//
  //  ImmutableMappble.swift
  //  ObjectMapper
  //
  //  Created by Suyeol Jeon on 23/09/2016.
  //
  //  The MIT License (MIT)
  //
  //  Copyright (c) 2014-2016 Hearst
  //
  //  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.
  
  public protocol ImmutableMappable: BaseMappable {
  	init(map: Map) throws
  }
  
  public extension ImmutableMappable {
  	
  	/// Implement this method to support object -> JSON transform.
  	public func mapping(map: Map) {}
  	
  	/// Initializes object from a JSON String
  	public init(JSONString: String, context: MapContext? = nil) throws {
  		self = try Mapper(context: context).map(JSONString: JSONString)
  	}
  	
  	/// Initializes object from a JSON Dictionary
  	public init(JSON: [String: Any], context: MapContext? = nil) throws {
  		self = try Mapper(context: context).map(JSON: JSON)
  	}
  	
  	/// Initializes object from a JSONObject
  	public init(JSONObject: Any, context: MapContext? = nil) throws {
  		self = try Mapper(context: context).map(JSONObject: JSONObject)
  	}
  	
  }
  
  public extension Map {
  
  	fileprivate func currentValue(for key: String, nested: Bool? = nil, delimiter: String = ".") -> Any? {
  		let isNested = nested ?? key.contains(delimiter)
  		return self[key, nested: isNested, delimiter: delimiter].currentValue
  	}
  	
  	// MARK: Basic
  
  	/// Returns a value or throws an error.
  	public func value<T>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> T {
  		let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
  		guard let value = currentValue as? T else {
  			throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '\(T.self)'", file: file, function: function, line: line)
  		}
  		return value
  	}
  
  	/// Returns a transformed value or throws an error.
  	public func value<Transform: TransformType>(_ key: String, nested: Bool? = nil, delimiter: String = ".", using transform: Transform, file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> Transform.Object {
  		let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
  		guard let value = transform.transformFromJSON(currentValue) else {
  			throw MapError(key: key, currentValue: currentValue, reason: "Cannot transform to '\(Transform.Object.self)' using \(transform)", file: file, function: function, line: line)
  		}
  		return value
  	}
  	
  	/// Returns a RawRepresentable type or throws an error.
  	public func value<T: RawRepresentable>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> T {
  		return try self.value(key, nested: nested, delimiter: delimiter, using: EnumTransform(), file: file, function: function, line: line)
  	}
  
  	// MARK: BaseMappable
  
  	/// Returns a `BaseMappable` object or throws an error.
  	public func value<T: BaseMappable>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> T {
  		let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
  		guard let JSONObject = currentValue else {
  			throw MapError(key: key, currentValue: currentValue, reason: "Found unexpected nil value", file: file, function: function, line: line)
  		}
  		return try Mapper<T>(context: context).mapOrFail(JSONObject: JSONObject)
  	}
  
  	// MARK: [BaseMappable]
  
  	/// Returns a `[BaseMappable]` or throws an error.
  	public func value<T: BaseMappable>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [T] {
  		let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
  		guard let jsonArray = currentValue as? [Any] else {
  			throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '[Any]'", file: file, function: function, line: line)
  		}
  		return try jsonArray.enumerated().map { i, JSONObject -> T in
  			return try Mapper<T>(context: context).mapOrFail(JSONObject: JSONObject)
  		}
  	}
  
  	/// Returns a `[BaseMappable]` using transform or throws an error.
  	public func value<Transform: TransformType>(_ key: String, nested: Bool? = nil, delimiter: String = ".", using transform: Transform, file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [Transform.Object] {
  		let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
  		guard let jsonArray = currentValue as? [Any] else {
  			throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '[Any]'", file: file, function: function, line: line)
  		}
  		return try jsonArray.enumerated().map { i, json -> Transform.Object in
  			guard let object = transform.transformFromJSON(json) else {
  				throw MapError(key: "\(key)[\(i)]", currentValue: json, reason: "Cannot transform to '\(Transform.Object.self)' using \(transform)", file: file, function: function, line: line)
  			}
  			return object
  		}
  	}
  
  	// MARK: [String: BaseMappable]
  
  	/// Returns a `[String: BaseMappable]` or throws an error.
  	public func value<T: BaseMappable>(_ key: String, nested: Bool? = nil, delimiter: String = ".", file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [String: T] {
  		let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
  		guard let jsonDictionary = currentValue as? [String: Any] else {
  			throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '[String: Any]'", file: file, function: function, line: line)
  		}
  		var value: [String: T] = [:]
  		for (key, json) in jsonDictionary {
  			value[key] = try Mapper<T>(context: context).mapOrFail(JSONObject: json)
  		}
  		return value
  	}
  
  	/// Returns a `[String: BaseMappable]` using transform or throws an error.
  	public func value<Transform: TransformType>(_ key: String, nested: Bool? = nil, delimiter: String = ".", using transform: Transform, file: StaticString = #file, function: StaticString = #function, line: UInt = #line) throws -> [String: Transform.Object] {
  		let currentValue = self.currentValue(for: key, nested: nested, delimiter: delimiter)
  		guard let jsonDictionary = currentValue as? [String: Any] else {
  			throw MapError(key: key, currentValue: currentValue, reason: "Cannot cast to '[String: Any]'", file: file, function: function, line: line)
  		}
  		var value: [String: Transform.Object] = [:]
  		for (key, json) in jsonDictionary {
  			guard let object = transform.transformFromJSON(json) else {
  				throw MapError(key: key, currentValue: json, reason: "Cannot transform to '\(Transform.Object.self)' using \(transform)", file: file, function: function, line: line)
  			}
  			value[key] = object
  		}
  		return value
  	}
  
