import SwiftUI

// MARK: - Form Control

struct FormControl: View {
    let schema: ControlSchema
    @ObservedObject var engine: BricksEngine
    @State private var fieldValues: [String: String] = [:]
    @State private var errors: [String: String] = [:]
    @State private var isSubmitting: Bool = false
    @State private var submitMessage: String = ""
    
    var body: some View {
        VStack(alignment: .leading, spacing: 16) {
            // 标题
            if let title = schema.options.title {
                Text(engine.i18n.t(title))
                    .font(.title3.bold())
            }
            
            // 字段
            ForEach(fields, id: \.name) { field in
                formField(field)
            }
            
            // 错误信息
            if !submitMessage.isEmpty {
                Text(submitMessage)
                    .font(.caption)
                    .foregroundColor(.red)
            }
            
            // 按钮栏
            HStack {
                Spacer()
                Button("重置") { resetForm() }
                    .buttonStyle(.bordered)
                Button("提交") { submitForm() }
                    .buttonStyle(.borderedProminent)
                    .disabled(isSubmitting)
                if isSubmitting {
                    ProgressView().scaleEffect(0.7)
                }
            }
        }
        .padding(16)
        .onAppear { initializeValues() }
    }
    
    // MARK: - 表单字段渲染
    
    @ViewBuilder
    private func formField(_ field: FieldSchema) -> some View {
        VStack(alignment: .leading, spacing: 4) {
            HStack(spacing: 4) {
                Text(field.effectiveLabel)
                    .font(.subheadline)
                if field.required == true {
                    Text("*").foregroundColor(.red)
                }
            }
            
            switch field.effectiveUitype {
            case "text":
                TextEditor(text: Binding(
                    get: { fieldValues[field.name] ?? "" },
                    set: { fieldValues[field.name] = $0 }
                ))
                .frame(minHeight: 80)
                .border(Color.secondary.opacity(0.3))
                
            case "code", "select":
                Picker("", selection: Binding(
                    get: { fieldValues[field.name] ?? "" },
                    set: { fieldValues[field.name] = $0 }
                )) {
                    Text("--请选择--").tag("")
                    if let codes = field.codes ?? field.data {
                        ForEach(codes, id: \.value) { item in
                            Text(item.text).tag(item.value)
                        }
                    }
                }
                .pickerStyle(.menu)
                
            case "number":
                TextField("", text: Binding(
                    get: { fieldValues[field.name] ?? "" },
                    set: { fieldValues[field.name] = $0 }
                ))
                .textFieldStyle(.roundedBorder)
                #if os(iOS)
                .keyboardType(.decimalPad)
                #endif
                
            case "date":
                DatePicker("", selection: Binding(
                    get: { parseDate(fieldValues[field.name] ?? "") },
                    set: { fieldValues[field.name] = formatDate($0) }
                ), displayedComponents: [.date])
                .labelsHidden()
                
            default: // str
                TextField(field.placeholder ?? field.effectiveLabel, text: Binding(
                    get: { fieldValues[field.name] ?? "" },
                    set: { fieldValues[field.name] = $0 }
                ))
                .textFieldStyle(.roundedBorder)
            }
            
            if let error = errors[field.name] {
                Text(error)
                    .font(.caption2)
                    .foregroundColor(.red)
            }
        }
    }
    
    // MARK: - 字段列表
    
    private var fields: [FieldSchema] {
        schema.options.fields ?? []
    }
    
    // MARK: - 初始化
    
    private func initializeValues() {
        for field in fields {
            fieldValues[field.name] = field.value ?? field.defaultvalue ?? ""
        }
        engine.store.setFormValues(formId: schema.effectiveId, data: fieldValues)
    }
    
