import Foundation
import SwiftUI
import Combine

/// Bricks引擎 — 核心控制器
/// 负责加载JSON schema、管理状态、处理binds事件
@MainActor
public final class BricksEngine: ObservableObject {
    
    /// 当前渲染的根schema
    @Published public var rootSchema: ControlSchema?
    
    /// 数据存储
    public let store = BricksStore()
    
    /// 事件总线
    public let eventBus = BricksEventBus()
    
    /// RPC网络层
    public let rpc = BricksRPC()
    
    /// 国际化
    public let i18n = BricksI18n()
    
    /// Widget注册表: widgettype → factory
    private var widgetRegistry: [String: WidgetFactory] = [:]
    
    /// Widget实例索引: id → schema
    @Published public var widgetIndex: [String: ControlSchema] = [:]
    
    /// 当前弹窗
    @Published public var activePopup: PopupInfo?
    
    /// 导航栈（urlwidget加载的内容）
    @Published public var navigationStack: [String: ControlSchema] = [:]
    
    /// 加载状态
    @Published public var isLoading: Bool = false
    
    /// 错误信息
    @Published public var errorMessage: String?
    
    public init() {
        registerBuiltInWidgets()
        setupBuiltinEvents()
    }
    
    // MARK: - 加载JSON
    
    /// 从JSON字符串加载
    public func loadJSON(_ jsonString: String) throws {
        let data = jsonString.data(using: .utf8)!
        let schema = try JSONDecoder().decode(ControlSchema.self, from: data)
        loadSchema(schema)
    }
    
    /// 从URL加载JSON
    public func loadFromURL(_ urlString: String) async throws {
        isLoading = true
        defer { isLoading = false }
        
        let response = try await rpc.get(urlString)
        guard response.isSuccess else {
            throw BricksRPCError.httpError(response.statusCode, response.text)
        }
        let schema = try JSONDecoder().decode(ControlSchema.self, from: response.data)
        loadSchema(schema)
    }
    
    /// 从schema对象加载
    public func loadSchema(_ schema: ControlSchema) {
        rootSchema = schema
        indexWidgets(schema)
        setupBinds(schema)
    }
    
    // MARK: - Widget注册
    
    /// 注册自定义widget
    public func registerWidget(type: String, factory: @escaping WidgetFactory) {
        widgetRegistry[type] = factory
    }
    
    /// 获取widget工厂
    public func getWidgetFactory(type: String) -> WidgetFactory? {
        widgetRegistry[type]
    }
    
    // MARK: - Widget索引
    
    /// 递归索引所有widget
    private func indexWidgets(_ schema: ControlSchema) {
        let id = schema.effectiveId
        widgetIndex[id] = schema
        if let subwidgets = schema.subwidgets {
            for sub in subwidgets {
                indexWidgets(sub)
            }
        }
    }
    
    /// 按ID查找widget schema
    public func findWidget(id: String) -> ControlSchema? {
        // 支持 "app.content" 点链语法
        if id.contains(".") {
            let parts = id.split(separator: ".")
            if let lastPart = parts.last {
                return widgetIndex[String(lastPart)]
            }
        }
        // 支持 "-" 前缀向上查找
        let cleanId = id.hasPrefix("-") ? String(id.dropFirst()) : id
        return widgetIndex[cleanId]
    }
    
    // MARK: - Binds处理
    
    /// 递归设置所有binds
    private func setupBinds(_ schema: ControlSchema) {
        if let binds = schema.binds {
            for bind in binds {
                setupBind(bind, sourceId: schema.effectiveId)
            }
        }
        if let subwidgets = schema.subwidgets {
            for sub in subwidgets {
                setupBinds(sub)
            }
        }
    }
    
    /// 设置单个bind
    private func setupBind(_ bind: BindSchema, sourceId: String) {
        let wid = bind.wid == "self" ? sourceId : bind.wid
        
        eventBus.on("\(wid).\(bind.event)") { [weak self] data in
            guard let self else { return }
            await self.handleBind(bind, sourceId: sourceId, eventData: data)
        }
    }
    
