<?php
namespace JVBase\managers\Notifications;

use JVBase\managers\Cache;
use JVBase\managers\CustomTable;
use JVBase\meta\Meta;
use JVBase\registrar\Registrar;
use WP_Error;
use WP_Query;

if (!defined('ABSPATH')) {
	exit; // Exit if accessed directly
}
/**
 * EmailDigests
 *  Prepares the email digest for daily/weekly/monthly email summaries
 **/
class EmailDigests
{
	protected string $campaign;
	protected Cache $terms;
	protected Cache $users;
	protected CustomTable $userIndex;
	protected CustomTable $termIndex;
	public function __construct()
	{
		$this->registerCron();
		$this->registerTable();

		add_filter(BASE . 'handle_bulk_operation', [ $this, 'processOperation' ], 10, 3);
	}

	protected function registerCron():void
	{
		add_action(BASE . 'notification_digest_daily', [ $this, 'runDailyDigests' ]);
		add_action(BASE . 'notification_digest_weekly', [ $this, 'runWeeklyDigests' ]);
		add_action(BASE . 'notification_digest_monthly', [ $this, 'runMonthlyDigests' ]);
	}

	protected function registerTable():void
	{
		$this->registerUserIndex();
		$this->registerTermIndex();
	}
		protected function registerUserIndex():void
		{
			$table = CustomTable::for('user_notification_email_digest');
//		$types = implode(',',array_map(function($item) { return "'{$item}'"; }, Registrar::getFeatured('favouritable')));
			$table->setColumns([
				'id'			=> 'bigint(20) unsigned NOT NULL AUTO_INCREMENT',
				'user_id'		=> "{$table->getUserIDType()} NOT NULL",
				'frequency'		=> "ENUM('daily', 'weekly', 'monthly') NOT NULL",
				'content_ids'	=> 'JSON DEFAULT NULL',
				'output'		=> 'TEXT DEFAULT NULL',
				'total_sent'	=> 'int unsigned DEFAULT 0',
				'created_at'	=> 'datetime DEFAULT CURRENT_TIMESTAMP',
			]);

			$table->setKeys([
				['key' => 'PRIMARY', 'value' => '(`id`)'],
				['key' => 'UNIQUE', 'value' => '`user_frequency` (`user_id`, `frequency`)'],
				'user_id (`user_id`)'
			]);
			$base = BASE;
			$table->setConstraints([
				"CONSTRAINT `{$base}digest_user` FOREIGN KEY (`user_id`)
			REFERENCES `{$table->getUserTable()}` (`ID`) ON DELETE CASCADE"
			]);

			$table->defineTable();
			$this->userIndex = $table;
		}
		protected function registerTermIndex():void
		{
			$table = CustomTable::for('user_notification_email_digest');
			$types = implode(',',array_map(function($item) { return "'{$item}'"; }, Registrar::getFeatured('favouritable', 'term')));
			$table->setColumns([
				'id'			=> 'bigint(20) unsigned NOT NULL AUTO_INCREMENT',
				'term_id'		=> "{$table->getTermIDType()} NOT NULL",
				'type'			=> "ENUM({$types}) NOT NULL",
				'frequency'		=> "ENUM('daily', 'weekly', 'monthly') NOT NULL",
				'content_ids'	=> 'JSON DEFAULT NULL',
				'output'		=> 'TEXT DEFAULT NULL',
				'total_sent'	=> 'int unsigned DEFAULT 0',
				'created_at'	=> 'datetime DEFAULT CURRENT_TIMESTAMP',
			]);

			$table->setKeys([
				['key' => 'PRIMARY', 'value' => '(`id`)'],
				['key' => 'UNIQUE', 'value' => '`term_frequency` (`term_id`, `type`, `frequency`)'],
				'term_id (`term_id`)'
			]);
			$base = BASE;
			$table->setConstraints([
				"CONSTRAINT `{$base}digest_term` FOREIGN KEY (`term_id`)
				REFERENCES `{$table->getTermTable()}` (`term_id`) ON DELETE CASCADE"
			]);

