<?php
/**
 * The admin settings page: renders every tab from the templates in
 * templates/, with render-ready data. Templates receive arrays via
 * resolver_template(); no queries or data shaping happen in them.
 *
 * The Model, Training, Visibility and Chats tabs get their data from their
 * own controllers (RSVL_Model_Admin and so on), which also serve their AJAX
 * endpoints. The others are built here, along with the helpers every tab uses.
 */

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

class RSVL_Settings_Page
{
    private const POST_TYPE_ICONS = [
        'post'      => 'dashicons-admin-post',
        'page'      => 'dashicons-admin-page',
        'rsvl-pdf'  => 'dashicons-pdf',
        'rsvl-note' => 'dashicons-edit',
        'product'   => 'dashicons-products',
    ];

    /** Post types listed first in training tables and filters. */
    private const POST_TYPE_SORT_PRIORITY = ['page' => 0, 'post' => 1];

    /** Period filter values for the analytics-style tabs, in display order. */
    private const CALENDAR_PERIODS = ['this_month', 'last_month', '7', '30', '60', '90'];

    /** @var array Plugin settings merged with defaults. */
    private $settings;

    /** @var RSVL_Conversations */
    private $conversations;

    /** @var string */
    private $active_tab;

    public function __construct()
    {
        $this->settings      = RSVL_Settings::all();
        $this->conversations = new RSVL_Conversations();
        $this->active_tab    = isset($_GET['tab']) ? sanitize_key(wp_unslash($_GET['tab'])) : 'dashboard';
    }

    /**
     * Render the full settings page.
     */
    public function render(): void
    {
        resolver_template('settings-page', [
            'active_tab'       => $this->active_tab,
            'is_pro'           => resolver_is_pro(),
            'nav_tabs'         => RSVL_Admin::tabs(),
            'show_save_button' => ! in_array($this->active_tab, ['dashboard', 'analytics', 'help'], true)
                                      && ! ('training' === $this->active_tab && in_array(RSVL_Training_Admin::get_active_panel(), ['custom-fields', 'product-fields'], true)),
            'token_usage_percent' => RSVL_Token_Budget::usage_percent(),
            'token_usage_url'     => self::get_settings_tab_url('token-usage'),
            'onboarding'          => $this->get_onboarding_data(),
            'tabs'                => [
                'dashboard'   => $this->filter_tab_data('dashboard', $this->get_dashboard_data()),
                'model'       => $this->filter_tab_data('model', (new RSVL_Model_Admin())->get_tab_data('model' === $this->active_tab)),
                'training'    => $this->filter_tab_data('training', (new RSVL_Training_Admin())->get_tab_data('training' === $this->active_tab)),
                'appearance'  => $this->filter_tab_data('appearance', $this->get_appearance_data()),
                'visibility'  => $this->filter_tab_data('visibility', (new RSVL_Visibility_Admin())->get_tab_data('visibility' === $this->active_tab)),
                'chats'       => $this->filter_tab_data('chats', (new RSVL_Chats_Admin())->get_tab_data('chats' === $this->active_tab)),
                'analytics'   => $this->filter_tab_data('analytics', $this->get_analytics_data()),
                'token_usage' => $this->filter_tab_data('token_usage', $this->get_token_usage_data()),
            ],
        ]);
    }

    /**
     * Public so the dev-tools plugin can report the real onboarding state —
     * which steps are outstanding — instead of keeping its own copy of the
     * completion rules.
     */
    public function get_onboarding_data(): array
    {
        if (get_option('resolver_onboarding_dismissed', false)) {
            return ['dismissed' => true, 'all_done' => false];
        }

        $defaults  = RSVL_Settings::defaults();
        $provider  = $this->settings['chat_provider'] ?? '';
        $connected = '' !== $provider && self::is_provider_connected($provider);
        $base_url  = 'https://resolverchatbot.com/knowledgebase/';

