req, res, next) {
+    console.error(err);
+    if (err.code) {
+	return res.status(err.code).json({error: err.message})
+    } else {
+        res.status(500).json({error: err})
+    }
+}
+
+class ApiError extends Error {
+    constructor(code, message) {
+        super(message);
+        this.code = code;
+    }
+}
+
+class Generator {
+    constructor() {
+        this.fnames = [];
+        this.images = [];
+        this.texts = [];
+        this.template = null;
+        this.output = null;
+        this.tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'makesweet-api'));
+    }
+    useFile(fname) {
+        this.fnames.push(fname);
+    }
+    useTemplate(fname) {
+        this.useFile(fname);
+        this.template = fname;
+    }
+    addImages(files) {
+        if (!files) { return; }
+        for (const file of files) {
+            this.images.push(file.path);
+            this.fnames.push(file.path);
+        }
+    }
+    addTexts(textOrTexts, htmlTemplate) {
+        console.log({textOrTexts, htmlTemplate});
+        const texts = !textOrTexts ? [] :
+              (typeof textOrTexts === 'string') ? [textOrTexts] :
+              [...textOrTexts];
+        console.log("texts", texts)
+        let i = 0;
+        for (const txt of texts) {
+	    const fname = text2image(htmlTemplate, this.tmpDir, `text_${i}`, txt, 60);
+            this.texts.push(fname);
+            this.fnames.push(fname);
+            i++;
+        }
+    }
+    setOutput(output) {
+        this.output = output;
+        this.fnames.push(output);
+    }
+    getVolumes() {
+        const dirs = new Set(this.fnames.map(fname => path.resolve(path.dirname(fname))));
+        return [...dirs].sort();
+    }
+    getCommand() {
+        const command = ['run'];
+        for (const volume of this.getVolumes()) {
+            command.push('-v', `${volume}:${volume}`);
+        }
+        command.push('--mount', 'type=tmpfs,destination=/share')
+
+        command.push('paulfitz/makesweet');
+        command.push('--zip', path.resolve(this.template));
+        command.push('--in');
+        for (const image of this.images) {
+            command.push(image);
+        }
+        for (const text of this.texts) {
+            command.push(text);
+        }
+        command.push('--gif', this.output);
+        return command;
+    }
+    apply() {
+        const command = this.getCommand();
+        console.log("command:", command);
+	childProcess.execFileSync('docker', command);
+	return fs.readFileSync(this.output);
+    }
+    clean() {
+        try {
+            fs.rmSync(this.tmpDir, { recursive: true });
+            for (const image of this.images) {
+                fs.unlinkSync(image);
+            }
+            if (this.output) {
+                fs.unlinkSync(this.output);
+            }
+        } catch (e) {
+            console.error(`Error removing tmpDir: ${e}`);
+        }
+    }
+}

text.html

@@ -0,0 +1,41 @@
+<html>
+  <head>
+    <style>
+     body {
+       font-size: 240px;
+     }
+     #target {
+       text-align: center;
+       white-space: pre-line;
+       text-shadow: 0px 0px 8px #fff, 0px 0px 8px #fff, 0px 0px 8px #fff;
+     }
+    </style>
+  </head>
+<body>
+<p id="target">
+This is a test<br>my friend.
+</p>
+
+<script>
+function callback(txt) {
+  document.getElementById("target").innerHTML = JSON.parse(txt).text;
+  window.status = "ready_to_print";
+}
+function loadJSON() {   
+
+    var xobj = new XMLHttpRequest();
+        xobj.overrideMimeType("application/json");
+    xobj.open('GET', './text.json', true);
+    xobj.onreadystatechange = function () {
+          if (xobj.readyState == 4) {
+            // Required use of an anonymous callback as .open will NOT return a value but simply returns undefined in asynchronous mode
+            callback(xobj.responseText);
+          }
+    };
+    xobj.send(null);  
+}
+loadJSON();
+</script>
+
+</body>
+</html>