import type { FastifyReply, FastifyRequest } from 'fastify';
import { stringToColor } from '@iconify/utils/lib/colors';
import { getIconsCSS } from '@iconify/utils/lib/css/icons';
import { getStoredIconsData } from '../../data/icon-set/utils/get-icons';
import { iconSets } from '../../data/icon-sets';
import type { IconCSSIconSetOptions } from '@iconify/utils/lib/css/types';
import { paramToBoolean } from '../../misc/bool';

/**
 * Check selector for weird stuff
 */
function checkSelector(value: string | undefined): boolean {
	if (typeof value !== 'string') {
		return false;
	}
	const cleanValue = value.replaceAll('{name}', '').replaceAll('{prefix}', '');
	return cleanValue.indexOf('{') === -1 && cleanValue.indexOf('}') === -1;
}

/**
 * Generate icons style
 */
export function generateIconsStyleResponse(prefix: string, query: FastifyRequest['query'], res: FastifyReply) {
	const q = (query || {}) as Record<string, string>;
	const names = q.icons?.split(',');

	if (!names || !names.length) {
		// Missing or invalid icons parameter
		res.send(404);
		return;
	}

	// Get icon set
	const iconSet = iconSets[prefix];
	if (!iconSet) {
		// No such icon set
		res.send(404);
		return;
	}

	// Get icons
	getStoredIconsData(iconSet.item, names, (data) => {
		// Options
		const options: IconCSSIconSetOptions = {};
		const qOptions = q as IconCSSIconSetOptions;

		if (typeof qOptions.format === 'string') {
			const format = qOptions.format;
			switch (format) {
				case 'compact':
				case 'compressed':
				case 'expanded':
					options.format = format;
			}
		}

		// 'color': string
		// Sets color for monotone images
		const color = qOptions.color;
		if (typeof color === 'string' && stringToColor(color)) {
			options.color = color;
		}

		// 'mode': string
		// Forces mode
		// Alias for 'background': 'bg'
		const mode = qOptions.mode;
		if (mode) {
			switch (mode) {
				case 'background':
				case 'mask':
					options.mode = mode;

				default:
					if ((mode as string) === 'bg') {
						options.mode = 'background';
					}
			}
		}

		// 'forceSquare': boolean
		// Forces icon to be square, regardless of width/height ratio
		// Aliases: 'square', 'force-square'
		const forceSquare = paramToBoolean(q.square || q.forceSquare || q['force-square'], void 0);
		if (typeof forceSquare === 'boolean') {
			options.forceSquare = forceSquare;
		}

		// 'pseudoSelector': boolean
		// Adds `content: '';` to common selector. Useful when selector is a pseudo-selector
		// Aliases: 'pseudo', 'pseudo-selector'
		const pseudoSelector = paramToBoolean(q.pseudo || q.pseudoSelector || q['pseudo-selector'], void 0);
		if (typeof pseudoSelector === 'boolean') {
			options.pseudoSelector = pseudoSelector;
		}

		// 'commonSelector': string
		// Common selector for all requested icons
		// Alias: 'common'
		const commonSelector = qOptions.commonSelector || q.common;
		if (checkSelector(commonSelector)) {
			options.commonSelector = commonSelector;
		}

		// 'iconSelector': string
		// Icon selector
		// Alias: 'selector'
		const iconSelector = qOptions.iconSelector || q.selector;
		if (checkSelector(iconSelector)) {
			options.iconSelector = iconSelector;
		}

		// 'overrideSelector': string
		// Selector for rules in icon that override common rules
		// Alias: 'override'
		const overrideSelector = qOptions.overrideSelector || q.override;
		if (checkSelector(overrideSelector)) {
			options.overrideSelector = overrideSelector;
		}

		// 'varName': string
		// Variable name
		// Alias: 'var'
		const varName = q.varName || q.var;
		if (typeof varName === 'string' && varName.match(/^[a-z0-9_-]*$/)) {
			if (!varName || varName === 'null' || !paramToBoolean(varName, true)) {
				options.varName = null;
			} else {
				options.varName = varName;
			}
		}

		// Generate css
		const css = getIconsCSS(
			{
				// Data
				...data,
				// Info to detect palette
				info: iconSet.item.info,
			},
			names,
			options
		);

		// Send CSS, optionally as attachment
		if (q.download) {
			res.header('Content-Disposition', 'attachment; filename="' + prefix + '.css"');
		}

		res.type('text/css; charset=utf-8').send(css);
	});
}