<?php

namespace App\UCIC;

use Firebase\JWT\JWT;
use Illuminate\Support\Facades\Log;

/**
 * UCICService
 *
 * Handles all communication with the UCIC (Crego) external API.
 *
 * Authentication headers:
 *   x-api-key   : raw API key
 *   x-api-token : JWT HS256 — payload {"key": api_key} signed with api_secret
 *                 (mirrors Python: jwt.encode({"key": api_key}, api_secret, algorithm="HS256"))
 *
 * Required config in config/services.php under 'ucic':
 *   'api_key'      => env('UCIC_API_KEY'),
 *   'api_secret'   => env('UCIC_API_SECRET'),
 *   'base_url'     => env('UCIC_BASE_URL'),
 *   'source'       => env('UCIC_SOURCE', 'CREGO'),
 *   'product_name' => env('UCIC_PRODUCT_NAME', 'Working Capital Loan'),
 */
class UCICService
{
    // -------------------------------------------------------------------------
    // Configuration
    // -------------------------------------------------------------------------

    protected $baseUrl;
    protected $apiKey;
    protected $apiSecret;
    protected $source;
    protected $productName;

    // -------------------------------------------------------------------------
    // Constructor
    // -------------------------------------------------------------------------

    public function __construct()
    {
        $this->baseUrl     = rtrim(config('services.ucic.base_url', ''), '/');
        $this->apiKey      = config('services.ucic.api_key', '');
        $this->apiSecret   = config('services.ucic.api_secret', '');
        $this->source      = config('services.ucic.source', 'CREGO');
        $this->productName = config('services.ucic.product_name', 'Working Capital Loan');
    }

    // =========================================================================
    // PUBLIC API METHODS
    // =========================================================================

    /**
     * Push a full onboarding payload to UCIC.
     *
     * @param  array $params  Keys:
     *                          - anchor_id            (string)
     *                          - business_id          (string)
     *                          - product_name         (string, optional override)
     *                          - business_data        (array)
     *                          - business_person_data (array of arrays)
     *                          - anchor_data          (array)
     *                          - anchor_person_data   (array of arrays)
     *                          - loan_data            (array of arrays)
     * @return Response
     */
    public function pushOnboarding(array $params)
    {
        $payload = $this->buildOnboardingPayload($params);
        return $this->post('/api/onboarding', $payload);
    }

    // =========================================================================
    // PAYLOAD BUILDERS
    // =========================================================================

    /**
     * Build the top-level onboarding payload.
     */
    protected function buildOnboardingPayload(array $params): array
    {
        return [
            'data' => [
                'source'             => $this->source,
                'productName'        => $params['product_name']              ?? $this->productName,
                'anchorId'           => $params['anchor_id']                 ?? null,
                'businessId'         => $params['business_id']               ?? null,
                'businessData'       => $this->buildBusinessData($params['business_data']             ?? []),
                'businessPersonData' => $this->buildPersonDataCollection($params['business_person_data'] ?? []),
                'anchorData'         => $this->buildAnchorData($params['anchor_data']                ?? []),
                'anchorPersonData'   => $this->buildPersonDataCollection($params['anchor_person_data']   ?? []),
                'loanData'           => $this->buildLoanDataCollection($params['loan_data']           ?? []),
            ],
        ];
    }

    /**
     * Build businessData node.
     */
    protected function buildBusinessData(array $data): array
    {
        return $this->filterNull([
            'refId'                => $data['ref_id']                ?? null,
            'name'                 => $data['name']                  ?? null,
            'gstin'                => $data['gstin']                 ?? null,
            'pan'                  => $data['pan']                   ?? null,
            'customerType'         => $data['customer_type']         ?? null,
            'customerConstitution' => $data['customer_constitution'] ?? null,
            'email'                => $data['email']                 ?? null,
            'mobile'               => $data['mobile']                ?? null,
            'telephone'            => $data['telephone']             ?? null,
            'cin'                  => $data['cin']                   ?? null,
            'address'              => $this->buildAddressCollection($data['address'] ?? []),
        ]);
    }

