<?php

declare(strict_types=1);

namespace LIT\MCP\Admin;

use LIT\MCP\ChangeLog\ChangeLog;
use LIT\MCP\Integrations\IntegrationRegistry;
use LIT\MCP\Limits;

defined('ABSPATH') || exit;

/**
 * Tab "Protokoll": filterable list of change log entries, links to revisions, and
 * "Protokoll leeren" (spec §8.3). Page size and visible columns via WordPress'
 * "Ansicht anpassen" (screen options), as on the core list screens.
 */
final class LogTab implements AdminTab
{
    public const CLEAR_ACTION = 'lit_mcp_clear_log';

    /** Screen option "Einträge pro Seite" (user option; WordPress needs the "_per_page" end). */
    public const PER_PAGE_OPTION = 'lit_mcp_log_per_page';
    public const PER_PAGE_DEFAULT = 20;
    private const RESULTS = ['ok', 'partial', 'refused'];

    private AdminPostAction $action;

    /** Created on the screen's load hook so WordPress knows its columns for the screen options. */
    private ?LogListTable $table = null;

    public function __construct(
        private ChangeLog $log,
        private Limits $limits,
        private IntegrationRegistry $registry,
        ?callable $terminate = null
    ) {
        $this->action = new AdminPostAction($terminate);
    }

    public function slug(): string
    {
        return 'protokoll';
    }

    public function label(): string
    {
        return __('Protokoll', 'wp-lit-mcp');
    }

    public function registerSettings(): void
    {
    }

    public function registerActions(): void
    {
        add_action('admin_post_' . self::CLEAR_ACTION, [$this, 'handleClear']);
        add_action('load-' . SettingsPage::SCREEN_HOOK, [$this, 'loadScreen']);
        add_filter('set_screen_option_' . self::PER_PAGE_OPTION, [$this, 'savePerPage'], 10, 3);
    }

    /**
     * Load hook of the settings page: on this tab only, "Einträge pro Seite" in the screen
     * options, and the list table built early so its columns can be hidden there too
     * (WP_List_Table registers them for the screen, as on edit.php).
     */
    public function loadScreen(): void
    {
        // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- read-only tab switch.
        $tab = isset($_GET['tab']) ? sanitize_key(wp_unslash((string) $_GET['tab'])) : '';
        if ($tab !== $this->slug()) {
            return;
        }

        add_screen_option('per_page', [
            'label' => __('Einträge pro Seite', 'wp-lit-mcp'),
            'default' => self::PER_PAGE_DEFAULT,
            'option' => self::PER_PAGE_OPTION,
        ]);
        $this->table = $this->createTable();
    }

    /**
     * Lets WordPress save the page size (it already checked nonce and range 1–999).
     *
     * @return int|false
     */
    public function savePerPage(mixed $status, string $option, mixed $value): mixed
    {
        return $option === self::PER_PAGE_OPTION ? (int) $value : $status;
    }

    /** @param array<string, int|string> $filters */
    public static function hasActiveFilter(array $filters): bool
    {
        foreach ($filters as $value) {
            if ($value !== '' && $value !== 0) {
                return true;
            }
        }

        return false;
    }

    /** @return array{ability: string, user_id: int} */
    public function filters(): array
    {
        // phpcs:disable WordPress.Security.NonceVerification.Recommended -- read-only list filters.
        $ability = isset($_GET['ability']) ? sanitize_text_field(wp_unslash((string) $_GET['ability'])) : '';
        $userId = isset($_GET['user_id']) ? absint($_GET['user_id']) : 0;
        // phpcs:enable WordPress.Security.NonceVerification.Recommended

        return [
            'ability' => preg_match('#^[a-z0-9-]+/[a-z0-9-]+$#D', $ability) === 1 ? $ability : '',
            'user_id' => $userId,
        ];
    }

