//
//  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 = UIColor(hexStr: "#F5FBFB")
        setupUI()
        setupBinding()
        setupKeyboard()
        textView.becomeFirstResponder()
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        if textViewHeightConstraint == nil {
            updateTextViewHeight()
        }
    }

    // MARK: - UI

    private func setupUI() {
        view.addSubview(topBar)
        topBar.addSubview(closeBtn)
        topBar.addSubview(titleLabel)

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

        // 顶栏
        topBar.layoutChain
            .top()
            .edgesHorzontal()
            .height(kNaviHeight)

        closeBtn.layoutChain
            .bottom(12)
            .left(7)
            .width(24).height(24)

        titleLabel.layoutChain
            .centerY(closeBtn)
            .centerX()

        // 内容容器（textView + 按钮），键盘升起时整体上移
        contentView.layoutChain
            .topToBottomOfView(topBar, offset: 16)
            .edgesHorzontal(15)
            .bottom()

        // 输入框
        textView.layoutChain
            .top()
            .edgesHorzontal()
            .height(textViewMinHeight)

        // 字数统计（textView 右下角）
        countLabel.layoutChain
            .right(-10)
            .bottom(-8)

        // 确定按钮
        confirmBtn.layoutChain
            .topToBottomOfView(textView, offset: 50)
            .edgesHorzontal()
            .height(44)
            .bottom()
    }

    // MARK: - Binding

    private func setupBinding() {
        // 输入流
        textView.rx.text
            .compactMap { $0 }
            .subscribe(onNext: { [weak self] text in
                guard let self = self else { return }
                let realText = self.maxLength > 0 && text.count > self.maxLength
                    ? String(text.prefix(self.maxLength))
                    : text
                if realText != text {
                    self.textView.text = realText
                }
                self.textRelay.accept(realText)
            })
            .disposed(by: disposeBag)

        // 字数统计
        textRelay
            .map { [weak self] text in
                guard let self = self, self.maxLength > 0 else { return "" }
                return "\(text.count)/\(self.maxLength)"
            }
            .bind(to: countLabel.rx.text)
            .disposed(by: disposeBag)

        // 确定按钮状态 + 背景色
        let confirmEnabled = textRelay
            .map { [weak self] text in
                guard let self = self else { return false }
                if self.maxLength > 0 { return !text.isEmpty && text.count <= self.maxLength }
                return !text.isEmpty
            }
            .share(replay: 1)

        confirmEnabled
            .bind(to: confirmBtn.rx.isEnabled)
            .disposed(by: disposeBag)

        confirmEnabled
            .subscribe(onNext: { [weak self] enabled in
                self?.confirmBtn.backgroundColor = enabled
                    ? UIColor(hexStr: "#16B3FF")
                    : UIColor(hexStr: "#CCCCCC")
            })
            .disposed(by: disposeBag)

        // 动态高度
        textView.rx.text
            .observe(on: MainScheduler.asyncInstance)
            .subscribe(onNext: { [weak self] _ in
                self?.updateTextViewHeight()
            })
            .disposed(by: disposeBag)

        // 确定
        confirmBtn.rx.tap
            .withLatestFrom(textRelay)
            .subscribe(onNext: { [weak self] text in
                guard let self = self else { return }
                self.confirmAction?(text)
                self.dismiss(animated: true)
            })
            .disposed(by: disposeBag)

        // 关闭
        closeBtn.rx.tap
            .subscribe(onNext: { [weak self] _ in
                self?.dismiss(animated: true)
            })
            .disposed(by: disposeBag)
    }

    // MARK: - Keyboard

    private var originContentY: CGFloat = 0

    private func setupKeyboard() {
        NotificationCenter.default.rx.notification(UIResponder.keyboardWillShowNotification)
            .subscribe(onNext: { [weak self] noti in
                guard let self = self,
                      let userInfo = noti.userInfo,
                      let frame = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect
                else { return }
                let keyboardHeight = frame.height
                let duration = (userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double) ?? 0.25
                // 计算 contentView 需要上移的距离 = 键盘遮住底部的高度 - 安全区域
                let offset = keyboardHeight - kSafeBottomMargin
                UIView.animate(withDuration: duration) {
                    self.contentView.transform = CGAffineTransform(translationX: 0, y: -offset)
                    self.view.layoutIfNeeded()
                }
            })
            .disposed(by: disposeBag)

        NotificationCenter.default.rx.notification(UIResponder.keyboardWillHideNotification)
            .subscribe(onNext: { [weak self] noti in
                guard let self = self else { return }
                let duration = (noti.userInfo?[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double) ?? 0.25
                UIView.animate(withDuration: duration) {
                    self.contentView.transform = .identity
                    self.view.layoutIfNeeded()
                }
            })
            .disposed(by: disposeBag)
    }

    // MARK: - TextView Height

    private let textViewMinHeight: CGFloat = 150
    private let textViewMaxHeight: CGFloat = 300
    private var textViewHeightConstraint: NSLayoutConstraint?

    private func updateTextViewHeight() {
        let size = textView.sizeThatFits(CGSize(width: textView.bounds.width, height: CGFloat.greatestFiniteMagnitude))
        let height = min(max(size.height, textViewMinHeight), textViewMaxHeight)
        if textViewHeightConstraint == nil {
            textViewHeightConstraint = textView.layoutChain.height(height)
        } else {
            textViewHeightConstraint?.constant = height
        }
        UIView.setAnimationsEnabled(false)
        textView.layoutIfNeeded()
        UIView.setAnimationsEnabled(true)
    }

    // MARK: - Views

    private lazy var contentView: UIView = {
        let v = UIView()
        v.backgroundColor = .clear
        return v
    }()

    private lazy var topBar: UIView = {
        let v = UIView()
        v.backgroundColor = .clear
        return v
    }()

    private lazy var closeBtn: UIButton = {
        let btn = UIButton(type: .custom)
        btn.setImage(UIImage(named: "Common/back"), for: .normal)
        btn.extendEdgeInsets = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 30)
        return btn
    }()

    private lazy var titleLabel: UILabel = {
        let label = UILabel()
        label.font = .systemFont(ofSize: 17, weight: .medium)
        label.textColor = UIColor(hexStr: "#333333")
        label.text = titleText
        label.textAlignment = .center
        return label
    }()

    lazy var textView: UITextView = {
        let tv = UITextView()
        tv.font = .systemFont(ofSize: 15)
        tv.textColor = UIColor(hexStr: "#333333")
        tv.backgroundColor = .white
        tv.cornerRadius = 4
        tv.layer.borderWidth = 1
        tv.layer.borderColor = ThemeManager.shared.color.lineColor.cgColor
        tv.textContainerInset = UIEdgeInsets(top: 12, left: 12, bottom: 12, right: 12)
        tv.showsVerticalScrollIndicator = true
        tv.bounces = false
        tv.tintColor = UIColor(hexStr: "#16B3FF")
        return tv
    }()

    private lazy var countLabel: UILabel = {
        let label = UILabel()
        label.font = .systemFont(ofSize: 12)
        label.textColor = UIColor(hexStr: "#BBBBBB")
        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.setTitleColor(.white, for: .disabled)
        btn.titleLabel?.font = .systemFont(ofSize: 16, weight: .medium)
        btn.cornerRadius = 22
        btn.isEnabled = false
        return btn
    }()
}