Storm/Sources/StORM/StORM.swift

//
//  StORM.swift
//  StORM
//
//  Created by Jonathan Guthrie on 2016-09-30.
//
//  April 6, 2017: 1.0.3, add support for storing [String] as comma delimited strings


/// Variable defining the global debug state for all classes inheriting from the StORM superclass.
/// When true, certain methods will generate a debug message under certain conditions.
public var StORMdebug = false

/// Base StORM superclass from which all Database-Connector StORM classes inherit.
/// Provides base functionality and rules.
open class StORM : StORMMirror {
    
    /// Results container of type StORMResultSet.
    open var results        = StORMResultSet()
    
    /// connection error status of type StORMError.
    open var error            = StORMError()
    
    /// Contain last error message as string.
    open var errorMsg        = ""
    
    /// Base empty init function.
    public override init() {}
    
    /// Provides structure introspection to client methods.
    public func cols(_ offset : Int = 0) -> [(String, Any)] {
        
        var c = [(String, Any)]()
        var count = 0
        // If the StORM primary key is nil, we should assume the first will be the primary key.
        for child in self.allChildren(includingNilValues: true, primaryKey: self.primaryKeyLabel()) {
            guard let key = child.label else {
                continue
            }
            if !key.hasPrefix("internal_") && !key.hasPrefix("_") {
                c.append((child.label!, type(of:child.value)))
            }
            count += 1
        }
        
        return c
    }
    
    /// This modifyValue function now supports optional variables and forces the value as the type it is, so that the String(describing) doesn't include the optional string wrapping the actual value.
    open func modifyValue(_ v: Any, forKey k: String) -> Any {
        
        guard String(describing: v) != "nil" else { return v }
        switch type(of: v) {
        case is Int?.Type:
            return v as! Int
        case is String?.Type:
            return v as! String
        case is Double?.Type:
            return v as! Double
        case is Float?.Type:
            return v as! Float
        case is [String]?.Type:
            return v as! [String]
        case is [String:Any]?.Type:
            return try! (v as! [String:Any]).jsonEncodedString()
        default:
            // Here we will support new database types by returning what we need conforming to CustomStringConvertable.
            return String(describing: v)
        }
        
    }
    
    /// Returns a [(String,Any)] object representation of the current object.
    /// If any object property begins with an underscore, or with "internal_" it is omitted from the response.
    open func asData(_ offset : Int = 0) -> [(String, Any)] {
        var c = [(String, Any)]()
        var count = 0
        for case let (label?, value) in self.allChildren(primaryKey: self.primaryKeyLabel()) {
            if count >= offset && !label.hasPrefix("internal_") && !label.hasPrefix("_") {
                c.append((label, modifyValue(value, forKey: label)))
            }
            count += 1
        }
        return c
    }
    
    /// Returns a [String:Any] object representation of the current object.
    /// If any object property begins with an underscore, or with "internal_" it is omitted from the response.
    open func asDataDict(_ offset : Int = 0) -> [String: Any] {
        var c = [String: Any]()
        var count = 0
        for case let (label?, value) in self.allChildren(primaryKey: self.primaryKeyLabel()) {
            if count >= offset && !label.hasPrefix("internal_") && !label.hasPrefix("_") {
                c[label] = modifyValue(value, forKey: label)
            }
            count += 1
        }
        return c
    }
    
    /// Returns a tuple of name & value of the object's key
    /// The key is determined to be it's first property, which is assumed to be the object key.
    public func firstAsKey() -> (String, Any) {
        for case let (label, value) in self.allChildren(includingNilValues: true, primaryKey: self.primaryKeyLabel()) {
            return (label!, modifyValue(value, forKey: label!))
        }
        return ("id", "unknown")
    }
    
    /// Returns a boolean that is true if the first property in the class contains a value.
    public func keyIsEmpty() -> Bool {
        let (_, val) = firstAsKey()
        
        // Grab the type of value:
        let type = type(of: val)
        // Check if we are nil, we would then of course have an empty primary key.
        guard String(describing: val) != "nil" else {
            return true
        }
        
        // For now we will be expecting String & Integer key types:
        switch type {
        case is Int.Type, is Int?.Type:
            return (val as! Int == 0)
        case is String.Type, is String?.Type:
            return (val as! String).isEmpty
        default:
            print("[StORM] WARNING: [\(#function)] Unexpected \(type) for PRIMARY KEY.")
            return false
        }
        
    }
    
    /// The create method is designed to be overridden
    /// If not set in the chile class it will return an error of the enum value .notImplemented
    open func create() throws {
        throw StORMError.notImplemented
    }
    
}