'use client';

import { useEffect } from 'react';

/**
 * LoginBranding - Aplica cor primária da agência na página de login
 * Busca cor do localStorage ou da API se não houver cache
 */
export function LoginBranding() {
    useEffect(() => {

        const hexToRgb = (hex: string) => {
            const result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
            return result ? `${parseInt(result[1], 16)} ${parseInt(result[2], 16)} ${parseInt(result[3], 16)}` : null;
        };

        const applyTheme = (primary: string) => {
            if (!primary) return;

            const root = document.documentElement;
            const primaryRgb = hexToRgb(primary);

            root.style.setProperty('--brand-color', primary);
            root.style.setProperty('--gradient', `linear-gradient(135deg, ${primary}, ${primary})`);

            if (primaryRgb) {
                root.style.setProperty('--brand-rgb', primaryRgb);
                root.style.setProperty('--brand-strong-rgb', primaryRgb);
                root.style.setProperty('--brand-hover-rgb', primaryRgb);
            }
        };

        const updateFavicon = (url: string) => {
            if (typeof window === 'undefined' || typeof document === 'undefined') return;

            try {
                const newHref = `${url}${url.includes('?') ? '&' : '?'}v=${Date.now()}`;
                const existingLinks = document.querySelectorAll("link[rel*='icon']");

                if (existingLinks.length > 0) {
                    existingLinks.forEach(link => {
                        link.setAttribute('href', newHref);
                    });
                } else {
                    const newLink = document.createElement('link');
                    newLink.rel = 'icon';
                    newLink.type = 'image/x-icon';
                    newLink.href = newHref;
                    document.head.appendChild(newLink);
                }
            } catch (error) {
                console.error('❌ Erro ao atualizar favicon:', error);
            }
        };

        const loadBranding = async () => {
            if (typeof window === 'undefined') return;

            const hostname = window.location.hostname;
            const subdomain = hostname.split('.')[0];

            // Para dash.localhost ou localhost sem subdomínio, não buscar
            if (!subdomain || subdomain === 'localhost' || subdomain === 'www' || subdomain === 'dash') {
                return;
            }

            try {
                // 1. Buscar DIRETO do backend (bypass da rota Next.js que está com problema)
                console.log('LoginBranding: Buscando cores para:', subdomain);
                const apiUrl = `/api/tenant/config?subdomain=${subdomain}`;
                console.log('LoginBranding: URL:', apiUrl);

                const response = await fetch(apiUrl);

                if (response.ok) {
                    const data = await response.json();

                    if (data.primary_color) {
                        applyTheme(data.primary_color);
                        localStorage.setItem('agency-primary-color', data.primary_color);
                    }

                    if (data.logo_url) {
                        updateFavicon(data.logo_url);
                        localStorage.setItem('agency-logo-url', data.logo_url);
                    }
                    return;
                } else {
                    console.error('LoginBranding: API retornou:', response.status);
                }

                // 2. Fallback para cache
                const cachedPrimary = localStorage.getItem('agency-primary-color');
                const cachedLogo = localStorage.getItem('agency-logo-url');

                if (cachedPrimary) {
                    applyTheme(cachedPrimary);
                }
                if (cachedLogo) {
                    updateFavicon(cachedLogo);
                }
            } catch (error) {
                console.error('LoginBranding: Erro:', error);
                const cachedPrimary = localStorage.getItem('agency-primary-color');
                const cachedLogo = localStorage.getItem('agency-logo-url');

                if (cachedPrimary) {
                    applyTheme(cachedPrimary);
                }
                if (cachedLogo) {
                    updateFavicon(cachedLogo);
                }
            }
        };

        loadBranding();
    }, []);

    return null;
}