import SwiftUI

/// Shared Sidebar (Burger Menu) for all Montana views
/// Clean release: only implemented & working features
struct SharedSidebar: View {
    @Binding var isVisible: Bool
    @ObservedObject private var lang = LanguageManager.shared
    @ObservedObject private var sessionStore = ChatSessionStore.shared
    @State private var showLogoutConfirm = false
    @State private var chatsExpanded = true

    var body: some View {
        VStack(alignment: .leading, spacing: 0) {
            sidebarHeader
            Divider()

            ScrollView {
                VStack(alignment: .leading, spacing: 24) {
                    junonaSection
                    Divider()
                    montanaSection
                    Divider()
                    exchangeSection
                    Divider()
                    settingsSection
                    Divider()
                    logoutSection
                }
                .padding()
            }
        }
        .frame(width: 280)
        .background(Color(NSColor.controlBackgroundColor).opacity(0.95))
        .shadow(radius: 10)
        .alert(lang.isRu ? "\u{0412}\u{044B}\u{0439}\u{0442}\u{0438} \u{0438}\u{0437} Montana?" : "Log out of Montana?", isPresented: $showLogoutConfirm) {
            Button(lang.isRu ? "\u{0412}\u{044B}\u{0439}\u{0442}\u{0438}" : "Log Out", role: .destructive) {
                withAnimation { isVisible = false }
                CryptoManager.shared.deleteIdentity()
            }
            Button(lang.isRu ? "\u{041E}\u{0442}\u{043C}\u{0435}\u{043D}\u{0430}" : "Cancel", role: .cancel) {}
        } message: {
            Text(lang.isRu
                 ? "\u{041A}\u{043B}\u{044E}\u{0447}\u{0438} \u{0431}\u{0443}\u{0434}\u{0443}\u{0442} \u{0443}\u{0434}\u{0430}\u{043B}\u{0435}\u{043D}\u{044B} \u{0438}\u{0437} Keychain. \u{0423}\u{0431}\u{0435}\u{0434}\u{0438}\u{0442}\u{0435}\u{0441}\u{044C}, \u{0447}\u{0442}\u{043E} \u{0432}\u{044B} \u{0441}\u{043E}\u{0445}\u{0440}\u{0430}\u{043D}\u{0438}\u{043B}\u{0438} seed-\u{0444}\u{0440}\u{0430}\u{0437}\u{0443} \u{0434}\u{043B}\u{044F} \u{0432}\u{043E}\u{0441}\u{0441}\u{0442}\u{0430}\u{043D}\u{043E}\u{0432}\u{043B}\u{0435}\u{043D}\u{0438}\u{044F}."
                 : "Keys will be deleted from Keychain. Make sure you saved your seed phrase for recovery.")
        }
    }

    // MARK: - Header

    private var sidebarHeader: some View {
        HStack {
            if let logoPath = Bundle.main.path(forResource: "JunonaLogo", ofType: "jpg"),
               let nsImage = NSImage(contentsOfFile: logoPath) {
                Image(nsImage: nsImage)
                    .resizable()
                    .aspectRatio(contentMode: .fill)
                    .frame(width: 32, height: 32)
                    .clipShape(Circle())
                    .overlay(
                        Circle()
                            .stroke(
                                LinearGradient(
                                    colors: [
                                        Color(red: 0.83, green: 0.69, blue: 0.22),
                                        Color(red: 0.94, green: 0.82, blue: 0.38)
                                    ],
                                    startPoint: .topLeading,
                                    endPoint: .bottomTrailing
                                ),
                                lineWidth: 1.5
                            )
                    )
            } else {
                Circle()
                    .fill(
                        LinearGradient(
                            colors: [
                                Color(red: 0.0, green: 0.83, blue: 1.0),
                                Color(red: 0.48, green: 0.18, blue: 1.0)
                            ],
                            startPoint: .topLeading,
                            endPoint: .bottomTrailing
                        )
                    )
                    .frame(width: 32, height: 32)
                    .overlay(
                        Text("\u{042E}")
                            .font(.system(size: 16, weight: .bold))
                            .foregroundColor(.white)
                    )
            }

