//
//  SettingsController.swift
//  CapCollector
//
//  Created by Christoph on 15.10.18.
//  Copyright © 2018 CH. All rights reserved.
//

import UIKit

class SettingsController: UITableViewController {

    @IBOutlet weak var totalCapsLabel: UILabel!
    
    @IBOutlet weak var totalImagesLabel: UILabel!
    
    @IBOutlet weak var recognizedCapsLabel: UILabel!
    
    @IBOutlet weak var imagesStatsLabel: UILabel!
    
    @IBOutlet weak var databaseUpdatesLabel: UILabel!
    
    @IBOutlet weak var dropboxAccountLabel: UILabel!
    
    @IBOutlet weak var countsLabel: UILabel!
    
    private var isUpdatingCounts = false
    
    private var isUploadingNameFile = false
    
    private var isUpdatingThumbnails = false
    
    private var isUpdatingColors = false
    
    override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
        return .portrait
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func viewWillAppear(_ animated: Bool) {
        updateDropboxStatus()
        updateNameFileStats()
        updateDatabaseStats()
        
        (navigationController as! NavigationController).allowLandscape = false
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        setClassifierChoice(Persistence.useMobileNet)
    }
    
    private func updateThumbnails() {
        isUpdatingThumbnails = true
        for cap in Cap.all.values {
            cap.makeThumbnail()
        }
        isUpdatingThumbnails = false
    }
    
    private func updateColors() {
        isUpdatingColors = true
        Cap.shouldSave = false
        for cap in Cap.all.values {
            cap.makeAverageColor()
        }
        Cap.shouldSave = true
        isUpdatingColors = false
    }
    
    private func updateDatabaseStats() {
        let totalCaps = Cap.totalCapCount
        totalCapsLabel.text = "\(totalCaps) caps"
        totalImagesLabel.text = "\(Cap.imageCount) images"
        let recognizedCaps = Persistence.recognizedCapCount
        let newCapCount = totalCaps - recognizedCaps
        recognizedCapsLabel.text = "\(newCapCount) new caps"
        let ratio = Float(Cap.imageCount)/Float(Cap.totalCapCount)
        let (images, count) = Cap.getCapStatistics().enumerated().first(where: { $0.element != 0 })!
        imagesStatsLabel.text = String(format: "%.2f images per cap, lowest count: %d (%dx)", ratio, images, count)
    }
    
    private func updateNameFileStats() {
        let capCount = Cap.totalCapCount - Persistence.lastUploadedCapCount
        let imageCount = Cap.imageCount - Persistence.lastUploadedImageCount
        databaseUpdatesLabel.text = "\(capCount) new caps and \(imageCount) new images"
    }
    
    private func updateDropboxStatus() {
        dropboxAccountLabel.text = DropboxController.shared.isEnabled ? "Sign out" : "Sign in"
    }
    
    private func setClassifierChoice(_ useMobileNet: Bool) {
        tableView.cellForRow(at: IndexPath(row: 0, section: 0))?.accessoryType = useMobileNet ? .checkmark : .none
    }
    
    private func toggleClassifier() {
        let newValue = !Persistence.useMobileNet
        Persistence.useMobileNet = newValue
        setClassifierChoice(newValue)
    }
    
    override func tableView(_ tableView: UITableView, shouldHighlightRowAt indexPath: IndexPath) -> Bool {
        switch indexPath.section {
        case 0: // Choose models
            return true
        case 1: // Mosaic
            return true
        case 2: // Database
            return indexPath.row == 2 && !isUploadingNameFile
        case 3: // Refresh
            switch indexPath.row {
            case 0:
                return !isUpdatingCounts
            case 1:
                return !isUpdatingThumbnails
            case 2:
                return !isUpdatingColors
            default:
                return false
            }
        case 4: // Dropbox account
            return true
        case 5: // Log file
            return true
        default: return false
        }
    }
    
    override func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? {
        switch indexPath.section {
        case 0: // Choose models
            return indexPath
        case 1: // Mosaic
            return indexPath
        case 2: // Database
            return (indexPath.row == 2 && !isUploadingNameFile) ? indexPath : nil
        case 3: // Refresh count
            switch indexPath.row {
            case 0:
                 return isUpdatingCounts ? nil : indexPath
            case 1:
                return isUpdatingThumbnails ? nil : indexPath
            case 2:
                return isUpdatingColors ? nil : indexPath
            default:
                return nil
            }
        case 4: // Dropbox account
            return indexPath
        case 5: // Log file
            return indexPath
        default: return nil
        }
    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.deselectRow(at: indexPath, animated: true)
        switch indexPath.section {
        case 0: // Choose models
            toggleClassifier()
        case 2: // Upload
            if indexPath.row == 2 && !isUploadingNameFile {
                uploadNameFile()
            }
        case 3: // Refresh count
            switch indexPath.row {
            case 0:
                updateCounts()
            case 1:
                updateThumbnails()
            case 2:
                updateColors()
            default:
                break
            }
        default:
            break
        }
    }

    private func updateCounts() {
        isUpdatingCounts = true
        Cap.shouldSave = false
        // TODO: Don't make all requests at the same time
        DispatchQueue.global(qos: .userInitiated).async {
            let list = Cap.all.keys.sorted()
            let total = list.count
            var finished = 0
            let chunks = list.chunked(into: 10)
            for chunk in chunks {
                self.updateCounts(ids: chunk)
                finished += 10
                DispatchQueue.main.async {
                    self.countsLabel.text = "\(finished) / \(total) finished"
                }
            }
            self.isUpdatingCounts = false
            Cap.shouldSave = true
            DispatchQueue.main.async {
                self.countsLabel.text = "Refresh image counts"
                self.updateDatabaseStats()
            }
        }
    }
    
    private func updateCounts(ids: [Int]) {
        var count = ids.count
        let s = DispatchSemaphore(value: 0)
        for cap in ids {
            Cap.all[cap]!.updateCount { _ in
                count -= 1
                if count == 0 {
                    s.signal()
                }
            }
        }
        _ = s.wait(timeout: .now() + .seconds(30))
        event("Finished updating ids \(ids.first!) to \(ids.last!)")
    }
    
    private func uploadNameFile() {
        event("Uploading name file")
        isUploadingNameFile = true
        Cap.saveAndUpload() { _ in
            self.isUploadingNameFile = false
            self.updateNameFileStats()
        }
    }
    
    private func toggleDropbox() {
        guard !DropboxController.shared.isEnabled else {
            DropboxController.shared.signOut()
            updateDropboxStatus()
            return
        }
        
        DropboxController.shared.setup(in: self)
        updateDropboxStatus()
    }
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        guard let id = segue.identifier else {
            return
        }
        switch id {
        case "showMosaic":
            (navigationController as! NavigationController).allowLandscape = true
        case "showLog":
            return
        default:
            return
        }
        
    }
}

extension SettingsController: Logger {
    
    static let logToken = "[Settings]"
}

private extension Array {
    func chunked(into size: Int) -> [[Element]] {
        return stride(from: 0, to: count, by: size).map {
            Array(self[$0 ..< Swift.min($0 + size, count)])
        }
    }
}