import SwiftUI
import CoreData

struct HistoryView: View {
    @StateObject private var coreDataManager = CoreDataManager.shared
    @State private var searchText = ""
    @State private var selectedFilter: HistoryFilter = .all
    @State private var showingCreateSheet = false
    @State private var showingClearAlert = false
    
    enum HistoryFilter: String, CaseIterable {
        case all = "all"
        case barcode = "barcode"
        case qrcode = "qrcode"
        case scanned = "scanned"
        case created = "created"
        case favorites = "favorites"
        
        var displayName: String {
            switch self {
            case .all:
                return "全部"
            case .barcode:
                return "条形码"
            case .qrcode:
                return "二维码"
            case .scanned:
                return "扫描获得"
            case .created:
                return "手动创建"
            case .favorites:
                return "收藏"
            }
        }
        
        var icon: String {
            switch self {
            case .all:
                return "list.bullet"
            case .barcode:
                return "barcode"
            case .qrcode:
                return "qrcode"
            case .scanned:
                return "camera.viewfinder"
            case .created:
                return "plus.circle"
            case .favorites:
                return "heart.fill"
            }
        }
    }
    
    var filteredItems: [HistoryItem] {
        let allItems = coreDataManager.fetchHistoryItems()
        
        let searchResults = allItems.filter { item in
            if !searchText.isEmpty {
                let content = item.content ?? ""
                let barcodeType = item.barcodeType ?? ""
                let qrCodeType = item.qrCodeType ?? ""
                
                return content.localizedCaseInsensitiveContains(searchText) ||
                       barcodeType.localizedCaseInsensitiveContains(searchText) ||
                       qrCodeType.localizedCaseInsensitiveContains(searchText)
            }
            return true
        }
        
        switch selectedFilter {
        case .all:
            return searchResults
        case .barcode:
            return searchResults.filter { $0.dataType == DataType.barcode.rawValue }
        case .qrcode:
            return searchResults.filter { $0.dataType == DataType.qrcode.rawValue }
        case .scanned:
            return searchResults.filter { $0.dataSource == DataSource.scanned.rawValue }
        case .created:
            return searchResults.filter { $0.dataSource == DataSource.created.rawValue }
        case .favorites:
            return searchResults.filter { $0.isFavorite }
        }
    }
    
    var body: some View {
        NavigationView {
            VStack(spacing: 0) {
                // 搜索栏
                searchBar
                
                // 过滤器
                filterBar
                
                // 内容列表
                if filteredItems.isEmpty {
                    emptyStateView
                } else {
                    historyList
                }
            }
            .navigationTitle("历史记录")
            .navigationBarTitleDisplayMode(.large)
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button(action: {
                        showingClearAlert = true
                    }) {
                        Image(systemName: "trash")
                            .foregroundColor(.red)
                    }
                    .disabled(coreDataManager.fetchHistoryItems().isEmpty)
                }
                
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button(action: {
                        showingCreateSheet = true
                    }) {
                        Image(systemName: "plus")
                    }
                }
            }
            .sheet(isPresented: $showingCreateSheet) {
                CreateCodeView()
            }
            .overlay(
                // 二维码详情页面导航按钮
                VStack {
                    Spacer()
                    HStack {
                        Spacer()
                        if let firstQRCode = filteredItems.first(where: { $0.dataType == DataType.qrcode.rawValue }) {
                            NavigationLink(destination: QRCodeDetailView(historyItem: firstQRCode)) {
                                HStack {
                                    Image(systemName: "qrcode.viewfinder")
                                    Text("查看二维码详情")
                                }
                                .font(.title3)
                                .foregroundColor(.white)
                                .padding()
                                .background(Color.orange)
                                .cornerRadius(10)
                                .shadow(radius: 4)
                            }
                        }
                        Spacer()
                    }
                    .padding(.bottom, 20)
                }
            )
            .alert("清空历史记录", isPresented: $showingClearAlert) {
                Button("取消", role: .cancel) { }
                Button("清空", role: .destructive) {
                    clearHistory()
                }
            } message: {
                Text("确定要清空所有历史记录吗？此操作不可撤销。")
            }
        }
    }
    
    // MARK: - 清空历史记录
    private func clearHistory() {
        coreDataManager.clearAllHistory()
    }
    
    // MARK: - 切换收藏状态
    private func toggleFavorite(_ item: HistoryItem) {
        item.isFavorite.toggle()
        coreDataManager.save()
    }
    
    // MARK: - 删除历史记录
    private func deleteHistoryItem(_ item: HistoryItem) {
        coreDataManager.deleteHistoryItem(item)
    }
    
    // MARK: - 搜索栏
    private var searchBar: some View {
        HStack {
            Image(systemName: "magnifyingglass")
                .foregroundColor(.gray)
            
            TextField("搜索历史记录...", text: $searchText)
                .textFieldStyle(RoundedBorderTextFieldStyle())
        }
        .padding(.horizontal)
        .padding(.vertical, 8)
        .background(Color(.systemBackground))
    }
    
    // MARK: - 过滤器栏
    private var filterBar: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            HStack(spacing: 12) {
                ForEach(HistoryFilter.allCases, id: \.self) { filter in
                    FilterChip(
                        filter: filter,
                        isSelected: selectedFilter == filter,
                        action: {
                            selectedFilter = filter
                        }
                    )
                }
            }
            .padding(.horizontal)
        }
        .padding(.vertical, 8)
        .background(Color(.systemBackground))
    }
    
    // MARK: - 历史记录列表
    private var historyList: some View {
        List {
            ForEach(filteredItems) { item in
                HistoryItemRow(
                    item: item,
                    onToggleFavorite: {
                        toggleFavorite(item)
                    },
                    onDelete: {
                        deleteHistoryItem(item)
                    }
                )
            }
        }
        .listStyle(PlainListStyle())
    }
    
