<?php
namespace Abdiel_AMM;

if ( ! defined( 'ABSPATH' ) ) { exit; }

class SEO {

    public function hooks() {
        // Canonical/redirect should run early.
        add_action( 'template_redirect', [ $this, 'maybe_redirect_to_prefixed' ], 1 );
        add_action( 'wp_head', [ $this, 'maybe_print_canonical' ], 2 );

        add_action( 'wp_head', [ $this, 'print_hreflang' ], 3 );
        add_filter( 'language_attributes', [ $this, 'html_lang_attribute' ] );

        // Integrations (Yoast SEO / sitemaps)
        add_filter( 'wpseo_canonical', [ $this, 'filter_wpseo_canonical' ], 20 );
        add_filter( 'wpseo_xml_sitemap_post_url', [ $this, 'filter_wpseo_sitemap_post_url' ], 20, 2 );
        add_filter( 'wpseo_sitemap_entry', [ $this, 'filter_wpseo_sitemap_entry' ], 20, 3 );
        add_filter( 'get_canonical_url', [ $this, 'filter_wp_core_canonical' ], 20, 2 );
    }

    private function content() {
        return abdiel_amm_boot()->content;
    }

    private function languages() {
        $langs = Settings::get_languages_option();
        $items = $langs['items'];
        uasort( $items, function( $a, $b ) { return (int) $a['order'] <=> (int) $b['order']; } );
        $langs['items'] = $items;
        return $langs;
    }

    private function is_prefix_seo_forced() {
        $settings = Settings::get_settings_option();
        return ( ( $settings['url_mode'] ?? 'none' ) === 'prefix' ) && ! empty( $settings['prefix_force_canonical'] );
    }

    private function normalize_html_lang( $code ) {
        $code = (string) $code;
        if ( $code === '' ) { return $code; }
        if ( strpos( $code, '-' ) !== false || strpos( $code, '_' ) !== false ) {
            return str_replace( '_', '-', $code );
        }
        $map = [
            'en' => 'en-US',
            'es' => 'es-ES',
            'fr' => 'fr-FR',
            'pt' => 'pt-PT',
            'de' => 'de-DE',
            'it' => 'it-IT',
            'nl' => 'nl-NL',
        ];
        $tag = $map[ $code ] ?? $code;
        return apply_filters( 'abdiel_amm_html_lang', $tag, $code );
    }

    private function normalize_locale_for_yoast( $code ) {
            $tag = '';
            if ( ! empty( $row['locale'] ) ) {
                $tag = str_replace( '_', '-', sanitize_text_field( $row['locale'] ) );
            }
            if ( empty( $tag ) ) { $tag = $this->normalize_html_lang( $code ); }
        // Yoast typically expects underscore locale like en_US.
        $loc = str_replace( '-', '_', $tag );
        return apply_filters( 'abdiel_amm_yoast_locale', $loc, $code, $tag );
    }

    private function build_lang_url( $target_post_id, $lang_code ) {
        $settings = Settings::get_settings_option();
        $mode     = $settings['url_mode'] ?? 'none';
        $default  = $this->content()->get_default_language_code();

        $url = $target_post_id ? get_permalink( $target_post_id ) : home_url( '/' );

        if ( $mode === 'query' ) {
            if ( $default && $lang_code === $default ) { return $url; }
            return add_query_arg( 'lang', $lang_code, $url );
        }

        if ( $mode === 'prefix' ) {
            if ( $default && $lang_code === $default ) { return $url; }
            $parsed = wp_parse_url( $url );
            $host = ( isset( $parsed['scheme'] ) ? $parsed['scheme'] . '://' : '' ) . ( $parsed['host'] ?? '' );
            if ( isset( $parsed['port'] ) ) { $host .= ':' . $parsed['port']; }
            $path = $parsed['path'] ?? '/';
            $path = '/' . ltrim( $path, '/' );
            // Remove existing /xx/ if present
            $path = preg_replace( '#^/([a-z]{2})(/|$)#i', '/', $path, 1 );
            $path = '/' . $lang_code . rtrim( $path, '/' );
            if ( substr( $path, -1 ) !== '/' ) { $path .= '/'; }
            return $host . $path;
        }

