import SwiftUI

struct MessagesView: View {
    @StateObject private var model: MessagesViewModel

    init(model: MessagesViewModel? = nil) {
        _model = StateObject(wrappedValue: model ?? DefaultContainer.makeMessagesModel())
    }

    var body: some View {
        ZStack {
            AITheme.canvas.ignoresSafeArea()
            ScrollView {
                LazyVStack(spacing: 12) {
                    filterBar
                    if let errorMessage = model.errorMessage {
                        AICard {
                            Text(errorMessage)
                                .font(.subheadline)
                                .foregroundStyle(AITheme.warning)
                        }
                    }
                    if model.filteredRows.isEmpty && !model.isLoading {
                        AICard {
                            VStack(spacing: 10) {
                                Image(systemName: "message")
                                    .font(.system(size: 28))
                                    .foregroundStyle(AITheme.muted)
                                Text("暂无消息")
                                    .font(.headline)
                                Text("刷新后从实例同步短信。")
                                    .font(.subheadline)
                                    .foregroundStyle(AITheme.muted)
                            }
                            .frame(maxWidth: .infinity)
                            .padding(.vertical, 18)
                        }
                    }
                    ForEach(model.filteredRows) { message in
                        messageCard(message)
                    }
                }
                .padding(16)
            }
        }
        .navigationTitle("消息中心")
        .toolbar {
            ToolbarItemGroup(placement: .primaryAction) {
                Button {
                    model.showingSendForm = true
                } label: {
                    Label("发送", systemImage: "paperplane")
                }
                .buttonStyle(AIButtonStyle(kind: .primary, size: .regular))
            }
        }
        .refreshable {
            await model.refresh()
        }
        .task {
            await model.refresh()
        }
        .sheet(isPresented: $model.showingSendForm) {
            SendMessageFormView(model: model)
        }
    }

    private var filterBar: some View {
        AICard {
            VStack(spacing: 10) {
                Picker("方向", selection: $model.direction) {
                    ForEach(MessagesViewModel.DirectionFilter.allCases) { item in
                        Text(item.rawValue).tag(item)
                    }
                }
                .pickerStyle(.segmented)

                Picker("实例", selection: $model.selectedInstanceID) {
                    Text("全部实例").tag(Optional<UUID>.none)
                    ForEach(model.instances) { instance in
                        Text(instance.name).tag(Optional(instance.id))
                    }
                }
                .pickerStyle(.menu)

                TextField("搜索号码或内容", text: $model.searchText)
                    .textFieldStyle(.plain)
                    .padding(.horizontal, 12)
                    .frame(minHeight: AITheme.buttonHeight)
                    .background(AITheme.canvas)
                    .clipShape(RoundedRectangle(cornerRadius: AITheme.buttonRadius))
                    .overlay {
                        RoundedRectangle(cornerRadius: AITheme.buttonRadius)
                            .strokeBorder(AITheme.line)
                    }
            }
        }
    }

    private func messageCard(_ message: SMSMessage) -> some View {
        AICard {
            VStack(alignment: .leading, spacing: 10) {
                HStack(spacing: 8) {
                    Text(message.phoneNumber.isEmpty ? "未知号码" : message.phoneNumber)
                        .font(.headline)
                    Spacer()
                    AITag(message.direction.label, tint: message.direction == .outgoing ? AITheme.primary : AITheme.success)
                }
                Text(message.content)
                    .font(.subheadline)
                    .foregroundStyle(AITheme.ink)
                HStack {
                    Text(message.instanceName)
                        .font(.caption)
                        .foregroundStyle(AITheme.muted)
                    Spacer()
                    Button("删除") {
                        Task { await model.delete(message) }
                    }
                    .buttonStyle(AIButtonStyle(kind: .danger, size: .compact))
                }
            }
        }
    }
}