OASIS_MOBILE/src/backend/smartContractPdf.js

228 lines
9.7 KiB
JavaScript

const fs = require('fs');
const path = require('path');
const LOGO_PATH = path.join(__dirname, '..', 'client', 'assets', 'images', 'snh-oasis.jpg');
const escapePdf = s => String(s || '').replace(/\\/g, '\\\\').replace(/\(/g, '\\(').replace(/\)/g, '\\)');
const wrap = (txt, max = 82) => {
const out = [];
for (const raw of String(txt || '').split('\n')) {
let line = raw;
while (line.length > max) {
let cut = line.lastIndexOf(' ', max);
if (cut <= 0) cut = max;
out.push(line.slice(0, cut));
line = line.slice(cut).replace(/^\s+/, '');
}
out.push(line);
}
return out;
};
const readJpegDims = (buf) => {
let i = 2;
while (i < buf.length) {
if (buf[i] !== 0xFF) return null;
const marker = buf[i + 1];
if (marker === 0xD8 || marker === 0xD9) { i += 2; continue; }
const len = buf.readUInt16BE(i + 2);
if (marker >= 0xC0 && marker <= 0xCF && marker !== 0xC4 && marker !== 0xC8 && marker !== 0xCC) {
const h = buf.readUInt16BE(i + 5);
const w = buf.readUInt16BE(i + 7);
const c = buf[i + 9];
return { w, h, c };
}
i += 2 + len;
}
return null;
};
function buildSmartContractPdf({ transfer, block, viewerId }) {
const pageW = 612;
const pageH = 792;
const marginX = 50;
const headerH = 90;
const footerH = 40;
const bodyTop = pageH - headerH - 24;
const bodyBottom = footerH + 10;
const lineH = 14;
let logoBuf = null;
let logoDims = null;
try {
logoBuf = fs.readFileSync(LOGO_PATH);
logoDims = readJpegDims(logoBuf);
} catch (_) {}
const t = transfer || {};
const b = block || {};
const fmt = v => (v === undefined || v === null) ? '' : String(v);
const fmtAmount = () => {
const cat = String(t.category || 'ECONOMIC').toUpperCase();
const unit = cat === 'TIME' ? 'h' : cat === 'TRUST' ? 'trust' : 'ECO';
return `${Number(t.amount || 0).toFixed(6)} ${unit}`;
};
const fmtDate = v => v ? new Date(v).toISOString().replace('T', ' ').slice(0, 19) + ' UTC' : '';
const confirmedBy = Array.isArray(t.confirmedBy) ? t.confirmedBy : [];
const required = t.from === t.to ? 1 : 2;
const confirmedCount = confirmedBy.length;
const tags = Array.isArray(t.tags) ? t.tags.join(', ') : '';
const sections = [];
sections.push({ kind: 'title', text: `Concept: ${t.concept || '-'}` });
sections.push({ kind: 'blank' });
sections.push({ kind: 'section', text: 'OASIS IDs' });
sections.push({ kind: 'kv', label: 'From', value: fmt(t.from) });
sections.push({ kind: 'kv', label: 'To', value: fmt(t.to) });
sections.push({ kind: 'blank' });
sections.push({ kind: 'section', text: 'TERMS' });
sections.push({ kind: 'kv', label: 'Category', value: String(t.category || 'ECONOMIC').toUpperCase() });
if (String(t.category || '').toUpperCase() !== 'TRUST') sections.push({ kind: 'kv', label: 'Amount', value: fmtAmount() });
sections.push({ kind: 'kv', label: 'Status', value: fmt(t.status) });
if (t.deadline) sections.push({ kind: 'kv', label: 'Deadline', value: fmtDate(t.deadline) });
if (tags) sections.push({ kind: 'kv', label: 'Tags', value: tags });
sections.push({ kind: 'blank' });
sections.push({ kind: 'section', text: 'CONFIRMATIONS' });
