<?php

declare(strict_types=1);

if (! defined('ABSPATH')) {
    exit;
}

/**
 * Server-side client for the PowrPractice public API.
 * Bearer token never leaves PHP / never reaches the browser.
 */
class Powr_Dir_Api_Client
{
    private const CACHE_TTL = 300;

    /** @var string */
    private $base_url;

    /** @var string */
    private $token;

    public function __construct(?string $base_url = null, ?string $token = null)
    {
        $this->base_url = rtrim($base_url ?? (string) get_option('powr_api_base_url', ''), '/');
        $this->token = $token ?? (string) get_option('powr_api_token', '');
    }

    public function is_configured(): bool
    {
        return $this->base_url !== '' && $this->token !== '';
    }

    /**
     * @param array<string, mixed> $args
     * @return array{data: list<array<string, mixed>>, meta: array<string, mixed>}|WP_Error
     */
    public function get_providers(array $args = [])
    {
        $query = array_filter([
            'search' => $args['search'] ?? null,
            'location_id' => $args['location_id'] ?? null,
            'specialty' => $args['specialty'] ?? null,
            'gender' => $args['gender'] ?? null,
            'accepting_new_patients' => $args['accepting_new_patients'] ?? null,
            'telehealth_available' => $args['telehealth_available'] ?? null,
        ], static function ($value) {
            return $value !== null && $value !== '';
        });

        $path = '/api/v1/providers';
        if ($query !== []) {
            $path .= '?' . http_build_query($query);
        }

        $response = $this->request('GET', $path, [], true);

        if (is_wp_error($response)) {
            return $response;
        }

        $data = $response['body'];

        return [
            'data' => is_array($data['data'] ?? null) ? $data['data'] : (is_array($data) && ! isset($data['data']) ? $data : []),
            'meta' => is_array($data['meta'] ?? null) ? $data['meta'] : [],
        ];
    }

    /**
     * @return array<string, mixed>|WP_Error
     */
    public function get_provider(string $slug)
    {
        $response = $this->request('GET', '/api/v1/providers/' . rawurlencode($slug), [], true);

        if (is_wp_error($response)) {
            return $response;
        }

        $body = $response['body'];

        return is_array($body['data'] ?? null) ? $body['data'] : $body;
    }

    /**
     * @return array{data: list<array<string, mixed>>, meta: array<string, mixed>}|WP_Error
     */
    public function get_locations()
    {
        $response = $this->request('GET', '/api/v1/locations', [], true);

        if (is_wp_error($response)) {
            return $response;
        }

        $body = $response['body'];

        return [
            'data' => is_array($body['data'] ?? null) ? $body['data'] : (is_array($body) && ! isset($body['data']) ? $body : []),
            'meta' => is_array($body['meta'] ?? null) ? $body['meta'] : [],
        ];
    }

    /**
     * @return array<string, mixed>|WP_Error
     */
    public function get_location(string $slug)
    {
        $response = $this->request('GET', '/api/v1/locations/' . rawurlencode($slug), [], true);

        if (is_wp_error($response)) {
            return $response;
        }

        $body = $response['body'];

        return is_array($body['data'] ?? null) ? $body['data'] : $body;
    }

    /**
     * @return array{
     *   specialties: list<string>,
     *   languages: list<string>,
     *   genders: list<string>,
     *   insurances: list<string>,
     *   locationTypes: list<string>,
     *   cities: list<string>,
     *   locationServices: list<string>
     * }|WP_Error
     */
    public function get_filters()
    {
        $response = $this->request('GET', '/api/v1/filters', [], true);

        if (is_wp_error($response)) {
            return $response;
        }

        $body = $response['body'];

        return [
            'specialties' => is_array($body['specialties'] ?? null) ? $body['specialties'] : [],
            'languages' => is_array($body['languages'] ?? null) ? $body['languages'] : [],
            'genders' => is_array($body['genders'] ?? null) ? $body['genders'] : [],
            'insurances' => is_array($body['insurances'] ?? null) ? $body['insurances'] : [],
            'locationTypes' => is_array($body['locationTypes'] ?? null) ? $body['locationTypes'] : [],
            'cities' => is_array($body['cities'] ?? null) ? $body['cities'] : [],
            'locationServices' => is_array($body['locationServices'] ?? null) ? $body['locationServices'] : [],
        ];
    }

    /**
     * @return array{name: string, colors: array{primary: ?string, secondary: ?string, accent: ?string}}|WP_Error
     */
    public function get_brand()
    {
        $response = $this->request('GET', '/api/v1/brand', [], true);

        if (is_wp_error($response)) {
            return $response;
        }

        $body = $response['body'];
        $colors = is_array($body['colors'] ?? null) ? $body['colors'] : [];

        return [
            'name' => isset($body['name']) ? (string) $body['name'] : '',
            'colors' => [
                'primary' => isset($colors['primary']) && is_string($colors['primary']) ? $colors['primary'] : null,
                'secondary' => isset($colors['secondary']) && is_string($colors['secondary']) ? $colors['secondary'] : null,
                'accent' => isset($colors['accent']) && is_string($colors['accent']) ? $colors['accent'] : null,
            ],
        ];
    }

    /**
     * @return array<string, mixed>|WP_Error
     */
    public function verify_token(?string $plain_token = null)
    {
        $token = $plain_token ?? $this->token;

        if ($token === '' || $this->base_url === '') {
            return new WP_Error('powr_not_configured', __('API base URL and token are required.', 'sondy'));
        }

        $response = $this->request('POST', '/api/v1/token/verify', [
            'token' => $token,
        ], false, $token);

        if (is_wp_error($response)) {
            return $response;
        }

        return $response['body'];
    }

    /**
     * @param array<string, mixed> $body
     * @return array{status: int, body: array<string, mixed>}|WP_Error
     */
    private function request(string $method, string $path, array $body = [], bool $use_cache = false, ?string $bearer = null)
    {
        if ($this->base_url === '') {
            return new WP_Error('powr_no_base', __('API base URL is not configured.', 'sondy'));
        }

        $url = $this->base_url . $path;
        $cache_key = 'powr_api_' . md5($method . '|' . $url . '|' . ($bearer ?? $this->token));

        if ($use_cache && $method === 'GET') {
            $cached = get_transient($cache_key);
            if (is_array($cached)) {
                return $cached;
            }
        }

        $token = $bearer ?? $this->token;
        $args = [
            'method' => $method,
            'timeout' => 20,
            'headers' => [
                'Accept' => 'application/json',
                'Content-Type' => 'application/json',
            ],
        ];

        if ($token !== '') {
            $args['headers']['Authorization'] = 'Bearer ' . $token;
        }

        if ($method === 'POST' && $body !== []) {
            $args['body'] = wp_json_encode($body);
        }

        $raw = wp_remote_request($url, $args);

        if (is_wp_error($raw)) {
            return $raw;
        }

        $status = (int) wp_remote_retrieve_response_code($raw);
        $decoded = json_decode((string) wp_remote_retrieve_body($raw), true);

        if (! is_array($decoded)) {
            $decoded = [];
        }

        if ($status < 200 || $status >= 300) {
            $message = isset($decoded['message']) ? (string) $decoded['message'] : sprintf(
                /* translators: %d: HTTP status code */
                __('API request failed (HTTP %d).', 'sondy'),
                $status
            );

            return new WP_Error('powr_api_http', $message, ['status' => $status, 'body' => $decoded]);
        }

        $result = [
            'status' => $status,
            'body' => $decoded,
        ];

        if ($use_cache && $method === 'GET') {
            set_transient($cache_key, $result, self::CACHE_TTL);
        }

        return $result;
    }
}