<?php

declare(strict_types=1);

namespace app\common\service\qywx;

use app\common\model\QywxExternalContact;
use app\common\model\QywxMediaChannel;
use think\facade\Db;
use think\db\Query;

class MediaChannelService
{
    /**
     * @return array<int, array{code: string, name: string}>
     */
    public static function getOptions(): array
    {
        $rows = QywxMediaChannel::where('status', 1)
            ->field('channel_code, channel_name')
            ->order('channel_name asc, id asc')
            ->select()
            ->toArray();

        return array_map(static fn (array $row): array => [
            'code' => (string) ($row['channel_code'] ?? ''),
            'name' => (string) ($row['channel_name'] ?? ''),
        ], $rows);
    }

    public static function getDefaultCode(): string
    {
        return (string) QywxMediaChannel::where('status', 1)
            ->order('id asc')
            ->value('channel_code');
    }

    public static function isValidCode(string $channelCode): bool
    {
        $channelCode = trim($channelCode);
        if ($channelCode === '') {
            return false;
        }

        return QywxMediaChannel::where('status', 1)
            ->where('channel_code', $channelCode)
            ->count() > 0;
    }

    public static function normalizeStatsCode(string $channelCode): string
    {
        return self::isValidCode($channelCode) ? trim($channelCode) : '';
    }

    /**
     * @return array<string, mixed>|null
     */
    public static function getChannelByCode(string $channelCode): ?array
    {
        $channelCode = trim($channelCode);
        if ($channelCode === '') {
            return null;
        }

        $row = QywxMediaChannel::where('status', 1)
            ->where('channel_code', $channelCode)
            ->find();

        return $row ? $row->toArray() : null;
    }

    public static function getNameByCode(string $channelCode): string
    {
        $channel = self::getChannelByCode($channelCode);
        return (string) ($channel['channel_name'] ?? '');
    }

    /**
     * 挂号老数据渠道：doctor_appointment.channels 对应 dict_data(type_value=channels) 的 value。
     *
     * @param array<string, mixed>|null $channel
     * @return int[]
     */
    public static function getLegacyAppointmentChannelValues(?array $channel): array
    {
        if ($channel === null) {
            return [];
        }

        $names = array_values(array_unique(array_filter([
            trim((string) ($channel['channel_name'] ?? '')),
            trim((string) ($channel['source_tag_name'] ?? '')),
        ])));

        if ($names === []) {
            return [];
        }

        $rows = Db::name('dict_data')
            ->where('type_value', 'channels')
            ->whereIn('name', $names)
            ->column('value');

        return array_values(array_filter(array_map('intval', $rows), static fn (int $value): bool => $value > 0));
    }

    /**
     * @param array<string, mixed>|null $channel
     */
    public static function applyFollowUsersChannelFilter(Query $query, string $field, ?array $channel): void
    {
        if ($channel === null) {
            return;
        }

        $patterns = self::buildLikePatterns($channel);
        if ($patterns === []) {
            $query->whereRaw('1 = 0');
            return;
        }

        $segments = [];
        $bindings = [];
        foreach ($patterns as $pattern) {
            $segments[] = $field . ' LIKE ?';
            $bindings[] = $pattern;
        }

        $query->whereRaw('(' . implode(' OR ', $segments) . ')', $bindings);
    }

    /**
     * @return array{scanned_contacts: int, discovered_tags: int, inserted_or_updated: int}
     */
    public static function scanFromContacts(int $batchSize = 200): array
    {
        $lastId = 0;
        $scannedContacts = 0;
        $discoveredTags = [];
        $upserted = 0;
        $now = time();

        while (true) {
            $rows = QywxExternalContact::where('id', '>', $lastId)
                ->field('id, follow_users')
                ->order('id asc')
                ->limit($batchSize)
                ->select()
                ->toArray();

            if ($rows === []) {
                break;
            }

            foreach ($rows as $row) {
                $lastId = (int) ($row['id'] ?? 0);
                if ($lastId <= 0) {
                    continue;
                }

                $scannedContacts++;
                $followUsers = json_decode((string) ($row['follow_users'] ?? '[]'), true);
                $followUsers = is_array($followUsers) ? $followUsers : [];

                foreach (self::extractTagsFromFollowUsers($followUsers) as $tag) {
                    $tagKey = self::buildTagUniqKey($tag['source_tag_id'], $tag['source_tag_name']);
                    if ($tagKey === '' || isset($discoveredTags[$tagKey])) {
                        continue;
                    }

