//
//  GroupBy.swift
//  HardcoreData
//
//  Copyright (c) 2015 John Rommel Estropia
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in all
//  copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//  SOFTWARE.
//

import Foundation


// MARK: - GroupBy

public struct GroupBy: QueryClause {
    
    // MARK: Public
    
    public init(_ keyPaths: [KeyPath]) {
        
        self.keyPaths = keyPaths
    }
    
    public init() {
        
        self.init([])
    }
    
    public init(_ keyPath: KeyPath, _ subKeyPaths: KeyPath...) {
        
        self.init([keyPath] + subKeyPaths)
    }
    
    public let keyPaths: [KeyPath]
    
    
    // MARK: QueryClause
    
    public func applyToFetchRequest(fetchRequest: NSFetchRequest) {
        
        if fetchRequest.propertiesToGroupBy != nil {
            
            HardcoreData.log(.Warning, message: "An existing \"propertiesToGroupBy\" for the <\(NSFetchRequest.self)> was overwritten by \(typeName(self)) query clause.")
        }
        
        fetchRequest.propertiesToGroupBy = self.keyPaths
    }
}