        $instructions_changed = (
            ($this->settings['prompt_identity'] ?? '') !== $defaults['prompt_identity'] ||
            ($this->settings['prompt_rules'] ?? '') !== $defaults['prompt_rules'] ||
            ($this->settings['prompt_tone'] ?? '') !== $defaults['prompt_tone'] ||
            ($this->settings['prompt_fallback'] ?? '') !== $defaults['prompt_fallback']
        );

        $styles_changed = (
            ($this->settings['accent_color'] ?? '') !== $defaults['accent_color'] ||
            ($this->settings['bot_name'] ?? '') !== $defaults['bot_name'] ||
            ($this->settings['greeting_message'] ?? '') !== $defaults['greeting_message']
        );

        $steps = [
            [
                'key'      => 'install',
                'title'    => __('Install Resolver', 'resolver-ai-chatbot'),
                'desc'     => __('Resolver has been installed and activated on your site!', 'resolver-ai-chatbot'),
                'done'     => true,
                'tab'      => '',
                'docs_url' => '',
            ],
            [
                'key'      => 'connect',
                'title'    => __('Connect an AI platform', 'resolver-ai-chatbot'),
                'desc'     => __('Connecting to an AI platform requires entering an API key.', 'resolver-ai-chatbot'),
                'done'     => $connected,
                'tab'      => 'model',
                'docs_url' => $base_url . 'getting-started/connect-ai-platforms/',
            ],
            [
                'key'      => 'model',
                'title'    => __('Choose an AI model', 'resolver-ai-chatbot'),
                'desc'     => __('The AI model is the source of intelligence for your chatbot\'s replies.', 'resolver-ai-chatbot'),
                'done'     => '' !== ($this->settings['chat_model'] ?? ''),
                'tab'      => 'model',
                'docs_url' => $base_url . 'getting-started/choose-ai-model/',
            ],
            [
                'key'      => 'embedding',
                'title'    => __('Pick a training platform', 'resolver-ai-chatbot'),
                'desc'     => __('The training platform helps your chatbot find relevant content from your site.', 'resolver-ai-chatbot'),
                'done'     => '' !== ($this->settings['embedding_provider'] ?? ''),
                'tab'      => 'model',
                'docs_url' => $base_url . 'common-questions/what-is-embedding-provider/',
            ],
            [
                'key'      => 'train',
                'title'    => __('Train your chatbot', 'resolver-ai-chatbot'),
                'desc'     => __('Select the pages you want to train your chatbot with, so it can provide relevant answers to your visitors.', 'resolver-ai-chatbot'),
                'done'     => RSVL_Index::has_trained_content(),
                'tab'      => 'training',
                'docs_url' => $base_url . 'training/train-chatbot/',
            ],
            [
                'key'      => 'instructions',
                'title'    => __('Edit the instructions', 'resolver-ai-chatbot'),
                'desc'     => __('Give your chatbot a persona, set rules, and define its tone of voice.', 'resolver-ai-chatbot'),
                'done'     => $instructions_changed,
                'tab'      => 'training&panel=instructions',
                'docs_url' => $base_url . 'training/edit-chatbot-instructions/',
            ],
            [
                'key'      => 'styles',
                'title'    => __('Customize your chatbot', 'resolver-ai-chatbot'),
                'desc'     => __('Change the accent color, bot name, and greeting message to match your brand.', 'resolver-ai-chatbot'),
                'done'     => $styles_changed,
                'tab'      => 'appearance',
                'docs_url' => $base_url . 'getting-started/customize-chatbot/',
            ],
            [
                'key'      => 'launch',
                'title'    => __('Launch your new chatbot', 'resolver-ai-chatbot'),
                'desc'     => __('Choose where the chatbot should and shouldn\'t display, then publish it.', 'resolver-ai-chatbot'),
                'done'     => 'none' !== ($this->settings['display_mode'] ?? 'none'),
                'tab'      => 'visibility',
                'docs_url' => $base_url . 'getting-started/edit-visibility/',
            ],
        ];

