Add support for multiple inputs

demo/another.md

@@ -0,0 +1,6 @@
+Here's another file.
+
+It has a list!
+
+- See?
+- Fancy!

demo/index.md

@@ -0,0 +1,3 @@
+# Demo Data
+
+This is just a folder of markdown files for testing purposes.

src/index.ts

@@ -9,7 +9,7 @@ import defaultTemplate from "./defaults/default-template.html" with {
   type: "text",
 };
 import { CLIError } from "./error";
-import { mkdir } from "node:fs/promises";
+import type { BunFile } from "bun";
 
 const DEFAULT_TEMPLATE_FILE = "_template.html";
 const DEFAULT_STYLESHEET_FILE = "_style.css";
@@ -35,15 +35,17 @@ function replacePlaceholders(
 }
 
 interface CLIOptions {
-  infile: string | null;
   outfile: string | null;
+  outdir: string | null;
+  stdout: boolean;
   templateFilePath: string | null;
   stylesheetFilePath: string | null;
-  forceStdout: boolean;
   help: boolean;
+  title: string | null;
+  cwd: string;
 }
 
-function parseCLIArgs(): CLIOptions {
+function parseCLIArgs(): { options: CLIOptions; args: string[] } {
   const { values: flags, positionals } = parseArgs({
     args: Bun.argv.slice(2),
     options: {
@@ -51,16 +53,28 @@ function parseCLIArgs(): CLIOptions {
         type: "string",
         short: "o",
       },
+      outdir: {
+        type: "string",
+        short: "d",
+      },
+      stdout: {
+        type: "boolean",
+      },
       template: {
         type: "string",
         short: "t",
       },
+      title: {
+        type: "string",
+        short: "T",
+      },
       stylesheet: {
         type: "string",
         short: "s",
       },
-      stdout: {
-        type: "boolean",
+      cwd: {
+        type: "string",
+        default: process.cwd(),
       },
       help: {
         type: "boolean",
@@ -70,20 +84,136 @@ function parseCLIArgs(): CLIOptions {
     allowPositionals: true,
   });
 
+  // Validation
+
+  if (positionals.length > 1 && flags.outfile) {
+    throw new CLIError("--outfile cannot be used with multiple inputs.");
+  }
+
+  if (flags.outdir && flags.outfile) {
+    throw new CLIError("--outdir and --outfile cannot be used together.");
+  }
+
   return {
-    infile: positionals[0] ?? null,
+    options: {
+      cwd: flags.cwd,
       outfile: flags.outfile ?? null,
+      outdir: flags.outdir ?? null,
+      stdout: flags.stdout ?? false,
       templateFilePath: flags.template ?? null,
       stylesheetFilePath: flags.stylesheet ?? null,
-    forceStdout: flags.stdout ?? false,
       help: flags.help ?? false,
+      title: flags.title ?? null,
+    },
+    args: positionals,
   };
 }
 
-async function main() {
-  const args = parseCLIArgs();
+async function loadTemplate(options: CLIOptions): Promise<string> {
+  if (options.templateFilePath) {
+    return readFile(options.templateFilePath);
+  }
 
-  if (args.help) {
+  const defaultTemplateFilePath = Path.join(options.cwd, DEFAULT_TEMPLATE_FILE);
+  const defaultTemplateFile = Bun.file(defaultTemplateFilePath);
+
+  if (await defaultTemplateFile.exists()) {
+    return defaultTemplateFile.text();
+  }
+
+  return defaultTemplate;
+}
+
+async function loadStylesheet(options: CLIOptions): Promise<string> {
+  if (options.stylesheetFilePath) {
+    return readFile(options.stylesheetFilePath);
+  }
+
+  const defaultStylesheetFilePath = Path.join(
+    options.cwd,
+    DEFAULT_STYLESHEET_FILE,
+  );
+  const defaultStylesheetFile = Bun.file(defaultStylesheetFilePath);
+
+  if (await defaultStylesheetFile.exists()) {
+    return defaultStylesheetFile.text();
+  }
+
+  return defaultStylesheet;
+}
+
+async function buildFile(
+  infile: BunFile,
+  outfile: BunFile,
+  options: CLIOptions,
+): Promise<string> {
+  const input = await infile.text();
+  const template = await loadTemplate(options);
+  const stylesheet = await loadStylesheet(options);
+
+  const { content, ...props } = EMDY.parse(input) as Record<string, unknown> & {
+    content: string;
+  };
+
+  const html = await marked.parse(content, {
+    gfm: true,
+  });
+
+  const title = [options.title, props.title].find((t) => t) || "Untitled";
+
+  const replacers = {
+    content: html,
+    title,
+    stylesheet: stylesheet,
+    timestamp: new Date().toISOString(),
+    datetime: new Date().toLocaleString(),
+    ...props,
+  };
+
+  const output = replacePlaceholders(template, replacers);
+
+  Bun.write(outfile, output);
+
+  return output;
+}
+
+async function getOutputPath(inputPath: string, options: CLIOptions) {
+  const inputDirname = Path.dirname(inputPath);
+  const inputBasename = Path.basename(inputPath);
+  const outputBasename = inputBasename.replace(/\.md$/, ".html");
+
+  if (options.outdir) {
+    const dirPath = Path.relative(options.cwd, inputDirname);
+    const outputPath = Path.join(options.outdir, dirPath, outputBasename);
+    return Path.resolve(outputPath);
+  }
+
+  return Path.join(inputDirname, outputBasename);
+}
+
+async function getOutputFile(
+  inputPath: string,
+  options: CLIOptions,
+): Promise<BunFile> {
+  // --stdout option -> Force stdout
+  if (options.stdout) {
+    return Bun.stdout;
+  }
+
+  // Exact outfile defined -> write to file
+  if (options.outfile) {
+    return Bun.file(options.outfile);
+  }
+
+  // Input path with --outdir -> calculate output path
+  const outputPath = await getOutputPath(inputPath, options);
+  return Bun.file(outputPath);
+}
+
+async function main() {
+  const { options, args } = parseCLIArgs();
+
+  if (options.help) {
     console.log(
       `
 buildmd - Build markdown files to html with templates and metadata
@@ -95,103 +225,44 @@ Usage:
 