			$table->defineTable();
			$this->termIndex = $table;
		}

	public function runDailyDigests():void
	{
		$this->campaign = 'daily_digest_' .date('Y-m-d');
		$this->processDigest('daily');
	}
	public function runWeeklyDigests():void
	{
		$this->campaign = 'weekly_digest_'.date('Y-m-d');
		$this->processDigest('weekly');
	}

	public function runMonthlyDigests():void
	{
		$this->campaign = 'monthly_digest_'.date('Y-m-d');
		$this->processDigest('monthly');
	}

	protected function processDigest(string $frequency):void
	{
		$users = $this->getUsers($frequency);
		if (empty($users)){
			return;
		}

		JVB()->queue()->add(
			'email_notification_digest',
			0,
			[
				'frequency' => $frequency,
				'users'		=> $users,
			],
			[
				'chunk_key'	=> 'users',
				'chunk_size'=> 20,
				'operation_id'=> 'notification_digest_'.date('Y_m_d_His')
			]
		);
	}

	public function getUsers(string $frequency):array
	{
		if (!in_array($frequency, ['never', 'daily', 'weekly', 'monthly'])) {
			return [];
		}
		return JVB()->notification()->getUsersByFrequency($frequency);
	}

	public function processOperation(WP_Error|array $result, object $operation, array $data):WP_Error|array
	{
		if ($operation->type !== 'email_notification_digest') {
			return $result;
		}

		$results = [];
		foreach ($data['user'] as $userID) {
			$result = $this->generateUserDigest($userID, $data['frequency']);
			if ($result) {
				$results[$userID] = $result;
			}
			usleep(50);
		}

		return [
			'success'	=> true,
			'result'	=> $results
		];
	}
	protected function getSinceDate(string $frequency):string
	{
		return match ($frequency) {
			'weekly' => '-1 week',
			'monthly' => '-1 month',
			default => '-1 day',
		};
	}

	protected function generateUserDigest(int $userID, string $frequency):string|false
	{
		$subscription = JVB()->notification()->getUserSubscriptions($userID, $frequency);

		//TODO
		$notifications = JVB()->notification()->getUserNotifications($userID);

		if (empty($subscription) && empty($notifications)) {
			return false;
		}
		$content = '';
		foreach ($subscription as $item) {
			$temp = match ($item['item_type']) {
				array_merge(['user'], Registrar::getFeatured('favouritable', 'user')) => $this->getUserUpdates($item['item_id'], $frequency),
				Registrar::getFeatured('favouritable', 'term') => $this->getTermUpdates($item['item_id'], $item['item_type'], $frequency),
				default => false,
			};
			if ($temp) {
				$content .= $temp;
			}
		}
		if (empty($content)) {
			return false;
		}
		return $content;
	}

	protected function getUserUpdates(int $userID, string $frequency):string|false
	{
		$frequency = strtolower($frequency);
		$frequency = in_array($frequency, ['daily', 'weekly', 'monthly']) ? $frequency : 'daily';
		$user = get_userdata($userID);
		if (!$user || is_wp_error($user)) {
			return false;
		}
		$since = $this->getSinceDate($frequency);

		$entry = $this->userIndex->get([
			'user_id'	=> $userID,
			'frequency'	=> $frequency
		]);
		if ($entry) {
			return $entry->output;
		}
		$new = [
			'user_id'	=> $userID,
			'frequency'	=> $frequency,
		];
		//Didn't do it yet, create it here
		$IDs = Content::forUser($userID, $since);
		$new['content_ids'] = json_encode($IDs);
		$new['output'] = $this->contentForUser($userID, $IDs);

		$this->userIndex->insert($new);
		return $new['output'];
	}

	protected function contentForUser(int $userID, array $IDs):string
	{
		if (empty($IDs)) {
			return '';
		}
		$user = get_userdata($userID);
		if (!$user || is_wp_error($user)) {
			return '';
		}
		$role = jvbUserRole($userID);
		$registrar = Registrar::getInstance($role);
		if (!$registrar) {
			return '';
		}
		if ($registrar->profile_link) {
			$meta = Meta::forPost(jvbUserProfileLink($userID));
			$title = $meta->get('post_title');
			$goTo = get_the_permalink(jvbUserProfileLink($userID));
		}else {
			$meta = Meta::forUser($userID);
			$title = $meta->get('display_name');
			$goTo = get_author_posts_url($userID);
		}