        $done_count = count(array_filter($steps, function ($s) { return $s['done']; }));

        return [
            'dismissed'  => false,
            'steps'      => $steps,
            'done_count' => $done_count,
            'total'      => count($steps),
            'all_done'   => $done_count === count($steps),
            // Whether the floating checklist was closed, which admin.js keeps
            // in a cookie, so the page is sent with it already closed.
            'collapsed' => isset($_COOKIE['rsvl_onboarding_collapsed']) && '1' === sanitize_text_field(wp_unslash($_COOKIE['rsvl_onboarding_collapsed'])),
        ];
    }

    /**
     * Let other code add to a tab's data before it's rendered. Pro fills in
     * its training panels, analytics and dashboard charts this way.
     */
    private function filter_tab_data(string $tab, array $data): array
    {
        /**
         * Filter the data a settings tab is rendered with.
         *
         * @param array               $data Tab data; 'is_active' says whether it's the open tab.
         * @param RSVL_Settings_Page $page The settings page, for its helpers.
         */
        return (array) apply_filters("resolver_{$tab}_tab_data", $data, $this);
    }

    private function get_current_chat_provider(): string
    {
        return $this->settings['chat_provider'] ?? '';
    }

    /* ---------------------------------------------------------------------
     * Dashboard tab
     * ------------------------------------------------------------------- */

    private function get_dashboard_data(): array
    {
        $provider_id        = $this->get_current_chat_provider();
        $provider           = RSVL_Provider::get_provider($provider_id);
        $models             = $provider ? $provider->get_available_models() : [];
        $chat_model         = $this->settings['chat_model'] ?? '';
        $embedding_provider = self::get_current_embedding_provider();

        $data = [
            'is_active'              => 'dashboard' === $this->active_tab,
            'is_pro'                 => resolver_is_pro(),
            'provider_name'          => $provider ? $provider->get_name() : ($provider_id ? ucfirst($provider_id) : '—'),
            'model_label'            => $models[ $chat_model ] ?? ($chat_model ?: '—'),
            'model_connected'        => '' !== $chat_model,
            'provider_connected'     => self::is_provider_connected($provider_id),
            'embedding_model_label'  => $this->get_provider_name($embedding_provider) ?: '—',
            'embedding_connected'    => self::is_provider_connected($embedding_provider),
            'conversations_tab_url'  => self::get_settings_tab_url('chats'),
            'training_tab_url'       => self::get_settings_tab_url('training'),
            'token_usage_tab_url'    => self::get_settings_tab_url('token-usage'),
            'help_tab_url'           => self::get_settings_tab_url('help'),
            'total_conversations'    => 0,
            'trained_page_count'     => 0,
            'tokens_used_30d'        => 0,
            'recent_conversations'   => [],
            'recently_trained_pages' => [],
            'chart'                  => ['labels' => [], 'embedding' => [], 'input' => [], 'output' => []],
            'show_token_chart'       => false,
        ];

        if (! $data['is_active']) {
            return $data;
        }

        $stats        = RSVL_Index::get_stats();
        $token_series = $this->build_daily_token_series(...self::get_calendar_period_range('30'));

        $data['total_conversations']    = $this->conversations->get_conversation_count('all');
        $data['trained_page_count']     = (int) $stats['total_posts'];
        $data['tokens_used_30d']        = (int) array_sum($token_series['input']) + (int) array_sum($token_series['output']);
        $data['recent_conversations']   = $this->get_recent_conversation_summaries(4);
        $data['recently_trained_pages'] = $this->get_recently_trained_pages(4);
        $data['chart']                  = $token_series;
        $data['show_token_chart']       = (bool) (array_sum($token_series['input']) + array_sum($token_series['output']) + array_sum($token_series['embedding']));

        return $data;
    }

    /** A provider's name, or '' for none. */
    private function get_provider_name(string $provider_id): string
    {
        $provider = RSVL_Provider::get_provider($provider_id);

        return $provider ? $provider->get_name() : '';
    }

    /**
     * Latest conversations, formatted for a dashboard list section.
     */
    private function get_recent_conversation_summaries(int $limit): array
    {
        $summaries = [];

        foreach ($this->conversations->get_conversation_sessions($limit, 0) as $session) {
            $preview = wp_trim_words($session['first_message'], 12, '…');