sections.push({ kind: 'kv', label: 'Required', value: String(required) });
sections.push({ kind: 'kv', label: 'Confirmed', value: String(confirmedCount) });
if (confirmedBy.length) {
for (const f of confirmedBy) sections.push({ kind: 'kv', label: 'Signed by', value: fmt(f) });
}
sections.push({ kind: 'blank' });
sections.push({ kind: 'section', text: 'BLOCK VERIFICATION' });
if (b && b.id) {
sections.push({ kind: 'kv', label: 'Block ID', value: fmt(b.id) });
if (b.ts) sections.push({ kind: 'kv', label: 'Block Timestamp', value: fmtDate(b.ts) });
if (b.type) sections.push({ kind: 'kv', label: 'Block Type', value: String(b.type).toUpperCase() });
if (b.author) sections.push({ kind: 'kv', label: 'Block Author', value: fmt(b.author) });
if (b.size) sections.push({ kind: 'kv', label: 'Block Size', value: `${b.size} bytes` });
} else {
sections.push({ kind: 'kv', label: 'Block ID', value: fmt(t.id) });
}
sections.push({ kind: 'blank' });
sections.push({ kind: 'section', text: 'METADATA' });
sections.push({ kind: 'kv', label: 'Transfer ID', value: fmt(t.id) });
if (t.createdAt) sections.push({ kind: 'kv', label: 'Created At', value: fmtDate(t.createdAt) });
if (t.updatedAt) sections.push({ kind: 'kv', label: 'Updated At', value: fmtDate(t.updatedAt) });
const lines = [];
for (const s of sections) {
if (s.kind === 'kv') {
const txt = `${s.label}: ${s.value}`;
for (const w of wrap(txt, 82)) lines.push({ kind: 'kv', text: w });
} else {
lines.push(s);
}
}
const maxBodyLines = Math.floor((bodyTop - bodyBottom) / lineH);
const pages = [];
for (let i = 0; i < lines.length; i += maxBodyLines) pages.push(lines.slice(i, i + maxBodyLines));
if (!pages.length) pages.push([]);
const objects = [];
const addObj = body => { objects.push(body); return objects.length; };
const catalogId = addObj(null);
const pagesId = addObj(null);
const fontId = addObj('<< /Type /Font /Subtype /Type1 /BaseFont /Courier >>');
const fontBoldId = addObj('<< /Type /Font /Subtype /Type1 /BaseFont /Courier-Bold >>');
let logoXObjId = null;
if (logoBuf && logoDims) {
const cs = logoDims.c === 1 ? '/DeviceGray' : '/DeviceRGB';
const dict = `<< /Type /XObject /Subtype /Image /Width ${logoDims.w} /Height ${logoDims.h} /ColorSpace ${cs} /BitsPerComponent 8 /Filter /DCTDecode /Length ${logoBuf.length} >>`;
logoXObjId = addObj({ dict, stream: logoBuf });
}
const exportDate = new Date().toISOString().replace('T', ' ').slice(0, 19) + ' UTC';
const footerLeft = `Generated: ${exportDate}`;
const pageIds = [];
const contentIds = [];
pages.forEach((pg, pgIdx) => {
const parts = [];
if (logoXObjId) {
const logoH = 60;
const logoW = Math.round((logoDims.w / logoDims.h) * logoH);
parts.push(`q\n${logoW} 0 0 ${logoH} ${marginX} ${pageH - headerH + 15} cm\n/Logo Do\nQ`);
}
const titleX = (logoXObjId ? marginX + 80 : marginX);
const titleY = pageH - 45;
parts.push(`BT\n/F2 16 Tf\n${titleX} ${titleY} Td\n(${escapePdf('OASIS - Smart Contract')}) Tj\nET`);
const prefix = 'Issued to: ';
const prefixW = prefix.length * 5.4;
parts.push(`BT\n/F1 9 Tf\n${titleX} ${titleY - 16} Td\n(${escapePdf(prefix)}) Tj\nET`);
