import figlet from './vendor/figlet.js';
import {fonts} from './font-catalog.js';

export const styles = fonts;
export const FONT_CACHE = `ascii-pwa-fonts-${encodeURIComponent(new URL('./', import.meta.url).href)}-figlet-1.8.2`;
const pendingFonts = new Map();

// Keep existing lowercase font links working with the library's font names.
export function resolveFont(name) {
    return fonts.find(font => font.toLowerCase() === String(name).toLowerCase()) || 'Standard';
}

export function registerFont(name, data) {
    if (!fonts.includes(name)) throw new Error('Unknown lettering style');
    figlet.parseFont(name, data);
}

export function renderLoaded(text, font = 'Standard') {
    if (text.length > 500) throw new Error('Text is too long');
    if (!fonts.includes(font)) throw new Error('Unknown lettering style');
    return figlet.textSync(text, {
        font, width: 80, whitespaceBreak: true,
    }).split('\n').filter(line => line.trim()).join('\n');
}

export async function render(text, font = 'Standard') {
    if (text.length > 500) throw new Error('Text is too long');
    if (!fonts.includes(font)) throw new Error('Unknown lettering style');
    if (!figlet.figFonts[font]) {
        if (!pendingFonts.has(font)) {
            pendingFonts.set(font, (async () => {
                const url = new URL(`./fonts/figlet/${font}.flf`, import.meta.url).href;
                let cache;
                let cached;
                try {
                    if ('caches' in globalThis) {
                        cache = await caches.open(FONT_CACHE);
                        cached = await cache.match(url);
                    }
                } catch { /* Rendering still works if browser storage is unavailable. */ }
                const response = cached || await fetch(url);
                if (!response.ok) throw new Error('Cannot load font');
                registerFont(font, await response.clone().text());
                if (cache && !cached) {
                    try { await cache.put(url, response); } catch { /* Storage may be full. */ }
                }
            })().finally(() => pendingFonts.delete(font)));
        }
        await pendingFonts.get(font);
    }
    return renderLoaded(text, font);
}