<?php

declare(strict_types=1);

namespace App\Services;

use Illuminate\Http\Client\PendingRequest;
use Illuminate\Http\Client\Response;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use RuntimeException;

final class MailwizzService
{
    public function __construct(
        private readonly string $apiKey,
        private readonly string $baseUrl = 'https://www.mailwizz.nl/api'
    ) {}

    private function client(): PendingRequest
    {
        return Http::withHeaders(['X-Api-Key' => $this->apiKey])->asForm();
    }

    private function logInteraction(string $action, string $url, Response $response): void
    {
        Log::debug('Mailwizz API', [
            'action' => $action,
            'url' => $url,
            'http_status' => $response->status(),
            'response_preview' => mb_substr($response->body(), 0, 2000),
        ]);
    }

    /**
     * @return list<array{list_uid: string, name: string}>
     */
    public function getLists(): array
    {
        $url = "{$this->baseUrl}/lists";
        $response = $this->client()->get($url);
        $this->logInteraction('getLists', $url, $response);

        if ($response->failed()) {
            throw new RuntimeException(__('Invalid API key or connection failed.'));
        }

        $json = $response->json();
        if (! is_array($json)) {
            throw new RuntimeException(__('Invalid API key or connection failed.'));
        }

        if (($json['status'] ?? null) === 'error') {
            throw new RuntimeException(__('Invalid API key or connection failed.'));
        }

        return $this->normalizeListsPayload($json);
    }

    /**
     * @return list<array{tag: string, label: string, type_identifier: string, options: array<string, string>}>
     */
    public function getListFields(string $listUid): array
    {
        $url = "{$this->baseUrl}/lists/{$listUid}/fields";
        $response = $this->client()->get($url);
        $this->logInteraction('getListFields', $url, $response);

        if ($response->failed()) {
            throw new RuntimeException(__('Failed to fetch list fields.'));
        }

        $json = $response->json();
        if (! is_array($json)) {
            throw new RuntimeException(__('Failed to fetch list fields.'));
        }

        if (($json['status'] ?? null) === 'error') {
            throw new RuntimeException(__('Failed to fetch list fields.'));
        }

        return $this->normalizeFieldsPayload($json);
    }

    /**
     * Search by email. Mailwizz uses query param EMAIL regardless of list field mapping.
     *
     * @return array{subscriber_uid: string}|null
     */
    public function searchSubscriber(string $listUid, string $email): ?array
    {
        $url = "{$this->baseUrl}/lists/{$listUid}/subscribers/search-by-email";
        $response = $this->client()->get($url, [
            'EMAIL' => $email,
        ]);
        $this->logInteraction('searchSubscriber', $url, $response);

        if ($response->failed()) {
            if ($response->status() === 404) {
                return null;
            }

            throw new RuntimeException(__('Mailwizz subscriber search failed.'));
        }

        $json = $response->json();
        if (! is_array($json)) {
            return null;
        }

        if (($json['status'] ?? null) !== 'success') {
            return null;
        }

        $uid = data_get($json, 'data.subscriber_uid')
            ?? data_get($json, 'data.record.subscriber_uid');

        if (! is_string($uid) || $uid === '') {
            return null;
        }

        return ['subscriber_uid' => $uid];
    }

    /**
     * Full subscriber payload from Mailwizz (structure varies; callers inspect data.record).
     *
     * @return array<string, mixed>|null
     */
    public function getSubscriber(string $listUid, string $subscriberUid): ?array
    {
        $url = "{$this->baseUrl}/lists/{$listUid}/subscribers/{$subscriberUid}";
        $response = $this->client()->get($url);
        $this->logInteraction('getSubscriber', $url, $response);

        if ($response->failed()) {
            throw new RuntimeException(__('Mailwizz could not load subscriber.'));
        }

        $json = $response->json();
        if (! is_array($json) || ($json['status'] ?? null) !== 'success') {
            return null;
        }

        return $json;
    }

    /**
     * @param  array<string, mixed>  $data  Form fields; checkboxlist values as string[] per field tag
     * @return array<string, mixed>
     */
    public function createSubscriber(string $listUid, array $data): array
    {
        $url = "{$this->baseUrl}/lists/{$listUid}/subscribers";
        $response = $this->client()->post($url, $this->encodeFormPayload($data));
        $this->logInteraction('createSubscriber', $url, $response);

        if ($response->failed()) {
            throw new RuntimeException(__('Mailwizz rejected subscriber creation.'));
        }