    /**
     * Build anchorData node.
     */
    protected function buildAnchorData(array $data): array
    {
        return $this->filterNull([
            'refId'                => $data['ref_id']                ?? null,
            'name'                 => $data['name']                  ?? null,
            'pan'                  => $data['pan']                   ?? null,
            'customerType'         => $data['customer_type']         ?? null,
            'customerConstitution' => $data['customer_constitution'] ?? null,
            'email'                => $data['email']                 ?? null,
            'mobile'               => $data['mobile']                ?? null,
            'cin'                  => $data['cin']                   ?? null,
            'address'              => $this->buildAddressCollection($data['address'] ?? []),
        ]);
    }

    /**
     * Build a collection of person/entity data nodes.
     * Each entry may optionally contain `related_parties` (e.g. partners of a guarantor).
     */
    protected function buildPersonDataCollection(array $items): array
    {
        return array_map(function($item) { return $this->buildPersonData($item); }, $items);
    }

    /**
     * Build a single person / entity node.
     * Handles both individuals and non-individual entities uniformly.
     */
    protected function buildPersonData(array $data): array
    {
        $node = $this->filterNull([
            'refId'                => $data['ref_id']                ?? null,
            'name'                 => $data['name']                  ?? null,
            'pan'                  => $data['pan']                   ?? null,
            'mobile'               => $data['mobile']                ?? null,
            'customerConstitution' => $data['customer_constitution'] ?? null,
            'customerType'         => $data['customer_type']         ?? null,
            'email'                => $data['email']                 ?? null,
            'gender'               => $data['gender']                ?? null,
            'fatherName'           => $data['father_name']           ?? null,
            'spouseName'           => $data['spouse_name']           ?? null,
            'dob'                  => $data['dob']                   ?? null,
            'maritalStatus'        => $data['marital_status']        ?? null,
            'profession'           => $data['profession']            ?? null,
            'passportNumber'       => $data['passport_number']       ?? null,
            'voterId'              => $data['voter_id']              ?? null,
            'address'              => $this->buildAddressCollection($data['address'] ?? []),
        ]);

        // Recursively handle relatedParties (e.g. partners within a guarantor entity)
        if (!empty($data['related_parties'])) {
            $node['relatedParties'] = $this->buildPersonDataCollection($data['related_parties']);
        }

        return $node;
    }

    /**
     * Build a collection of address nodes.
     */
    protected function buildAddressCollection(array $addresses): array
    {
        return array_map(function($addr) { return $this->buildAddress($addr); }, $addresses);
    }

    /**
     * Build a single address node.
     * Handles snake_case, camelCase and mixed pincode key variants.
     */
    protected function buildAddress(array $addr): array
    {
        return $this->filterNull([
            'type'          => $addr['type']            ?? null,
            'address'       => $addr['address']         ?? null,
            'area'          => $addr['area']            ?? null,
            'city'          => $addr['city']            ?? null,
            'state'         => $addr['state']           ?? null,
            'pinCode'       => $addr['pin_code']        ?? $addr['pinCode'] ?? $addr['pincode'] ?? null,
            'country'       => $addr['country']         ?? null,
            'wef'           => $addr['wef']             ?? null,
            'applicationId' => $addr['application_id'] ?? null,
            'loanId'        => $addr['loan_id']         ?? null,
            'segmentId'     => $addr['segment_id']      ?? null,
        ]);
    }

    /**
     * Build a collection of loan data nodes.
     */
    protected function buildLoanDataCollection(array $items): array
    {
        return array_map(function($item) { return $this->buildLoanData($item); }, $items);
    }

    /**
     * Build a single loan data node.
     */
    protected function buildLoanData(array $data): array
    {
        return $this->filterNull([
            'applicationId' => $data['application_id'] ?? null,
            'loanId'        => $data['loan_id']        ?? null,
            'segmentId'     => $data['segment_id']     ?? null,
        ]);
    }

