#pragma once

#include <memory>
#include <optional>
#include <string>
#include <vector>

#include <clickhouse/client.h>
#include "clickhouse/base/uuid.h"
#include "skwyward-api-utils.hpp"

namespace database_utils {

clickhouse::UUID parse_uuid(const std::string& str);
std::string uuid_to_string(const clickhouse::UUID& u);

// ---------- DB Handle ----------

using CHClient = std::shared_ptr<clickhouse::Client>;

// ---------- User ----------

struct UserRecord {
    std::string user_id;     // UUID
    api_utils::Login login;
};

// ---------- Snapshot ----------

struct GradeSnapshot {
    std::string response_id;
    api_utils::GradesResponse response;
};

// ---------- Assignment Diff ----------

struct AssignmentDiff {
    std::string class_grade_id;
    std::string assignment_id;

    std::optional<api_utils::AssignmentGrade> old_grade;
    api_utils::AssignmentGrade new_grade;
};

// ---------- User ops ----------

std::vector<UserRecord>
get_all_users(const CHClient& client);

bool
register_user(
    const CHClient& client,
    const std::string& username,
    const std::string& password
);

bool
authenticate_user(
    const CHClient& client,
    const std::string& username,
    const std::string& password
);

// ---------- Grades ----------

std::optional<GradeSnapshot>
load_latest_grades(
    const CHClient& client,
    const std::string& user_id
);

// ---------- Diff ----------

std::vector<AssignmentDiff>
diff_grade_responses(
    const api_utils::GradesResponse& old_resp,
    const api_utils::GradesResponse& new_resp
);

// ---------- Conditional insert ----------

bool
conditionally_insert_grades(
    const CHClient& client,
    const std::string& user_id,
    const api_utils::GradesResponse& new_resp
);

// ---------- Persist diffs ----------

void
insert_grade_updates(
    const CHClient& client,
    const std::string& user_id,
    const std::string& old_response_id,
    const std::string& new_response_id,
    const std::vector<AssignmentDiff>& diffs
);

std::optional<clickhouse::UUID> get_user_uuid(const CHClient& client, const std::string& username);

} // namespace database_utils