//
//  ContributeView.swift
//  Toki Trainer
//
//  Created by Madeline Pace on 12/16/23.
//

import SwiftUI
import StoreKit

typealias Transaction = StoreKit.Transaction

public enum StoreError: Error {
    case failedVerification
}

// MARK: ContributeView
struct ContributeView: View {

    private let supportString = """
Hi 👋

I'm Maddie, the primary developer for Toki Trainer.

This app is free and open source. If you find it \
useful, please consider supporting my development efforts.

I don't collect your data and am committed to providing \
a high-quality, ad-free experience. Learning toki pona \
easily and comfortably is the whole point, and ads would \
ruin that!

Taking a moment to add an App Store Review helps a ton. \
Please also consider donating financially if you can. 💕
"""



    
    private var recurringIAPs = ["TierThree"]

    @EnvironmentObject var transactions: TransactionObserver

    var body: some View {
        VStack {
            Spacer()
            if transactions.hasDonated {
                ThankYouBannerView(donationHearts: $transactions.donationHearts)
            }
            Text(supportString)
                .padding(16)
            Spacer()

//            Link("Source Code", destination: URL(string: "https://git.corrupt.link/maddiefuzz/TokiTrainer")!)
//                .padding(12)

//            .padding([.bottom], 12)
            HStack {
                ReviewButton()
                SourceCodeButton()
            }
            HStack {
                SingleDonationButton()
                RecurringDonationButton()
            }
            Spacer()
        }
    }
}

// MARK: ThankYouBannerView
struct ThankYouBannerView: View {

    @Binding var donationHearts: Int

    var body: some View {
        ZStack {
            Rectangle()
                .fill(.blue)
                .cornerRadius(15)
            VStack {
                Text("Thank you for donating!")
                    .multilineTextAlignment(.center)
                    .font(.title)
                Text("\(donationHearts) 💕")
                    .padding(10)
                    .font(.title3)
            }
        }
        .frame(width: 250, height: 140)
    }
}

struct SourceCodeButton: View {
    var body: some View {
        Link(destination: URL(string: "https://git.corrupt.link/maddiefuzz/TokiTrainer")!) {
            VStack {
                Image(systemName: "apple.terminal")
                    .font(.system(size: 24, weight: .regular))
                    .padding(2)
                Text("Source Code")
            }
        }
        .frame(width: 100)
        .padding(8)
    }
}

// MARK: ReviewButton
struct ReviewButton: View  {
    @Environment(\.requestReview) private var requestReview

    var body: some View {
        Button(action: {
            print("Review requested")
            presentReviewRequest()
        }, label: {
            VStack {
                Image(systemName: "star.bubble")
                    .font(.system(size: 24, weight: .regular))
                    .padding(2)
                Text("Write Review")
            }
        })
        .frame(width: 100)
        .padding(8)
    }

    func presentReviewRequest() {
        Task {
            await requestReview()
        }
    }
}

// Workaround for .sheet(item:) expecting an Identifiable
struct DonationProducts: Identifiable {
    let id = UUID()
    var products = [Product]()
}

// MARK: SingleDonationButton
struct SingleDonationButton: View {
    @Environment(\.purchase) private var purchase: PurchaseAction

    @EnvironmentObject var transactions: TransactionObserver

    @State private var IAPs: DonationProducts?
    @State private var productsFetched = false
    @State private var disabledPurchaseButtons = false


    private var singleIAPs = ["SingleTimeTipTierOne",
                              "SingleTimeTipTierTwo",
                              "SingleTimeTipTierThree",
                              "SingleTimeTipTierFour"]