            VStack(alignment: .leading, spacing: 2) {
                Text("Montana Protocol")
                    .font(.headline)
                Text("\u{0248}")
                    .font(.caption2)
                    .foregroundColor(.secondary)
            }

            Spacer()

            Button(action: {
                withAnimation { isVisible = false }
            }) {
                Image(systemName: "xmark")
                    .font(.system(size: 14))
                    .foregroundColor(.secondary)
            }
            .buttonStyle(.plain)
        }
        .padding()
    }

    // MARK: - Junona Section (with collapsible chats)

    private var junonaSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("Junona AI")
                .font(.caption)
                .fontWeight(.semibold)
                .foregroundColor(.secondary)

            // New chat button
            Button(action: {
                _ = sessionStore.createNewSession()
                NotificationCenter.default.post(name: .switchToTab, object: nil, userInfo: ["tab": 0])
                withAnimation { isVisible = false }
            }) {
                HStack(spacing: 8) {
                    Image(systemName: "plus.message")
                        .font(.system(size: 14))
                        .foregroundColor(Color(red: 0.0, green: 0.83, blue: 1.0))
                        .frame(width: 20)
                    Text(lang.isRu ? "\u{041D}\u{043E}\u{0432}\u{044B}\u{0439} \u{0447}\u{0430}\u{0442}" : "New Chat")
                        .font(.callout)
                        .foregroundColor(.primary)
                    Spacer()
                }
                .padding(.vertical, 6)
                .padding(.horizontal, 12)
                .contentShape(Rectangle())
            }
            .buttonStyle(.plain)
            .onHover { h in if h { NSCursor.pointingHand.push() } else { NSCursor.pop() } }

            // Collapsible saved chats
            if !sessionStore.sessions.isEmpty {
                DisclosureGroup(isExpanded: $chatsExpanded) {
                    VStack(spacing: 2) {
                        ForEach(sessionStore.sessions.prefix(15)) { session in
                            Button(action: {
                                sessionStore.selectSession(session.id)
                                NotificationCenter.default.post(name: .switchToTab, object: nil, userInfo: ["tab": 0])
                                withAnimation { isVisible = false }
                            }) {
                                HStack(spacing: 8) {
                                    Image(systemName: session.id == sessionStore.currentSessionId ? "message.fill" : "message")
                                        .font(.system(size: 11))
                                        .foregroundColor(session.id == sessionStore.currentSessionId
                                            ? Color(red: 0.83, green: 0.69, blue: 0.22)
                                            : .secondary)
                                        .frame(width: 16)

                                    Text(session.title)
                                        .font(.caption)
                                        .foregroundColor(session.id == sessionStore.currentSessionId ? .primary : .secondary)
                                        .lineLimit(1)

                                    Spacer()
                                }
                                .padding(.vertical, 4)
                                .padding(.horizontal, 12)
                                .background(
                                    RoundedRectangle(cornerRadius: 5)
                                        .fill(session.id == sessionStore.currentSessionId
                                            ? Color(red: 0.83, green: 0.69, blue: 0.22).opacity(0.1)
                                            : Color.clear)
                                )
                                .contentShape(Rectangle())
                            }
                            .buttonStyle(.plain)
                            .onHover { h in if h { NSCursor.pointingHand.push() } else { NSCursor.pop() } }
                            .contextMenu {
                                Button(role: .destructive) {
                                    sessionStore.deleteSession(session.id)
                                } label: {
                                    Label(lang.isRu ? "\u{0423}\u{0434}\u{0430}\u{043B}\u{0438}\u{0442}\u{044C}" : "Delete", systemImage: "trash")
                                }
                            }
                        }
                    }
                } label: {
                    HStack(spacing: 6) {
                        Image(systemName: "bubble.left.and.bubble.right")
                            .font(.system(size: 11))
                        Text(lang.isRu ? "\u{0427}\u{0430}\u{0442}\u{044B} (\(sessionStore.sessions.count))" : "Chats (\(sessionStore.sessions.count))")
                            .font(.caption)
                    }
                    .foregroundColor(.secondary)
                    .padding(.horizontal, 12)
                }
            }
        }
    }

    // MARK: - Montana Section (only working features)

    private var montanaSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("Montana")
                .font(.caption)
                .fontWeight(.semibold)
                .foregroundColor(.secondary)

