//
//  CreateScheduleView.swift
//  QuickLocation
//
//  Created by 八条 on 2026/6/23.
//

import UIKit
import RxSwift
import RxCocoa
#if !targetEnvironment(simulator)
import AMapNaviKit
#endif

class CreateScheduleView: UIView {

    var disposeBag = DisposeBag()

    let createSchedulePopView = CreateSchedulePopView()

    // MARK: - PopView 拖拽
    private var popTopConstraint: NSLayoutConstraint?
    private var popUpLimit: CGFloat = 0
    private var popDownLimit: CGFloat = 0
    private var isLimitsSet = false
    private var panStartTop: CGFloat = 0
    private var isSubCanScroll = false

    private func setupRx() {
        backBtn.rx.tap.subscribe(onNext: { _ in
            AppRouter.shared.popOrDismiss()
        }).disposed(by: disposeBag)

        // tableView 到达顶部继续下拉时，改由 PopView 的 pan 手势接管
        createSchedulePopView.scrollView.rx.contentOffset
            .subscribe(onNext: { [weak self] offset in
                guard let self = self else { return }
                if self.isSubCanScroll {
                    if offset.y <= 0 {
                        self.isSubCanScroll = false
                        self.createSchedulePopView.scrollView.setContentOffset(.zero, animated: false)
                    }
                } else if offset.y != 0 {
                    self.createSchedulePopView.scrollView.setContentOffset(.zero, animated: false)
                }
            })
            .disposed(by: disposeBag)
    }

    private func setupUI() {
#if !targetEnvironment(simulator)
        addSubview(mapView)
#endif
        addSubview(navBgView)
        addSubview(navBarView)
        navBarView.addSubview(backBtn)
        navBarView.addSubview(navTitleLabel)
        addSubview(createSchedulePopView)

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

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

        backBtn.layoutChain
            .centerY(navTitleLabel)
            .left(15)
            .width(24).height(24)

        navTitleLabel.layoutChain
            .top(kStatusBarHeight + 12)
            .centerX()

        #if !targetEnvironment(simulator)
        mapView.layoutChain
            .top()
            .edgesHorzontal()
            .bottom()
        #endif

        // PopView: 初始底部 1/3，最大滑到 navBar 底部
        createSchedulePopView.layoutChain
            .edgesHorzontal()
            .bottom()
            .top(kScreenHeight / 3 * 2)

        popTopConstraint = createSchedulePopView.jh_constraint(
            .top, toAttribute: .top, otherView: createSchedulePopView.superview, relation: .equal
        )

        let pan = UIPanGestureRecognizer(target: self, action: #selector(handlePopPan(_:)))
        pan.delegate = self
        createSchedulePopView.addGestureRecognizer(pan)
    }

    // MARK: - Pan Gesture

    @objc private func handlePopPan(_ pan: UIPanGestureRecognizer) {
        guard isLimitsSet, let topConstraint = popTopConstraint else { return }

        switch pan.state {
        case .began:
            layoutIfNeeded()
            panStartTop = createSchedulePopView.frame.minY

        case .changed:
            let newTop = panStartTop + pan.translation(in: self).y

            if isSubCanScroll {
                let tableViewOffset = self.createSchedulePopView.scrollView.contentOffset.y
                if tableViewOffset > 0, newTop >= popUpLimit {
                    return
                }
                isSubCanScroll = false
                panStartTop = createSchedulePopView.frame.minY
            }

            let clamped = max(popUpLimit, min(popDownLimit, newTop))
            topConstraint.constant = clamped

        case .ended, .cancelled:
            let velocity = pan.velocity(in: self)
            let isNearUp = abs(createSchedulePopView.frame.minY - popUpLimit) < abs(createSchedulePopView.frame.minY - popDownLimit)
            let target: CGFloat
            if abs(velocity.y) > 200 {
                target = velocity.y < 0 ? popUpLimit : popDownLimit
            } else {
                target = isNearUp ? popUpLimit : popDownLimit
            }
            topConstraint.constant = target

            UIView.animate(withDuration: 0.2, delay: 0,
                           options: [.curveEaseInOut, .allowUserInteraction]) {
                self.layoutIfNeeded()
            } completion: { _ in
                let atTop = target == self.popUpLimit
                self.isSubCanScroll = atTop
                if !atTop {
                    self.createSchedulePopView.scrollView.contentOffset.y = 0
                }
            }

        default:
            break
        }
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        if !isLimitsSet {
            isLimitsSet = true
            popDownLimit = kScreenHeight / 3 * 2
            popUpLimit = navBarView.frame.maxY
        }
    }

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

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

    lazy var backBtn: 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
    }()

    lazy var navTitleLabel: UILabel = {
        let label = UILabel()
        label.font = .systemFont(ofSize: 18, weight: .medium)
        label.textColor = ThemeManager.shared.color.titleAuxColor
        label.text = "创建行程"
        return label
    }()

    #if !targetEnvironment(simulator)
    lazy var mapView: MAMapView = {
        let mv = MAMapView()
        mv.zoomLevel = 14
        mv.showsUserLocation = false
        mv.showsCompass = false
        mv.userTrackingMode = .none
        return mv
    }()
    #endif

    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .clear
        setupUI()
        setupRx()
    }

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

}

// MARK: - UIGestureRecognizerDelegate
extension CreateScheduleView: UIGestureRecognizerDelegate {
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
                           shouldRecognizeSimultaneouslyWith other: UIGestureRecognizer) -> Bool {
        return true
    }
}