//
//  ImportedTrack.swift
//  TagTunes
//
//  Created by Kim Wittenburg on 17.03.16.
//  Copyright © 2016 Kim Wittenburg. All rights reserved.
//

import SearchAPI

public class ImportedTrack: TagTunesTrack {

    /// The `iTunesTrack` represented by this instance.
    private var track: iTunesTrack

    public override func readTrackID() throws -> SearchAPIID {
        guard let fileTrack = self.track as? iTunesFileTrack, fileURL = fileTrack.location where fileURL.checkResourceIsReachableAndReturnError(nil) else {
            throw TagTunesTrackErrors.FileNotFound
        }
        let fileHandle = try? NSFileHandle(forReadingFromURL: fileTrack.location)
        // Read the first 1024 bytes from the file. The file's ID seems to always
        // be at around 600-700 bytes so we don't need to read more than that.
        guard let data = fileHandle?.readDataOfLength(1024) else {
            throw TagTunesTrackErrors.FileNotReadable
        }
        let dataToFind = "song".dataUsingEncoding(NSASCIIStringEncoding)!
        let dataRange = data.rangeOfData(dataToFind, options: [], range: NSRange(location: 0, length: data.length))
        guard dataRange.location != NSNotFound else {
            throw TagTunesTrackErrors.NoIDFound
        }
        var rawID: UInt32 = 0
        data.getBytes(&rawID, range: NSRange(location: NSMaxRange(dataRange), length: 4))
        return SearchAPIID(UInt32(bigEndian: rawID))
    }

    /// Initializes the track with the specified `iTunesTrack`.
    public init(track: iTunesTrack) {
        self.track = track
        super.init()
    }

    public required init?(coder aDecoder: NSCoder) {
        if let track = aDecoder.decodeObjectOfClass(iTunesTrack.self, forKey: "track") {
            self.track = track
            super.init()
        } else {
            track = iTunesTrack()
            super.init()
            return nil
        }
    }

    public override func encodeWithCoder(aCoder: NSCoder) {
        aCoder.encodeObject(track, forKey: "track")
    }

    public override func valueForTag(tag: Tag) -> AnyObject! {
        return track.valueForKey(tag.rawValue)
    }

    public override func reveal() {
        track.reveal()
        iTunes.activate()
    }

    public override var supportsBatchSaving: Bool {
        return false
    }

    public override func saveValue(value: AnyObject?, forTag tag: Tag) throws {
        if tag == .Artwork {
            track.artworks().removeAllObjects()
            if let artwork = value as? NSImage {
                track.artworks().objectAtIndex(0).propertyWithCode(AEKeyword("pPCT")).setTo(artwork)
            }
        } else if let theValue = value {
            track.propertyWithCode(tag.code).setTo(theValue)
        } else {
            track.propertyWithCode(tag.code).setTo("")
        }
    }

    public override var hashValue: Int {
        return track.id()
    }

}

public func ==(lhs: ImportedTrack, rhs: ImportedTrack) -> Bool {
    return lhs.track.id() == rhs.track.id()
}