            VStack(spacing: 4) {
                SidebarNavItem(icon: "banknote", label: lang.isRu ? "\u{041A}\u{043E}\u{0448}\u{0435}\u{043B}\u{0451}\u{043A}" : "Wallet", tag: 1, isVisible: $isVisible)
                SidebarNavItem(icon: "pentagon", label: lang.isRu ? "\u{0422}\u{0430}\u{0439}\u{043C}\u{0447}\u{0435}\u{0439}\u{043D}" : "TimeChain", tag: 8, isVisible: $isVisible)
                SidebarNavItem(icon: "clock.arrow.circlepath", label: lang.isRu ? "\u{0418}\u{0441}\u{0442}\u{043E}\u{0440}\u{0438}\u{044F}" : "History", tag: 7, isVisible: $isVisible)
            }
        }
    }

    // MARK: - Exchange Section

    private var exchangeSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text(lang.isRu ? "\u{041E}\u{0431}\u{043C}\u{0435}\u{043D}" : "Exchange")
                .font(.caption)
                .fontWeight(.semibold)
                .foregroundColor(.secondary)

            VStack(spacing: 4) {
                SidebarExchangeItem(icon: "bitcoinsign.circle.fill", label: "BTC \u{2192} \u{0248}")
                SidebarExchangeItem(icon: "dollarsign.circle.fill", label: "USD \u{2192} \u{0248}")
                SidebarExchangeItem(icon: "rublesign.circle.fill", label: "RUB \u{2192} \u{0248}")
            }
        }
    }

    // MARK: - Settings

    private var settingsSection: some View {
        SidebarNavItem(icon: "gear", label: lang.isRu ? "\u{041D}\u{0430}\u{0441}\u{0442}\u{0440}\u{043E}\u{0439}\u{043A}\u{0438}" : "Settings", tag: 9, isVisible: $isVisible)
    }

    // MARK: - Logout

    private var logoutSection: some View {
        Button(action: { showLogoutConfirm = true }) {
            HStack(spacing: 8) {
                Image(systemName: "rectangle.portrait.and.arrow.right")
                    .font(.system(size: 14))
                    .foregroundColor(.red.opacity(0.8))
                    .frame(width: 20)

                Text(lang.isRu ? "\u{0412}\u{044B}\u{0445}\u{043E}\u{0434}" : "Log Out")
                    .font(.callout)
                    .foregroundColor(.red.opacity(0.8))

                Spacer()
            }
            .padding(.vertical, 6)
            .padding(.horizontal, 12)
            .contentShape(Rectangle())
        }
        .buttonStyle(.plain)
        .onHover { h in if h { NSCursor.pointingHand.push() } else { NSCursor.pop() } }
    }
}

// MARK: - Nav Item

struct SidebarNavItem: View {
    let icon: String
    let label: String
    let tag: Int
    @Binding var isVisible: Bool

    var body: some View {
        Button(action: {
            NotificationCenter.default.post(name: .switchToTab, object: nil, userInfo: ["tab": tag])
            withAnimation { isVisible = false }
        }) {
            HStack(spacing: 8) {
                Image(systemName: icon)
                    .font(.system(size: 14))
                    .foregroundColor(Color(red: 0.0, green: 0.83, blue: 1.0))
                    .frame(width: 20)
                Text(label)
                    .font(.callout)
                    .foregroundColor(.primary)
                Spacer()
            }
            .padding(.vertical, 6)
            .padding(.horizontal, 12)
            .contentShape(Rectangle())
        }
        .buttonStyle(.plain)
        .onHover { h in if h { NSCursor.pointingHand.push() } else { NSCursor.pop() } }
    }
}

// MARK: - Exchange Item

struct SidebarExchangeItem: View {
    let icon: String
    let label: String
    @State private var showExchange = false

    var currency: String {
        if label.contains("BTC") { return "BTC" }
        if label.contains("USD") { return "USD" }
        if label.contains("RUB") { return "RUB" }
        return "USD"
    }

    var body: some View {
        Button(action: { showExchange = true }) {
            HStack(spacing: 8) {
                Image(systemName: icon)
                    .font(.system(size: 14))
                    .foregroundColor(Color(red: 0.0, green: 0.83, blue: 1.0))
                    .frame(width: 20)
                Text(label)
                    .font(.callout)
                    .foregroundColor(.primary)
                Spacer()
            }
            .padding(.vertical, 6)
            .padding(.horizontal, 12)
            .contentShape(Rectangle())
        }
        .buttonStyle(.plain)
        .onHover { h in if h { NSCursor.pointingHand.push() } else { NSCursor.pop() } }
        .popover(isPresented: $showExchange) {
            ExchangeCalculatorView(currency: currency)
        }
    }
}

