const { test } = require('node:test');
const assert = require('node:assert');
const fs = require('node:fs');
const os = require('node:os');
const path = require('node:path');
const { execFileSync } = require('node:child_process');
global.PDFLib = require('pdf-lib');
const { buildStudyLoadPdf, compactProgram, deriveDateRange, formatSchedule, formatFullName, formatTeacher, truncateToWidth } = require('../pdf.js');

const sampleData = {
  header: {
    fullName: 'ADRIAN ALFRED CHIONG BONPIN',
    studentId: '22103625',
    program: 'BACHELOR OF SCIENCE IN INFORMATION TECHNOLOGY',
    yearLevel: '4',
    semester: '1ST Semester 2026',
    dateEnrolled: '8/5/2024',
    dateRange: 'AUGUST - JANUARY'
  },
  courses: [
    { group: '7', courseCode: 'CIS 2101', description: 'DATA STRUCTURES AND ALGORITHMS', units: '3.00', teacher: 'CHRISTIAN MADERAZO', schedule: 'M,W 03:00 PM - 05:30 PM LB443TC', status: 'REGULAR' },
    { group: '2', courseCode: 'IT 3103N', description: 'SYSTEMS INTEGRATION AND ARCHITECTURE', units: '3.00', teacher: 'KHENT DELA PAZ', schedule: 'T,Th 01:30 PM - 03:00 PM DCISMVR3TC', status: 'REGULAR' }
  ],
  totalUnits: '6.00'
};

function extractPdfText(bytes) {
  const tmp = path.join(os.tmpdir(), 'study-load-test.pdf');
  fs.writeFileSync(tmp, Buffer.from(bytes));
  const script = [
    'import fitz',
    `doc = fitz.open('${tmp}')`,
    'text = ""',
    'for page in doc:',
    '    text += page.get_text()',
    'print(text)'
  ].join('\n');
  return execFileSync('python3', ['-c', script], { encoding: 'utf8' });
}

test('buildStudyLoadPdf returns valid PDF bytes', async () => {
  const bytes = await buildStudyLoadPdf(sampleData);
  assert.ok(bytes instanceof Uint8Array);
  const head = Buffer.from(bytes.slice(0, 5)).toString('latin1');
  assert.strictEqual(head, '%PDF-');
  const doc = await PDFLib.PDFDocument.load(bytes);
  assert.strictEqual(doc.getPageCount(), 1);

  const text = extractPdfText(bytes);
  assert.ok(text.includes('CIS 2101'), 'PDF text should contain course code CIS 2101');
  assert.ok(text.includes("STUDENT'S STUDY LOAD"), 'PDF text should contain the title');
  assert.ok(text.includes('CHRISTIAN MADERAZO'), 'PDF text should contain the teacher');
  assert.ok(text.includes('BS IT'), 'PDF text should contain the compacted program');
});

test('compactProgram shortens degree names', () => {
  assert.strictEqual(compactProgram('BACHELOR OF SCIENCE IN INFORMATION TECHNOLOGY'), 'BS IT');
  assert.strictEqual(compactProgram('BACHELOR OF SCIENCE IN COMPUTER SCIENCE'), 'BS CS');
  assert.strictEqual(compactProgram('BACHELOR OF ARTS IN POLITICAL SCIENCE'), 'AB PS');
  assert.strictEqual(compactProgram('BACHELOR OF SCIENCE IN ACCOUNTANCY'), 'BS Accountancy');
  assert.strictEqual(compactProgram('UNKNOWN PROGRAM'), 'UNKNOWN PROGRAM');
});

test('formatSchedule normalizes schedule text', () => {
  assert.strictEqual(formatSchedule('M W 07:30 AM - 10:00 AM LB447TC TC'), 'M,W 07:30 AM - 10:00 AM LB447TC');
  assert.strictEqual(formatSchedule('T Th 09:00 AM - 10:30 AM LB443TC TC'), 'T,Th 09:00 AM - 10:30 AM LB443TC');
  assert.strictEqual(formatSchedule('M,W 03:00 PM - 05:30 PM LB443TC'), 'M,W 03:00 PM - 05:30 PM LB443TC');
  assert.strictEqual(
    formatSchedule('T 07:30 AM - 10:30 AM LB448TC TC Th 07:30 AM - 10:30 AM LB448TC'),
    'T 07:30 AM - 10:30 AM LB448TC\nTh 07:30 AM - 10:30 AM LB448TC'
  );
  assert.strictEqual(
    formatSchedule('W 01:30 PM - 04:30 PM LB448TC TC M 01:30 PM - 04:30 PM LB448TC'),
    'W 01:30 PM - 04:30 PM LB448TC\nM 01:30 PM - 04:30 PM LB448TC'
  );
});

test('formatFullName reorders first-last names to last-first', () => {
  assert.strictEqual(formatFullName('ADRIAN ALFRED CHIONG BONPIN'), 'BONPIN, ADRIAN ALFRED CHIONG');
  assert.strictEqual(formatFullName('BONPIN, ADRIAN ALFRED CHIONG'), 'BONPIN, ADRIAN ALFRED CHIONG');
  assert.strictEqual(formatFullName('JOHN DOE'), 'DOE, JOHN');
  assert.strictEqual(formatFullName(''), '');
});

test('formatTeacher renders names First [MiddleInitial] Last like the reference', () => {
  assert.strictEqual(formatTeacher('FILLO, FR. PETER'), 'FR. PETER FILLO');
  assert.strictEqual(formatTeacher('BACALSO, REUELLA J. AWAYAN'), 'REUELLA J. BACALSO');
  assert.strictEqual(formatTeacher('PEPITO, GLENN BULLECER'), 'GLENN PEPITO');
  assert.strictEqual(formatTeacher('MADERAZO, CHRISTIAN'), 'CHRISTIAN MADERAZO');
  assert.strictEqual(formatTeacher('DELA PAZ, KHENT'), 'KHENT DELA PAZ');
  assert.strictEqual(formatTeacher('CHRISTIAN MADERAZO'), 'CHRISTIAN MADERAZO');
  assert.strictEqual(formatTeacher(''), '');
});

test('deriveDateRange maps semesters', () => {
  assert.strictEqual(deriveDateRange('1ST Semester 2026'), 'AUGUST - JANUARY');
  assert.strictEqual(deriveDateRange('2ND Semester 2026'), 'JANUARY - MAY');
  assert.strictEqual(deriveDateRange('Summer 2026'), 'JUNE - JULY');
  assert.strictEqual(deriveDateRange(''), '');
});

test('truncateToWidth hard-cuts text to fit within maxWidth', async () => {
  const doc = await global.PDFLib.PDFDocument.create();
  const font = doc.embedStandardFont(global.PDFLib.StandardFonts.Helvetica);
  const longText = 'APPLICATION DEVELOPMENT AND EMERGING TECHNOLOGIES';
  const tr = truncateToWidth(longText, font, 8, 100);
  assert.ok(tr.length < longText.length, 'long text should be cut down');
  assert.ok(longText.startsWith(tr), 'result must be a prefix of the input');
  assert.ok(font.widthOfTextAtSize(tr, 8) <= 100, 'truncated line must fit maxWidth');
  const short = 'DATA STRUCTURES';
  assert.strictEqual(truncateToWidth(short, font, 8, 200), short);
  assert.strictEqual(truncateToWidth('', font, 8, 200), '');
});