  }
  
  public extension Mapper where N: ImmutableMappable {
  
  	public func map(JSON: [String: Any]) throws -> N {
  		return try self.mapOrFail(JSON: JSON)
  	}
  
  	public func map(JSONString: String) throws -> N {
  		return try mapOrFail(JSONString: JSONString)
  	}
  
  	public func map(JSONObject: Any) throws -> N {
  		return try mapOrFail(JSONObject: JSONObject)
  	}
  
  	// MARK: Array mapping functions
  	
  	public func mapArray(JSONArray: [[String: Any]]) throws -> [N] {
  		return try JSONArray.flatMap(mapOrFail)
  	}
  	
  	public func mapArray(JSONString: String) throws -> [N] {
  		guard let JSONObject = Mapper.parseJSONString(JSONString: JSONString) else {
  			throw MapError(key: nil, currentValue: JSONString, reason: "Cannot convert string into Any'")
  		}
  		
  		return try mapArray(JSONObject: JSONObject)
  	}
  	
  	public func mapArray(JSONObject: Any) throws -> [N] {
  		guard let JSONArray = JSONObject as? [[String: Any]] else {
  			throw MapError(key: nil, currentValue: JSONObject, reason: "Cannot cast to '[[String: Any]]'")
  		}
  		
  		return try mapArray(JSONArray: JSONArray)
  	}
  
  	// MARK: Dictionary mapping functions
  
  	public func mapDictionary(JSONString: String) throws -> [String: N] {
  		guard let JSONObject = Mapper.parseJSONString(JSONString: JSONString) else {
  			throw MapError(key: nil, currentValue: JSONString, reason: "Cannot convert string into Any'")
  		}
  
  		return try mapDictionary(JSONObject: JSONObject)
  	}
  
  	public func mapDictionary(JSONObject: Any?) throws -> [String: N] {
  		guard let JSON = JSONObject as? [String: [String: Any]] else {
  			throw MapError(key: nil, currentValue: JSONObject, reason: "Cannot cast to '[String: [String: Any]]''")
  		}
  
  		return try mapDictionary(JSON: JSON)
  	}
  
  	public func mapDictionary(JSON: [String: [String: Any]]) throws -> [String: N] {
  		return try JSON.filterMap(mapOrFail)
  	}
  
  	// MARK: Dictinoary of arrays mapping functions
  
  	public func mapDictionaryOfArrays(JSONObject: Any?) throws -> [String: [N]] {
  		guard let JSON = JSONObject as? [String: [[String: Any]]] else {
  			throw MapError(key: nil, currentValue: JSONObject, reason: "Cannot cast to '[String: [String: Any]]''")
  		}
  		return try mapDictionaryOfArrays(JSON: JSON)
  	}
  
  	public func mapDictionaryOfArrays(JSON: [String: [[String: Any]]]) throws -> [String: [N]] {
  		return try JSON.filterMap { array -> [N] in
  			try mapArray(JSONArray: array)
  		}
  	}
  
  	// MARK: 2 dimentional array mapping functions
  
  	public func mapArrayOfArrays(JSONObject: Any?) throws -> [[N]] {
  		guard let JSONArray = JSONObject as? [[[String: Any]]] else {
  			throw MapError(key: nil, currentValue: JSONObject, reason: "Cannot cast to '[[[String: Any]]]''")
  		}
  		return try JSONArray.map(mapArray)
  	}
  
  }
  
  internal extension Mapper where N: BaseMappable {
  
  	internal func mapOrFail(JSON: [String: Any]) throws -> N {
  		let map = Map(mappingType: .fromJSON, JSON: JSON, context: context, shouldIncludeNilValues: shouldIncludeNilValues)
  		
  		// Check if object is ImmutableMappable, if so use ImmutableMappable protocol for mapping
  		if let klass = N.self as? ImmutableMappable.Type,
  			var object = try klass.init(map: map) as? N {
  			object.mapping(map: map)
  			return object
  		}
  		
  		// If not, map the object the standard way
  		guard let value = self.map(JSON: JSON) else {
  			throw MapError(key: nil, currentValue: JSON, reason: "Cannot map to '\(N.self)'")
  		}
  		return value
  	}
  
  	internal func mapOrFail(JSONString: String) throws -> N {
  		guard let JSON = Mapper.parseJSONStringIntoDictionary(JSONString: JSONString) else {
  			throw MapError(key: nil, currentValue: JSONString, reason: "Cannot parse into '[String: Any]'")
  		}
  		return try mapOrFail(JSON: JSON)
  	}
  
  	internal func mapOrFail(JSONObject: Any) throws -> N {
  		guard let JSON = JSONObject as? [String: Any] else {
  			throw MapError(key: nil, currentValue: JSONObject, reason: "Cannot cast to '[String: Any]'")
  		}
  		return try mapOrFail(JSON: JSON)
  	}
  
  }