//
//  GroupItineraryView.swift
//  QuickLocation
//

import UIKit
import RxSwift
import RxCocoa
import SwiftDate

/// 圈子 Tab 下的「行程」内容页
final class GroupItineraryView: UIView {

    var disposeBag = DisposeBag()

    var onSwitchGroup: (() -> Void)?
    var onDeleteSchedule: ((ScheduleModel) -> Void)?
    var onSelectSchedule: ((ScheduleModel) -> Void)?

    func updateGroupName(_ name: String) {
        groupNameLab.text = name.isEmpty ? " " : name
    }

    func reloadMembers(_ members: [GroupMemberModel], selectedId: String, groupKey: String = "") {
        memberList = Self.sortedMemberList(members, groupKey: groupKey)
        // 保留有效选中；无效则用传入 selectedId → 自己 → 第一项（对齐首页）
        if memberList.contains(where: { $0.user_id == selectedMemberId }) {
            // keep selectedMemberId
        } else if memberList.contains(where: { $0.user_id == selectedId }) {
            selectedMemberId = selectedId
        } else if let me = memberList.first(where: { $0.user_id == AppContextManager.shared.userId }) {
            selectedMemberId = me.user_id
        } else {
            selectedMemberId = memberList.first?.user_id ?? ""
        }
        memberCV.reloadData()
        scrollToSelectedMember(animated: false)
    }

    func reloadSchedules(_ list: [ScheduleModel]) {
        scheduleSections = Self.groupByDay(list)
        tableView.reloadData()
        emptyLab.isHidden = !list.isEmpty
    }

    private var memberList: [GroupMemberModel] = []
    private var selectedMemberId: String = ""
    private var scheduleSections: [(title: String, items: [ScheduleModel])] = []

    /// 与 HomeViewModel / GroupMemberView2 一致：圈主 -> 自己 -> 在线；同优先级保持接口原始顺序
    private static func sortedMemberList(_ list: [GroupMemberModel], groupKey: String) -> [GroupMemberModel] {
        list.enumerated()
            .sorted { lhs, rhs in
                let lhsPriority = memberSortPriority(lhs.element, groupKey: groupKey)
                let rhsPriority = memberSortPriority(rhs.element, groupKey: groupKey)
                if lhsPriority != rhsPriority { return lhsPriority < rhsPriority }
                return lhs.offset < rhs.offset
            }
            .map(\.element)
    }

    private static func memberSortPriority(_ member: GroupMemberModel, groupKey: String) -> Int {
        if !groupKey.isEmpty, groupKey.contains(member.user_id) { return 0 }
        if member.user_id == AppContextManager.shared.userId { return 1 }
        if member.is_online { return 2 }
        return 3
    }

    private func scrollToSelectedMember(animated: Bool) {
        guard !selectedMemberId.isEmpty,
              let idx = memberList.firstIndex(where: { $0.user_id == selectedMemberId }) else { return }
        let indexPath = IndexPath(item: idx, section: 0)
        DispatchQueue.main.async { [weak self] in
            guard let self = self,
                  self.memberCV.numberOfSections > 0,
                  self.memberCV.numberOfItems(inSection: 0) > idx else { return }
            self.memberCV.scrollToItem(at: indexPath, at: .centeredHorizontally, animated: animated)
        }
    }

    private func setupUI() {
        addSubview(headerRow)
        headerRow.addSubview(groupIcon)
        headerRow.addSubview(groupNameLab)
        headerRow.addSubview(changeGroupBtn)
        
        let memberView = UIView()
        memberView.backgroundColor = .white
        memberView.cornerRadius = 20
        memberView.addSubview(memberCV)
        addSubview(memberView)
        
        memberView.layoutChain
            .topToBottomOfView(headerRow, offset: 12)
            .edgesHorzontal(15)
            .height(100)
        
        addSubview(tableView)
        addSubview(emptyLab)

        headerRow.layoutChain
            .top(8)
            .edgesHorzontal(16)
            .height(28)

        groupIcon.layoutChain
            .left()
            .centerY()
            .width(22)
            .height(22)

        changeGroupBtn.layoutChain
            .right()
            .centerY()
            .height(28)

