import CodeiumService
import Foundation
import SharedUIComponents
import SwiftUI

struct CodeiumView: View {
    class ViewModel: ObservableObject {
        let codeiumAuthService = CodeiumAuthService()
        let installationManager = CodeiumInstallationManager()
        @Published var isSignedIn: Bool
        @Published var installationStatus: CodeiumInstallationManager.InstallationStatus
        @Published var installationStep: CodeiumInstallationManager.InstallationStep?
        @AppStorage(\.codeiumVerboseLog) var codeiumVerboseLog
        @AppStorage(\.codeiumEnterpriseMode) var codeiumEnterpriseMode
        @AppStorage(\.codeiumPortalUrl) var codeiumPortalUrl
        @AppStorage(\.codeiumApiUrl) var codeiumApiUrl

        init() {
            isSignedIn = codeiumAuthService.isSignedIn
            installationStatus = installationManager.checkInstallation()
        }

        init(
            isSignedIn: Bool,
            installationStatus: CodeiumInstallationManager.InstallationStatus,
            installationStep: CodeiumInstallationManager.InstallationStep?
        ) {
            assert(isPreview)
            self.isSignedIn = isSignedIn
            self.installationStatus = installationStatus
            self.installationStep = installationStep
        }

        func generateAuthURL() -> URL {
            if codeiumEnterpriseMode && (codeiumPortalUrl != "") {
                return URL(
                    string: codeiumPortalUrl +
                        "/profile?response_type=token&redirect_uri=show-auth-token&state=\(UUID().uuidString)&scope=openid%20profile%20email&redirect_parameters_type=query"
                )!
            }

            return URL(
                string: "https://www.codeium.com/profile?response_type=token&redirect_uri=show-auth-token&state=\(UUID().uuidString)&scope=openid%20profile%20email&redirect_parameters_type=query"
            )!
        }

        func signIn(token: String) async throws {
            try await codeiumAuthService.signIn(token: token)
            Task { @MainActor in isSignedIn = true }
        }

        func signOut() async throws {
            try await codeiumAuthService.signOut()
            Task { @MainActor in isSignedIn = false }
        }

        func refreshInstallationStatus() {
            Task { @MainActor in
                installationStatus = installationManager.checkInstallation()
            }
        }

        func install() async throws {
            defer { refreshInstallationStatus() }
            do {
                for try await step in installationManager.installLatestVersion() {
                    Task { @MainActor in
                        self.installationStep = step
                    }
                }
                Task {
                    try await Task.sleep(nanoseconds: 1_000_000_000)
                    Task { @MainActor in
                        self.installationStep = nil
                    }
                }
            } catch {
                Task { @MainActor in
                    installationStep = nil
                }
                throw error
            }
        }

        func uninstall() {
            Task {
                defer { refreshInstallationStatus() }
                try await installationManager.uninstall()
            }
        }
    }

    @StateObject var viewModel = ViewModel()
    @Environment(\.toast) var toast
    @State var isSignInPanelPresented = false

    var installButton: some View {
        Button(action: {
            Task {
                do {
                    try await viewModel.install()
                } catch {
                    toast(error.localizedDescription, .error)
                }
            }
        }) {
            Text("Install")
        }
        .disabled(viewModel.installationStep != nil)
    }

    var updateButton: some View {
        Button(action: {
            Task {
                do {
                    try await viewModel.install()
                } catch {
                    toast(error.localizedDescription, .error)
                }
            }
        }) {
            Text("Update")
        }
        .disabled(viewModel.installationStep != nil)
    }

    var uninstallButton: some View {
        Button(action: {
            viewModel.uninstall()
        }) {
            Text("Uninstall")
        }
        .disabled(viewModel.installationStep != nil)
    }

    var body: some View {
        VStack(alignment: .leading) {
            VStack(alignment: .leading) {
                switch viewModel.installationStatus {
                case .notInstalled:
                    HStack {
                        Text("Language Server Version: Not Installed")
                        installButton
                    }
                case let .installed(version):
                    HStack {
                        Text("Language Server Version: \(version)")
                        uninstallButton
                    }
                case let .outdated(current: current, latest: latest):
                    HStack {
                        Text("Language Server Version: \(current) (Update Available: \(latest))")
                        uninstallButton
                        updateButton
                    }
                case let .unsupported(current: current, latest: latest):
                    HStack {
                        Text("Language Server Version: \(current) (Supported Version: \(latest))")
                        uninstallButton
                        updateButton
                    }
                }

                if viewModel.isSignedIn {
                    Text("Status: Signed In")

