//
//  PriceLockup.swift
//  VDS
//
//  Created by Kanamarlapudi, Vasavi on 06/08/24.
//

import Foundation
import UIKit
import VDSCoreTokens

@objcMembers
@objc(VDSPriceLockup)
open class PriceLockup: View {
    
    //--------------------------------------------------
    // MARK: - Initializers
    //--------------------------------------------------
    required public init() {
        super.init(frame: .zero)
    }
    
    public override init(frame: CGRect) {
        super.init(frame: .zero)
    }
    
    public required init?(coder: NSCoder) {
        super.init(coder: coder)
    }
    
    //--------------------------------------------------
    // MARK: - Enums
    //--------------------------------------------------
    /// Enum used to describe the term of PriceLockup.
    public enum Term: String, CaseIterable {
        case month, year, biennial, none
        
        /// The default term is 'month'.
        public static var defaultValue : Self { .month }
        
        /// Text for this term of PriceLockup.
        public var type: String {
            switch self {
            case .month:
                return "mo"
            case .year:
                return "yr"
            case .biennial:
                return "biennial"
            case .none:
                return ""
            }
        }
    }
    
    /// Enum that represents the size availble for PriceLockup.
    public enum Size: String, CaseIterable {
        case xxxsmall
        case xxsmall
        case xsmall
        case small
        case medium
        case large
        case xlarge
        case xxlarge
        
        public static var defaultValue: Self { .medium }
    }
    
    /// Enum used to describe the kind of PriceLockup.
    public enum Kind: String, CaseIterable {
        case primary, secondary, savings
        
        /// The default kind is 'primary'.
        public static var defaultValue : Self { .primary }
        
        /// Color configuation relative to kind.
        public var colorConfiguration: ViewColorConfiguration {
            switch self {
            case .primary:
                return ViewColorConfiguration().with {
                    $0.setSurfaceColors(VDSColor.elementsPrimaryOnlight, VDSColor.elementsPrimaryOndark, forDisabled: false)}
            case .secondary:
                return ViewColorConfiguration().with {
                    $0.setSurfaceColors(VDSColor.elementsSecondaryOnlight, VDSColor.elementsSecondaryOndark, forDisabled: false)}
            case .savings:
                return ViewColorConfiguration().with {
                    $0.setSurfaceColors(VDSColor.paletteGreen26, VDSColor.paletteGreen36, forDisabled: false)}
            }
        }
    }
    
    //--------------------------------------------------
    // MARK: - Public Properties
    //--------------------------------------------------
    
    /// If true, the component will render as bold.
    open var bold: Bool = false { didSet { setNeedsUpdate() } }
    
    /// Currency - If hideCurrency true, the component will render without currency.
    open var hideCurrency: Bool = false { didSet { setNeedsUpdate() } }
    
    /// Leading text for the component.
    open var leadingText: String? { didSet { setNeedsUpdate() } }
    
    /// Value rendered for the component.
    open var price: Float? { didSet { setNeedsUpdate() } }
    
    /// Color to the component. The default kind is primary.
    open var kind: Kind = Kind.defaultValue { didSet { setNeedsUpdate() } }
    
    /// Size of the component. It varies by size and viewport(mobile/Tablet).
    /// The default size is medium with viewport mobile.
    open var size: Size = Size.defaultValue { didSet { setNeedsUpdate() } }
    
    /// If true, the component with a strikethrough. It applies only when uniformSize is true.
    /// Does not apply a strikethrough format to leading and trailing text.
    open var strikethrough: Bool = false { didSet { setNeedsUpdate() } }
    
    /// Term text for the component. The default term is 'month'.
    /// Superscript placement can vary when term and delimeter are "none".
    open var term: Term = Term.defaultValue { didSet { setNeedsUpdate() } }
    
    /// Trailing text for the component.
    open var trailingText: String? { didSet { setNeedsUpdate() } }
    
    /// Superscript text for the component.
    open var superscript: String? { didSet { setNeedsUpdate() } }
    
    /// If true, currency and value have the same font text style as delimeter, term label and superscript.
    /// This will render the pricing and term sections as a uniform size.
    open var uniformSize: Bool = false { didSet { setNeedsUpdate() } }
    
    //--------------------------------------------------
    // MARK: - Private Properties
    //--------------------------------------------------
    internal var priceLockupLabel = Label().with {
        $0.isAccessibilityElement = true
        $0.lineBreakMode = .byWordWrapping
    }
    
    internal var delimiterIndex = 0
    internal var strikethroughLocation = 0
    internal var strikethroughLength = 0
    
    internal var textPosition:TextPosition = .preDelimiter
    enum TextPosition: String, CaseIterable {
        case preDelimiter, postDelimiter
    }
    
    //--------------------------------------------------
    // MARK: - Configuration Properties
    //--------------------------------------------------
    internal var containerSize: CGSize { CGSize(width: 45, height: 44) }
    
