//
//  HomeView2.swift
//  QuickLocation
//
//  Created by 八条 on 2026/8/4.
//

import UIKit
import RxSwift
import RxCocoa
import AMapNaviKit
import MarqueeLabel

class HomeView2: UIView {

    var disposeBag = DisposeBag()

    let groupMemberView = GroupMemberView2(frame: .zero)

    /// 三段高度（可见区域）
    private let stage1Height: CGFloat = 160 + 49 + kSafeBottomMargin
    private let stage2Height: CGFloat = 327 + 49 + kSafeBottomMargin

    // MARK: - groupMemberView 拖拽（三段）
    private var groupMemberTopConstraint: NSLayoutConstraint?
    /// 第三段：贴顶
    private var stage3Top: CGFloat = 0
    /// 第二段：初始
    private var stage2Top: CGFloat = 0
    /// 第一段：最小
    private var stage1Top: CGFloat = 0
    private var isGroupMemberLimitsSet = false
    private var panStartTop: CGFloat = 0
    /// 内嵌 scrollView 是否可滑动（仅第三段）
    private var isSubCanScroll = false

    private var groupMemberScrollTopOffset: CGFloat {
        -groupMemberView.scrollView.adjustedContentInset.top
    }

    private var stageTops: [CGFloat] {
        [stage3Top, stage2Top, stage1Top]
    }
    
    var gpsSignalViewList: [UIView] = []
    /// 根据信号格数更新信号条颜色
    func updateGPSSignal(bars: Int) {
        let filled = max(0, min(bars, gpsSignalViewList.count))
        for (i, view) in gpsSignalViewList.enumerated() {
            view.backgroundColor = i < filled ? UIColor(hexStr: "#4ED178") : UIColor(hexStr: "#E0E0E0")
        }
    }
    
    private func setupRx() {
        // 感叹号
        warningView.rx.tapGesture.subscribe { _ in
            LocationPermissionPopView.show()
        }.disposed(by: disposeBag)
    }
    
    private func setupUI() {
        addSubview(mapView)
        addSubview(gpsSignalView)
        addSubview(warningView)
        addSubview(inviteBtn)
        addSubview(locationView)
        addSubview(groupMemberView)
        
        mapView.layoutChain
            .edges(excludingEdge: .bottom)
            .bottom(49 + kSafeBottomMargin)
        
        gpsSignalView.layoutChain
            .top(kStatusBarHeight + 11)
            .left(15)

        warningView.layoutChain
            .topToBottomOfView(gpsSignalView, offset: 11)
            .leftToView(gpsSignalView)
        
        groupMemberView.layoutChain
            .top(kScreenHeight - stage2Height)
            .edgesHorzontal()
            .bottom()

        inviteBtn.layoutChain
            .bottomToTopOfView(groupMemberView, offset: -9)
            .edgesHorzontal(15)
            .heightToWidth(50/345)

        locationView.layoutChain
            .bottomToTopOfView(inviteBtn, offset: -8)
            .left(15)
            .width(40)
            .height(40)
        
        groupMemberTopConstraint = groupMemberView.jh_constraint(
            .top, toAttribute: .top, otherView: self, relation: .equal
        )

        let pan = UIPanGestureRecognizer(target: self, action: #selector(handleGroupMemberPan(_:)))
        pan.delegate = self
        groupMemberView.addGestureRecognizer(pan)
        groupMemberView.scrollView.delegate = self
        groupMemberView.scrollView.isScrollEnabled = false
    }
    
    // MARK: - Map
    lazy var mapView: MAMapView! = {
        let mv = MAMapView()
        mv.zoomLevel = 16
        mv.showsUserLocation = true
        mv.userTrackingMode = .none
        mv.showsCompass = false
        mv.showsScale = false
        mv.isRotateEnabled = false
        mv.isRotateCameraEnabled = false
        DispatchQueue.main.async { mv.logoCenter = CGPoint(x: kScreenWidth - 50, y: kStatusBarHeight) }
        return mv
    }()
    