    /// 执行bind动作
    public func handleBind(_ bind: BindSchema, sourceId: String, eventData: EventData = EventData()) async {
        guard let actionType = ActionType(rawValue: bind.actiontype) else {
            print("[SwiftBricks] Invalid actiontype: \(bind.actiontype)")
            return
        }
        
        switch actionType {
        case .urlwidget:
            await handleUrlWidget(bind, sourceId: sourceId, eventData: eventData)
        case .urldata:
            await handleUrlData(bind, sourceId: sourceId)
        case .method:
            await handleMethod(bind, sourceId: sourceId, eventData: eventData)
        case .event:
            await handleEvent(bind, eventData: eventData)
        case .newwindow:
            if let url = bind.options?.url {
                #if os(macOS)
                NSWorkspace.shared.open(URL(string: url)!)
                #elseif os(iOS)
                await UIApplication.shared.open(URL(string: url)!)
                #endif
            }
        case .bricks:
            await handleBricksAction(bind)
        case .script:
            // SwiftBricks不支持内联脚本（符合Bricks无代码哲学）
            print("[SwiftBricks] actiontype 'script' not supported in SwiftBricks")
        case .iframe, .registerfunction:
            // 不适用于Swift环境
            break
        }
    }
    
    // MARK: - 动作处理器
    
    private func handleUrlWidget(_ bind: BindSchema, sourceId: String, eventData: EventData) async {
        guard let url = bind.options?.url else { return }
        
        // 构建参数
        var params: [String: String] = bind.options?.params ?? [:]
        
        // 合并事件数据（如表单值、选中行数据）
        for (key, value) in eventData.asDictionary {
            if let strVal = value as? String {
                params[key] = strVal
            } else if let intVal = value as? Int {
                params[key] = "\(intVal)"
            }
        }
        
        // 处理 ${field}$ 变量替换
        let resolvedURL = resolveTemplate(url, params: params)
        
        // 获取选中行数据（如果是toolbar按钮）
        if let selectedData = store.getSelectedRowData(tabularId: sourceId) {
            for (key, value) in selectedData {
                if let strVal = value as? String {
                    params[key] = strVal
                }
            }
        }
        
        do {
            isLoading = true
            let response = try await rpc.get(resolvedURL, params: params)
            isLoading = false
            
            if response.isSuccess {
                if let schema = try? JSONDecoder().decode(ControlSchema.self, from: response.data) {
                    if let target = bind.target {
                        if target == "PopupWindow" || target == "Popup" {
                            let opts = bind.popup_options ?? PopupOptions()
                            activePopup = PopupInfo(schema: schema, options: opts)
                        } else {
                            navigationStack[target] = schema
                        }
                    }
                }
            }
        } catch {
            isLoading = false
            errorMessage = error.localizedDescription
        }
    }
    
    private func handleUrlData(_ bind: BindSchema, sourceId: String) async {
        guard let url = bind.options?.url else { return }
        let params = bind.options?.params ?? [:]
        let resolvedURL = resolveTemplate(url, params: params)
        
        do {
            let response = try await rpc.get(resolvedURL, params: params)
            if response.isSuccess, let target = bind.target {
                store.setValue(id: target, value: response.text)
            }
        } catch {
            errorMessage = error.localizedDescription
        }
    }
    
    private func handleMethod(_ bind: BindSchema, sourceId: String, eventData: EventData) async {
        guard let methodName = bind.method, let target = bind.target else { return }
        
        // 内置方法
        switch methodName {
        case "render":
            // 重新加载Tabular数据
            if let schema = findWidget(id: target), let url = schema.options.data_url {
                await reloadTabular(id: target, url: url, params: eventData.asDictionary as? [String: String] ?? [:])
            }
        case "toggle_collapse":
            if store.collapsedMenus.contains(target) {
                store.collapsedMenus.remove(target)
            } else {
                store.collapsedMenus.insert(target)
            }
        case "setValue":
            if let value = eventData["value"] as? String {
                store.setValue(id: target, value: value)
            }
        case "reset":
            store.clearForm(formId: target)
        default:
            await eventBus.dispatch("\(target).\(methodName)", data: eventData)
        }
    }
    
    private func handleEvent(_ bind: BindSchema, eventData: EventData) async {
        if let target = bind.target {
            await eventBus.dispatch(target, data: eventData)
        }
    }
    
    private func handleBricksAction(_ bind: BindSchema) async {
        // bricks actiontype: 从配置实例化widget（暂不实现远程加载）
        print("[SwiftBricks] actiontype 'bricks' - remote widget instantiation not yet supported")
    }
    
