import SwiftUI

struct OverviewPanel: View {
    @ObservedObject var model: AppViewModel
    let compactLayout: Bool

    var body: some View {
        VStack(alignment: .leading, spacing: AppLayout.sectionSpacing(for: compactLayout)) {
            if let profile = model.profile, let session = model.session {
                OverviewHero(
                    profile: profile,
                    session: session,
                    pendingCount: model.pendingRequests.count,
                    unreadCount: model.unreadNotificationCount,
                    compactLayout: compactLayout
                )
            }
        }
    }
}

struct RequestsPanel: View {
    @ObservedObject var model: AppViewModel
    let compactLayout: Bool
    let onOpenRequest: (ApprovalRequest) -> Void

    var body: some View {
        VStack(alignment: .leading, spacing: AppLayout.sectionSpacing(for: compactLayout)) {
            if model.requests.isEmpty {
                AppPanel(compactLayout: compactLayout) {
                    EmptyStateCopy(
                        title: "No checks waiting",
                        systemImage: "checkmark.circle",
                        message: "Identity proof requests from sites and devices appear here."
                    )
                }
            } else {
                RequestList(
                    requests: model.requests,
                    compactLayout: compactLayout,
                    activeRequestID: model.activeRequestID,
                    onApprove: { request in
                        Task { await model.approve(request) }
                    },
                    onReject: { request in
                        Task { await model.reject(request) }
                    },
                    onOpenRequest: onOpenRequest
                )
            }
        }
    }
}

struct ActivityPanel: View {
    @ObservedObject var model: AppViewModel
    let compactLayout: Bool

    var body: some View {
        VStack(alignment: .leading, spacing: AppLayout.sectionSpacing(for: compactLayout)) {
            if model.notifications.isEmpty {
                AppPanel(compactLayout: compactLayout) {
                    EmptyStateCopy(
                        title: "No proof activity yet",
                        systemImage: "clock.badge.xmark",
                        message: "Identity proofs and security events will appear here."
                    )
                }
            } else {
                NotificationList(
                    notifications: model.notifications,
                    compactLayout: compactLayout,
                    onMarkRead: { notification in
                        Task { await model.markNotificationRead(notification) }
                    }
                )
            }
        }
    }
}

struct NotificationsPanel: View {
    @ObservedObject var model: AppViewModel
    let compactLayout: Bool

    var body: some View {
        VStack(alignment: .leading, spacing: AppLayout.sectionSpacing(for: compactLayout)) {
            AppSectionCard(title: "Delivery", compactLayout: compactLayout) {
                NotificationPermissionSummary(model: model, compactLayout: compactLayout)
            }

            AppSectionCard(title: "Alerts", compactLayout: compactLayout) {
                if model.notifications.isEmpty {
                    EmptyStateCopy(
                        title: "No alerts yet",
                        systemImage: "bell.slash",
                        message: "New passport and identity-proof alerts will accumulate here."
                    )
                } else {
                    NotificationList(
                        notifications: model.notifications,
                        compactLayout: compactLayout,
                        onMarkRead: { notification in
                            Task { await model.markNotificationRead(notification) }
                        }
                    )
                }
            }
        }
    }
}

struct AccountPanel: View {
    @ObservedObject var model: AppViewModel
    let compactLayout: Bool

    var body: some View {
        VStack(alignment: .leading, spacing: AppLayout.sectionSpacing(for: compactLayout)) {
            if let profile = model.profile, let session = model.session {
                AccountHero(profile: profile, session: session, compactLayout: compactLayout)

                AppSectionCard(title: "Session", compactLayout: compactLayout) {
                    AccountFactsGrid(profile: profile, session: session, compactLayout: compactLayout)
                }
            }

            AppSectionCard(title: "Pairing payload", compactLayout: compactLayout) {
                AppTextSurface(text: model.suggestedPairingPayload, monospaced: true)
            }

            AppSectionCard(title: "Actions", compactLayout: compactLayout) {
                Button(role: .destructive) {
                    model.signOut()
                } label: {
                    Label("Sign Out", systemImage: "rectangle.portrait.and.arrow.right")
                }
                .buttonStyle(.bordered)
            }
        }
    }
}

private struct OverviewHero: View {
    let profile: MemberProfile
    let session: AuthSession
    let pendingCount: Int
    let unreadCount: Int
    let compactLayout: Bool

    private var detailColumns: [GridItem] {
        Array(repeating: GridItem(.flexible(), spacing: 16), count: compactLayout ? 1 : 2)
    }

    private var metricColumns: [GridItem] {
        Array(repeating: GridItem(.flexible(), spacing: 16), count: 3)
    }

    var body: some View {
        AppPanel(compactLayout: compactLayout, radius: AppLayout.largeCardRadius) {
            AppBadge(title: "Digital passport", tone: dashboardAccent)

            VStack(alignment: .leading, spacing: 6) {
                Text(profile.name)
                    .font(.system(size: compactLayout ? 30 : 38, weight: .bold, design: .rounded))
                    .lineLimit(2)

