/**
* ─────────────────────────────────────────────────────────────────────────────────────────────────┐
* This web service class handle the custom respons which we send while authenticate user
* Insert the user refresh token into the configuration custom settings.
* Saved refresh token into installer User's org.
* Shopify API Documentation: https://shopify.dev/docs/admin-api/rest/reference
* Create Shopify Store: https://www.shopify.com/signup?itcat=identity&itterm=create-new-store
* Shopify API Release 2020: https://www.shopify.in/partners/blog/shopify-api-release-january-2020
* What is Person Account in Salesforce ? https://help.salesforce.com/articleView?id=account_person.htm&type=5
* ──────────────────────────────────────────────────────────────────────────────────────────────────
* @author         Sumit    <sumit@hicShopify.com>
* ────────────────────────────────────────────────────────────────────────────────────────────────── 
*/
@RestResource(UrlMapping='/UpdateAccessToken/*') 
global with sharing class UpdateAccessToken  
{
    /**
    * Accepts an access token pushed in by the authenticator.
    *
    * WHAT WAS WRONG: this endpoint used to do
    *     listofConfiguration[0].HIC_ShopifySync__Access_Token__c = JSONResponseBody;
    * i.e. it stored the ENTIRE RAW REQUEST BODY as the access token, unparsed and unvalidated, and never
    * touched Refresh_Token__c. Two consequences:
    *
    *  1. Any JSON body (e.g. {"access_token":"..."}) was stored verbatim, so Access_Token__c held a JSON
    *     blob rather than a token. Every subsequent authenticated callout then failed, and because
    *     the field was non-blank, nothing detected it: RefreshTokenKeepAlive's String.isBlank() passed and
    *     ShopifyController.refreshTokenCheck handed the blob back as if the org were connected.
    *  2. It updated the access token WITHOUT updating the refresh token. Under mandatory Refresh Token
    *     Rotation, if the caller obtained that access token via grant_type=refresh_token then the stored
    *     refresh token has ALREADY been consumed and is dead — so the org looks freshly authenticated
    *     while its refresh token is guaranteed to fail on next use. That is the "worked for days, then
    *     asks to re-initialize" signature.
    *
    * Now: the body is parsed, only a real token value is accepted, and if the caller supplies a rotated
    * refresh token alongside it BOTH are written in one DML via the shared, compare-and-swap-protected
    * persistRotatedToken. Failures are reported instead of swallowed.
    */
    @HTTPPost
    global static void updatetoken(){
        Restrequest request = restContext.request;
        Restresponse response = restContext.response;
        String rawBody = (request != null && request.requestBody != null)
            ? request.requestBody.toString().trim()
            : null;

        if (String.isBlank(rawBody)) {
            if (response != null) response.statusCode = 400;
            return;
        }

        String accessToken;
        String refreshToken;
        try {
            Map<String, Object> meta = (Map<String, Object>) JSON.deserializeUntyped(rawBody);
            if (meta != null) {
                // Accept the packaged field name and the plain OAuth name.
                Object a = meta.containsKey('HIC_ShopifySync__Access_Token__c')
                    ? meta.get('HIC_ShopifySync__Access_Token__c') : meta.get('access_token');
                Object r = meta.containsKey('HIC_ShopifySync__Refresh_Token__c')
                    ? meta.get('HIC_ShopifySync__Refresh_Token__c') : meta.get('refresh_token');
                accessToken  = (a == null) ? null : String.valueOf(a).trim();
                refreshToken = (r == null) ? null : String.valueOf(r).trim();
            }
        } catch (Exception parseEx) {
            // Not JSON. Treat the body as a bare token only if it cannot be a structured payload —
            // never store something that merely looks like JSON/HTML.
            if (!rawBody.startsWith('{') && !rawBody.startsWith('[') && !rawBody.startsWith('<')
                    && !rawBody.contains(' ') && rawBody.length() >= 20) {
                accessToken = rawBody;
            }
        }

        if (String.isBlank(accessToken)
                || accessToken.equalsIgnoreCase('null') || accessToken.equalsIgnoreCase('undefined')) {
            System.debug(LoggingLevel.ERROR,
                'SME_TOKEN UpdateAccessToken: no usable access token in body — refusing to store it');
            if (response != null) {
                response.statusCode = 400;
                response.addHeader('Content-Type', 'application/json');
                response.responseBody = Blob.valueOf(
                    '{"error":"no_access_token","error_description":"body did not contain a usable access token"}');
            }
            return;
        }

        Map<String, Object> payload = new Map<String, Object>{
            'HIC_ShopifySync__Access_Token__c' => accessToken
        };
        if (String.isNotBlank(refreshToken)) {
            payload.put('HIC_ShopifySync__Refresh_Token__c', refreshToken);
        }

        Boolean stored = AuthenticateAllApexClass.persistRotatedToken(JSON.serialize(payload));

        if (response != null) {
            response.statusCode = stored ? 200 : 500;
            response.addHeader('Content-Type', 'application/json');
            response.responseBody = Blob.valueOf(stored
                ? '{"status":"ok"}'
                : '{"error":"token_not_stored","error_description":"access token could not be persisted"}');
        }
    }
    
}