import { readFileSync } from 'fs';
import { getIconsCSSData } from '@iconify/utils/lib/css/icons';
import { matchIconName } from '@iconify/utils/lib/icon/name';
const missingIconsListError = 'TailwindCSS cannot dynamically find all used icons. Need to pass list of used icons to Iconify plugin.';
/**
 * Locate icon set
 */
function locateIconSet(prefix) {
    try {
        return require.resolve(`@iconify-json/${prefix}/icons.json`);
    }
    catch { }
    try {
        return require.resolve(`@iconify/json/json/${prefix}.json`);
    }
    catch { }
}
/**
 * Load icon set
 */
function loadIconSet(prefix) {
    const filename = locateIconSet(prefix);
    if (filename) {
        try {
            return JSON.parse(readFileSync(filename, 'utf8'));
        }
        catch { }
    }
}
/**
 * Get icon names from list
 */
function getIconNames(icons) {
    const prefixes = Object.create(null);
    // Add entry
    const add = (prefix, name) => {
        if (typeof prefix === 'string' &&
            prefix.match(matchIconName) &&
            typeof name === 'string' &&
            name.match(matchIconName)) {
            (prefixes[prefix] || (prefixes[prefix] = new Set())).add(name);
        }
    };
    // Comma or space separated string
    let iconNames;
    if (typeof icons === 'string') {
        iconNames = icons.split(/[\s,.]/);
    }
    else if (icons instanceof Array) {
        iconNames = [];
        // Split each array entry
        icons.forEach((item) => {
            item.split(/[\s,.]/).forEach((name) => iconNames.push(name));
        });
    }
    else {
        throw new Error(missingIconsListError);
    }
    // Parse array
    if (iconNames?.length) {
        iconNames.forEach((icon) => {
            if (!icon.trim()) {
                return;
            }
            // Attempt prefix:name split
            const nameParts = icon.split(':');
            if (nameParts.length === 2) {
                add(nameParts[0], nameParts[1]);
                return;
            }
            // Attempt icon class: .icon--{prefix}--{name}
            // with or without dot
            const classParts = icon.split('--');
            if (classParts[0].match(/^\.?icon$/)) {
                if (classParts.length === 3) {
                    add(classParts[1], classParts[2]);
                    return;
                }
                if (classParts.length === 2) {
                    // Partial match
                    return;
                }
            }
            // Throw error
            throw new Error(`Cannot resolve icon: "${icon}"`);
        });
    }
    else {
        throw new Error(missingIconsListError);
    }
    return prefixes;
}
/**
 * Get CSS rules for icon
 */
export function getCSSRules(icons, options = {}) {
    const rules = Object.create(null);
    // Get all icons
    const prefixes = getIconNames(icons);
    // Parse all icon sets
    for (const prefix in prefixes) {
        const iconSet = loadIconSet(prefix);
        if (!iconSet) {
            throw new Error(`Cannot load icon set for "${prefix}"`);
        }
        const generated = getIconsCSSData(iconSet, Array.from(prefixes[prefix]), options);
        const result = generated.common
            ? [generated.common, ...generated.css]
            : generated.css;
        result.forEach((item) => {
            const selector = item.selector instanceof Array
                ? item.selector.join(', ')
                : item.selector;
            rules[selector] = item.rules;
        });
    }
    return rules;
}