                    $discoveredTags[$tagKey] = true;
                    $channelCode = self::buildChannelCode($tag['source_tag_id'], $tag['source_tag_name']);
                    $channelName = $tag['source_tag_name'] !== '' ? $tag['source_tag_name'] : $tag['source_tag_id'];

                    $rowData = [
                        'channel_code' => $channelCode,
                        'channel_name' => $channelName,
                        'source_tag_id' => $tag['source_tag_id'],
                        'source_tag_name' => $tag['source_tag_name'],
                        'source_group_name' => $tag['source_group_name'],
                        'tag_uniq_key' => $tagKey,
                        'status' => 1,
                        'last_seen_time' => $now,
                        'create_time' => $now,
                        'update_time' => $now,
                    ];

                    Db::name('qywx_media_channel')->duplicate([
                        'channel_name',
                        'source_tag_id',
                        'source_tag_name',
                        'source_group_name',
                        'status',
                        'last_seen_time',
                        'update_time',
                    ])->insert($rowData);
                    $upserted++;
                }
            }
        }

        return [
            'scanned_contacts' => $scannedContacts,
            'discovered_tags' => count($discoveredTags),
            'inserted_or_updated' => $upserted,
        ];
    }

    /**
     * @param array<string, mixed> $channel
     * @return string[]
     */
    private static function buildLikePatterns(array $channel): array
    {
        $patterns = [];
        $tagId = trim((string) ($channel['source_tag_id'] ?? ''));
        $tagName = trim((string) ($channel['source_tag_name'] ?? ''));

        if ($tagId !== '') {
            $escapedTagId = addcslashes($tagId, '%_\\');
            $patterns[] = '%"tag_id":"' . $escapedTagId . '"%';
            $patterns[] = '%"id":"' . $escapedTagId . '"%';
        }

        if ($tagName !== '') {
            $escapedTagName = addcslashes($tagName, '%_\\');
            $patterns[] = '%"name":"' . $escapedTagName . '"%';
            $patterns[] = '%"tag_name":"' . $escapedTagName . '"%';
        }

        return array_values(array_unique($patterns));
    }

    /**
     * @param array<int, mixed> $followUsers
     * @return array<int, array{source_tag_id: string, source_tag_name: string, source_group_name: string}>
     */
    private static function extractTagsFromFollowUsers(array $followUsers): array
    {
        $tags = [];
        foreach ($followUsers as $followUser) {
            if (!is_array($followUser)) {
                continue;
            }

            $rawTags = $followUser['tags'] ?? [];
            if (!is_array($rawTags)) {
                continue;
            }

            foreach ($rawTags as $tag) {
                if (!is_array($tag)) {
                    continue;
                }

                $tagId = trim((string) ($tag['tag_id'] ?? $tag['id'] ?? ''));
                $tagName = trim((string) ($tag['name'] ?? $tag['tag_name'] ?? ''));
                $groupName = trim((string) ($tag['group_name'] ?? ''));
                $uniqKey = self::buildTagUniqKey($tagId, $tagName);
                if ($uniqKey === '') {
                    continue;
                }

                $tags[$uniqKey] = [
                    'source_tag_id' => $tagId,
                    'source_tag_name' => $tagName,
                    'source_group_name' => $groupName,
                ];
            }
        }

        return array_values($tags);
    }

    private static function buildTagUniqKey(string $tagId, string $tagName): string
    {
        $tagId = trim($tagId);
        $tagName = trim($tagName);
        if ($tagId !== '') {
            return 'tag_id:' . $tagId;
        }
        if ($tagName !== '') {
            return 'tag_name:' . md5(mb_strtolower($tagName, 'UTF-8'));
        }

        return '';
    }

    private static function buildChannelCode(string $tagId, string $tagName): string
    {
        $tagId = trim($tagId);
        if ($tagId !== '') {
            return 'tag_' . preg_replace('/[^A-Za-z0-9_\-]/', '_', $tagId);
        }

        $normalizedName = trim(mb_strtolower($tagName, 'UTF-8'));
        return 'tagname_' . substr(md5($normalizedName), 0, 16);
    }
}