            $summaries[] = [
                // Rendered as data-session on the row. The pages list that
                // shares this template has no session and simply omits it.
                'session_id' => $session['session_id'],
                'url'        => RSVL_Admin::tab_url('chats', ['open_session' => $session['session_id']]),
                'preview'    => $preview ?: __('(no message)', 'resolver-ai-chatbot'),
                'external'   => false,
                'meta'       => [
                    ['text' => wp_date(get_option('date_format'), strtotime($session['updated_at'])), 'class' => ''],
                    ['text' => wp_date(get_option('time_format'), strtotime($session['updated_at'])), 'class' => ''],
                ],
            ];
        }

        return $summaries;
    }

    /**
     * Most recently trained posts, formatted for a dashboard list section.
     */
    private function get_recently_trained_pages(int $limit): array
    {
        $pages = [];
        foreach (RSVL_Index::get_recent_posts($limit) as ['post' => $post, 'indexed_at' => $indexed_at]) {
            $pages[] = [
                // Rendered as data-post-id on the row. The chats list that
                // shares this template has no post and simply omits it.
                'post_id'  => (int) $post->ID,
                'url'      => get_edit_post_link($post->ID) ?: (string) get_permalink($post->ID),
                'preview'  => get_the_title($post) ?: __('(untitled)', 'resolver-ai-chatbot'),
                'external' => true,
                'meta'     => [
                    ['text' => wp_date(get_option('date_format'), strtotime($indexed_at)), 'class' => ''],
                    ['text' => wp_date(get_option('time_format'), strtotime($indexed_at)), 'class' => ''],
                ],
            ];
        }

        return $pages;
    }

    /* ---------------------------------------------------------------------
     * Appearance tab
     * ------------------------------------------------------------------- */

    private function get_appearance_data(): array
    {
        $is_active = 'appearance' === $this->active_tab;

        return [
            'is_active'        => $is_active,
            'is_pro'           => resolver_is_pro(),
            'model_configured' => $is_active && $this->settings['chat_model'] !== ''
                && self::is_provider_connected($this->settings['chat_provider']),
            'has_training_data' => $is_active && RSVL_Index::has_sources(),
            'model_tab_url'     => self::get_settings_tab_url('model'),
            'training_tab_url'  => self::get_settings_tab_url('training'),
            'accent_color'      => $this->settings['accent_color'],
            'bot_name'          => $this->settings['bot_name'],
            'greeting_message'  => $this->settings['greeting_message'],
            'position'          => $this->settings['position'] ?? 'bottom-right',
            'show_attribution'  => ! empty($this->settings['show_attribution']),
        ];
    }

    /* ---------------------------------------------------------------------
     * Analytics tab
     * ------------------------------------------------------------------- */

    /**
     * The Analytics tab only shows the Pro upgrade notice here; Pro replaces
     * its template and fills in the data.
     */
    private function get_analytics_data(): array
    {
        return [
            'is_active' => 'analytics' === $this->active_tab,
            'is_pro'    => resolver_is_pro(),
        ];
    }

    /* ---------------------------------------------------------------------
     * Token Usage tab
     * ------------------------------------------------------------------- */

    private function get_token_usage_data(): array
    {
        $period = self::get_calendar_period('tu_period', 'this_month');
        $limit  = (int) ($this->settings['monthly_token_limit'] ?? 0);