    /**
     * Additional whitelisted filters (ruling C5/Q13: ability, result, user, date range).
     * Kept separate from filters() so that method's return shape stays exactly what is
     * unit-tested (and what earlier callers of this tab may already rely on).
     *
     * @return array{result: string, date_from: string, date_to: string}
     */
    public function extraFilters(): array
    {
        // phpcs:disable WordPress.Security.NonceVerification.Recommended -- read-only list filters.
        $result = isset($_GET['result']) ? sanitize_text_field(wp_unslash((string) $_GET['result'])) : '';
        $dateFrom = isset($_GET['date_from']) ? sanitize_text_field(wp_unslash((string) $_GET['date_from'])) : '';
        $dateTo = isset($_GET['date_to']) ? sanitize_text_field(wp_unslash((string) $_GET['date_to'])) : '';
        // phpcs:enable WordPress.Security.NonceVerification.Recommended

        return [
            'result' => in_array($result, self::RESULTS, true) ? $result : '',
            'date_from' => self::isDate($dateFrom) ? $dateFrom : '',
            'date_to' => self::isDate($dateTo) ? $dateTo : '',
        ];
    }

    private static function isDate(string $value): bool
    {
        return preg_match('#^\d{4}-\d{2}-\d{2}$#D', $value) === 1;
    }

    private function createTable(): LogListTable
    {
        if (! class_exists('WP_List_Table')) {
            require_once ABSPATH . 'wp-admin/includes/class-wp-list-table.php';
        }

        $filters = $this->filters();
        $extra = $this->extraFilters();

        return new LogListTable($this->log, $filters + $extra, $this->toolLabels());
    }

    /** @return array<string, string> ability name => label */
    private function toolLabels(): array
    {
        $labels = [];
        foreach ($this->registry->abilities() as $ability) {
            $labels[$ability->name()] = $ability->label();
        }

        return $labels;
    }

    public function render(): void
    {
        $days = $this->limits->logRetentionDays();
        printf(
            '<p class="description">%s %s</p>',
            esc_html__('Das Protokoll enthält nur Verweise, keine Inhalte.', 'wp-lit-mcp'),
            sprintf(
                /* translators: %s: link "N Tagen" to the Limits tab */
                esc_html__('Einträge werden nach %s automatisch gelöscht.', 'wp-lit-mcp'),
                sprintf(
                    '<a href="%s">%s</a>',
                    esc_url(SettingsPage::url('limits')),
                    esc_html(sprintf(
                        /* translators: %d: number of days */
                        _n('%d Tag', '%d Tagen', $days, 'wp-lit-mcp'),
                        $days
                    ))
                )
            )
        );

        echo '<form method="get">';
        printf('<input type="hidden" name="page" value="%s">', esc_attr(SettingsPage::SLUG));
        printf('<input type="hidden" name="tab" value="%s">', esc_attr($this->slug()));
        // Own block, not the table nav: core hides ".tablenav .actions" on phones.
        echo '<div class="lit-mcp-log-filters">';
        $this->renderFilterControls($this->filters(), $this->extraFilters(), $this->toolLabels());
        echo '</div>';
        $table = $this->table ?? $this->createTable();
        $table->prepare_items();
        $table->display();
        echo '</form>';

        // The whole log, not the filtered page: "leeren" removes everything.
        $total = $this->log->count();
        if ($total > 0) {
            $this->renderClearForm($total);
        }
    }

    /**
     * @param array{ability: string, user_id: int}                     $filters
     * @param array{result: string, date_from: string, date_to: string} $extra
     * @param array<string, string>                                     $labels ability name => label
     */
    private function renderFilterControls(array $filters, array $extra, array $labels): void
    {
        self::filterLabel('ability', __('Nach Tool filtern', 'wp-lit-mcp'));
        echo '<select name="ability" id="lit-mcp-filter-ability"><option value="">'
            . esc_html__('Alle Tools', 'wp-lit-mcp') . '</option>';
        foreach ($this->toolOptionGroups() as $group => $abilities) {
            printf('<optgroup label="%s">', esc_attr($group));
            foreach ($abilities as $ability) {
                printf(
                    '<option value="%s"%s>%s</option>',
                    esc_attr($ability),
                    selected($filters['ability'], $ability, false),
                    esc_html($labels[$ability] ?? $ability)
                );
            }
            echo '</optgroup>';
        }
        echo '</select>';