    // MARK: - 卫星信号
    lazy var gpsSignalView: UIView = {
        let view = UIView()
        view.cornerRadius = 6
        view.backgroundColor = .white
        
        let signalView1 = UIView()
        signalView1.backgroundColor = UIColor(hexStr: "#E6E6E6")
        view.addSubview(signalView1)
        signalView1.layoutChain
            .left(7)
            .bottom(5)
            .width(3)
            .height(4)
        
        let signalView2 = UIView()
        signalView2.backgroundColor = UIColor(hexStr: "#E6E6E6")
        view.addSubview(signalView2)
        signalView2.layoutChain
            .leftToRightOfView(signalView1, offset: 2)
            .bottomToView(signalView1)
            .width(3)
            .height(6)
        
        let signalView3 = UIView()
        signalView3.backgroundColor = UIColor(hexStr: "#E6E6E6")
        view.addSubview(signalView3)
        signalView3.layoutChain
            .leftToRightOfView(signalView2, offset: 2)
            .bottomToView(signalView1)
            .width(3)
            .height(8)
        
        let signalView4 = UIView()
        signalView4.backgroundColor = UIColor(hexStr: "#E6E6E6")
        view.addSubview(signalView4)
        signalView4.layoutChain
            .leftToRightOfView(signalView3, offset: 2)
            .bottomToView(signalView1)
            .width(3)
            .height(10)
        
        let label = UILabel()
        label.text = "卫星信号"
        label.font = .systemFont(ofSize: 10, weight: .medium)
        label.textColor = UIColor(hexStr: "#353B4F")
        view.addSubview(label)
        label.layoutChain
            .leftToRightOfView(signalView4, offset: 2)
            .edgesVertical(4)
            .right(7)
        
        gpsSignalViewList = [signalView1, signalView2, signalView3, signalView4]
        
        return view
    }()
    
    // MARK: - warning
    lazy var warningView: UIView = {
        let view = UIView()
        view.backgroundColor = .white
        view.cornerRadius = 8
        view.isHidden = true
        
        let icon = UIImageView()
        
        let label = UILabel()
        label.text = "有权限未开启，数据可能会异常"
        label.textColor = UIColor(hexStr: "#353B4F")
        label.font = .systemFont(ofSize: 12, weight: .medium)
        view.addSubview(label)
        label.layoutChain
            .edgesHorzontal(8)
            .edgesVertical(10)
        
        return view
    }()
    
    // MARK: - 定位按钮
    lazy var locationView: UIView = {
        let view = UIView()
        view.backgroundColor = .black.withAlphaComponent(0.4)
        view.cornerRadius = 20
        
        view.addSubview(locationIconView)
        locationIconView.layoutChain.centerX().centerY()
        
        return view
    }()

    lazy var locationIconView: UIImageView = {
        let view = UIImageView()
        view.backgroundColor = .clear
        view.image = UIImage(named: "Home/location")
        return view
    }()
    
    // MARK: - 邀请加入
    lazy var inviteBtn: UIButton = {
        let btn = UIButton(type: .custom)
        btn.setBackgroundImage(UIImage(named: "Home/invite"), for: .normal)
        return btn
    }()
    
    override init(frame: CGRect) {
        super.init(frame: .zero)
        backgroundColor = .white
        setupUI()
        setupRx()
    }

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

    // MARK: - Layout
    override func layoutSubviews() {
        super.layoutSubviews()
        if !isGroupMemberLimitsSet, bounds.height > 0 {
            isGroupMemberLimitsSet = true
            stage3Top = 0
            stage2Top = bounds.height - stage2Height
            stage1Top = bounds.height - stage1Height
            groupMemberTopConstraint?.constant = stage2Top
        }
    }

    // MARK: - Pan Gesture
    @objc private func handleGroupMemberPan(_ pan: UIPanGestureRecognizer) {
        guard isGroupMemberLimitsSet, let topConstraint = groupMemberTopConstraint else { return }