        $data = [
            'is_active'      => 'token-usage' === $this->active_tab,
            'period_filters' => self::build_calendar_period_filters('token-usage', 'tu_period', $period),
            'limit'          => $limit,
            'limit_preset'   => in_array($limit, [0, 100000, 500000, 1000000, 2000000, 5000000], true) ? (string) $limit : 'custom',
            'limit_presets'  => $this->get_token_limit_presets(),
            'portal'         => $this->get_provider_usage_portal(),
            'alert_enabled'  => ! empty($this->settings['token_alert_enabled']),
            'alert_email'    => $this->settings['token_alert_email'] !== '' ? $this->settings['token_alert_email'] : get_option('admin_email'),
            'chart'          => ['labels' => [], 'embedding' => [], 'input' => [], 'output' => []],
            'has_chart_data' => false,
        ];

        if (! $data['is_active']) {
            return $data;
        }

        list($since, $until) = self::get_calendar_period_range($period);

        $data['chart']          = $this->build_daily_token_series($since, $until);
        $data['has_chart_data'] = array_sum($data['chart']['embedding']) > 0 || array_sum($data['chart']['input']) > 0 || array_sum($data['chart']['output']) > 0;

        return $data;
    }

    /**
     * Daily chat and indexing token totals over an inclusive date range, with
     * missing days filled with zeros so the chart has a continuous axis.
     */
    private function build_daily_token_series(string $since, string $until): array
    {
        $by_day = [];
        foreach (RSVL_Analytics::get_daily_token_usage($since, $until) as $row) {
            $by_day[ $row['day'] ]['input']  = (int) $row['prompt_tokens'];
            $by_day[ $row['day'] ]['output'] = (int) $row['completion_tokens'];
        }
        foreach (RSVL_Analytics::get_daily_indexing_token_usage($since, $until) as $row) {
            $by_day[ $row['day'] ]['embedding'] = (int) $row['total_tokens'];
        }

        $days = resolver_daily_rows($since, $until, $by_day, ['embedding' => 0, 'input' => 0, 'output' => 0]);

        return [
            'labels'    => array_map('resolver_day_label', array_column($days, 'date')),
            'embedding' => array_column($days, 'embedding'),
            'input'     => array_column($days, 'input'),
            'output'    => array_column($days, 'output'),
        ];
    }

    private function get_token_limit_presets(): array
    {
        return [
            '0'       => __('No Limit', 'resolver-ai-chatbot'),
            '100000'  => __('100K', 'resolver-ai-chatbot'),
            '500000'  => __('500K', 'resolver-ai-chatbot'),
            '1000000' => __('1M', 'resolver-ai-chatbot'),
            '2000000' => __('2M', 'resolver-ai-chatbot'),
            '5000000' => __('5M', 'resolver-ai-chatbot'),
            'custom'  => __('Custom', 'resolver-ai-chatbot'),
        ];
    }

    /**
     * Billing/usage dashboard link for the current chat provider.
     */
    private function get_provider_usage_portal(): array
    {
        $provider = RSVL_Provider::get_provider($this->get_current_chat_provider());

        return $provider ? $provider->get_usage_portal() : [];
    }

    /* ---------------------------------------------------------------------
     * Shared helpers
     * ------------------------------------------------------------------- */

    public static function is_provider_connected(string $provider): bool
    {
        $provider = RSVL_Provider::get_provider($provider);

        return $provider && $provider->is_connected();
    }

    public static function get_current_embedding_provider(): string
    {
        return (string) resolver_get_setting('embedding_provider');
    }

    /** Whether the embedding provider is connected, which training and retraining need. */
    public static function is_embedding_connected(): bool
    {
        return self::is_provider_connected(self::get_current_embedding_provider());
    }

    public static function get_settings_tab_url(string $tab): string
    {
        return add_query_arg(['page' => RSVL_Admin::PAGE, 'tab' => $tab]);
    }

