// Tyk plugin for validating TPP headers and certificates

function PreInsertHeaderRequest(request, session, config) {
    // Extract `header.signature` from the incoming request
    const signature = request.headers["signature"];
    if (!signature) {
        console.log("Signature header missing");
        return TykJsResponseFromError(400, "Signature header is required");
    }

    // Set up the API endpoint and country codes for the POST request
    const apiEndpoint = "https://api.tppvalidation.com/v3?cc=SE,DK"; // adjust cc parameter as needed

    // Prepare the options for the POST request
    const postOptions = {
        method: "POST",
        headers: {
            "Content-Type": "text/plain"
        },
        body: signature
    };

    // Execute the POST request and wait for the response
    const apiResponse = TykMakeHttpRequest(apiEndpoint, postOptions);

    // Check if the response status is 200 OK
    if (apiResponse.status !== 200) {
        console.log(`Received non-200 status: ${apiResponse.status}`);
        return TykJsResponseFromError(apiResponse.status, "TPP Validation failed");
    }

    // Extract the `x-tpp-entity` and `x-tpp-passports` headers from the response
    const xTppEntity = apiResponse.headers["x-tpp-entity"];
    const xTppPassports = apiResponse.headers["x-tpp-passports"];

    if (!xTppEntity || !xTppPassports) {
        console.log("Missing required x-tpp- headers in the response");
        return TykJsResponseFromError(400, "Invalid TPP Validation response");
    }

    // Validate that `x-tpp-entity` is listed in `x-tpp-passports` and matches country codes
    const countryCodes = ["SE", "DK"]; // Update as per the original request `cc` parameter
    const passportEntries = xTppPassports.split(";");

    let validationPassed = true;
    countryCodes.forEach((cc) => {
        const expectedEntry = `${cc}=${xTppEntity}`;
        if (!passportEntries.includes(expectedEntry)) {
            validationPassed = false;
            console.log(`Mismatch for country code ${cc}: expected ${expectedEntry}`);
        }
    });

    // If validation fails, return a 403 response
    if (!validationPassed) {
        return TykJsResponseFromError(403, "TPP Entity and Passport validation failed");
    }

    // Proceed with the request if validation passes
    return request;
}

// Export the function for Tyk to use
module.exports = {
    PreInsertHeaderRequest
};