 Options:
   --outfile, -o <file>    Output file path
+  --outdir,  -d <dir>     Output directory path
   --template, -t <file>   Template file path
   --stylesheet, -s <file> Stylesheet file path
-  --stdout                Force output to stdout
+  --title, -T <string>    Override title in template
   --help, -h              Show this help message
 `.trim(),
     );
     process.exit(0);
   }
 
-  // == INPUT ==
-  const infile = args.infile ? Bun.file(args.infile) : Bun.stdin;
-
-  // If using a file for input, it must exist
-  if (infile !== Bun.stdin && !(await infile.exists())) {
-    throw new CLIError(`Input file ${args.infile} does not exist.`);
+  // stdin mode
+  if (args.length === 0) {
+    const outfile = options.outfile ? Bun.file(options.outfile) : Bun.stdout;
+    await buildFile(Bun.stdin, outfile, options);
+    process.exit(0);
   }
 
-  const input = await infile.text();
+  // file mode
+  for (const arg of args) {
+    const file = Bun.file(arg);
 
-  // == TEMPLATE ==
-  let template = defaultTemplate;
-
-  if (args.templateFilePath) {
-    template = await readFile(args.templateFilePath);
-  } else {
-    const defaultTemplateFilePath = Path.join(
-      process.cwd(),
-      DEFAULT_TEMPLATE_FILE,
-    );
-    const defaultTemplateFile = Bun.file(defaultTemplateFilePath);
-
-    if (await defaultTemplateFile.exists()) {
-      template = await defaultTemplateFile.text();
-    }
+    // Ensure input files exist
+    if (!(await file.exists())) {
+      throw new CLIError(`File ${arg} does not exist.`);
     }
 
-  // == STYLESHEET ==
-  let stylesheet = defaultStylesheet;
-
-  if (args.stylesheetFilePath) {
-    stylesheet = await readFile(args.stylesheetFilePath);
-  } else {
-    const defaultStylesheetFilePath = Path.join(
-      process.cwd(),
-      DEFAULT_STYLESHEET_FILE,
-    );
-    const defaultStylesheetFile = Bun.file(defaultStylesheetFilePath);
-
-    if (await defaultStylesheetFile.exists()) {
-      stylesheet = await defaultStylesheetFile.text();
+    const outfile = await getOutputFile(arg, options);
+    await buildFile(file, outfile, options);
   }
 }
 
-  // == RENDER ==
-  const { content, ...props } = EMDY.parse(input) as Record<string, unknown> & {
-    content: string;
-  };
-
-  const html = await marked.parse(content, {
-    gfm: true,
-  });
-
-  // == REPALCE ==
-  const replacers = {
-    content: html,
-    title: props.title
-      ? props.title
-      : args.infile
-        ? Path.basename(args.infile)
-        : "Untitled",
-    stylesheet: stylesheet,
-    ...props,
-  };
-
-  // == OUTPUT ==
-  const output = replacePlaceholders(template, replacers);
-
-  if (args.forceStdout || (!args.infile && !args.outfile)) {
-    Bun.write(Bun.stdout, output);
-    return;
-  }
-
-  // Compute the output file path
-  const writeFilePath =
-    args.outfile ?? args.infile?.replace(/\.md$/, ".html") ?? "out.html";
-
-  // Ensure the output path exists
-  const writeFileDirname = Path.dirname(writeFilePath);
-  await mkdir(writeFileDirname, { recursive: true });
-
-  // Write the output to disk
-  await Bun.write(writeFilePath, output);
-}
-
 try {
   await main();
 } catch (error) {
-  console.error(error);
+  if (error instanceof CLIError) {
+    console.error(error.message);
     process.exit(1);
   }
+
+  throw error;
+}