import SwiftUI

struct ConnectionView: View {
    var state: AppState

    var body: some View {
        VStack(spacing: 0) {
            header
            Divider()
            deviceList
        }
        .navigationTitle("Connection")
    }

    private var header: some View {
        HStack {
            Circle()
                .fill(statusColor)
                .frame(width: 10, height: 10)
            Text(state.ble.state.rawValue)
                .font(.headline)
            Spacer()
            if state.ble.state == .connected {
                Button("Disconnect") { state.ble.disconnect() }
                    .buttonStyle(.bordered)
                    .tint(.red)
            } else if state.ble.state == .scanning {
                Button("Stop") { state.ble.stopScanning() }
                    .buttonStyle(.bordered)
            } else {
                Button("Scan") { state.ble.startScanning() }
                    .buttonStyle(.borderedProminent)
            }
        }
        .padding()
    }

    private var statusColor: Color {
        switch state.ble.state {
        case .connected: .green
        case .scanning: .orange
        case .connecting: .yellow
        case .disconnected: .red
        }
    }

    private var deviceList: some View {
        List {
            if state.ble.discoveredDevices.isEmpty && state.ble.state == .scanning {
                HStack {
                    ProgressView()
                    Text("Scanning for devices...")
                        .foregroundStyle(.secondary)
                }
            }

            ForEach(state.ble.discoveredDevices) { device in
                Button {
                    state.ble.connectTo(device)
                } label: {
                    HStack {
                        VStack(alignment: .leading, spacing: 2) {
                            Text(device.name)
                                .font(.body.weight(.medium))
                            if !device.serviceUUIDs.isEmpty {
                                Text(device.serviceUUIDs.map(\.uuidString).joined(separator: ", "))
                                    .font(.caption2)
                                    .foregroundStyle(.secondary)
                                    .lineLimit(1)
                            }
                        }
                        Spacer()
                        Text("\(device.rssi) dBm")
                            .font(.caption)
                            .foregroundStyle(.secondary)
                        if device.name == "EIS4" {
                            Image(systemName: "star.fill")
                                .foregroundStyle(.yellow)
                                .font(.caption)
                        }
                    }
                }
                .disabled(state.ble.state == .connecting)
            }
        }
    }
}