/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package gudusoft.gsqlparser.ext.calcite.catalog.impl;

import gudusoft.gsqlparser.ext.calcite.catalog.Catalog;
import gudusoft.gsqlparser.ext.calcite.catalog.Column;
import gudusoft.gsqlparser.ext.calcite.catalog.Schema;
import gudusoft.gsqlparser.ext.calcite.catalog.Table;

import org.checkerframework.checker.nullness.qual.Nullable;

import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import static java.util.Objects.requireNonNull;

/**
 * Simple, mutable implementation of {@link Catalog}.
 *
 * <p>This implementation uses LinkedHashMap to maintain insertion order.
 */
public class SimpleCatalog implements Catalog {
  private final String name;
  private final Map<String, SimpleSchema> schemas;
  private @Nullable String defaultSchemaName;

  public SimpleCatalog(String name) {
    this.name = requireNonNull(name, "name");
    this.schemas = new LinkedHashMap<>();
  }

  @Override public String getName() {
    return name;
  }

  @Override public List<Schema> getSchemas() {
    return new ArrayList<>(schemas.values());
  }

  @Override public @Nullable Schema getSchema(String schemaName) {
    return schemas.get(schemaName);
  }

  @Override public List<String> getSchemaNames() {
    return new ArrayList<>(schemas.keySet());
  }

  @Override public @Nullable Table getTable(String schemaName, String tableName) {
    Schema schema = getSchema(schemaName);
    return schema == null ? null : schema.getTable(tableName);
  }

  @Override public @Nullable String getDefaultSchemaName() {
    return defaultSchemaName;
  }

  /**
   * Adds a schema to this catalog.
   *
   * @param schema Schema to add
   * @return This catalog (for chaining)
   */
  public SimpleCatalog addSchema(SimpleSchema schema) {
    schemas.put(schema.getName(), schema);
    return this;
  }

  /**
   * Creates and adds a new schema to this catalog.
   *
   * @param schemaName Schema name
   * @return The newly created schema
   */
  public SimpleSchema createSchema(String schemaName) {
    SimpleSchema schema = new SimpleSchema(schemaName, this);
    addSchema(schema);
    return schema;
  }

  /**
   * Sets the default schema name.
   *
   * @param defaultSchemaName Default schema name
   * @return This catalog (for chaining)
   */
  public SimpleCatalog setDefaultSchemaName(String defaultSchemaName) {
    this.defaultSchemaName = defaultSchemaName;
    return this;
  }

  /**
   * Simple, mutable implementation of {@link Schema}.
   */
  public static class SimpleSchema implements Schema {
    private final String name;
    private final SimpleCatalog catalog;
    private final Map<String, SimpleTable> tables;

    public SimpleSchema(String name, SimpleCatalog catalog) {
      this.name = requireNonNull(name, "name");
      this.catalog = requireNonNull(catalog, "catalog");
      this.tables = new LinkedHashMap<>();
    }

    @Override public String getName() {
      return name;
    }

    @Override public Catalog getCatalog() {
      return catalog;
    }

    @Override public List<Table> getTables() {
      return new ArrayList<>(tables.values());
    }

    @Override public @Nullable Table getTable(String tableName) {
      return tables.get(tableName);
    }

    @Override public List<String> getTableNames() {
      return new ArrayList<>(tables.keySet());
    }

    /**
     * Adds a table to this schema.
     *
     * @param table Table to add
     * @return This schema (for chaining)
     */
    public SimpleSchema addTable(SimpleTable table) {
      tables.put(table.getName(), table);
      return this;
    }

    /**
     * Creates and adds a new table to this schema.
     *
     * @param tableName Table name
     * @param tableType Table type (e.g., "TABLE", "VIEW")
     * @return The newly created table
     */
    public SimpleTable createTable(String tableName, String tableType) {
      SimpleTable table = new SimpleTable(tableName, tableType, this);
      addTable(table);
      return table;
    }

    /**
     * Creates and adds a new table to this schema with type "TABLE".
     *
     * @param tableName Table name
     * @return The newly created table
     */
    public SimpleTable createTable(String tableName) {
      return createTable(tableName, "TABLE");
    }
  }

  /**
   * Simple, mutable implementation of {@link Table}.
   */
  public static class SimpleTable implements Table {
    private final String name;
    private final String tableType;
    private final SimpleSchema schema;
    private final Map<String, SimpleColumn> columns;
    private final List<String> primaryKeys;
    private @Nullable String comment;

    public SimpleTable(String name, String tableType, SimpleSchema schema) {
      this.name = requireNonNull(name, "name");
      this.tableType = requireNonNull(tableType, "tableType");
      this.schema = requireNonNull(schema, "schema");
      this.columns = new LinkedHashMap<>();
      this.primaryKeys = new ArrayList<>();
    }