        return $url;
    }

    private function get_prefixed_canonical_url( $post_id ) {
        if ( ! $post_id || get_post_status( $post_id ) !== 'publish' ) { return ''; }
        $code    = $this->content()->get_current_language_code( $post_id );
        $default = $this->content()->get_default_language_code();
        if ( ! $code || ! $default || $code === $default ) { return ''; }
        $canonical = $this->build_lang_url( $post_id, $code );
        return $canonical ? $canonical : '';
    }

    public function filter_wpseo_canonical( $canonical ) {
        if ( ! is_singular() || ! $this->is_prefix_seo_forced() ) { return $canonical; }
        $pref = $this->get_prefixed_canonical_url( get_queried_object_id() );
        return $pref ? $pref : $canonical;
    }

    public function filter_wp_core_canonical( $canonical, $post ) {
        if ( ! is_singular() || ! $this->is_prefix_seo_forced() ) { return $canonical; }
        $post_id = ( is_object( $post ) && ! empty( $post->ID ) ) ? (int) $post->ID : (int) get_queried_object_id();
        $pref = $this->get_prefixed_canonical_url( $post_id );
        return $pref ? $pref : $canonical;
    }

    public function filter_wpseo_sitemap_post_url( $url, $post ) {
        if ( ! $post || empty( $post->ID ) ) { return $url; }
        $settings = Settings::get_settings_option();
        if ( ( $settings['url_mode'] ?? 'none' ) !== 'prefix' ) { return $url; }
        $code    = $this->content()->get_current_language_code( (int) $post->ID );
        $default = $this->content()->get_default_language_code();
        if ( ! $code || ! $default || $code === $default ) { return $url; }
        $pref = $this->build_lang_url( (int) $post->ID, $code );
        return $pref ? $pref : $url;
    }

    public function filter_wpseo_sitemap_entry( $entry, $type, $obj ) {
        if ( $type !== 'post' || ! is_array( $entry ) ) { return $entry; }
        if ( empty( $entry['loc'] ) || ! is_object( $obj ) || empty( $obj->ID ) ) { return $entry; }
        $settings = Settings::get_settings_option();
        if ( ( $settings['url_mode'] ?? 'none' ) !== 'prefix' ) { return $entry; }
        $code    = $this->content()->get_current_language_code( (int) $obj->ID );
        $default = $this->content()->get_default_language_code();
        if ( ! $code || ! $default || $code === $default ) { return $entry; }
        $pref = $this->build_lang_url( (int) $obj->ID, $code );
        if ( $pref ) { $entry['loc'] = $pref; }
        return $entry;
    }

    public function maybe_print_canonical() {
        if ( ! is_singular() ) { return; }
        $settings = Settings::get_settings_option();
        if ( ( $settings['url_mode'] ?? 'none' ) !== 'prefix' ) { return; }
        if ( empty( $settings['prefix_force_canonical'] ) ) { return; }

        // If Yoast is present, it will output canonical. We still print as a fallback,
        // but the main source of truth is our wpseo_canonical filter.
        $post_id = get_queried_object_id();
        $canonical = $this->get_prefixed_canonical_url( $post_id );
        if ( ! $canonical ) { return; }

        echo "\n" . '<link rel="canonical" href="' . esc_url( $canonical ) . '" />' . "\n";
    }

    public function maybe_redirect_to_prefixed() {
        if ( ! is_singular() ) { return; }
        $settings = Settings::get_settings_option();
        if ( ( $settings['url_mode'] ?? 'none' ) !== 'prefix' ) { return; }
        if ( empty( $settings['prefix_force_redirect_301'] ) ) { return; }

        $post_id = get_queried_object_id();
        if ( ! $post_id || get_post_status( $post_id ) !== 'publish' ) { return; }

