filecache.swift

//
//  SavedContestFileCache.swift
//  Pingo
//
//  Created by Jeff Potter on 10/16/14.
//  Copyright (c) 2014 Byron Mackay. All rights reserved.
//

import Foundation
import Swift

class SavedContestFileCache {

    class func getStorageUrl() -> NSURL {
        let user = PFUser.currentUser() as PFUser
        let userId = user.objectId ?? "annonymous"
        let fileName = "user-\(userId)-contests.json"
        let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as NSString
        let url: NSURL = NSURL(fileURLWithPath: documentsPath.stringByAppendingPathComponent(fileName))!
        return url
    }
    
    // MARK: Collection methods

    class func saveAll(contests: [PFContest]) {
        println("Save --> URL: \(self.getStorageUrl())")
        var contestArray: [[String: AnyObject]] = [];
    
        contestArray.extend(contests.map({
                (var contest) -> [String: AnyObject] in
                    return contest.toDictionary()
            }))
        
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
            self.writeData(contestArray);
        }
    }
    
    class func readAll(delegate: SavedFileCacheDelegate){
        println("Read --> URL: \(self.getStorageUrl())")
        var contestArray: [PFContest] = []
        
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
            contestArray = self.readData()
            dispatch_async(dispatch_get_main_queue()) {
                delegate.myContestsDidLoad!(contestArray)
            }
        }
    }
    
    // MARK: Collection Item methods
    
    class func delete(contest:PFContest){
        self.deleteImages(contest)
        var contestArray: [PFContest] = []
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
            contestArray = self.readData()
            if let index = find(contestArray, contest) {
                contestArray.removeAtIndex(index)
                self.saveAll(contestArray)
            }
        }
    }
    
    
    class func findOne(delegate: SavedFileCacheDelegate, contestId: String) {
        var contestArray: [PFContest] = []
        
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
            contestArray = self.readData()
            var filteredContests = filter(contestArray, { $0.objectId == contestId })
            dispatch_async(dispatch_get_main_queue()) {
                delegate.contestWasFoundById!(filteredContests.count > 0 ? filteredContests[0] : nil)
            }
        }
    }
    
    class func saveOrUpdate(contest: PFContest, imageCache:[UIImage?]?) {
        var contestArray: [PFContest] = []
        
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
            self.saveImages(contest, imageCache: imageCache)

            contestArray = self.readData()
            if contains(contestArray, contest) {
                contestArray[find(contestArray, contest)!] = contest
            } else {
                contestArray.append(contest)
            }
            self.saveAll(contestArray)
        }
    }
    
    
    // MARK: File Storage and Retrieval
    
    class func readData() -> [PFContest]{
        var contestArray: [PFContest] = []
        if var data: NSData = NSData(contentsOfURL: self.getStorageUrl()) {
            if var contests = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions(0), error: nil) as? [[String: AnyObject]] {
                contestArray.extend(contests.map {
                    (var dict) -> PFContest in
                    return PFContest.fromDictionary(dict)
                    })
            } else {
                println("Couldn't serialize to NSData")
            }
        } else {
            println("Not contests file found")
        }
        return contestArray
    }
    
    class func writeData(contests: [[String: AnyObject]]){
        if NSJSONSerialization.isValidJSONObject(contests) {
            let data = NSJSONSerialization.dataWithJSONObject(contests, options:NSJSONWritingOptions.PrettyPrinted, error: nil)!
            println("Write <-- URL: \(self.getStorageUrl())")
            data.writeToURL(self.getStorageUrl(), atomically: true)
        } else {
            println("Error -> ContestFile cannot be converted into JSON object")
        }
    }
    
    // MARK: Save Images to Contest
    
    class func saveImages(contest:PFContest, imageCache:[UIImage?]?) {
        if let cache = imageCache {
            for var i = 0 ; i < cache.count ; i++ {
                if let image = cache[i] {
                    let data = UIImagePNGRepresentation(image)
                    let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
                    let path = "\(paths[0] as String)/contest-\(contest.objectId)-imageIndex-\(i)"
                    contest.imagesURIs![i] = path
                    NSFileManager.defaultManager().fileExistsAtPath(path)
                    
                    data.writeToFile(path, atomically: false)
                }
            }
        }
    }
    
    class func deleteImages(contest:PFContest) {
        if let imageURIs = contest.imagesURIs {
            for uri:String in imageURIs {
                dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
                    let manager = NSFileManager.defaultManager()
                    if manager.fileExistsAtPath(uri) {
                        manager.removeItemAtPath(uri, error: nil)
                        println("deleted ---> Images")
                    }
                }
            }
        }
    }
}