//
//  TextInputViewController.swift
//  QuickLocation
//
//  Created by 八条 on 2026/6/9.
//

import UIKit
import RxSwift
import RxCocoa

/// 通用文本输入页面
/// 用法：
///   let vc = TextInputViewController(title: "编辑昵称", maxLength: 20) { text in
///       print("用户输入: \(text)")
///   }
///   present(vc, animated: true)
final class TextInputViewController: UIViewController {

    private let titleText: String
    private let maxLength: Int
    private let confirmAction: ((String) -> Void)?

    private let disposeBag = DisposeBag()
    private let textRelay = BehaviorRelay<String>(value: "")

    // MARK: - Init

    /// - Parameters:
    ///   - title: 页面标题
    ///   - maxLength: 文字输入上限（0 表示不限制）
    ///   - initialText: 初始文本，默认空
    ///   - confirmAction: 确定回调
    init(title: String,
         maxLength: Int = 0,
         initialText: String = "",
         confirmAction: ((String) -> Void)? = nil) {
        self.titleText = title
        self.maxLength = maxLength
        self.confirmAction = confirmAction
        self.textRelay.accept(initialText)
        super.init(nibName: nil, bundle: nil)
        modalPresentationStyle = .fullScreen
        modalTransitionStyle = .coverVertical
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    // MARK: - Lifecycle

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white
        setupUI()
        setupBinding()
        
        textView.becomeFirstResponder()
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
    }

    // MARK: - UI

    private func setupUI() {
        view.addSubview(navBgView)
        view.addSubview(navView)

        view.addSubview(inputTextView)
        inputTextView.addSubview(textView)
        view.addSubview(countLabel)
        view.addSubview(confirmBtn)

        navBgView.layoutChain
            .edges(excludingEdge: .bottom)
            .heightToWidth(160/375)

        navView.layoutChain
            .edges(excludingEdge: .bottom)
            .height(kNaviHeight)

        inputTextView.layoutChain
            .topToBottomOfView(navView, offset: 15)
            .edgesHorzontal(15)
        
        // 输入框
        textView.layoutChain
            .edgesVertical(5)
            .edgesHorzontal(10)

        countLabel.layoutChain
            .topToBottomOfView(inputTextView, offset: 5)
            .rightToView(textView)

        confirmBtn.layoutChain
            .topToBottomOfView(inputTextView, offset: 50)
            .edgesHorzontal(15).height(50)
    }

    // MARK: - Binding
    private func setupBinding() {
        textView.text = textRelay.value
        updateCommittedText()

        Observable.merge(
            textView.rx.didChange.asObservable(),
            textView.rx.text.map { _ in () },
            textView.rx.methodInvoked(#selector(UITextView.paste(_:))).map { _ in () }
        )
            .throttle(.milliseconds(100), scheduler: MainScheduler.instance)
            .subscribe(onNext: { [weak self] in
                self?.updateCommittedText()
            })
            .disposed(by: disposeBag)
        
        confirmBtn.rx.tap.subscribe(onNext: { [weak self] in
            guard let self = self, let text = self.textView.text else { return }
                self.confirmAction?(text)
                self.dismiss(animated: true)
            })
            .disposed(by: disposeBag)
    }

    private func updateCommittedText() {
        guard !textView.isComposingText else { return }

        if textView.text.last == "\n" {
            textView.text = String(textView.text.dropLast())
            textView.selectedRange = NSRange(
                location: (textView.text as NSString).length,
                length: 0
            )
            textView.resignFirstResponder()
        }

        let text: String
        if maxLength > 0 {
            text = textView.limitCommittedText(to: maxLength) ?? textView.text
        } else {
            text = textView.text
        }
        countLabel.text = maxLength > 0 ? "\(text.count)/\(maxLength)" : ""
        confirmBtn.isEnabled = !text.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
    }

    // MARK: - Views
    lazy var navBgView: UIImageView = {
        let iv = UIImageView()
        iv.image = UIImage(named: "Common/navBar_bg_2")
        iv.contentMode = .scaleAspectFill
        return iv
    }()

    lazy var navView: BaseNavigationView = {
        let nav = BaseNavigationView(title: titleText)
        nav.onBackTapped = { [weak self] in
            self?.dismiss(animated: true)
        }
        return nav
    }()

    lazy var inputTextView: UIView = {
        let view = UIView()
        view.backgroundColor = .white
        view.cornerRadius = 4
        view.borderWidth = 0.5
        view.borderColor = ThemeManager.shared.color.lineColor
        return view
    }()

    lazy var textView: UITextView = {
        let tv = UITextView()
        tv.font = .systemFont(ofSize: 15)
        tv.textColor = ThemeManager.shared.color.titleAuxColor
        tv.backgroundColor = .clear
        tv.showsVerticalScrollIndicator = false
        tv.isScrollEnabled = false
        tv.bounces = false
        tv.returnKeyType = .done
        return tv
    }()

    private lazy var countLabel: UILabel = {
        let label = UILabel()
        label.font = .systemFont(ofSize: 13)
        label.textColor = UIColor(hexStr: "#999999")
        label.text = maxLength > 0 ? "0/\(maxLength)" : ""
        return label
    }()

    private lazy var confirmBtn: UIButton = {
        let btn = UIButton(type: .custom)
        btn.setTitle("确定", for: .normal)
        btn.setTitleColor(.white, for: .normal)
        btn.setBackgroundImage(UIImage(named: "Common/button_bg_2"), for: .normal)
        btn.titleLabel?.font = .systemFont(ofSize: 16, weight: .bold)
        btn.cornerRadius = 25
        btn.isEnabled = false
        return btn
    }()
}