import SwiftUI

struct InstanceFormView: View {
    @Environment(\.dismiss) private var dismiss
    @ObservedObject var model: FleetViewModel
    @State private var name = ""
    @State private var originText = ""
    @State private var tagsText = ""
    @State private var password = ""
    @State private var validationMessage: String?

    var body: some View {
        NavigationStack {
            ZStack {
                AITheme.canvas.ignoresSafeArea()
                ScrollView {
                    VStack(spacing: 12) {
                        AICard {
                            VStack(alignment: .leading, spacing: 14) {
                                field("名称", text: $name, placeholder: "Home Node")
                                field("地址", text: $originText, placeholder: "http://192.168.1.10:3000")
                                field("标签", text: $tagsText, placeholder: "home, primary")
                                SecureField("实例密码（可选）", text: $password)
                                    .textContentType(.password)
                                    .padding(.horizontal, 12)
                                    .frame(minHeight: 38)
                                    .background(AITheme.canvas)
                                    .clipShape(RoundedRectangle(cornerRadius: AITheme.buttonRadius))
                            }
                        }
                        if let validationMessage {
                            Text(validationMessage)
                                .font(.subheadline)
                                .foregroundStyle(AITheme.danger)
                                .frame(maxWidth: .infinity, alignment: .leading)
                        }
                    }
                    .padding(16)
                }
            }
            .navigationTitle("添加实例")
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("取消") { dismiss() }
                        .buttonStyle(AIButtonStyle(kind: .secondary, size: .regular))
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button("保存") {
                        save()
                    }
                    .buttonStyle(AIButtonStyle(kind: .primary, size: .regular))
                }
            }
        }
    }

    private func field(_ title: String, text: Binding<String>, placeholder: String) -> some View {
        VStack(alignment: .leading, spacing: 6) {
            Text(title)
                .font(.subheadline.weight(.semibold))
                .foregroundStyle(AITheme.ink)
            TextField(placeholder, text: text)
                .textFieldStyle(.plain)
                .padding(.horizontal, 12)
                .frame(minHeight: 38)
                .background(AITheme.canvas)
                .clipShape(RoundedRectangle(cornerRadius: AITheme.buttonRadius))
        }
    }

    private func save() {
        guard let origin = URL(string: originText.trimmingCharacters(in: .whitespacesAndNewlines)),
              origin.scheme == "http" || origin.scheme == "https",
              origin.host != nil
        else {
            validationMessage = "请输入有效的 HTTP 或 HTTPS 根地址。"
            return
        }
        let tags = tagsText
            .split(separator: ",")
            .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
            .filter { !$0.isEmpty }
        let input = InstanceInput(
            name: name,
            origin: origin,
            tags: tags,
            password: password.isEmpty ? nil : password
        )
        Task {
            do {
                try await model.add(input)
                dismiss()
            } catch {
                validationMessage = "保存失败，请检查地址是否重复。"
            }
        }
    }
}