parts.push(`BT\n/F2 9 Tf\n${titleX + prefixW} ${titleY - 16} Td\n(${escapePdf(String(viewerId || ''))}) Tj\nET`);
parts.push(`q\n0.6 0.6 0.6 RG\n0.5 w\n${marginX} ${pageH - headerH} m\n${pageW - marginX} ${pageH - headerH} l\nS\nQ`);
let y = bodyTop;
for (const ln of pg) {
if (ln.kind === 'title') {
parts.push(`BT\n/F2 14 Tf\n0 0 0 rg\n${marginX} ${y} Td\n(${escapePdf(ln.text)}) Tj\nET`);
} else if (ln.kind === 'subtitle') {
parts.push(`BT\n/F1 11 Tf\n0.2 0.2 0.2 rg\n${marginX} ${y} Td\n(${escapePdf(ln.text)}) Tj\nET`);
} else if (ln.kind === 'section') {
parts.push(`BT\n/F2 11 Tf\n0 0 0 rg\n${marginX} ${y} Td\n(${escapePdf(ln.text)}) Tj\nET`);
parts.push(`q\n0 0 0 RG\n0.5 w\n${marginX} ${y - 3} m\n${pageW - marginX} ${y - 3} l\nS\nQ`);
} else if (ln.kind === 'kv') {
parts.push(`BT\n/F1 10 Tf\n0 0 0 rg\n${marginX} ${y} Td\n(${escapePdf(ln.text)}) Tj\nET`);
}
y -= lineH;
}
parts.push(`q\n0.6 0.6 0.6 RG\n0.5 w\n${marginX} ${footerH + 5} m\n${pageW - marginX} ${footerH + 5} l\nS\nQ`);
parts.push(`BT\n/F1 8 Tf\n${marginX} ${footerH - 10} Td\n(${escapePdf(footerLeft)}) Tj\nET`);
const pageLabel = `Page ${pgIdx + 1} of ${pages.length}`;
const pageLabelW = pageLabel.length * 4.8;
parts.push(`BT\n/F1 8 Tf\n${pageW - marginX - pageLabelW} ${footerH - 10} Td\n(${escapePdf(pageLabel)}) Tj\nET`);
const content = parts.join('\n');
const stream = `<< /Length ${Buffer.byteLength(content)} >>\nstream\n${content}\nendstream`;
const cid = addObj(stream);
contentIds.push(cid);
const pid = addObj(null);
pageIds.push(pid);
});
for (let i = 0; i < pageIds.length; i++) {
const resources = logoXObjId
? `<< /Font << /F1 ${fontId} 0 R /F2 ${fontBoldId} 0 R >> /XObject << /Logo ${logoXObjId} 0 R >> >>`
: `<< /Font << /F1 ${fontId} 0 R /F2 ${fontBoldId} 0 R >> >>`;
objects[pageIds[i] - 1] = `<< /Type /Page /Parent ${pagesId} 0 R /MediaBox [0 0 ${pageW} ${pageH}] /Contents ${contentIds[i]} 0 R /Resources ${resources} >>`;
}
objects[catalogId - 1] = `<< /Type /Catalog /Pages ${pagesId} 0 R >>`;
objects[pagesId - 1] = `<< /Type /Pages /Kids [${pageIds.map(id => `${id} 0 R`).join(' ')}] /Count ${pageIds.length} >>`;
const chunks = [];
const offsets = [0];
let byteLen = 0;
const push = (buf) => { chunks.push(buf); byteLen += buf.length; };
push(Buffer.from('%PDF-1.4\n%\xE2\xE3\xCF\xD3\n', 'binary'));
for (let i = 0; i < objects.length; i++) {
offsets.push(byteLen);
const obj = objects[i];
if (obj && typeof obj === 'object' && obj.dict && obj.stream) {
push(Buffer.from(`${i + 1} 0 obj\n${obj.dict}\nstream\n`, 'binary'));
push(obj.stream);
push(Buffer.from('\nendstream\nendobj\n', 'binary'));
} else {
push(Buffer.from(`${i + 1} 0 obj\n${obj}\nendobj\n`, 'binary'));
}
}
const xrefStart = byteLen;
let xref = `xref\n0 ${objects.length + 1}\n0000000000 65535 f \n`;
for (let i = 1; i <= objects.length; i++) xref += `${String(offsets[i]).padStart(10, '0')} 00000 n \n`;
xref += `trailer\n<< /Size ${objects.length + 1} /Root ${catalogId} 0 R >>\nstartxref\n${xrefStart}\n%%EOF`;
push(Buffer.from(xref, 'binary'));
return Buffer.concat(chunks);
}
module.exports = { buildSmartContractPdf };