    // =========================================================================
    // HTTP CLIENT
    // =========================================================================

    /**
     * Make a POST request to the UCIC API.
     */
    protected function post($endpoint, array $payload)
    {
        return $this->executeCurl('POST', $this->baseUrl . $endpoint, $payload);
    }

    /**
     * Make a GET request to the UCIC API.
     */
    protected function get($endpoint, array $query = [])
    {
        $url = $this->baseUrl . $endpoint;
        if (!empty($query)) {
            $url .= '?' . http_build_query($query);
        }
        return $this->executeCurl('GET', $url);
    }

    protected function executeCurl($method, $url, array $payload = [])
    {
        try {
            $ch = curl_init();
            
            $headers = [];
            foreach ($this->buildHeaders() as $key => $value) {
                $headers[] = "$key: $value";
            }
            
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $method);
            curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
            curl_setopt($ch, CURLOPT_TIMEOUT, 30);
            
            if ($method === 'POST') {
                curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
            }
            
            $responseBody = curl_exec($ch);
            $statusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
            $error = curl_error($ch);
            
            curl_close($ch);
            
            if ($error) {
                throw new \Exception("cURL Error: " . $error);
            }
            
            $response = new UcicHttpResponse($statusCode, (string)$responseBody);
            
            $this->logRequest($method, $url, $payload, $response);
            
            return $response;
            
        } catch (\Throwable $e) {
            Log::error("[UCICService] $method request failed", [
                'url'     => $url,
                'error'   => $e->getMessage(),
                'payload' => $payload,
            ]);
            throw $e;
        }
    }

    // =========================================================================
    // AUTHENTICATION / HEADERS
    // =========================================================================

    /**
     * Build the request headers with API auth.
     *
     * x-api-key   : the raw API key
     * x-api-token : JWT HS256 token — mirrors the Python pattern:
     *               jwt.encode({"key": api_key}, api_secret, algorithm="HS256")
     */
    protected function buildHeaders(): array
    {
        return [
            'Content-Type' => 'application/json',
            'Accept'       => 'application/json',
            'x-api-key'    => $this->apiSecret,
            'x-api-token'  => $this->generateApiToken(),
        ];
    }

    /**
     * Generate the x-api-token JWT using Firebase\JWT (same library as JWTAccess.php).
     *
     * Python equivalent:
     *   token = jwt.encode({"key": api_key}, api_secret, algorithm="HS256")
     */
    protected function generateApiToken(): string
    {
        $payload = [
            'key' => $this->apiKey,
            'exp' => time() + 300,
        ];

        return JWT::encode($payload, $this->apiSecret, 'HS256');
    }

    // =========================================================================
    // UTILITIES
    // =========================================================================

    /**
     * Strip null and empty-array values from a single-level array.
     */
    protected function filterNull(array $data): array
    {
        return array_filter($data, function($value) { return $value !== null && $value !== []; });
    }

    /**
     * Log API request/response details (request body is omitted from logs for security).
     */
    protected function logRequest(string $method, string $url, array $data, UcicHttpResponse $response)
    {
        Log::info('[UCICService] API Call', [
            'method'  => $method,
            'url'     => $url,
            'status'  => $response->status(),
            'success' => $response->successful(),
            'response' => $response->json(),
        ]);
    }
}

class UcicHttpResponse
{
    protected $statusCode;
    protected $body;

    public function __construct($statusCode, $body)
    {
        $this->statusCode = $statusCode;
        $this->body = $body;
    }

    public function successful()
    {
        return $this->statusCode >= 200 && $this->statusCode < 300;
    }

    public function status()
    {
        return $this->statusCode;
    }

    public function body()
    {
        return $this->body;
    }

    public function json()
    {
        return json_decode($this->body, true);
    }
}