        $json = $response->json();
        if (! is_array($json) || ($json['status'] ?? null) !== 'success') {
            $msg = is_array($json) ? (string) ($json['error'] ?? $json['message'] ?? '') : '';

            throw new RuntimeException($msg !== '' ? $msg : __('Mailwizz rejected subscriber creation.'));
        }

        return $json;
    }

    /**
     * @param  array<string, mixed>  $data
     * @return array<string, mixed>
     */
    public function updateSubscriber(string $listUid, string $subscriberUid, array $data): array
    {
        $url = "{$this->baseUrl}/lists/{$listUid}/subscribers/{$subscriberUid}";
        $response = $this->client()->put($url, $this->encodeFormPayload($data));
        $this->logInteraction('updateSubscriber', $url, $response);

        if ($response->failed()) {
            throw new RuntimeException(__('Mailwizz rejected subscriber update.'));
        }

        $json = $response->json();
        if (! is_array($json) || ($json['status'] ?? null) !== 'success') {
            $msg = is_array($json) ? (string) ($json['error'] ?? $json['message'] ?? '') : '';

            throw new RuntimeException($msg !== '' ? $msg : __('Mailwizz rejected subscriber update.'));
        }

        return $json;
    }

    /**
     * @param  array<string, mixed>  $data
     * @return array<string, mixed>
     */
    private function encodeFormPayload(array $data): array
    {
        $out = [];
        foreach ($data as $key => $value) {
            if (is_array($value)) {
                // Empty arrays are omitted by Laravel's multipart encoder (no KEY[] parts), so Mailwizz never clears checkboxlist fields.
                $out[$key] = $value === [] ? '' : $value;

                continue;
            }
            if ($value === null) {
                continue;
            }
            $out[$key] = $value;
        }

        return $out;
    }

    /**
     * @return list<array{list_uid: string, name: string}>
     */
    private function normalizeListsPayload(array $json): array
    {
        $out = [];
        $records = data_get($json, 'data.records');
        if (! is_array($records)) {
            return $out;
        }

        foreach ($records as $row) {
            if (! is_array($row)) {
                continue;
            }
            $uid = data_get($row, 'general.list_uid') ?? data_get($row, 'list_uid');
            $name = data_get($row, 'general.name') ?? data_get($row, 'name');
            if (is_string($uid) && $uid !== '' && is_string($name) && $name !== '') {
                $out[] = ['list_uid' => $uid, 'name' => $name];
            }
        }

        return $out;
    }

    /**
     * @return list<array{tag: string, label: string, type_identifier: string, options: array<string, string>}>
     */
    private function normalizeFieldsPayload(array $json): array
    {
        $out = [];
        $records = data_get($json, 'data.records');
        if (! is_array($records)) {
            return $out;
        }

        foreach ($records as $row) {
            if (! is_array($row)) {
                continue;
            }
            $tag = data_get($row, 'tag');
            $label = data_get($row, 'label');
            $typeId = data_get($row, 'type.identifier');
            if (! is_string($tag) || $tag === '' || ! is_string($label)) {
                continue;
            }
            $typeIdentifier = is_string($typeId) ? $typeId : '';
            $rawOptions = data_get($row, 'options');
            $options = $this->normalizeFieldOptions($rawOptions);

            $out[] = [
                'tag' => $tag,
                'label' => $label,
                'type_identifier' => $typeIdentifier,
                'options' => $options,
            ];
        }

        return $out;
    }

    /**
     * @return array<string, string>
     */
    private function normalizeFieldOptions(mixed $rawOptions): array
    {
        if ($rawOptions === null || $rawOptions === '') {
            return [];
        }

        if (is_string($rawOptions)) {
            $decoded = json_decode($rawOptions, true);
            if (is_array($decoded)) {
                $rawOptions = $decoded;
            } else {
                return [];
            }
        }

        if (! is_array($rawOptions)) {
            return [];
        }

        $out = [];
        foreach ($rawOptions as $key => $value) {
            if (is_string($key) || is_int($key)) {
                $k = (string) $key;
                $out[$k] = is_scalar($value) ? (string) $value : '';
            }
        }

        return $out;
    }
}