<?php

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

class AdGhost_Sidebar_Handler {

    private $seen = [];

    private $target = null;

    private $placed = [];

    public function init() {
        add_action('widgets_init', function () {
            if (class_exists('AdGhost_Ad_Widget')) {
                register_widget('AdGhost_Ad_Widget');
            }
        });

        if (!$this->units()) {
            return;
        }
        add_filter('dynamic_sidebar_params', [$this, 'inject']);
    }

    public function inject($params) {
        if (empty($params[0]['id']) || is_admin() || !AdGhost_Helper::ads_live()) {
            return $params;
        }

        $sidebar = (string) $params[0]['id'];
        $position = $this->seen[$sidebar] = ($this->seen[$sidebar] ?? 0) + 1;

        $total = 0;
        $all = get_option('sidebars_widgets', []);
        if (is_array($all)) {
            $total = isset($all[$sidebar]) ? count((array) $all[$sidebar]) : 0;
        }

        foreach ($this->units() as $i => $unit) {
            if (isset($this->placed[$i])) {
                continue;
            }

            $pinned = trim((string) ($unit['sidebarId'] ?? ''));
            if ($pinned !== '') {
                if ($pinned !== $sidebar) {
                    continue;
                }
            } else {

                if ($this->target === null) {
                    $this->target = self::primary_sidebar() ?? $sidebar;
                }
                if ($this->target !== $sidebar) {
                    continue;
                }
            }

            $after = max(1, absint($unit['insertionValue'] ?? 1));
            if ($total > 0) {
                $after = min($after, $total);
            }
            if ($position !== $after) {
                continue;
            }

            $this->placed[$i] = true;

            if (class_exists('AdGhost_Targeting')
                && (AdGhost_Targeting::page_exclusion_reason() !== null || AdGhost_Targeting::unit_exclusion_reason($unit) !== null)) {
                continue;
            }
            if (class_exists('AdGhost_IVT_Manager') && !AdGhost_IVT_Manager::ads_allowed()) {
                continue;
            }

            $index = AdGhost_Placement_State::get_zone_count('sidebar');
            if (!$this->budget_left()) {
                continue;
            }
            AdGhost_Placement_State::mark_block_inserted('sidebar_' . $index, 'sidebar', [
                'unit_name' => $unit['name'] ?? 'sidebar',
            ]);

            $params[0]['after_widget'] = ($params[0]['after_widget'] ?? '')
                . AdGhost_Ad_Container::render($unit, 'sidebar', $index);
        }

        return $params;
    }

    public static function primary_sidebar() {
        global $wp_registered_sidebars;
        if (empty($wp_registered_sidebars) || !is_array($wp_registered_sidebars)) {
            return null;
        }
        $active = function ($id) {
            return function_exists('is_active_sidebar') ? is_active_sidebar($id) : true;
        };

        foreach (['sidebar-1', 'sidebar', 'primary', 'primary-sidebar', 'main-sidebar', 'sidebar-primary', 'right-sidebar', 'blog-sidebar'] as $id) {
            if (isset($wp_registered_sidebars[$id]) && $active($id)) {
                return $id;
            }
        }
        foreach ($wp_registered_sidebars as $id => $area) {
            $label = strtolower($id . ' ' . ($area['name'] ?? ''));
            if (preg_match('/sidebar|primary/', $label) && !preg_match('/footer|header|bottom|top|content|below|above|shop|off-?canvas/', $label) && $active($id)) {
                return (string) $id;
            }
        }
        return null;
    }

    private function budget_left() {
        $max = absint(get_option('adghost_max_ads_per_page', 5));
        if ($max <= 0) {
            return true;
        }
        $placed = 0;
        foreach (AdGhost_Placement_Engine::CAPPED_ZONES as $zone) {
            $placed += AdGhost_Placement_State::get_zone_count($zone);
        }
        return $placed < $max;
    }

    private function units() {
        static $units = null;
        if ($units === null) {
            $units = array_values(array_filter(AdGhost_Helper::units(), function ($unit) {
                return ($unit['placementMode'] ?? 'auto') !== 'manual'
                    && AdGhost_Helper::get_unit_position($unit) === 'sidebar';
            }));
        }
        return $units;
    }
}