/*
 * Strawberry Music Player
 * This file was part of Clementine.
 * Copyright 2010, David Sansome <me@davidsansome.com>
 * Copyright 2018-2021, Jonas Kvinge <jonas@jkvinge.net>
 *
 * Strawberry is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Strawberry is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef COLLECTIONQUERY_H
#define COLLECTIONQUERY_H

#include "config.h"

#include <QMetaType>
#include <QVariant>
#include <QString>
#include <QStringList>
#include <QSqlDatabase>
#include <QSqlQuery>

class Song;

// This structure let's you customize behaviour of any CollectionQuery.
struct QueryOptions {
  // Modes of CollectionQuery:
  // - use the all songs table
  // - use the duplicated songs view; by duplicated we mean those songs for which the (artist, album, title) tuple is found more than once in the songs table
  // - use the untagged songs view; by untagged we mean those for which at least one of the (artist, album, title) tags is empty
  // Please note that additional filtering based on FTS table (the filter attribute) won't work in Duplicates and Untagged modes.
  enum QueryMode {
    QueryMode_All,
    QueryMode_Duplicates,
    QueryMode_Untagged
  };

  QueryOptions();

  bool Matches(const Song &song) const;

  QString filter() const { return filter_; }
  void set_filter(const QString &filter) {
    this->filter_ = filter;
    this->query_mode_ = QueryMode_All;
  }

  int max_age() const { return max_age_; }
  void set_max_age(int max_age) { this->max_age_ = max_age; }

  QueryMode query_mode() const { return query_mode_; }
  void set_query_mode(QueryMode query_mode) {
    this->query_mode_ = query_mode;
    this->filter_ = QString();
  }

 private:
  QString filter_;
  int max_age_;
  QueryMode query_mode_;
};

class CollectionQuery : public QSqlQuery {
 public:
  explicit CollectionQuery(const QSqlDatabase &db, const QString &songs_table, const QString &fts_table, const QueryOptions &options = QueryOptions());

  // Sets contents of SELECT clause on the query (list of columns to get).
  void SetColumnSpec(const QString &spec) { column_spec_ = spec; }

  // Sets an ORDER BY clause on the query.
  void SetOrderBy(const QString &order_by) { order_by_ = order_by; }

  // Adds a fragment of WHERE clause. When executed, this Query will connect all the fragments with AND operator.
  // Please note that IN operator expects a QStringList as value.
  void AddWhere(const QString &column, const QVariant &value, const QString &op = "=");
  void AddWhereArtist(const QVariant &value);

  void SetWhereClauses(const QStringList &where_clauses) { where_clauses_ = where_clauses; }
  void SetBoundValues(const QVariantList &bound_values) { bound_values_ = bound_values; }
  void SetDuplicatesOnly(const bool duplicates_only) { duplicates_only_ = duplicates_only; }
  void SetIncludeUnavailable(const bool include_unavailable) { include_unavailable_ = include_unavailable; }
  void SetLimit(const int limit) { limit_ = limit; }
  void AddCompilationRequirement(const bool compilation);

  bool Exec();
  bool Next();
  QVariant Value(const int column) const;

  QString column_spec() const { return column_spec_; }
  QString order_by() const { return order_by_; }
  QStringList where_clauses() const { return where_clauses_; }
  QVariantList bound_values() const { return bound_values_; }
  bool include_unavailable() const { return include_unavailable_; }
  bool join_with_fts() const { return join_with_fts_; }
  bool duplicates_only() const { return duplicates_only_; }
  int limit() const { return limit_; }

 private:
  QString GetInnerQuery();

  QSqlDatabase db_;
  QString songs_table_;
  QString fts_table_;

  QString column_spec_;
  QString order_by_;
  QStringList where_clauses_;
  QVariantList bound_values_;

  bool include_unavailable_;
  bool join_with_fts_;
  bool duplicates_only_;
  int limit_;
};

#endif // COLLECTIONQUERY_H