        groupNameLab.layoutChain
            .leftToRightOfView(groupIcon, offset: 8)
            .centerY()
            .rightToLeftOfView(changeGroupBtn, offset: -8, relation: .lessThanOrEqual)

        memberCV.layoutChain
            .edges(all: 5, excludingEdge: .bottom)
            .bottom()

        tableView.layoutChain
            .topToBottomOfView(memberCV, offset: 8)
            .edgesHorzontal()
            .bottom()

        emptyLab.layoutChain
            .centerX()
            .centerY(tableView)
    }

    private func setupRx() {
        changeGroupBtn.rx.tap
            .subscribe(onNext: { [weak self] in self?.onSwitchGroup?() })
            .disposed(by: disposeBag)
    }

    private static func groupByDay(_ list: [ScheduleModel]) -> [(title: String, items: [ScheduleModel])] {
        let sorted = list.sorted { $0.timestamp > $1.timestamp }
        var map: [String: [ScheduleModel]] = [:]
        var order: [String] = []
        let fmt = DateFormatter()
        fmt.locale = Locale(identifier: "zh_CN")
        let calendar = Calendar.current
        for item in sorted {
            let date = Date(timeIntervalSince1970: TimeInterval(item.timestamp) / 1000)
            fmt.dateFormat = "M月d日"
            let day = fmt.string(from: date)
            let title: String
            if calendar.isDateInToday(date) {
                title = "今天 \(day)"
            } else if calendar.isDateInYesterday(date) {
                title = "昨天 \(day)"
            } else {
                fmt.dateFormat = "EEEE M月d日"
                title = fmt.string(from: date)
            }
            if map[title] == nil {
                order.append(title)
                map[title] = []
            }
            map[title]?.append(item)
        }
        return order.map { ($0, map[$0] ?? []) }
    }

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

    lazy var groupIcon: UIImageView = {
        let iv = UIImageView(image: UIImage(named: "Home/group_name_icon"))
        iv.contentMode = .scaleAspectFit
        return iv
    }()

    lazy var groupNameLab: UILabel = {
        let label = UILabel()
        label.font = .systemFont(ofSize: 16, weight: .bold)
        label.textColor = UIColor(hexStr: "#353B4F")
        label.text = " "
        return label
    }()

    lazy var changeGroupBtn: UIButton = {
        let btn = UIButton(type: .custom)
        btn.setTitle("切换圈子 ", for: .normal)
        btn.setTitleColor(UIColor(hexStr: "#353B4F"), for: .normal)
        btn.titleLabel?.font = .systemFont(ofSize: 12, weight: .medium)
        btn.setImage(UIImage(named: "Common/arrow_right"), for: .normal)
        btn.semanticContentAttribute = .forceRightToLeft
        return btn
    }()

    lazy var memberCV: UICollectionView = {
        let layout = UICollectionViewFlowLayout()
        layout.itemSize = CGSize(width: 61, height: 95)
        layout.minimumLineSpacing = 15
        layout.sectionInset = UIEdgeInsets(top: 0, left: 8, bottom: 0, right: 8)
        layout.scrollDirection = .horizontal
        let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
        cv.backgroundColor = .clear
        cv.showsHorizontalScrollIndicator = false
        cv.register(GroupMemberListCell.self)
        cv.dataSource = self
        cv.delegate = self
        return cv
    }()

    lazy var tableView: UITableView = {
        let tv = UITableView(frame: .zero, style: .grouped)
        tv.backgroundColor = .clear
        tv.separatorStyle = .none
        tv.showsVerticalScrollIndicator = false
        tv.register(GroupItineraryCell.self)
        tv.dataSource = self
        tv.delegate = self
        tv.estimatedRowHeight = 100
        tv.rowHeight = UITableView.automaticDimension
        tv.sectionHeaderHeight = 36
        tv.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: 97 + kSafeBottomMargin, right: 0)
        if #available(iOS 15.0, *) {
            tv.sectionHeaderTopPadding = 0
        }
        return tv
    }()

    lazy var emptyLab: UILabel = {
        let label = UILabel()
        label.text = "暂无行程"
        label.font = .systemFont(ofSize: 14, weight: .medium)
        label.textColor = UIColor(hexStr: "#999999")
        label.isHidden = true
        return label
    }()

