// tests/build/fonts-present.test.ts — Plan 01-12 Wave 0 RED unit test.
//
// Asserts that the self-hosted WOFF2 font bundle lives at src/shared/fonts/
// per D-05 typography pairing + R2 Lora substitution (designer reply
// 2026-05-19; Newsreader → Lora for Cyrillic coverage).
//
// Polarity at Wave 0 land: RED across the board (src/shared/fonts/ does
// not exist). Flips GREEN after Wave 1 Task 1 lands the WOFF2 bundle.
//
// NOTE on Lora italic: per RESEARCH §A5, if upstream Lora variable file
// ships italic via the `ital` axis (single multi-axis file), the
// `Lora-Italic-VariableFont.woff2` file is omitted and the @font-face
// rule in tokens.css uses `font-style: oblique 0deg 14deg`. This test
// permits both layouts via the OPTIONAL_FILES set.

import { describe, expect, it } from 'vitest';
import { existsSync, readFileSync, statSync } from 'node:fs';
import { resolve as resolvePath } from 'node:path';

const FONTS_DIR = resolvePath(process.cwd(), 'src/shared/fonts');
const TOKENS_CSS_PATH = resolvePath(process.cwd(), 'src/shared/tokens.css');

/** Required WOFF2 faces — Plex Sans + Plex Mono fixed weights + Lora normal */
const REQUIRED_FONT_FILES: ReadonlyArray<string> = [
  'Lora-VariableFont.woff2',
  'IBMPlexSans-Regular.woff2',
  'IBMPlexSans-Medium.woff2',
  'IBMPlexSans-SemiBold.woff2',
  'IBMPlexSans-Bold.woff2',
  'IBMPlexMono-Regular.woff2',
  'IBMPlexMono-Medium.woff2',
];

/** Optional faces — A5 verify: present iff upstream ships separate italic file */
const OPTIONAL_FONT_FILES: ReadonlyArray<string> = [
  'Lora-Italic-VariableFont.woff2',
];

/** Companion artifacts (LICENSE + README) */
const REQUIRED_LICENSE_FILES: ReadonlyArray<string> = [
  'LICENSE-Lora.txt',
  'LICENSE-IBM-Plex.txt',
  'README.md',
];

/** WOFF2 magic bytes (RFC 8081): 'wOF2' */
const WOFF2_SIGNATURE = Buffer.from([0x77, 0x4f, 0x46, 0x32]);

describe('Plan 01-12: self-hosted OFL font bundle (Lora + Plex Sans + Plex Mono)', () => {
  describe('required WOFF2 faces', () => {
    for (const name of REQUIRED_FONT_FILES) {
      it(`src/shared/fonts/${name} exists + non-empty + WOFF2 signature`, () => {
        const filePath = resolvePath(FONTS_DIR, name);
        expect(existsSync(filePath), `Expected ${filePath} (RED until Wave 1 Task 1)`).toBe(true);
        const size = statSync(filePath).size;
        expect(size, `${name} must be non-empty`).toBeGreaterThan(0);
        const head = Buffer.alloc(4);
        const fd = require('node:fs').openSync(filePath, 'r');
        try {
          require('node:fs').readSync(fd, head, 0, 4, 0);
        } finally {
          require('node:fs').closeSync(fd);
        }
        expect(
          head.equals(WOFF2_SIGNATURE),
          `${name} signature must be 'wOF2' (0x77 0x4F 0x46 0x32); got ${head.toString('hex')}`,
        ).toBe(true);
      });
    }
  });

  it('tokens.css references every required WOFF2 file by filename', () => {
    if (!existsSync(TOKENS_CSS_PATH)) {
      // Will be RED until Wave 1 Task 2 lands tokens.css. Surface a clear diagnostic
      // rather than letting downstream substring assertions fail with confusing output.
      throw new Error(`src/shared/tokens.css missing — Wave 1 Task 2 lands this file`);
    }
    const css = readFileSync(TOKENS_CSS_PATH, 'utf8');
    for (const name of REQUIRED_FONT_FILES) {
      expect(
        css.includes(name),
        `tokens.css must reference ${name} in a @font-face src url(); RED until Wave 1 Task 2 lands the @font-face block`,
      ).toBe(true);
    }
  });

  it('LICENSE-Lora.txt + LICENSE-IBM-Plex.txt + README.md exist (OFL attribution)', () => {
    for (const name of REQUIRED_LICENSE_FILES) {
      const filePath = resolvePath(FONTS_DIR, name);
      expect(existsSync(filePath), `Expected ${filePath} (RED until Wave 1 Task 1)`).toBe(true);
      expect(statSync(filePath).size, `${name} must be non-empty`).toBeGreaterThan(0);
    }
  });

  it('optional Lora-Italic-VariableFont.woff2 — present iff upstream ships separate italic file', () => {
    // A5 in RESEARCH Assumptions Log: variable Lora may consolidate italic
    // via the `ital` axis. This test is informational — passes either way.
    for (const name of OPTIONAL_FONT_FILES) {
      const filePath = resolvePath(FONTS_DIR, name);
      if (existsSync(filePath)) {
        expect(statSync(filePath).size).toBeGreaterThan(0);
      }
      // If absent, the README.md should document the consolidation (verified
      // empirically at execute time; not asserted here to avoid coupling).
    }
  });
});