    // MARK: - Tabular数据加载
    
    public func reloadTabular(id: String, url: String, params: [String: String] = [:]) async {
        let resolvedURL = resolveTemplate(url, params: params)
        do {
            let response = try await rpc.get(resolvedURL, params: params)
            if response.isSuccess, let dict = response.dictionary, let rows = dict["rows"] as? [[String: Any]] {
                store.setTableData(id: id, rows: rows)
            }
        } catch {
            errorMessage = "加载数据失败: \(error.localizedDescription)"
        }
    }
    
    // MARK: - 模板变量替换
    
    public func resolveTemplate(_ template: String, params: [String: String]) -> String {
        var result = template
        for (key, value) in params {
            result = result.replacingOccurrences(of: "${\(key)}$", with: value)
        }
        return result
    }
    
    // MARK: - 触发事件
    
    /// 触发widget事件
    public func triggerEvent(widgetId: String, event: String, data: EventData = EventData()) async {
        await eventBus.dispatch("\(widgetId).\(event)", data: data)
    }
    
    // MARK: - 表单提交
    
    public func submitForm(formId: String, submitURL: String) async -> Bool {
        let values = store.getFormValues(formId: formId)
        
        // 验证
        if let schema = findWidget(id: formId), let fields = schema.options.fields {
            for field in fields {
                if let rules = field.rules {
                    let value = values[field.name] ?? ""
                    for rule in rules {
                        if !validateRule(rule, value: value) {
                            errorMessage = rule.message ?? "验证失败: \(field.effectiveLabel)"
                            return false
                        }
                    }
                }
                if field.required == true {
                    let value = values[field.name] ?? ""
                    if value.isEmpty {
                        errorMessage = "\(field.effectiveLabel)不能为空"
                        return false
                    }
                }
            }
        }
        
        // 提交
        do {
            let response = try await rpc.postForm(submitURL, fields: values)
            if response.isSuccess {
                return true
            } else {
                errorMessage = "提交失败: HTTP \(response.statusCode)"
                return false
            }
        } catch {
            errorMessage = error.localizedDescription
            return false
        }
    }
    
    // MARK: - 表单验证
    
    private func validateRule(_ rule: ValidationRule, value: String) -> Bool {
        switch rule.type {
        case "required":
            return !value.isEmpty
        case "minlength":
            guard let minLen = Int(rule.value ?? "0") else { return true }
            return value.count >= minLen
        case "maxlength":
            guard let maxLen = Int(rule.value ?? "0") else { return true }
            return value.count <= maxLen
        case "min":
            guard let minVal = Double(rule.value ?? "0"), let val = Double(value) else { return true }
            return val >= minVal
        case "max":
            guard let maxVal = Double(rule.value ?? "0"), let val = Double(value) else { return true }
            return val <= maxVal
        case "email":
            let emailRegex = #"^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}$"#
            return value.range(of: emailRegex, options: .regularExpression) != nil
        case "number":
            return Double(value) != nil
        case "pattern":
            guard let pattern = rule.value else { return true }
            return value.range(of: pattern, options: .regularExpression) != nil
        default:
            return true
        }
    }
    
    // MARK: - 内置事件
    
    private func setupBuiltinEvents() {
        // 可在此注册全局事件
    }
    
    // MARK: - 内置Widget注册
    
    private func registerBuiltInWidgets() {
        // 所有widget类型都通过ControlRenderer处理
        // 这里可以注册自定义widget工厂
    }
}

/// Widget工厂函数类型
public typealias WidgetFactory = (ControlSchema, BricksEngine) -> AnyView

/// 弹窗信息
public struct PopupInfo: Identifiable {
    public let id = UUID()
    public let schema: ControlSchema
    public let options: PopupOptions
}