		$output = [];

		$count = count($IDs);
		$max = (min($count, 5));
		$canIncrease = $count > $max;
		for ($i = 0; $i <=$max; $i++) {
			$ID = $IDs[$i];
			$m = Meta::forPost($ID);
			$img = $m->get('post_thumbnail');
			if (empty($img)) {
				if ($canIncrease){
					$max++;
				}
				continue;
			}
			$image =  wp_get_attachment_image_src($img, 'medium');
			if (!$image) {
				if ($canIncrease){
					$max++;
				}
				continue;
			}
			$url = get_the_permalink($ID);
			$image = sprintf(
				'<a href="%s">%s</a>',
				$url,
				JVB()->email()->image($image[0], get_post_meta($img, '_wp_attachment_image_alt', true))
			);
			$t = sprintf(
				'<a href="%s">%s</a>',
				$url,
				$m->get('post_title')
			);
			$output[] = JVB()->email()->card($image, $t);
		}

		$final = JVB()->email()->button($goTo, 'Want to See More?');
		return JVB()->email()->grid($output, 3, 'New from '.$title,'',$final);
	}

	protected function getTermUpdates(int $termID, string $type, string $frequency):string|false
	{
		$frequency = strtolower($frequency);
		$frequency = in_array($frequency, ['daily', 'weekly', 'monthly']) ? $frequency : 'daily';
		$taxonomy = jvbCheckBase($type);
		$term = get_term($termID, $taxonomy);
		if (!$term || is_wp_error($term)) {
			return false;
		}
		$since = $this->getSinceDate($frequency);

		$entry = $this->termIndex->get([
			'term_id'	=> $termID,
			'type'		=> $type,
			'frequency'	=> $frequency
		]);
		if ($entry) {
			return $entry->output;
		}
		$new = [
			'term_id'	=> $termID,
			'type'		=> $type,
			'frequency'	=> $frequency
		];
		//Didn't do it yet, create it here
		$IDs = Content::forTerm($termID, $taxonomy, $since);
		$new['content_ids'] = json_encode($IDs);
		$new['output'] = $this->contentForTerm($termID, $type, $IDs);

		$this->termIndex->insert($new);
		return $new['output'];
	}

	protected function contentForTerm(int $termID, string $tax, array $IDs):string
	{
		if (empty($IDs)) {
			return '';
		}
		$taxonomy = jvbCheckBase($tax);
		$term = get_term($termID, $taxonomy);
		if (!$term || is_wp_error($term)) {
			return '';
		}
		$registrar = Registrar::getInstance($tax);
		if (!$registrar) {
			return '';
		}
		$meta = Meta::forTerm($termID);
		$title = $meta->get('name');

		$goTo = get_term_link($termID,$taxonomy);

		$output = [];

		$count = count($IDs);
		$max = (min($count, 5));
		$canIncrease = $count > $max;
		for ($i = 0; $i <=$max; $i++) {
			$ID = $IDs[$i];
			$m = Meta::forPost($ID);
			$img = $m->get('post_thumbnail');
			if (empty($img)) {
				if ($canIncrease){
					$max++;
				}
				continue;
			}
			$image =  wp_get_attachment_image_src($img, 'medium');
			if (!$image) {
				if ($canIncrease){
					$max++;
				}
				continue;
			}
			$url = get_the_permalink($ID);
			$image = sprintf(
				'<a href="%s">%s</a>',
				$url,
				JVB()->email()->image($image[0], get_post_meta($img, '_wp_attachment_image_alt', true))
			);
			$t = sprintf(
				'<a href="%s">%s</a>',
				$url,
				$m->get('post_title')
			);
			$output[] = JVB()->email()->card($image, $t);
		}

		$final = JVB()->email()->button($goTo, 'See More');
		return JVB()->email()->grid($output, 3, 'New in '.$title, '', $final);
	}
}