1import { existsSync, readdirSync, readFileSync } from "fs";
2import { join, basename } from "path";
3import { PDFDocument } from "pdf-lib";
4 
5interface PageInfo {
6  filename: string;
7  path: string;
8  index: number;
9  promptPath?: string;
10}
11 
12function parseArgs(): { dir: string; output?: string } {
13  const args = process.argv.slice(2);
14  let dir = "";
15  let output: string | undefined;
16 
17  for (let i = 0; i < args.length; i++) {
18    if (args[i] === "--output" || args[i] === "-o") {
19      output = args[++i];
20    } else if (!args[i].startsWith("-")) {
21      dir = args[i];
22    }
23  }
24 
25  if (!dir) {
26    console.error("Usage: bun merge-to-pdf.ts <comic-dir> [--output filename.pdf]");
27    process.exit(1);
28  }
29 
30  return { dir, output };
31}
32 
33function findComicPages(dir: string): PageInfo[] {
34  if (!existsSync(dir)) {
35    console.error(`Directory not found: ${dir}`);
36    process.exit(1);
37  }
38 
39  const files = readdirSync(dir);
40  const pagePattern = /^(\d+)-(cover|page)(-[\w-]+)?\.(png|jpg|jpeg)$/i;
41  const promptsDir = join(dir, "prompts");
42  const hasPrompts = existsSync(promptsDir);
43 
44  const pages: PageInfo[] = files
45    .filter((f) => pagePattern.test(f))
46    .map((f) => {
47      const match = f.match(pagePattern);
48      const baseName = f.replace(/\.(png|jpg|jpeg)$/i, "");
49      const promptPath = hasPrompts ? join(promptsDir, `${baseName}.md`) : undefined;
50 
51      return {
52        filename: f,
53        path: join(dir, f),
54        index: parseInt(match![1], 10),
55        promptPath: promptPath && existsSync(promptPath) ? promptPath : undefined,
56      };
57    })
58    .sort((a, b) => a.index - b.index);
59 
60  if (pages.length === 0) {
61    console.error(`No comic pages found in: ${dir}`);
62    console.error("Expected format: 00-cover-slug.png, 01-page-slug.png, etc.");
63    process.exit(1);
64  }
65 
66  return pages;
67}
68 
69async function createPdf(pages: PageInfo[], outputPath: string) {
70  const pdfDoc = await PDFDocument.create();
71  pdfDoc.setAuthor("baoyu-comic");
72  pdfDoc.setSubject("Generated Comic");
73 
74  for (const page of pages) {
75    const imageData = readFileSync(page.path);
76    const ext = page.filename.toLowerCase();
77    const image = ext.endsWith(".png")
78      ? await pdfDoc.embedPng(imageData)
79      : await pdfDoc.embedJpg(imageData);
80 
81    const { width, height } = image;
82    const pdfPage = pdfDoc.addPage([width, height]);
83 
84    pdfPage.drawImage(image, {
85      x: 0,
86      y: 0,
87      width,
88      height,
89    });
90 
91    console.log(`Added: ${page.filename}${page.promptPath ? " (prompt available)" : ""}`);
92  }
93 
94  const pdfBytes = await pdfDoc.save();
95  await Bun.write(outputPath, pdfBytes);
96 
97  console.log(`\nCreated: ${outputPath}`);
98  console.log(`Total pages: ${pages.length}`);
99}
100 
101async function main() {
102  const { dir, output } = parseArgs();
103  const pages = findComicPages(dir);
104 
105  const dirName = basename(dir) === "comic" ? basename(join(dir, "..")) : basename(dir);
106  const outputPath = output || join(dir, `${dirName}.pdf`);
107 
108  console.log(`Found ${pages.length} pages in: ${dir}\n`);
109 
110  await createPdf(pages, outputPath);
111}
112 
113main().catch((err) => {
114  console.error("Error:", err.message);
115  process.exit(1);
116});
117