LocationsViewController.swift

//
//  LocationsViewController.swift
//  MyLocations
//
//  Created by Donald Lee on 2015-05-10.
//  Copyright (c) 2015 mylocations. All rights reserved.
//

import UIKit
import CoreData
import CoreLocation

class LocationsViewController: UITableViewController {
    var managedObjectContext: NSManagedObjectContext!
    lazy var fetchedResultsController: NSFetchedResultsController = {
        let fetchRequest = NSFetchRequest()
        
        let entity = NSEntityDescription.entityForName("Location", inManagedObjectContext: self.managedObjectContext)
        
        fetchRequest.entity = entity
        
        let sortDescriptor1 = NSSortDescriptor(key: "category", ascending: true)
        let sortDescriptor2 = NSSortDescriptor(key: "date", ascending: true)
        
        fetchRequest.sortDescriptors = [sortDescriptor1, sortDescriptor2]
        
        fetchRequest.fetchBatchSize = 20
        
        let fetchedResultsController = NSFetchedResultsController(
            fetchRequest: fetchRequest,
            managedObjectContext: self.managedObjectContext,
            sectionNameKeyPath: "category",
            cacheName: "Locations")
        
        fetchedResultsController.delegate = self
        return fetchedResultsController
    }()
    
    // MARK: - UITableViewDataSource
    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        let sectionInfo = fetchedResultsController.sections![section] as! NSFetchedResultsSectionInfo
        return sectionInfo.numberOfObjects
    }
    
    override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        let sectionInfo = fetchedResultsController.sections![section] as! NSFetchedResultsSectionInfo
        return sectionInfo.name!.uppercaseString
    }
    override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        return fetchedResultsController.sections!.count
    }
    override func tableView(tableView: UITableView,
        cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier( "LocationCell") as! LocationCell
        
        let location = fetchedResultsController.objectAtIndexPath(indexPath) as! Location
        cell.configureForLocation(location)
        
        return cell
    }
    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.backgroundColor = UIColor.blackColor()
        tableView.separatorColor = UIColor(white: 1.0, alpha: 0.2)
        tableView.indicatorStyle = .White
        NSFetchedResultsController.deleteCacheWithName("Locations")
        performFetch()
        navigationItem.rightBarButtonItem = editButtonItem()
    }
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == "EditLocation" {
            let navigationController = segue.destinationViewController as! UINavigationController
            let controller = navigationController.topViewController as! LocationDetailsViewController
        
            controller.managedObjectContext = managedObjectContext
        
            if let indexPath = tableView.indexPathForCell(sender as! UITableViewCell) {
                let location = fetchedResultsController.objectAtIndexPath(indexPath) as! Location
                controller.locationToEdit = location
            }
        }
    }
    
    override func tableView(tableView: UITableView,
        commitEditingStyle editingStyle: UITableViewCellEditingStyle,
        forRowAtIndexPath indexPath: NSIndexPath) {
            if editingStyle == .Delete {
                let location = fetchedResultsController.objectAtIndexPath(indexPath) as! Location
                location.removePhotoFile()
            managedObjectContext.deleteObject(location)
            
            var error: NSError?
            if !managedObjectContext.save(&error) {
                fatalCoreDataError(error)
            }
        }
    }
    
    override func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
        let labelRect = CGRect(x: 15, y: tableView.sectionHeaderHeight - 14, width: 300, height: 14)
        
        let label = UILabel(frame: labelRect)
        label.font = UIFont.boldSystemFontOfSize(11)
        
        label.text = tableView.dataSource!.tableView!(tableView, titleForHeaderInSection: section)
        
        label.textColor = UIColor(white: 1.0, alpha: 0.4)
        label.backgroundColor = UIColor.clearColor()
        
        let separatorRect = CGRect(x: 15, y: tableView.sectionHeaderHeight - 0.5, width: tableView.bounds.size.width - 15, height: 0.5)
        let separator = UIView(frame: separatorRect)
        separator.backgroundColor = tableView.separatorColor
        
        let viewRect = CGRect(x: 0, y: 0, width: tableView.bounds.size.width, height: tableView.sectionHeaderHeight)
        let view = UIView(frame: viewRect)
        view.backgroundColor = UIColor(white: 0, alpha: 0.85)
        view.addSubview(label)
        view.addSubview(separator)
        return view
    }
    
    func performFetch() {
        var error: NSError?
        if !fetchedResultsController.performFetch(&error) {
            fatalCoreDataError(error)
        }
    }
    
    deinit {
        fetchedResultsController.delegate = nil
    }
}

extension LocationsViewController: NSFetchedResultsControllerDelegate {

    func controllerWillChangeContent(controller: NSFetchedResultsController) {
        println("*** controllerWillChangeContent")
        tableView.beginUpdates()
    }
    
    func controller(controller: NSFetchedResultsController,
                    didChangeObject anObject: AnyObject,
                    atIndexPath indexPath: NSIndexPath?,
                    forChangeType type: NSFetchedResultsChangeType,
                    newIndexPath: NSIndexPath?) {
        switch type {
            case .Insert:
                println("*** NSFetchedResultsChangeInsert (object)")
                tableView.insertRowsAtIndexPaths([newIndexPath!],withRowAnimation: .Fade)
            case .Delete:
                println("*** NSFetchedResultsChangeDelete (object)")
                tableView.deleteRowsAtIndexPaths([indexPath!],withRowAnimation: .Fade)
            case .Update:
                println("*** NSFetchedResultsChangeUpdate (object)")
                let cell = tableView.cellForRowAtIndexPath(indexPath!) as! LocationCell
                let location = controller.objectAtIndexPath(indexPath!) as! Location
                cell.configureForLocation(location)
            case .Move:
                println("*** NSFetchedResultsChangeMove (object)")
                tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: .Fade)
                tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: .Fade)
        }
    }
    
    func controller(controller: NSFetchedResultsController,
                    didChangeSection sectionInfo: NSFetchedResultsSectionInfo,
                    atIndex sectionIndex: Int,
                    forChangeType type: NSFetchedResultsChangeType) {
        switch type {
            case .Insert:
                println("*** NSFetchedResultsChangeInsert (section)")
                tableView.insertSections(NSIndexSet(index: sectionIndex), withRowAnimation: .Fade)
            
            case .Delete:
                println("*** NSFetchedResultsChangeDelete (section)")
                tableView.deleteSections(NSIndexSet(index: sectionIndex), withRowAnimation: .Fade)
            
            case .Update:
                println("*** NSFetchedResultsChangeUpdate (section)")
            
            case .Move:
                println("*** NSFetchedResultsChangeMove (section)")
        }
    }
    
    func controllerDidChangeContent(controller: NSFetchedResultsController) {
        println("*** controllerDidChangeContent")
        tableView.endUpdates()
    }
}