    /**
     * Read a validated calendar period from a query parameter, defaulting to $default.
     */
    public static function get_calendar_period(string $param, string $default): string
    {
        $value = isset($_GET[ $param ]) ? sanitize_text_field(wp_unslash($_GET[ $param ])) : '';

        return in_array($value, self::CALENDAR_PERIODS, true) ? $value : $default;
    }

    /**
     * Resolve a calendar period to an inclusive [since, until] range of the
     * site's calendar days (Y-m-d). Queries turn these into UTC bounds with
     * resolver_utc_bounds().
     */
    public static function get_calendar_period_range(string $period): array
    {
        // Every boundary below is derived from today's date, so a caller that
        // needs deterministic windows — an automated test asserting on "This
        // Month" — can pin the whole calendar through resolver_current_time,
        // rather than reimplementing the month arithmetic somewhere else. The
        // arithmetic itself is on dates alone, so it's done in UTC, which has
        // no daylight saving days to trip over.
        $today       = resolver_today();
        $month_start = substr($today, 0, 8) . '01';

        switch ($period) {
            case 'this_month':
                return [$month_start, $today];

            case 'last_month':
                $last_month_end = gmdate('Y-m-d', strtotime($month_start . ' UTC') - DAY_IN_SECONDS);

                return [substr($last_month_end, 0, 8) . '01', $last_month_end];

            default:
                $days = (int) $period;

                return [gmdate('Y-m-d', strtotime($today . ' UTC') - ($days - 1) * DAY_IN_SECONDS), $today];
        }
    }

    /**
     * Period filter buttons (This Month/Last Month/7d/30d/60d/90d) for the analytics-style tabs.
     */
    public static function build_calendar_period_filters(string $tab, string $param, string $current): array
    {
        $labels = [
            'this_month' => __('This Month', 'resolver-ai-chatbot'),
            'last_month' => __('Last Month', 'resolver-ai-chatbot'),
        ];

        $query_base = ['page' => RSVL_Admin::PAGE, 'tab' => $tab];
        $panel      = isset($_GET['panel']) ? sanitize_key($_GET['panel']) : '';
        if ('' !== $panel) {
            $query_base['panel'] = $panel;
        }

        $filters = [];
        foreach (self::CALENDAR_PERIODS as $value) {
            $filters[] = [
                /* translators: %s: number of days. Short label for a period filter button, e.g. "30d" for the last 30 days. */
                'label'  => $labels[ $value ] ?? sprintf(__('%sd', 'resolver-ai-chatbot'), number_format_i18n((int) $value)),
                'url'    => add_query_arg(array_merge($query_base, [$param => $value])),
                'active' => $value === $current,
            ];
        }

        return $filters;
    }

    public static function get_post_type_icon(string $type_slug): array
    {
        if (isset(self::POST_TYPE_ICONS[ $type_slug ])) {
            return ['type' => 'dashicon', 'value' => self::POST_TYPE_ICONS[ $type_slug ]];
        }

        $post_type = get_post_type_object($type_slug);
        $icon      = $post_type->menu_icon ?? '';

        if ('' === $icon || null === $icon) {
            return ['type' => 'dashicon', 'value' => 'dashicons-admin-generic'];
        }

        if (str_starts_with($icon, 'dashicons-')) {
            return ['type' => 'dashicon', 'value' => $icon];
        }

        return ['type' => 'url', 'value' => $icon];
    }

    /**
     * Public post types eligible for training and visibility settings.
     */
    public static function get_public_post_types(): array
    {
        $post_types = get_post_types(['public' => true], 'objects');
        unset($post_types['attachment']);

        return $post_types;
    }

    /**
     * Sort comparator: pages first, posts second, everything else alphabetical.
     */
    public static function compare_post_type_priority(string $a, string $b): int
    {
        $priority_a = self::POST_TYPE_SORT_PRIORITY[ $a ] ?? 99;
        $priority_b = self::POST_TYPE_SORT_PRIORITY[ $b ] ?? 99;

        return $priority_a !== $priority_b ? $priority_a - $priority_b : strcmp($a, $b);
    }
}