    // MARK: - 验证
    
    private func validate() -> Bool {
        errors = [:]
        for field in fields {
            let value = fieldValues[field.name] ?? ""
            
            if field.required == true && value.isEmpty {
                errors[field.name] = "\(field.effectiveLabel)不能为空"
                continue
            }
            
            if let rules = field.rules {
                for rule in rules {
                    if !validateRule(rule, value: value) {
                        errors[field.name] = rule.message ?? "验证失败"
                        break
                    }
                }
            }
        }
        return errors.isEmpty
    }
    
    private func validateRule(_ rule: ValidationRule, value: String) -> Bool {
        switch rule.type {
        case "required": return !value.isEmpty
        case "minlength": return value.count >= (Int(rule.value ?? "0") ?? 0)
        case "maxlength": return value.count <= (Int(rule.value ?? "999999") ?? 999999)
        case "min": return (Double(value) ?? -999999) >= (Double(rule.value ?? "0") ?? 0)
        case "max": return (Double(value) ?? 999999) <= (Double(rule.value ?? "999999") ?? 999999)
        case "email":
            return value.range(of: #"^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}$"#, options: .regularExpression) != nil
        case "number": return Double(value) != nil
        case "pattern": return value.range(of: rule.value ?? "", options: .regularExpression) != nil
        default: return true
        }
    }
    
    // MARK: - 提交
    
    private func submitForm() {
        guard validate() else { return }
        guard let url = schema.options.submit_url else { return }
        
        isSubmitting = true
        submitMessage = ""
        engine.store.setFormValues(formId: schema.effectiveId, data: fieldValues)
        
        Task {
            do {
                let response = try await engine.rpc.postForm(url, fields: fieldValues)
                isSubmitting = false
                if response.isSuccess {
                    submitMessage = "提交成功"
                    await engine.triggerEvent(widgetId: schema.effectiveId, event: "submit",
                                             data: EventData(fieldValues as [String: Any]))
                } else {
                    submitMessage = "提交失败: HTTP \(response.statusCode)"
                }
            } catch {
                isSubmitting = false
                submitMessage = "提交失败: \(error.localizedDescription)"
            }
        }
    }
    
    private func resetForm() {
        fieldValues = [:]
        errors = [:]
        submitMessage = ""
        engine.store.clearForm(formId: schema.effectiveId)
    }
    
    // MARK: - 日期工具
    
    private func parseDate(_ str: String) -> Date {
        let f = DateFormatter()
        f.dateFormat = "yyyy-MM-dd"
        return f.date(from: str) ?? Date()
    }
    
    private func formatDate(_ date: Date) -> String {
        let f = DateFormatter()
        f.dateFormat = "yyyy-MM-dd"
        return f.string(from: date)
    }
}

// MARK: - InlineForm Control

struct InlineFormControl: View {
    let schema: ControlSchema
    @ObservedObject var engine: BricksEngine
    @State private var fieldValues: [String: String] = [:]
    
    var body: some View {
        HStack(spacing: 8) {
            ForEach(fields, id: \.name) { field in
                inlineField(field)
            }
            
            Button(submitLabel) {
                engine.store.setFormValues(formId: schema.effectiveId, data: fieldValues)
                Task {
                    await engine.triggerEvent(widgetId: schema.effectiveId, event: "submit",
                                             data: EventData(fieldValues as [String: Any]))
                }
            }
            .buttonStyle(.borderedProminent)
        }
        .padding(8)
        .background(Color.secondary.opacity(0.05))
        .cornerRadius(8)
    }
    
    @ViewBuilder
    private func inlineField(_ field: FieldSchema) -> some View {
        switch field.effectiveUitype {
        case "code", "select":
            Picker("", selection: Binding(
                get: { fieldValues[field.name] ?? "" },
                set: { fieldValues[field.name] = $0 }
            )) {
                Text(field.placeholder ?? "全部").tag("")
                if let codes = field.codes ?? field.data {
                    ForEach(codes, id: \.value) { item in
                        Text(item.text).tag(item.value)
                    }
                }
            }
            .pickerStyle(.menu)
            .fixedSize()
        default:
            TextField(field.placeholder ?? field.name, text: Binding(
                get: { fieldValues[field.name] ?? "" },
                set: { fieldValues[field.name] = $0 }
            ))
            .textFieldStyle(.roundedBorder)
            .frame(width: 120)
        }
    }
    
    private var fields: [FieldSchema] { schema.options.fields ?? [] }
    private var submitLabel: String {
        let label = schema.options.submit_label ?? "提交"
        return (schema.options.i18n != false) ? engine.i18n.t(label) : label
    }
}