#include "common/OidcUserClaims.h"

#include <algorithm>

namespace visione::oidc
{
namespace
{
std::string claimString(const Json::Value &value,
                        const char *primary,
                        const char *secondary = nullptr)
{
    const auto primaryValue = value.get(primary, "");
    if (primaryValue.isString() && !primaryValue.asString().empty())
    {
        return primaryValue.asString();
    }
    if (secondary)
    {
        const auto secondaryValue = value.get(secondary, "");
        if (secondaryValue.isString())
        {
            return secondaryValue.asString();
        }
    }
    return {};
}

std::string trimFiscalPrefix(std::string value)
{
    const std::string prefix = "TINIT-";
    if (value.rfind(prefix, 0) == 0)
    {
        value.erase(0, prefix.size());
    }
    std::transform(value.begin(),
                   value.end(),
                   value.begin(),
                   [](unsigned char ch) { return static_cast<char>(std::toupper(ch)); });
    return value;
}
}  // namespace

std::optional<NormalizedUserClaims> normalizeIdTokenClaims(
    const std::string &issuer,
    const Json::Value &claims)
{
    if (!claims.isObject())
    {
        return std::nullopt;
    }

    const auto subject = claims.get("sub", "").asString();
    const auto fiscal = trimFiscalPrefix(
        claims.get("fiscal_number",
                   claims.get("https://attributes.eid.gov.it/fiscal_number", ""))
            .asString());
    if (subject.empty() || fiscal.empty())
    {
        return std::nullopt;
    }

    NormalizedUserClaims user;
    user.issuer = issuer;
    user.subject = subject;
    user.firstName = claims.get("given_name", "").asString();
    user.lastName = claims.get("family_name", "").asString();
    user.email = claims.get("email", "").asString();
    user.fiscalCode = fiscal;
    user.rawClaims = claims;
    return user;
}

std::optional<NormalizedUserClaims> mergeUserClaims(
    const std::string &issuer,
    const Json::Value &idTokenClaims,
    const Json::Value &userinfoClaims)
{
    if (!idTokenClaims.isObject() || !userinfoClaims.isObject())
    {
        return std::nullopt;
    }

    Json::Value merged = idTokenClaims;
    for (const auto &name : userinfoClaims.getMemberNames())
    {
        merged[name] = userinfoClaims[name];
    }

    const auto subject = claimString(merged, "sub");
    const auto fiscal = trimFiscalPrefix(claimString(
        merged,
        "fiscal_number",
        "https://attributes.eid.gov.it/fiscal_number"));
    if (subject.empty() || fiscal.empty())
    {
        return std::nullopt;
    }

    NormalizedUserClaims user;
    user.issuer = issuer;
    user.subject = subject;
    user.firstName = claimString(merged, "given_name");
    user.lastName = claimString(merged, "family_name");
    user.email = claimString(merged, "email");
    user.fiscalCode = fiscal;
    user.rawClaims = merged;
    return user;
}
}  // namespace visione::oidc