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#include <ctime>
#include <openssl/evp.h>
#include <iomanip>
#include <sstream>
#include <string>
#include <nlohmann/json.hpp>
#include <openssl/sha.h>
#include "nostr.hpp"
using nlohmann::json;
using std::hex;
using std::invalid_argument;
using std::make_shared;
using std::ostringstream;
using std::setw;
using std::setfill;
using std::shared_ptr;
using std::string;
using std::stringstream;
using std::time;
namespace nostr
{
string Event::serialize()
{
try
{
this->validate();
}
catch (const invalid_argument& e)
{
throw e;
}
json j = {
{"pubkey", this->pubkey},
{"created_at", this->createdAt},
{"kind", this->kind},
{"tags", this->tags},
{"content", this->content},
{"sig", this->sig}
};
j["id"] = this->generateId(j.dump());
return j.dump();
};
Event Event::fromString(string jstr)
{
json j = json::parse(jstr);
Event event;
try
{
event = Event::fromJson(j);
}
catch (const invalid_argument& e)
{
throw e;
}
return event;
};
Event Event::fromJson(json j)
{
Event event;
try {
event.id = j.at("id");
event.pubkey = j.at("pubkey");
event.createdAt = j.at("created_at");
event.kind = j.at("kind");
event.tags = j.at("tags");
event.content = j.at("content");
event.sig = j.at("sig");
} catch (const json::out_of_range& e) {
ostringstream oss;
oss << "Event::fromJson: Tried to access an out-of-range element: " << e.what();
throw invalid_argument(oss.str());
}
return event;
};
void Event::validate()
{
bool hasPubkey = this->pubkey.length() > 0;
if (!hasPubkey)
{
throw std::invalid_argument("Event::validate: The pubkey of the event author is required.");
}
bool hasCreatedAt = this->createdAt > 0;
if (!hasCreatedAt)
{
this->createdAt = time(nullptr);
}
bool hasKind = this->kind >= 0 && this->kind < 40000;
if (!hasKind)
{
throw std::invalid_argument("Event::validate: A valid event kind is required.");
}
bool hasSignature = this->sig.length() > 0;
if (!hasSignature)
{
throw std::invalid_argument("Event::validate: The event must be signed.");
}
};
string Event::generateId(string serializedData) const
{
unsigned char hash[SHA256_DIGEST_LENGTH];
EVP_Digest(serializedData.c_str(), serializedData.length(), hash, NULL, EVP_sha256(), NULL);
stringstream ss;
for (int i = 0; i < SHA256_DIGEST_LENGTH; i++)
{
ss << hex << setw(2) << setfill('0') << (int)hash[i];
}
return ss.str();
};
bool Event::operator==(const Event& other) const
{
if (this->id.empty())
{
throw invalid_argument("Event::operator==: Cannot check equality, the left-side argument is undefined.");
}
if (other.id.empty())
{
throw invalid_argument("Event::operator==: Cannot check equality, the right-side argument is undefined.");
}
return this->id == other.id;
};
} // namespace nostr
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