                Text("\(profile.handle) • \(profile.organization)")
                    .font(.subheadline)
                    .foregroundStyle(.secondary)
            }

            HStack(spacing: 8) {
                AppStatusTag(title: "Passport active", tone: dashboardAccent)
                AppStatusTag(title: session.pairingTransport.title, tone: dashboardGold)
            }

            Divider()

            LazyVGrid(columns: detailColumns, alignment: .leading, spacing: 16) {
                AppKeyValue(label: "Device", value: session.deviceName)
                AppKeyValue(label: "Origin", value: session.originHost, monospaced: true)
                AppKeyValue(label: "Linked", value: session.pairedAt.formatted(date: .abbreviated, time: .shortened))
                AppKeyValue(label: "Token", value: "...\(session.tokenPreview)", monospaced: true)
            }

            Divider()

            LazyVGrid(columns: metricColumns, alignment: .leading, spacing: 16) {
                AppMetric(title: "Pending", value: "\(pendingCount)")
                AppMetric(title: "Alerts", value: "\(unreadCount)")
                AppMetric(title: "Devices", value: "\(profile.deviceCount)")
            }
        }
    }
}

private struct NotificationPermissionSummary: View {
    @ObservedObject var model: AppViewModel
    let compactLayout: Bool

    var body: some View {
        VStack(alignment: .leading, spacing: 14) {
            HStack(alignment: .top, spacing: 12) {
                Image(systemName: model.notificationPermission.systemImage)
                    .font(.headline)
                    .foregroundStyle(dashboardAccent)
                    .frame(width: 28, height: 28)

                VStack(alignment: .leading, spacing: 4) {
                    Text(model.notificationPermission.title)
                        .font(.headline)
                    Text(model.notificationPermission.summary)
                        .font(.subheadline)
                        .foregroundStyle(.secondary)
                }
            }

            if compactLayout {
                VStack(alignment: .leading, spacing: 12) {
                    permissionButtons
                }
            } else {
                HStack(spacing: 12) {
                    permissionButtons
                }
            }
        }
    }

    @ViewBuilder
    private var permissionButtons: some View {
        Button {
            Task { await model.requestNotificationAccess() }
        } label: {
            Label("Enable notifications", systemImage: "bell.and.waves.left.and.right.fill")
                .frame(maxWidth: .infinity)
        }
        .buttonStyle(.borderedProminent)

        Button {
            Task { await model.sendTestNotification() }
        } label: {
            Label("Send test alert", systemImage: "paperplane.fill")
                .frame(maxWidth: .infinity)
        }
        .buttonStyle(.bordered)
    }
}

private struct AccountHero: View {
    let profile: MemberProfile
    let session: AuthSession
    let compactLayout: Bool

    var body: some View {
        AppPanel(compactLayout: compactLayout, radius: AppLayout.largeCardRadius) {
            AppBadge(title: "Account", tone: dashboardAccent)

            Text(profile.name)
                .font(.system(size: compactLayout ? 28 : 34, weight: .bold, design: .rounded))
                .lineLimit(2)

            Text(profile.handle)
                .font(.headline)
                .foregroundStyle(.secondary)

            Text("Active client: \(session.deviceName)")
                .font(.subheadline)
                .foregroundStyle(.secondary)
        }
    }
}

private struct AccountFactsGrid: View {
    let profile: MemberProfile
    let session: AuthSession
    let compactLayout: Bool

    private var columns: [GridItem] {
        Array(repeating: GridItem(.flexible(), spacing: 16), count: compactLayout ? 1 : 2)
    }

    var body: some View {
        LazyVGrid(columns: columns, alignment: .leading, spacing: 16) {
            AppKeyValue(label: "Organization", value: profile.organization)
            AppKeyValue(label: "Origin", value: session.originHost, monospaced: true)
            AppKeyValue(label: "Linked At", value: session.pairedAt.formatted(date: .abbreviated, time: .shortened))
            AppKeyValue(label: "Method", value: session.pairingTransport.title)
            AppKeyValue(label: "Token", value: "...\(session.tokenPreview)", monospaced: true)
            AppKeyValue(label: "Recovery", value: profile.recoverySummary)
            if let signedGPSPosition = session.signedGPSPosition {
                AppKeyValue(
                    label: "Signed GPS",
                    value: "\(signedGPSPosition.coordinateSummary) \(signedGPSPosition.accuracySummary)",
                    monospaced: true
                )
            }
            AppKeyValue(label: "Trusted Devices", value: "\(profile.deviceCount)")
        }
    }
}

private struct EmptyStateCopy: View {
    let title: String
    let systemImage: String
    let message: String

    var body: some View {
        ContentUnavailableView(
            title,
            systemImage: systemImage,
            description: Text(message)
        )
        .frame(maxWidth: .infinity)
        .padding(.vertical, 10)
    }
}