//
//  SeismicNetworksIntensityMapViewController.swift
//  Earthquake Network
//
//  Created by Andrea Busi on 27/02/25.
//  Copyright © 2025 Earthquake Network. All rights reserved.
//

import UIKit
import MapKit

class SeismicNetworksIntensityMapViewController: EQNBaseMapViewController {

    private let seismic: EQNSisma
    private var shakemaps: [EQNShakemap] = []
    private var pinStyle: MapPinStyle {
        get { AppPreferences.shared.mapPinStyle }
        set { AppPreferences.shared.mapPinStyle = newValue }
    }

    override var isFilterViewVisible: Bool { false }
    override var isCloseButtonVisible: Bool { false }

    // MARK: - UI
    
    lazy var descriptionView: UIView = {
        let view = UIView()
        view.translatesAutoresizingMaskIntoConstraints = false
        view.backgroundColor = AppTheme.Colors.pureBlue

        let descriptionLabel = UILabel()
        descriptionLabel.translatesAutoresizingMaskIntoConstraints = false
        descriptionLabel.numberOfLines = 0
        descriptionLabel.textColor = .white
        descriptionLabel.font = .preferredFont(forTextStyle: .subheadline)
        descriptionLabel.textAlignment = .center
        descriptionLabel.text = NSLocalizedString("shakemap_description", comment: "")
        
        view.addSubview(descriptionLabel)
        descriptionLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 2.0).isActive = true
        descriptionLabel.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -2.0).isActive = true
        descriptionLabel.topAnchor.constraint(equalTo: view.topAnchor, constant: 2.0).isActive = true
        descriptionLabel.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -2.0).isActive = true
        
        return view
    }()
    
    // MARK: - Init
    
    init(
        seismic: EQNSisma
    ) {
        self.seismic = seismic
        super.init()
    }
    
    @MainActor required init?(coder: NSCoder) {
        fatalError("Plase use init(seismic:) instead")
    }
    
    // MARK: - View Lifecycle
    
    override func extraUI() {
        super.extraUI()
        
        view.addSubview(descriptionView)
        descriptionView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
        descriptionView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
        descriptionView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
    }
    
    override func configureUI() {
        super.configureUI()
        
        navigationItem.leftBarButtonItem = UIBarButtonItem(systemItem: .done, primaryAction: .init(handler: { [weak self] _ in
            self?.dismiss(animated: true)
        }))
        navigationItem.rightBarButtonItems = [
            UIBarButtonItem(image: UIImage(named: "navbar-icon-screenshot"), primaryAction: .init(handler: { [weak self] _ in
                self?.shareScreenshot()
            })),
            UIBarButtonItem(image: UIImage(named: "navbar-icon-pin-arrow"), primaryAction: .init(handler: { [weak self] _ in
                self?.nextPinStyle()
            })),
        ]
    }
    
    override func registerMapAnnotationViews() {
        mapView.register(EQNSeismicAnnotationView.self, forAnnotationViewWithReuseIdentifier: EQNSeismicAnnotationView.identifier(for: .full))
        mapView.register(EQNSeismicAnnotationView.self, forAnnotationViewWithReuseIdentifier: EQNSeismicAnnotationView.identifier(for: .light))
        mapView.register(EQNSeismicAnnotationView.self, forAnnotationViewWithReuseIdentifier: EQNSeismicAnnotationView.identifier(for: .circle))
    }
    
    override func loadDataSource() {
        Task {
            let result = try await APIService.shared.fetchShakemap(isoCode: seismic.isoCode)
            elaborateShakemaps(result)
        }
    }
    
    override func elaborateMapCenter() {
        setMapCenter(for: seismic.coordinate, span: MKCoordinateSpan(latitudeDelta: 2, longitudeDelta: 2))
    }
    
    // MARK: - Private
    
    private func elaborateShakemaps(_ shakemaps: [EQNShakemap]) {
        self.shakemaps = shakemaps
        
        var shakemapPolyline = [MKPolyline]()
        var shakemapAnnotations: [MKAnnotation] = []
        for shakemap in shakemaps {
            // create coordinates for current shakemap
            let coordinates = zip(shakemap.lat, shakemap.lon).map { lat, lon in
                CLLocationCoordinate2D(latitude: Double(lat) / 10_000.0, longitude: Double(lon) / 10_000.0)
            }
            
            let intensityColors = getColors(for: shakemap.intensity)
            