    var body: some View {
        Button {
            Task {
                try await loadSingleProducts()
            }
        } label: {
            VStack {
                Image(systemName: "dollarsign.circle")
                    .font(.system(size: 24, weight: .regular))
                    .padding(2)
                Text("Donate Once")
            }
        }
        .frame(width: 100)
        .padding(8)
        .sheet(item: self.$IAPs) { IAPs in
            if(productsFetched) {
                VStack {
                    Spacer()
                    Text("One-Time Donation")
                        .font(.largeTitle)
                    Spacer()
                    ForEach(IAPs.products) { product in
                        HStack {
                            VStack {
                                Text(product.displayName)
                                    .font(.title)
                                    .frame(maxWidth: .infinity, alignment: .leading)
                                Text(product.description)
                                    .frame(maxWidth: .infinity, alignment: .leading)
                            }
                            .padding(.leading, 12)
                            Spacer()
                            Button {
                                print("Purchase this one: \(product)")
                                disabledPurchaseButtons = true
                                Task {
                                    let _ = try? await purchase(product)
                                    disabledPurchaseButtons = false
                                }
                            } label: {
                                Text(product.displayPrice)
                                    .frame(minWidth: 50)
                                    .padding(8)
                                    .fontWeight(/*@START_MENU_TOKEN@*/.bold/*@END_MENU_TOKEN@*/)
                            }
                            .padding(.trailing, 12)
                            .buttonStyle(.bordered)
                            .disabled(disabledPurchaseButtons)
                        }
                        .padding(12)
                    }
                    Spacer()
                    LegalLinksView()
                        .padding(16)
                        .padding([.bottom], 20)
                }
                //.padding([.top], 60)
            } else {
                ProgressView()
            }
        }
    }

    private func purchase(_ product: Product) async throws -> Transaction? {
        let result = try await product.purchase()

        switch result {
        case .success(let verification):
            let transaction = try checkVerified(verification)
            await transaction.finish()
            print("Purchase success")
            transactions.processConsumable(transaction.productID)
            return transaction
        case .userCancelled, .pending:
            return nil
        default:
            return nil
        }

    }

    func checkVerified<T>(_ result: VerificationResult<T>) throws -> T {
        //Check whether the JWS passes StoreKit verification.
        switch result {
        case .unverified:
            //StoreKit parses the JWS, but it fails verification.
            throw StoreError.failedVerification
        case .verified(let safe):
            //The result is verified. Return the unwrapped value.
            return safe
        }
    }

    private func loadSingleProducts() async throws {
        self.IAPs = DonationProducts()
        self.IAPs?.products = try await Product.products(for: singleIAPs).sorted(by: { p1, p2 in
            p1.price < p2.price
        })
        self.productsFetched = true
    }
}

// MARK: RecurringDonationButton
struct RecurringDonationButton: View {

    @State var toggleSheet = false

    private let groupID = "21424772"

    var body: some View {
        Button {
            print("Subscription button pressed")
            toggleSheet.toggle()
        } label: {
            VStack {
                Image(systemName: "dollarsign.arrow.circlepath")
                    .font(.system(size: 24, weight: .regular))
                    .padding(2)
                Text("Donate Monthly")
            }
        }
        .frame(width: 100)
        .padding(8)
        .sheet(isPresented: $toggleSheet, content: {
            VStack {
                SubscriptionStoreView(groupID: self.groupID)
//                HStack {
//                    Link("Terms of Use", destination: URL(string: "https://www.apple.com/legal/internet-services/itunes/dev/stdeula/")!)
//                        .padding(12)
//                    Link("Privacy Policy", destination: URL(string: "https://maddie.info/null_privacy_policy")!)
//                }
                LegalLinksView()
                    .padding(16)
                    .padding([.bottom], 20)
            }
        })
    }
}

struct LegalLinksView: View {

    var body: some View {
            HStack {
                Link("Terms of Use", destination: URL(string: "https://www.apple.com/legal/internet-services/itunes/dev/stdeula/")!)
                    .padding(12)
                Link("Privacy Policy", destination: URL(string: "https://maddie.info/null_privacy_policy")!)
            }
    }
}

#Preview {
    ContributeView().environmentObject(TransactionObserver())
}

#Preview {
    @State var donationHearts = 5000

    return ThankYouBannerView(donationHearts: $donationHearts)
}