    // MARK: - 空状态视图
    private var emptyStateView: some View {
        VStack(spacing: 20) {
            Image(systemName: "clock.arrow.circlepath")
                .font(.system(size: 60))
                .foregroundColor(.gray)
            
            Text("暂无历史记录")
                .font(.title2)
                .fontWeight(.medium)
                .foregroundColor(.gray)
            
            Text("扫描二维码或手动创建来开始记录")
                .font(.body)
                .foregroundColor(.gray)
                .multilineTextAlignment(.center)
            
            Button(action: {
                showingCreateSheet = true
            }) {
                HStack {
                    Image(systemName: "plus.circle.fill")
                    Text("创建第一个记录")
                }
                .font(.headline)
                .foregroundColor(.white)
                .padding()
                .background(Color.blue)
                .cornerRadius(10)
            }
        }
        .padding()
        .frame(maxWidth: .infinity, maxHeight: .infinity)
    }
}

#Preview {
    HistoryView()
}

// MARK: - 过滤器芯片
struct FilterChip: View {
    let filter: HistoryView.HistoryFilter
    let isSelected: Bool
    let action: () -> Void
    
    var body: some View {
        Button(action: action) {
            HStack(spacing: 6) {
                Image(systemName: filter.icon)
                    .font(.system(size: 14))
                
                Text(filter.displayName)
                    .font(.system(size: 14, weight: .medium))
            }
            .padding(.horizontal, 12)
            .padding(.vertical, 8)
            .background(isSelected ? Color.blue : Color(.systemGray5))
            .foregroundColor(isSelected ? .white : .primary)
            .cornerRadius(20)
        }
        .buttonStyle(PlainButtonStyle())
    }
}

// MARK: - 历史记录项行
struct HistoryItemRow: View {
    let item: HistoryItem
    let onToggleFavorite: () -> Void
    let onDelete: () -> Void
    @State private var showingDetail = false
    
    var body: some View {
        HStack(spacing: 12) {
            // 类型图标
            VStack {
                if let dataTypeString = item.dataType,
                   let dataType = DataType(rawValue: dataTypeString) {
                    Image(systemName: dataType.icon)
                        .font(.system(size: 24))
                        .foregroundColor(.blue)
                }
                
                if let dataSourceString = item.dataSource,
                   let dataSource = DataSource(rawValue: dataSourceString) {
                    Image(systemName: dataSource.icon)
                        .font(.system(size: 12))
                        .foregroundColor(.gray)
                }
            }
            .frame(width: 40)
            
            // 内容信息
            VStack(alignment: .leading, spacing: 4) {
                HStack {
                    Text(item.content ?? "")
                        .font(.headline)
                        .lineLimit(2)
                    
                    Spacer()
                    
                    Button(action: onToggleFavorite) {
                        Image(systemName: item.isFavorite ? "heart.fill" : "heart")
                            .foregroundColor(item.isFavorite ? .red : .gray)
                    }
                    .buttonStyle(PlainButtonStyle())
                }
                
                HStack {
                    // 类型标签
                    if let dataTypeString = item.dataType,
                       let dataType = DataType(rawValue: dataTypeString) {
                        HStack(spacing: 4) {
                            Image(systemName: dataType.icon)
                                .font(.system(size: 12))
                            Text(dataType.displayName)
                                .font(.caption)
                        }
                        .padding(.horizontal, 8)
                        .padding(.vertical, 2)
                        .background(Color.blue.opacity(0.1))
                        .foregroundColor(.blue)
                        .cornerRadius(8)
                    }
                    
                    // 具体类型标签
                    if let barcodeTypeString = item.barcodeType,
                       let barcodeType = BarcodeType(rawValue: barcodeTypeString) {
                        HStack(spacing: 4) {
                            Image(systemName: barcodeType.icon)
                                .font(.system(size: 12))
                            Text(barcodeType.displayName)
                                .font(.caption)
                        }
                        .padding(.horizontal, 8)
                        .padding(.vertical, 2)
                        .background(Color.green.opacity(0.1))
                        .foregroundColor(.green)
                        .cornerRadius(8)
                    }
                    
                    if let qrCodeTypeString = item.qrCodeType,
                       let qrCodeType = QRCodeType(rawValue: qrCodeTypeString) {
                        HStack(spacing: 4) {
                            Image(systemName: qrCodeType.icon)
                                .font(.system(size: 12))
                            Text(qrCodeType.displayName)
                                .font(.caption)
                        }
                        .padding(.horizontal, 8)
                        .padding(.vertical, 2)
                        .background(Color.orange.opacity(0.1))
                        .foregroundColor(.orange)
                        .cornerRadius(8)
                    }
                    
                    Spacer()
                    
                    // 时间
                    if let createdAt = item.createdAt {
                        Text(formatDate(createdAt))
                            .font(.caption)
                            .foregroundColor(.gray)
                    }
                }
            }
            
            Spacer()
        }
        .padding(.vertical, 8)
        .swipeActions(edge: .trailing, allowsFullSwipe: false) {
            Button("删除", role: .destructive) {
                onDelete()
            }
        }
        .onTapGesture {
            if item.dataType == DataType.qrcode.rawValue {
                showingDetail = true
            }
        }
        .sheet(isPresented: $showingDetail) {
            if item.dataType == DataType.qrcode.rawValue {
                NavigationView {
                    QRCodeDetailView(historyItem: item)
                }
            }
        }
    }
    
    private func formatDate(_ date: Date) -> String {
        let formatter = DateFormatter()
        formatter.dateStyle = .short
        formatter.timeStyle = .short
        return formatter.string(from: date)
    }
}