// MARK: - Exchange Calculator

struct ExchangeCalculatorView: View {
    let currency: String
    @ObservedObject private var lang = LanguageManager.shared
    @State private var amount: String = ""
    @State private var isReversed = false

    private let gold = Color(red: 0.85, green: 0.68, blue: 0.25)
    private let cyan = Color(red: 0.0, green: 0.83, blue: 1.0)

    private let rateUSD: Double = 0.1605
    private let rateRUB: Double = 12.04
    private let rateBTC: Double = 0.0000000165

    private var rate: Double {
        switch currency {
        case "BTC": return rateBTC
        case "RUB": return rateRUB
        default: return rateUSD
        }
    }

    private var currencySymbol: String {
        switch currency {
        case "BTC": return "BTC"
        case "RUB": return "\u{20BD}"
        default: return "$"
        }
    }

    private var convertedAmount: String {
        guard let value = Double(amount), value > 0 else { return "0" }
        let result: Double
        if isReversed { result = value * rate } else { result = value / rate }
        if currency == "BTC" && !isReversed { return String(format: "%.0f", result) }
        if result < 0.01 { return String(format: "%.8f", result) }
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        formatter.maximumFractionDigits = 2
        formatter.groupingSeparator = " "
        return formatter.string(from: NSNumber(value: result)) ?? "\(result)"
    }

    var body: some View {
        VStack(spacing: 16) {
            HStack {
                Image(systemName: "arrow.left.arrow.right.circle.fill")
                    .foregroundColor(gold)
                Text(lang.isRu ? "\u{041A}\u{043E}\u{043D}\u{0432}\u{0435}\u{0440}\u{0442}\u{0435}\u{0440}" : "Converter")
                    .font(.system(size: 14, weight: .bold))
                Spacer()
            }

            Text("1 \u{0248} = \(rateDisplay)")
                .font(.system(size: 11))
                .foregroundColor(.secondary)

            VStack(spacing: 8) {
                HStack {
                    Text(isReversed ? "\u{0248}" : currencySymbol)
                        .font(.system(size: 14, weight: .bold))
                        .foregroundColor(isReversed ? gold : cyan)
                        .frame(width: 30)
                    TextField("0", text: $amount)
                        .textFieldStyle(.plain)
                        .font(.system(size: 16, weight: .medium, design: .monospaced))
                }
                .padding(10)
                .background(Color(NSColor.controlBackgroundColor))
                .cornerRadius(8)

                Button(action: { isReversed.toggle() }) {
                    Image(systemName: "arrow.up.arrow.down")
                        .font(.system(size: 12))
                        .foregroundColor(gold)
                        .padding(6)
                        .background(gold.opacity(0.1))
                        .clipShape(Circle())
                }
                .buttonStyle(.plain)

                HStack {
                    Text(isReversed ? currencySymbol : "\u{0248}")
                        .font(.system(size: 14, weight: .bold))
                        .foregroundColor(isReversed ? cyan : gold)
                        .frame(width: 30)
                    Text(convertedAmount)
                        .font(.system(size: 16, weight: .bold, design: .monospaced))
                        .foregroundColor(.primary)
                    Spacer()
                }
                .padding(10)
                .background(Color(NSColor.controlBackgroundColor))
                .cornerRadius(8)
            }

            Text("Genesis Price (09.01.2026)")
                .font(.system(size: 9))
                .foregroundColor(.secondary)
        }
        .padding(16)
        .frame(width: 260)
    }

    private var rateDisplay: String {
        switch currency {
        case "BTC": return String(format: "%.10f BTC", rateBTC)
        case "RUB": return String(format: "%.2f \u{20BD}", rateRUB)
        default: return String(format: "$%.4f", rateUSD)
        }
    }
}