        self::filterLabel('user-id', __('Nach Benutzer filtern', 'wp-lit-mcp'));
        wp_dropdown_users([
            'name' => 'user_id',
            'id' => 'lit-mcp-filter-user-id',
            'show_option_all' => __('Alle Benutzer', 'wp-lit-mcp'),
            'selected' => $filters['user_id'],
        ]);

        self::filterLabel('result', __('Nach Ergebnis filtern', 'wp-lit-mcp'));
        echo '<select name="result" id="lit-mcp-filter-result">';
        printf('<option value="">%s</option>', esc_html__('Alle Ergebnisse', 'wp-lit-mcp'));
        $labels = [
            'ok' => __('erfolgreich', 'wp-lit-mcp'),
            'partial' => __('teilweise', 'wp-lit-mcp'),
            'refused' => __('abgelehnt', 'wp-lit-mcp'),
        ];
        foreach (self::RESULTS as $result) {
            printf(
                '<option value="%s"%s>%s</option>',
                esc_attr($result),
                selected($extra['result'], $result, false),
                esc_html($labels[$result])
            );
        }
        echo '</select>';

        foreach (['date_from' => __('von', 'wp-lit-mcp'), 'date_to' => __('bis', 'wp-lit-mcp')] as $name => $label) {
            $id = 'lit-mcp-filter-' . str_replace('_', '-', $name);
            printf(
                '<span class="lit-mcp-date"><label for="%1$s">%2$s</label>'
                    . '<input type="date" name="%3$s" id="%1$s" value="%4$s"></span>',
                esc_attr($id),
                esc_html($label),
                esc_attr($name),
                esc_attr($extra[$name])
            );
        }

        submit_button(__('Filtern', 'wp-lit-mcp'), '', 'filter_action', false, ['id' => 'lit-mcp-filter-submit']);

        if (self::hasActiveFilter($filters + $extra)) {
            printf(
                '<a class="lit-mcp-reset" href="%s">%s</a>',
                esc_url(SettingsPage::url($this->slug())),
                esc_html__('Filter zurücksetzen', 'wp-lit-mcp')
            );
        }
    }

    /**
     * The tools found in the log, grouped like the "Tools" tab (integration order);
     * tools no longer available land in "Weitere".
     *
     * @return array<string, list<string>> group label => ability names
     */
    private function toolOptionGroups(): array
    {
        $logged = array_flip($this->log->abilities());
        $groupLabels = $this->registry->labels();
        $groups = [];
        foreach ($this->registry->grouped() as $group => $abilities) {
            foreach ($abilities as $ability) {
                if (isset($logged[$ability->name()])) {
                    $groups[$groupLabels[$group] ?? $group][] = $ability->name();
                    unset($logged[$ability->name()]);
                }
            }
        }
        if ($logged !== []) {
            $groups[__('Weitere', 'wp-lit-mcp')] = array_map('strval', array_keys($logged));
        }

        return $groups;
    }

    private static function filterLabel(string $field, string $text): void
    {
        printf(
            '<label class="screen-reader-text" for="lit-mcp-filter-%s">%s</label>',
            esc_attr($field),
            esc_html($text)
        );
    }

    private function renderClearForm(int $total): void
    {
        printf('<div class="lit-mcp-clear-log"><form method="post" action="%s">', esc_url(admin_url('admin-post.php')));
        printf('<input type="hidden" name="action" value="%s">', esc_attr(self::CLEAR_ACTION));
        wp_nonce_field(self::CLEAR_ACTION);
        $confirmMessage = esc_js(__(
            'Das gesamte Protokoll unwiderruflich löschen?',
            'wp-lit-mcp'
        ));
        submit_button(
            sprintf(
                /* translators: %d: number of log entries */
                _n('Protokoll leeren (%d Eintrag)', 'Protokoll leeren (%d Einträge)', $total, 'wp-lit-mcp'),
                $total
            ),
            'delete',
            'submit',
            false,
            ['onclick' => "return window.confirm('" . $confirmMessage . "');"]
        );
        echo '</form></div>';
    }

    public function handleClear(): void
    {
        $this->action->guard();
        check_admin_referer(self::CLEAR_ACTION);
        $this->log->clear();
        $this->action->redirect($this->slug(), 'cleared');
    }
}