import SwiftUI

struct SetupView: View {
	@Environment(Settings.self) private var settings
	@Environment(MeshDataStore.self) private var store
	@Environment(\.dismiss) private var dismiss

	@State private var host: String = ""
	@State private var portText: String = "8080"
	@State private var token: String = ""
	@State private var useTLS: Bool = false

	@State private var testing = false
	@State private var testResult: String?
	@State private var testOK = false

	let isInitial: Bool

	var body: some View {
		NavigationStack {
			Form {
				if !isInitial { statusSection }
				Section("Server") {
					TextField("Host or IP", text: $host)
						.textContentType(.URL)
						.textInputAutocapitalization(.never)
						.autocorrectionDisabled()
						.keyboardType(.URL)
					TextField("Port", text: $portText)
						.keyboardType(.numberPad)
					Toggle("Use HTTPS", isOn: $useTLS)
				}
				Section("Authentication") {
					SecureField("Bearer token", text: $token)
						.textContentType(.password)
						.autocorrectionDisabled()
						.textInputAutocapitalization(.never)
					Link(destination: URL(string: "https://meshmonitor.org/development/api.html")!) {
						Label("How to create a token", systemImage: "questionmark.circle")
							.font(.footnote)
					}
				}
				Section {
					Button {
						Task { await testConnection() }
					} label: {
						HStack {
							Text("Test connection")
							Spacer()
							if testing { ProgressView() }
						}
					}
					.disabled(testing || host.trimmingCharacters(in: .whitespaces).isEmpty)
					if let r = testResult {
						Label(r, systemImage: testOK ? "checkmark.circle.fill" : "exclamationmark.triangle.fill")
							.foregroundStyle(testOK ? .green : .red)
							.font(.footnote)
					}
				}
				Section {
					Text("Configure your MeshMonitor server URL and a Bearer token. Token is stored in the iOS Keychain.")
						.font(.footnote)
						.foregroundStyle(.secondary)
				}
				Section {
					Link(destination: URL(string: "https://git.andros.dev/andros/ios-meshmonitor-chat")!) {
						Label("Source code", systemImage: "chevron.left.forwardslash.chevron.right")
					}
					Link(destination: URL(string: "https://git.andros.dev/andros/contribute")!) {
						Label("Report a bug", systemImage: "ant")
					}
				}
			}
			.navigationTitle(isInitial ? "Connect" : "Settings")
			.navigationBarTitleDisplayMode(.inline)
			.toolbar {
				if !isInitial {
					ToolbarItem(placement: .cancellationAction) {
						Button("Cancel") { dismiss() }
					}
				}
				ToolbarItem(placement: .confirmationAction) {
					Button("Save") { save() }
						.disabled(!canSave)
				}
			}
			.onAppear(perform: load)
		}
	}

	@ViewBuilder
	private var statusSection: some View {
		Section("Status") {
			if let s = store.status {
				row("Server", value: "Reachable", valueColor: .green)
				row("Mesh node",
					value: meshStateLabel(s.meshState),
					valueColor: meshStateColor(s.meshState))
				if let v = s.version { row("Version", value: v) }
				if let name = s.localNodeName {
					let id = s.localNodeId.map { " (\($0))" } ?? ""
					row("Node", value: "\(name)\(id)")
				}
				if let up = s.uptime {
					row("Uptime", value: formatUptime(up))
				}
				if let stats = s.statistics {
					if let n = stats.nodes { row("Nodes", value: "\(n)") }
					if let m = stats.messages { row("Messages", value: "\(m)") }
					if let c = stats.channels { row("Channels", value: "\(c)") }
				}
			} else if store.loading {
				HStack { Text("Status").foregroundStyle(.secondary); Spacer(); ProgressView() }
			} else if let err = store.error {
				row("Server", value: "Unreachable", valueColor: .red)
				Text(err).font(.footnote).foregroundStyle(.red)
			} else {
				Text("No data yet.").foregroundStyle(.secondary)
			}
		}
	}

	private func row(_ key: String, value: String, valueColor: Color? = nil) -> some View {
		HStack {
			Text(key).foregroundStyle(.secondary)
			Spacer()
			Text(value)
				.foregroundStyle(valueColor ?? .primary)
				.multilineTextAlignment(.trailing)
		}
	}

	private func meshStateLabel(_ state: ServerStatus.MeshState) -> String {
		switch state {
		case .online: return "Online"
		case .idle: return "Online (idle)"
		case .offline: return "Offline"
		}
	}

	private func meshStateColor(_ state: ServerStatus.MeshState) -> Color {
		switch state {
		case .online: return .green
		case .idle: return .orange
		case .offline: return .red
		}
	}

	private func formatUptime(_ secs: Double) -> String {
		let total = Int(secs)
		let days = total / 86400
		let hours = (total % 86400) / 3600
		let mins = (total % 3600) / 60
		if days > 0 { return "\(days)d \(hours)h" }
		if hours > 0 { return "\(hours)h \(mins)m" }
		return "\(mins)m"
	}

	private var canSave: Bool {
		!host.trimmingCharacters(in: .whitespaces).isEmpty &&
		!token.trimmingCharacters(in: .whitespaces).isEmpty &&
		(Int(portText) ?? 0) > 0
	}

	private func load() {
		host = settings.host
		portText = String(settings.port)
		useTLS = settings.useTLS
		token = settings.token
	}

	private func save() {
		settings.host = host.trimmingCharacters(in: .whitespaces)
		settings.port = Int(portText) ?? 8080
		settings.useTLS = useTLS
		settings.token = token.trimmingCharacters(in: .whitespaces)
		dismiss()
	}

	@MainActor
	private func testConnection() async {
		testing = true
		defer { testing = false }
		testResult = nil
		let probe = ServerConfig(
			host: host.trimmingCharacters(in: .whitespaces),
			port: Int(portText) ?? 8080,
			useTLS: useTLS,
			token: token.trimmingCharacters(in: .whitespaces)
		)
		guard probe.isConfigured else {
			testOK = false
			testResult = "Host and token are required."
			return
		}
		let client = APIClient(settings: settings, config: probe)
		do {
			let channels = try await client.fetchChannels()
			let status = try? await client.fetchStatus()
			testOK = true
			let nodeBit = status?.localNodeName.map { " — \($0)" } ?? ""
			testResult = "Connected, \(channels.count) channel\(channels.count == 1 ? "" : "s")\(nodeBit)"
		} catch APIError.unauthorized {
			testOK = false
			testResult = "Invalid token (unauthorized)."
		} catch {
			testOK = false
			testResult = error.localizedDescription
		}
	}
}

#Preview {
	SetupView(isInitial: true)
		.environment(Settings())
		.environment(MeshDataStore())
}