import { headers } from 'next/headers';
import { getBaseUrl } from '../utils/sitemap';

function toSafeDate(value) {
    if (!value) return new Date();
    const d = new Date(value);
    return isNaN(d.getTime()) ? new Date() : d;
}

const MAIN_DOMAIN = 'nobat724.com';

function getCurrentDomain() {
    try {
        const headersList = headers();
        const host = headersList.get('host');
        return host || MAIN_DOMAIN;
    } catch {
        return MAIN_DOMAIN;
    }
}

const NOW = new Date();

function getStaticPages(baseUrl) {
    return [
        { url: baseUrl, lastModified: NOW, changeFrequency: 'daily', priority: 1 },
        { url: `${baseUrl}/about-us`, lastModified: NOW, changeFrequency: 'monthly', priority: 0.8 },
        { url: `${baseUrl}/contact-us`, lastModified: NOW, changeFrequency: 'monthly', priority: 0.8 },
        { url: `${baseUrl}/blogs`, lastModified: NOW, changeFrequency: 'weekly', priority: 0.9 },
        { url: `${baseUrl}/doctors`, lastModified: NOW, changeFrequency: 'daily', priority: 0.9 },
        { url: `${baseUrl}/clinics`, lastModified: NOW, changeFrequency: 'daily', priority: 0.9 },
        { url: `${baseUrl}/specialties`, lastModified: NOW, changeFrequency: 'weekly', priority: 0.9 },
    ];
}

async function getDoctorUrls(baseUrl) {
    const API_URL = process.env.NEXT_PUBLIC_API_URL;
    if (!API_URL) return [];

    try {
        const res = await fetch(`${API_URL}/api/v1/doctors?page=1&limit=500`, {
            next: { revalidate: 3600 },
        });
        if (!res.ok) return [];
        const data = await res.json();
        const doctors = data?.data || data?.doctors || data || [];
        return doctors
            .filter((d) => d?.uuid)
            .map((d) => ({
                url: `${baseUrl}/doctor/${d.uuid}`,
                lastModified: NOW,
                changeFrequency: 'weekly',
                priority: 0.8,
            }));
    } catch {
        return [];
    }
}

async function getClinicUrls(baseUrl) {
    const API_URL = process.env.NEXT_PUBLIC_API_URL;
    if (!API_URL) return [];

    try {
        const res = await fetch(`${API_URL}/api/v1/clinics?page=1&limit=500`, {
            next: { revalidate: 3600 },
        });
        if (!res.ok) return [];
        const data = await res.json();
        const clinics = data?.data || data?.clinics || data || [];
        return clinics
            .filter((c) => c?.uuid)
            .map((c) => ({
                url: `${baseUrl}/clinic/${c.uuid}`,
                lastModified: NOW,
                changeFrequency: 'weekly',
                priority: 0.7,
            }));
    } catch {
        return [];
    }
}

async function getBlogUrls(baseUrl) {
    const API_URL = process.env.NEXT_PUBLIC_API_URL;
    if (!API_URL) return [];

    try {
        const res = await fetch(`${API_URL}/api/v1/blogs?page=1&limit=200`, {
            next: { revalidate: 3600 },
        });
        if (!res.ok) return [];
        const data = await res.json();
        const blogs = data?.blogs || data?.data || data || [];
        return blogs
            .filter((b) => b?.slug || b?.uuid)
            .map((b) => ({
                url: `${baseUrl}/blog/${b.slug || b.uuid}`,
                lastModified: toSafeDate(b.created),
                changeFrequency: 'monthly',
                priority: 0.6,
            }));
    } catch {
        return [];
    }
}

export default async function sitemap() {
    try {
        const domain = getCurrentDomain();
        const baseUrl = getBaseUrl(domain);

        const [staticPages, doctorUrls, clinicUrls, blogUrls] = await Promise.all([
            Promise.resolve(getStaticPages(baseUrl)),
            getDoctorUrls(baseUrl),
            getClinicUrls(baseUrl),
            getBlogUrls(baseUrl),
        ]);

        const allUrls = [...staticPages, ...doctorUrls, ...clinicUrls, ...blogUrls];

        return allUrls.filter(
            (item, index, arr) => arr.findIndex((i) => i.url === item.url) === index
        );
    } catch (error) {
        console.error('Error generating sitemap:', error);
        return [];
    }
}