            // create line to show on map
            let polyline = ShakemapPolyline(coordinates: coordinates, count: coordinates.count)
            polyline.intensity = shakemap.intensity
            polyline.intensityColor = intensityColors.lineColor
            shakemapPolyline.append(polyline)
            
            // create annotation to show on top of the line
            let middlePoint = coordinates[coordinates.count / 2]
            let annotation = EQNMapAnnotationShakemap(coordinate: middlePoint, shakemap: shakemap)
            annotation.intensityColor = intensityColors.lineColor
            annotation.intensityTextColor = intensityColors.textColor
            shakemapAnnotations.append(annotation)
        }

        let seismicAnnotation = EQNMapAnnotationSeismic(seismic: seismic)
        shakemapAnnotations.append(seismicAnnotation)
        
        // draw lines
        mapView.addOverlays(shakemapPolyline)
        updateMap(with: shakemapAnnotations)
    }
    
    private func nextPinStyle() {
        pinStyle.advance()
        reloadMap()
    }
    
    private func shareScreenshot() {
        let screenshot = createSnapshot(prepare: {
            descriptionView.isHidden = true
        }, restore:  {
            descriptionView.isHidden = false
        })
        
        let controller = UIActivityViewController(activityItems: [screenshot], applicationActivities: [])
        present(controller, animated: true)
    }
    
    // MARK: - MKMapViewDelegate

    override func setupAnnotationView(for annotation: MKAnnotation, on mapView: MKMapView) -> MKAnnotationView? {
        switch annotation {
        case let shakemapAnnotation as EQNMapAnnotationShakemap:
            return shakemapAnnotation.toAnnotationView(mapView: mapView, style: .light)
        case let seismicAnnotation as EQNMapAnnotationSeismic:
            return seismicAnnotation.toAnnotationView(mapView: mapView, style: pinStyle)
        default:
            return nil
        }
    }
    
    func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
        if let polyline = overlay as? ShakemapPolyline {
            let renderer = MKPolylineRenderer(polyline: polyline)
            renderer.strokeColor = polyline.intensityColor
            renderer.lineWidth = 6.0
            return renderer
        }
        return MKOverlayRenderer()
    }
    