    // TextStyle for the size.
    private var textStyle: TextStyle.StandardStyle {
        switch (size, textPosition) {
        case (.xxxsmall, .preDelimiter), (.xxxsmall, .postDelimiter):
            return .micro
            
        case (.xxsmall, .preDelimiter), (.xxsmall, .postDelimiter):
            return .bodySmall
            
        case (.xsmall, .preDelimiter), (.xsmall, .postDelimiter):
            return .bodyMedium
            
        case (.small, .preDelimiter), (.small, .postDelimiter):
            return .bodyLarge
            
        case (.medium, .preDelimiter):
            return  UIDevice.isIPad ? .titleSmall : .titleMedium
            
        case (.medium, .postDelimiter):
            return  .bodyLarge
            
        case (.large, .preDelimiter):
            return UIDevice.isIPad ? .titleMedium : .titleLarge
            
        case (.large, .postDelimiter):
            return UIDevice.isIPad ? .titleSmall : .titleMedium
            
        case (.xlarge, .preDelimiter):
            return UIDevice.isIPad ? .titleLarge : .titleXLarge
            
        case  (.xlarge, .postDelimiter):
            return UIDevice.isIPad ? .titleMedium : .titleLarge
            
        case (.xxlarge, .preDelimiter):
            return UIDevice.isIPad ? .titleXLarge : .featureSmall
            
        case  (.xxlarge, .postDelimiter):
            return UIDevice.isIPad ? .titleLarge : .titleXLarge
        }
    }
    
    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------
    /// Called once when a view is initialized and is used to Setup additional UI or other constants and configurations.
    open override func setup() {
        super.setup()
        
        // Price lockup label
        addSubview(priceLockupLabel)
        priceLockupLabel.pinToSuperView()
    }
    
    /// Used to make changes to the View based off a change events or from local properties.
    open override func updateView() {
        super.updateView()
        
        priceLockupLabel.text = fetchText()
        priceLockupLabel.surface = surface
        
        // Set the attributed text
        updateLabelAttributes()
    }
    
    /// Resets to default settings.
    open override func reset() {
        super.reset()
        shouldUpdateView = false
        priceLockupLabel.reset()
        shouldUpdateView = true
        setNeedsUpdate()
    }
    
    //--------------------------------------------------
    // MARK: - Private Methods
    //--------------------------------------------------
    // Update PriceLockup text attributes
    func updateLabelAttributes() {
        var attributes: [any LabelAttributeModel] = []
        attributes.append(ColorLabelAttribute(location: 0,
                                              length: priceLockupLabel.text.count,
                                              color: kind.colorConfiguration.getColor(self)))
        textPosition = .postDelimiter
        if strikethrough {
            
            // strike applies only when uniformSize true. Does not apply a strikethrough format to leading, trailing, and superscript text.
            attributes.append(TextStyleLabelAttribute(location: 0,
                                                      length: priceLockupLabel.text.count,
                                                      textStyle: bold ? textStyle.bold : textStyle.regular,
                                                      textPosition: .left))
            attributes.append(StrikeThroughLabelAttribute(location:strikethroughLocation, length: strikethroughLength))
            
        } else if uniformSize {
            
            // currency and value have the same font text style as delimeter, term, trailing text and superscript.
            attributes.append(TextStyleLabelAttribute(location: 0,
                                                      length: priceLockupLabel.text.count,
                                                      textStyle: bold ? textStyle.bold : textStyle.regular,
                                                      textPosition: .left))
            
        } else {
            
            // size updates relative to predelimiter, postdelimiter
            if delimiterIndex > 0 {
                textPosition = .preDelimiter
                attributes.append(TextStyleLabelAttribute(location: 0,
                                                          length: delimiterIndex,
                                                          textStyle: bold ? textStyle.bold : textStyle.regular,
                                                          textPosition: .left))
                
                textPosition = .postDelimiter
                attributes.append(TextStyleLabelAttribute(location: delimiterIndex,
                                                          length: priceLockupLabel.text.count-delimiterIndex,
                                                          textStyle: bold ? textStyle.bold : textStyle.regular,
                                                          textPosition: .left))
            }
        }
        priceLockupLabel.attributes = attributes
    }
    
    // Get text for PriceLockup.
    open func fetchText() -> String {
        var text : String = ""
        let space = " "
        let delimiter = "/"
        delimiterIndex = 0
        strikethroughLength = 0
        let currency: String = hideCurrency ? "" : "$"
        if let leadingStr = leadingText {
            text = text + leadingStr + space
            delimiterIndex = delimiterIndex + leadingStr.count + space.count
        }
        strikethroughLocation = delimiterIndex
        if let value = price {
            let valueStr = "\(value.clean)"
            text = text + currency + valueStr
            delimiterIndex = delimiterIndex + valueStr.count + currency.count
            strikethroughLength = valueStr.count + currency.count
        }
        if term != .none {
            text = text + delimiter + term.type
            strikethroughLength = strikethroughLength + delimiter.count + term.type.count
        }
        if let trailingStr = trailingText {
            text = text + space + trailingStr
        }
        text = text + (superscript ?? "")
        return text
    }
}

extension Float {
    // remove a decimal from a float if the decimal is equal to 0
    var clean: String {
        return self.truncatingRemainder(dividingBy: 1) == 0 ? String(format: "%.0f", self) : String(self)
    }
}