                    Button(action: {
                        Task {
                            do {
                                try await viewModel.signOut()
                            } catch {
                                toast(error.localizedDescription, .error)
                            }
                        }
                    }) {
                        Text("Sign Out")
                    }
                } else {
                    Text("Status: Not Signed In")

                    Button(action: {
                        isSignInPanelPresented = true
                    }) {
                        Text("Sign In")
                    }
                }
            }
            .padding(8)
            .frame(maxWidth: .infinity, alignment: .leading)
            .overlay {
                RoundedRectangle(cornerRadius: 8)
                    .stroke(Color(nsColor: .separatorColor), style: .init(lineWidth: 1))
            }
            .sheet(isPresented: $isSignInPanelPresented) {
                CodeiumSignInView(viewModel: viewModel, isPresented: $isSignInPanelPresented)
            }
            .onChange(of: viewModel.installationStep) { newValue in
                if let step = newValue {
                    switch step {
                    case .downloading:
                        toast("Downloading..", .info)
                    case .uninstalling:
                        toast("Uninstalling old version..", .info)
                    case .decompressing:
                        toast("Decompressing..", .info)
                    case .done:
                        toast("Done!", .info)
                    }
                }
            }

            Form {
                Toggle("Codeium Enterprise Mode", isOn: $viewModel.codeiumEnterpriseMode)
                TextField("Codeium Portal URL", text: $viewModel.codeiumPortalUrl)
                TextField("Codeium API URL", text: $viewModel.codeiumApiUrl)
            }
            .padding(8)
            .frame(maxWidth: .infinity, alignment: .leading)
            .overlay {
                RoundedRectangle(cornerRadius: 8)
                    .stroke(Color(nsColor: .separatorColor), style: .init(lineWidth: 1))
            }

            SettingsDivider("Advanced")

            Form {
                Toggle("Verbose Log", isOn: $viewModel.codeiumVerboseLog)
            }
        }
    }
}

struct CodeiumSignInView: View {
    let viewModel: CodeiumView.ViewModel
    @Binding var isPresented: Bool
    @Environment(\.openURL) var openURL
    @Environment(\.toast) var toast
    @State var isGeneratingKey = false
    @State var token = ""

    var body: some View {
        VStack {
            Text(
                "You will be redirected to codeium.com. Please paste the generated token below and click the \"Sign In\" button."
            )

            TextEditor(text: $token)
                .font(Font.system(.body, design: .monospaced))
                .padding(4)
                .frame(minHeight: 120)
                .multilineTextAlignment(.leading)
                .overlay(
                    RoundedRectangle(cornerRadius: 4)
                        .stroke(Color(nsColor: .separatorColor), lineWidth: 1)
                )

            HStack {
                Spacer()

                Button(action: {
                    isPresented = false
                }) {
                    Text("Cancel")
                }

                Button(action: {
                    isGeneratingKey = true
                    Task {
                        do {
                            try await viewModel.signIn(token: token)
                            isGeneratingKey = false
                            isPresented = false
                        } catch {
                            isGeneratingKey = false
                            toast(error.localizedDescription, .error)
                        }
                    }
                }) {
                    Text(isGeneratingKey ? "Signing In.." : "Sign In")
                }.disabled(isGeneratingKey)
            }
        }
        .padding()
        .onAppear {
            openURL(viewModel.generateAuthURL())
        }
    }
}

struct CodeiumView_Previews: PreviewProvider {
    class TestViewModel: CodeiumView.ViewModel {
        override func generateAuthURL() -> URL {
            return URL(string: "about:blank")!
        }

        override func signIn(token: String) async throws {}

        override func signOut() async throws {}

        override func refreshInstallationStatus() {}

        override func install() async throws {}

        override func uninstall() {}
    }

    static var previews: some View {
        VStack(alignment: .leading, spacing: 8) {
            CodeiumView(viewModel: TestViewModel(
                isSignedIn: false,
                installationStatus: .notInstalled,
                installationStep: nil
            ))

            CodeiumView(viewModel: TestViewModel(
                isSignedIn: true,
                installationStatus: .installed("1.2.9"),
                installationStep: nil
            ))

            CodeiumView(viewModel: TestViewModel(
                isSignedIn: true,
                installationStatus: .outdated(current: "1.2.9", latest: "1.3.0"),
                installationStep: .downloading
            ))

            CodeiumView(viewModel: TestViewModel(
                isSignedIn: true,
                installationStatus: .unsupported(current: "1.5.9", latest: "1.3.0"),
                installationStep: .downloading
            ))
        }
        .padding(8)
    }
}