    private func getColors(for intensity: Float) -> (textColor: UIColor, lineColor: UIColor) {
        let shakemapColors: [String] = [
            "#3E26A8","#3E27AC","#3F28AF","#3F29B2","#402AB4","#402BB7","#412CBA","#412DBD","#422EBF","#422FC2",
            "#4330C5","#4331C8","#4332CA","#4433CD","#4434D0","#4535D2","#4537D5","#4538D7","#4639D9","#463ADC",
            "#463BDE","#463DE0","#473EE1","#473FE3","#4741E5","#4742E6","#4744E8","#4745E9","#4746EB","#4848EC",
            "#4849ED","#484BEE","#484CF0","#484EF1","#484FF2","#4850F3","#4852F4","#4853F5","#4854F6","#4756F7",
            "#4757F7","#4759F8","#475AF9","#475BFA","#475DFA","#465EFB","#4660FB","#4661FC","#4562FC","#4564FD",
            "#4465FD","#4367FD","#4368FE","#426AFE","#416BFE","#406DFE","#3F6EFF","#3E70FF","#3C71FF","#3B73FF",
            "#3974FF","#3876FE","#3677FE","#3579FD","#337AFD","#327CFC","#317DFC","#307FFB","#2F80FA","#2F82FA",
            "#2E83F9","#2E84F8","#2E86F8","#2E87F7","#2D88F6","#2D8AF5","#2D8BF4","#2D8CF3","#2D8EF2","#2C8FF1",
            "#2C90F0","#2B91EF","#2A93EE","#2994ED","#2895EC","#2797EB","#2798EA","#2699E9","#269AE8","#259BE8",
            "#259CE7","#249EE6","#249FE5","#23A0E5","#23A1E4","#22A2E4","#21A3E3","#20A5E3","#1FA6E2","#1EA7E1",
            "#1DA8E1","#1DA9E0","#1CAADF","#1BABDE","#1AACDD","#19ADDC","#17AEDA","#16AFD9","#14B0D8","#12B1D6",
            "#10B2D5","#0EB3D4","#0BB3D2","#08B4D1","#06B5CF","#04B6CE","#02B7CC","#01B7CA","#00B8C9","#00B9C7",
            "#00BAC6","#01BAC4","#02BBC2","#04BBC1","#06BCBF","#09BDBD","#0DBDBC","#10BEBA","#14BEB8","#17BFB6",
            "#1AC0B5","#1DC0B3","#20C1B1","#23C1AF","#25C2AE","#27C2AC","#29C3AA","#2BC3A8","#2CC4A6","#2EC4A5",
            "#2FC5A3","#31C5A1","#32C69F","#33C79D","#35C79B","#36C899","#38C896","#39C994","#3BC992","#3DCA90",
            "#40CA8D","#42CA8B","#45CB89","#48CB86","#4BCB84","#4ECC81","#51CC7F","#54CC7C","#57CC7A","#5ACC77",
            "#5ECD74","#61CD72","#64CD6F","#67CD6C","#6BCD69","#6ECD66","#72CD64","#76CC61","#79CC5E","#7DCC5B",
            "#81CC59","#84CC56","#88CB53","#8BCB51","#8FCB4E","#93CA4B","#96CA48","#9AC946","#9DC943","#A1C840",
            "#A4C83E","#A7C73B","#ABC739","#AEC637","#B2C635","#B5C533","#B8C431","#BBC42F","#BEC32D","#C2C32C",
            "#C5C22A","#C8C129","#CBC128","#CEC027","#D0BF27","#D3BF27","#D6BE27","#D9BE28","#DBBD28","#DEBC29",
            "#E1BC2A","#E3BC2B","#E6BB2D","#E8BB2E","#EABA30","#ECBA32","#EFBA35","#F1BA37","#F3BA39","#F5BA3B",
            "#F7BA3D","#F9BA3E","#FBBB3E","#FCBC3E","#FEBD3D","#FEBE3C","#FEC03B","#FEC13A","#FEC239","#FEC438",
            "#FEC537","#FEC735","#FEC834","#FECA33","#FDCB32","#FDCD31","#FDCE31","#FCD030","#FBD22F","#FBD32E",
            "#FAD52E","#F9D62D","#F9D82C","#F8D92B","#F7DB2A","#F7DD2A","#F6DE29","#F6E028","#F5E128","#F5E327",
            "#F5E526","#F5E626","#F5E825","#F5E924","#F5EB23","#F5EC22","#F5EE21","#F6EF20","#F6F11F","#F6F21E",
            "#F7F41C","#F7F51B","#F8F71A","#F8F818","#F9F916","#F9FB15"
        ]
        
        let minIntensity = shakemaps.map { $0.intensity }.min() ?? 0
        let maxIntensity = shakemaps.map { $0.intensity }.max() ?? 255
        let indexColor = if minIntensity == maxIntensity {
            0
        } else {
            Int(round((intensity-minIntensity)/(maxIntensity-minIntensity)*255))
        }
        
        let lineColor = UIColor(hexString: shakemapColors[indexColor]) ?? .white
        let textColor: UIColor = indexColor < 65 ? .white : .black
        
        return (textColor: textColor, lineColor: lineColor)
    }
}

extension EQNMapAnnotationShakemap {
    func toAnnotationView(
        mapView: MKMapView,
        style: MapPinStyle,
        isUserSelection: Bool = false
    ) -> MKAnnotationView? {
        switch style {
        case .full, .light:
            let identifier = EQNSeismicAnnotationView.identifier(for: style)
            let annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier, for: self) as! EQNSeismicAnnotationView
            annotationView.magnitude = intensityString(from: shakemap.intensity)
            annotationView.magnitudeTextColor = intensityTextColor ?? .black
            annotationView.magnitudeBackgroundColor = intensityColor
            annotationView.canShowCallout = true
            return annotationView
        case .circle:
            return nil
        }
    }
    
    private func intensityString(from intensity: Float) -> String {
        let intensityRounded = (intensity * 10).rounded() / 10
        let intensityFloor = floor(intensityRounded)
        
        let romanNumerals: [Int: String] = [
            1: "I", 2: "II", 3: "III", 4: "IV",
            5: "V", 6: "VI", 7: "VII", 8: "VIII",
            9: "IX", 10: "X", 11: "XI", 12: "XII"
        ]
        
        var result = romanNumerals[Int(intensityFloor)] ?? ""

        if intensityRounded != intensityFloor {
            let reminder = Int(((intensityRounded - intensityFloor) * 10).rounded())
            result += ".\(reminder)"
        }
        
        return result
    }
}

fileprivate class ShakemapPolyline: MKPolyline {
    var intensity: Float = 0
    var intensityColor: UIColor = .white
}