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

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

            if isSubCanScroll {
                if scrollOffset > groupMemberScrollTopOffset + 0.5 {
                    return
                }

                if pan.velocity(in: self).y > 0 || groupMemberView.frame.minY > stage3Top + 1 {
                    isSubCanScroll = false
                    panStartTop = groupMemberView.frame.minY
                }
            } else {
                if groupMemberView.frame.minY <= stage3Top && newTop <= stage3Top {
                    isSubCanScroll = true
                    panStartTop = groupMemberView.frame.minY
                    topConstraint.constant = stage3Top
                    groupMemberView.setNavBarExpanded(true)
                    return
                }
            }

            let clamped = max(stage3Top, min(stage1Top, newTop))
            topConstraint.constant = clamped

        case .ended, .cancelled:
            let velocity = pan.velocity(in: self)
            let currentTop = groupMemberView.frame.minY
            let target = snapTarget(currentTop: currentTop, velocityY: velocity.y)
            applyStage(top: target, animated: true)

        default:
            break
        }
    }

    /// 按位置与速度吸附到最近一档
    private func snapTarget(currentTop: CGFloat, velocityY: CGFloat) -> CGFloat {
        if currentTop <= stage3Top + 5 {
            // 顶部附近优先按位置，避免 scroll 松手速度误回收
            return nearestStage(to: currentTop)
        }
        if abs(velocityY) > 200 {
            if velocityY < 0 {
                // 上滑：往上一档（更小的 top 中取最大，即最近一档）
                return stageTops.filter { $0 < currentTop - 1 }.max() ?? stage3Top
            } else {
                // 下滑：往下一档（更大的 top 中取最小，即最近一档）
                return stageTops.filter { $0 > currentTop + 1 }.min() ?? stage1Top
            }
        }
        return nearestStage(to: currentTop)
    }

    private func nearestStage(to top: CGFloat) -> CGFloat {
        stageTops.min(by: { abs($0 - top) < abs($1 - top) }) ?? stage2Top
    }

    private func applyStage(top: CGFloat, animated: Bool) {
        guard let topConstraint = groupMemberTopConstraint else { return }
        let atTop = abs(top - stage3Top) < 0.5
        topConstraint.constant = top

        if !atTop {
            isSubCanScroll = false
            groupMemberView.scrollView.isScrollEnabled = false
            groupMemberView.scrollView.setContentOffset(CGPoint(x: 0, y: groupMemberScrollTopOffset), animated: false)
        }
        isSubCanScroll = atTop
        groupMemberView.setNavBarExpanded(atTop)

        let animations = {
            self.layoutIfNeeded()
        }
        let completion: (Bool) -> Void = { _ in
            self.groupMemberView.scrollView.isScrollEnabled = atTop
        }

        if animated {
            UIView.animate(withDuration: 0.25, delay: 0,
                           options: [.curveEaseOut, .allowUserInteraction],
                           animations: animations, completion: completion)
        } else {
            animations()
            completion(true)
        }
    }

    /// 收起 GroupMemberView2 到第二段（初始段）
    func dismissGroupMemberView() {
        guard isGroupMemberLimitsSet else { return }
        applyStage(top: stage2Top, animated: true)
    }
}

// MARK: - UIScrollViewDelegate
extension HomeView2: UIScrollViewDelegate {
    func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
        guard scrollView == groupMemberView.scrollView else { return }
        if scrollView.contentOffset.y > groupMemberScrollTopOffset {
            isSubCanScroll = true
        }
    }

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        guard scrollView == groupMemberView.scrollView else { return }
        if isSubCanScroll {
            if scrollView.contentOffset.y <= groupMemberScrollTopOffset {
                isSubCanScroll = false
                scrollView.contentOffset = CGPoint(x: 0, y: groupMemberScrollTopOffset)
            }
        } else {
            scrollView.contentOffset = CGPoint(x: 0, y: groupMemberScrollTopOffset)
        }
    }
}

// MARK: - UIGestureRecognizerDelegate
extension HomeView2: UIGestureRecognizerDelegate {
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer,
                           shouldRecognizeSimultaneouslyWith other: UIGestureRecognizer) -> Bool {
        return true
    }
}