#include "database.h"
#include "binarydata.h"
#include "subfiledata.h"

#include <EasyLogging++/easylogging++.h>
#include <SQLite/lotrodat_sqlite3.h>
#include <yaml-cpp/yaml.h>


namespace LOTRO_DAT {
Database::Database() {
  LOG(DEBUG) << "Initialising new Database instance.";
  db_ = nullptr;
}

bool Database::CloseDatabase() {
  if (db_ == nullptr) {
    return true;
  }

  LOG(DEBUG) << "Closing database.";

  ExecSql("COMMIT TRANSACTION");
  lotrodat_sqlite3_finalize(insert_request_);
  lotrodat_sqlite3_finalize(fetch_one_request_);
  lotrodat_sqlite3_finalize(get_rows_number_request_);
  if (lotrodat_sqlite3_close_v2(db_) != SQLITE_OK)
      LOG(ERROR) << "Database error when closing: " <<lotrodat_sqlite3_errmsg(db_);
  db_ = nullptr;

  LOG(DEBUG) << "Database successfully closed.";
  return true;
}

Database::~Database() {
  CloseDatabase();
}

bool Database::InitDatabase(const std::string &filename) {
  LOG(DEBUG) << "Initializing database " << filename;

  CloseDatabase();
  if (lotrodat_sqlite3_open(filename.c_str(), &db_) != SQLITE_OK) {
    lotrodat_sqlite3_close(db_);
    db_ = nullptr;
    LOG(ERROR) << "sqlite3_open returned an error. Unable to open file " << filename;
    return false;
  }

  ExecSql("PRAGMA synchronous = OFF");
  ExecSql("PRAGMA count_changes = OFF");
  ExecSql("PRAGMA journal_mode = MEMORY");
  ExecSql("PRAGMA temp_store = MEMORY");
  ExecSql("PRAGMA encoding = \"UTF-8\";");

  ExecSql(CreateTableCommand_);

  lotrodat_sqlite3_prepare_v2(db_, InsertFileCommand_.c_str(), InsertFileCommand_.length(), &insert_request_, nullptr);
  lotrodat_sqlite3_prepare_v2(db_, FetchOneCommand.c_str(), FetchOneCommand.length(), &fetch_one_request_, nullptr);
  lotrodat_sqlite3_prepare_v2(db_, GetRowsNumberCommand_.c_str(), GetRowsNumberCommand_.length(),
                      &get_rows_number_request_, nullptr);

  ExecSql("BEGIN TRANSACTION");

  LOG(DEBUG) << "Database " << filename << " successfully initialized";
  return true;
}

void Database::ExecSql(const std::string &sql) {
  LOG(DEBUG) << "Executing SQL request: " << sql;
  if (db_ == nullptr) {
    LOG(WARNING) << "Trying to execute sql query to db, which hasn't been opened yet.";
    return;
  }
  char *error;
  if (lotrodat_sqlite3_exec(db_, sql.c_str(), nullptr, nullptr, &error) != SQLITE_OK) {
    LOG(ERROR) << "SQLite3 error: " << lotrodat_sqlite3_errmsg(db_);
    return;
  }
  LOG(DEBUG) << "SQL request " << sql << " executed successfully";
}

bool Database::PushFile(const SubfileData &data) {
  LOG(DEBUG) << "Pushing to database file with file_id " << data.options["fid"].as<long long>();

  if (db_ == nullptr) {
    LOG(WARNING) << "Trying to push file to db, which hasn't been opened yet.";
    return false;
  }

  std::stringstream options_;
  options_ << data.options;

  lotrodat_sqlite3_bind_blob(insert_request_, 1, data.binary_data.data(), data.binary_data.size(), SQLITE_TRANSIENT);
  lotrodat_sqlite3_bind_text16(insert_request_, 2, data.text_data.c_str(), -1, SQLITE_TRANSIENT);
  lotrodat_sqlite3_bind_text(insert_request_, 3, options_.str().c_str(), -1, SQLITE_TRANSIENT);

  if (lotrodat_sqlite3_step(insert_request_) != SQLITE_DONE) {
    LOG(ERROR) << "SQLite3 error: " << lotrodat_sqlite3_errmsg(db_);
    return false;
  }

  lotrodat_sqlite3_reset(insert_request_);

  LOG(DEBUG) << "File with file_id " << data.options["fid"].as<long long>() << " pushed to database successfully.";
  return true;
}

SubfileData Database::GetNextFile() {
  LOG(DEBUG) << "Getting next file from database..";

  if (db_ == nullptr) {
    LOG(WARNING) << "Trying to get next file from db, which hasn't been opened yet.";
    return SubfileData();
  }

  SubfileData data;
  int result = lotrodat_sqlite3_step(fetch_one_request_);

  if (result == SQLITE_ROW) {
    data.binary_data = BinaryData((char *) lotrodat_sqlite3_column_blob(fetch_one_request_, 0),
                                  unsigned(lotrodat_sqlite3_column_bytes(fetch_one_request_, 0)));

    data.text_data = std::u16string((char16_t *) lotrodat_sqlite3_column_text16(fetch_one_request_, 1));

    std::string _options = std::string((char *) lotrodat_sqlite3_column_text(fetch_one_request_, 2),
                                        unsigned(lotrodat_sqlite3_column_bytes(fetch_one_request_, 2)));
    data.options = YAML::Load(_options);
    return data;
  }

  if (result == SQLITE_DONE) {
    LOG(DEBUG) << "Next file fetched successfully.";
    return data;
  }

  LOG(ERROR) << "SQLite3 fetch_one request returned " << result << " code. SQLite message is: "<< lotrodat_sqlite3_errmsg(db_);
  return data;
}

size_t Database::CountRows() {
  LOG(INFO) << "Counting rows in database...";
  if (db_ == nullptr) {
    LOG(WARNING) << "Trying to execute sql query (Count rows) to db, which hasn't been opened yet.";
    return 0;
  }

  int result = lotrodat_sqlite3_step(get_rows_number_request_);

  if (result == SQLITE_ERROR) {
    LOG(ERROR) << "Error when counting rows " << lotrodat_sqlite3_errmsg(db_);
    return 0;
  }
  long long res = lotrodat_sqlite3_column_int64(get_rows_number_request_, 0);
  lotrodat_sqlite3_reset(get_rows_number_request_);
  LOG(INFO) << "Counted " << size_t(res) << " rows in database.";
  return size_t(res);
}

} // namespace LOTRO_DAT