    @Override public String getName() {
      return name;
    }

    @Override public String getTableType() {
      return tableType;
    }

    @Override public Schema getSchema() {
      return schema;
    }

    @Override public List<Column> getColumns() {
      return new ArrayList<>(columns.values());
    }

    @Override public @Nullable Column getColumn(String columnName) {
      return columns.get(columnName);
    }

    @Override public @Nullable String getComment() {
      return comment;
    }

    @Override public List<String> getPrimaryKeys() {
      return new ArrayList<>(primaryKeys);
    }

    /**
     * Adds a column to this table.
     *
     * @param column Column to add
     * @return This table (for chaining)
     */
    public SimpleTable addColumn(SimpleColumn column) {
      columns.put(column.getName(), column);
      return this;
    }

    /**
     * Creates and adds a new column to this table.
     *
     * @param columnName Column name
     * @param typeName SQL type name
     * @param nullable Whether the column is nullable
     * @return The newly created column
     */
    public SimpleColumn createColumn(String columnName, String typeName, boolean nullable) {
      int ordinal = columns.size() + 1;
      SimpleColumn column = new SimpleColumn(columnName, typeName, ordinal, nullable);
      addColumn(column);
      return column;
    }

    /**
     * Sets the comment for this table.
     *
     * @param comment Table comment
     * @return This table (for chaining)
     */
    public SimpleTable setComment(String comment) {
      this.comment = comment;
      return this;
    }

    /**
     * Sets the primary key columns.
     *
     * @param primaryKeys Primary key column names
     * @return This table (for chaining)
     */
    public SimpleTable setPrimaryKeys(List<String> primaryKeys) {
      this.primaryKeys.clear();
      this.primaryKeys.addAll(primaryKeys);
      return this;
    }

    /**
     * Adds a primary key column.
     *
     * @param columnName Primary key column name
     * @return This table (for chaining)
     */
    public SimpleTable addPrimaryKey(String columnName) {
      this.primaryKeys.add(columnName);
      return this;
    }
  }

  /**
   * Simple, mutable implementation of {@link Column}.
   */
  public static class SimpleColumn implements Column {
    private final String name;
    private final String typeName;
    private final int ordinalPosition;
    private final boolean nullable;
    private @Nullable Integer size;
    private @Nullable Integer decimalDigits;
    private @Nullable String defaultValue;
    private @Nullable String comment;

    public SimpleColumn(String name, String typeName, int ordinalPosition, boolean nullable) {
      this.name = requireNonNull(name, "name");
      this.typeName = requireNonNull(typeName, "typeName");
      this.ordinalPosition = ordinalPosition;
      this.nullable = nullable;
    }

    @Override public String getName() {
      return name;
    }

    @Override public String getTypeName() {
      return typeName;
    }

    @Override public int getOrdinalPosition() {
      return ordinalPosition;
    }

    @Override public boolean isNullable() {
      return nullable;
    }

    @Override public @Nullable Integer getSize() {
      return size;
    }

    @Override public @Nullable Integer getDecimalDigits() {
      return decimalDigits;
    }

    @Override public @Nullable String getDefaultValue() {
      return defaultValue;
    }

    @Override public @Nullable String getComment() {
      return comment;
    }

    /**
     * Sets the size of the column.
     *
     * @param size Column size
     * @return This column (for chaining)
     */
    public SimpleColumn setSize(Integer size) {
      this.size = size;
      return this;
    }

    /**
     * Sets the decimal digits of the column.
     *
     * @param decimalDigits Decimal digits
     * @return This column (for chaining)
     */
    public SimpleColumn setDecimalDigits(Integer decimalDigits) {
      this.decimalDigits = decimalDigits;
      return this;
    }

    /**
     * Sets the default value of the column.
     *
     * @param defaultValue Default value
     * @return This column (for chaining)
     */
    public SimpleColumn setDefaultValue(String defaultValue) {
      this.defaultValue = defaultValue;
      return this;
    }

    /**
     * Sets the comment for the column.
     *
     * @param comment Column comment
     * @return This column (for chaining)
     */
    public SimpleColumn setComment(String comment) {
      this.comment = comment;
      return this;
    }
  }
}