        $code    = $this->content()->get_current_language_code( $post_id );
        $default = $this->content()->get_default_language_code();
        if ( ! $code || ! $default || $code === $default ) { return; }

        $req_uri  = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
        $host     = isset( $_SERVER['HTTP_HOST'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HTTP_HOST'] ) ) : '';
        $req_path = wp_parse_url( ( is_ssl() ? 'https://' : 'http://' ) . $host . $req_uri, PHP_URL_PATH );
        $req_path = is_string( $req_path ) ? $req_path : '';

        if ( preg_match( '#^/' . preg_quote( $code, '#' ) . '(/|$)#i', $req_path ) ) { return; }

        $target = $this->build_lang_url( $post_id, $code );
        if ( ! $target ) { return; }

        $q = wp_parse_url( $req_uri, PHP_URL_QUERY );
        if ( is_string( $q ) && $q !== '' ) {
            $target = $target . ( strpos( $target, '?' ) === false ? '?' : '&' ) . $q;
        }

        wp_safe_redirect( $target, 301 );
        exit;
    }

    public function html_lang_attribute( $output ) {
        if ( ! is_singular() ) { return $output; }
        $post_id = get_queried_object_id();
        if ( ! $post_id ) { return $output; }

        $code = $this->content()->get_current_language_code( $post_id );
        if ( ! $code ) { return $output; }

            $tag = '';
            if ( ! empty( $row['locale'] ) ) {
                $tag = str_replace( '_', '-', sanitize_text_field( $row['locale'] ) );
            }
            if ( empty( $tag ) ) { $tag = $this->normalize_html_lang( $code ); }
        if ( ! $tag ) { return $output; }


        if ( preg_match( '/\blang\s*=\s*\"[^\"]*\"/i', $output ) ) {
            $output = preg_replace( '/\blang\s*=\s*\"[^\"]*\"/i', 'lang="' . esc_attr( $tag ) . '"', $output );
        } else {
            $output .= ' lang="' . esc_attr( $tag ) . '"';
        }
        return $output;
    }

    public function print_hreflang() {
        if ( ! is_singular() ) { return; }
        $post_id = get_queried_object_id();
        if ( ! $post_id ) { return; }

        if ( get_post_status( $post_id ) !== 'publish' ) { return; }

        $langs  = $this->languages();
        $active = [];
        foreach ( (array) $langs['items'] as $code => $row ) {
            if ( ! empty( $row['active'] ) ) { $active[ $code ] = $row; }
        }

        $map = $this->content()->get_translation_map( $post_id );
        if ( empty( $map ) ) { return; }

        $default = isset( $langs['default'] ) ? sanitize_key( $langs['default'] ) : '';
        $printed = 0;

        foreach ( $active as $code => $row ) {
            if ( empty( $map[ $code ] ) ) { continue; }
            $pid = absint( $map[ $code ] );
            if ( $pid <= 0 ) { continue; }
            if ( get_post_status( $pid ) !== 'publish' ) { continue; }

            $url = $this->build_lang_url( $pid, $code );
            if ( ! $url ) { continue; }

            $tag = '';
            if ( ! empty( $row['locale'] ) ) {
                $tag = str_replace( '_', '-', sanitize_text_field( $row['locale'] ) );
            }
            if ( empty( $tag ) ) { $tag = $this->normalize_html_lang( $code ); }
            echo "\n" . '<link rel="alternate" hreflang="' . esc_attr( $tag ) . '" href="' . esc_url( $url ) . '" />' . "\n";
            $printed++;
        }

        if ( $printed > 1 && $default && ! empty( $map[ $default ] ) ) {
            $pid = absint( $map[ $default ] );
            if ( $pid && get_post_status( $pid ) === 'publish' ) {
                $url = $this->build_lang_url( $pid, $default );
                if ( $url ) {
                    echo "\n" . '<link rel="alternate" hreflang="x-default" href="' . esc_url( $url ) . '" />' . "\n";
                }
            }
        }
    }
}