    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = UIColor(hexStr: "#FAFAFA")
        setupUI()
        setupRx()
    }

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

// MARK: - UICollectionView
extension GroupItineraryView: UICollectionViewDataSource, UICollectionViewDelegate {
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        memberList.count
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell: GroupMemberListCell = collectionView.dequeueReusableCell(for: indexPath)
        let model = memberList[indexPath.item]
        cell.configure(
            model: model,
            isCurrentUser: model.user_id == AppContextManager.shared.userId,
            isSelected: model.user_id == selectedMemberId
        )
        return cell
    }

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        selectedMemberId = memberList[indexPath.item].user_id
        memberCV.reloadData()
        scrollToSelectedMember(animated: true)
    }
}

// MARK: - UITableView
extension GroupItineraryView: UITableViewDataSource, UITableViewDelegate {
    func numberOfSections(in tableView: UITableView) -> Int {
        scheduleSections.count
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        scheduleSections[section].items.count
    }

    func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
        let header = UIView()
        header.backgroundColor = .clear
        let label = UILabel()
        label.text = scheduleSections[section].title
        label.font = .systemFont(ofSize: 13, weight: .semibold)
        label.textColor = UIColor(hexStr: "#353B4F")
        header.addSubview(label)
        label.layoutChain.left(16).centerY()
        return header
    }

    func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {
        .leastNormalMagnitude
    }

    func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? {
        UIView()
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell: GroupItineraryCell = tableView.dequeueReusableCell(for: indexPath)
        cell.configure(scheduleSections[indexPath.section].items[indexPath.row])
        return cell
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        onSelectSchedule?(scheduleSections[indexPath.section].items[indexPath.row])
    }

    func tableView(_ tableView: UITableView,
                   trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
        let model = scheduleSections[indexPath.section].items[indexPath.row]
        let delete = UIContextualAction(style: .destructive, title: nil) { [weak self] _, _, done in
            self?.onDeleteSchedule?(model)
            done(true)
        }
        delete.image = UIImage(systemName: "trash")
        delete.backgroundColor = UIColor(hexStr: "#FF5A5F")
        return UISwipeActionsConfiguration(actions: [delete])
    }
}

// MARK: - GroupItineraryCell
final class GroupItineraryCell: UITableViewCell {

    func configure(_ model: ScheduleModel) {
        avatarImg.image = model.userIcon
        nameLab.text = model.nick_name
        let count = max(model.points.count, 0)
        placeCountLab.text = "\(count)"
        let date = Date(timeIntervalSince1970: TimeInterval(model.timestamp) / 1000)
        let ongoing = Calendar.current.isDateInToday(date) || date > Date()
        statusLab.text = ongoing ? "进行中" : "已完成"
        statusLab.textColor = ongoing ? UIColor(hexStr: "#16B3FF") : UIColor(hexStr: "#999999")
        statusLab.backgroundColor = ongoing
            ? UIColor(hexStr: "#E3F6FF")
            : UIColor(hexStr: "#F0F0F0")

        let tag = model.groups.first?.group_name ?? ""
        tagLab.text = tag.isEmpty ? nil : "  \(tag)  "
        tagLab.isHidden = tag.isEmpty
        setNeedsLayout()
    }

    override init(style: CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        selectionStyle = .none
        backgroundColor = .clear
        contentView.backgroundColor = .clear

        contentView.addSubview(cardView)
        cardView.addSubview(avatarImg)
        cardView.addSubview(nameLab)
        cardView.addSubview(statusLab)
        cardView.addSubview(summaryLab)
        cardView.addSubview(placeCountLab)
        cardView.addSubview(summaryTailLab)
        cardView.addSubview(tagLab)

        cardView.layoutChain
            .edgesVertical(6)
            .edgesHorzontal(16)

        avatarImg.layoutChain
            .top(14)
            .left(14)
            .width(36)
            .height(36)

        nameLab.layoutChain
            .leftToRightOfView(avatarImg, offset: 10)
            .centerY(avatarImg)

        statusLab.layoutChain
            .right(14)
            .centerY(avatarImg)
            .height(22)

        summaryLab.layoutChain
            .topToBottomOfView(avatarImg, offset: 12)
            .left(14)

        placeCountLab.layoutChain
            .leftToRightOfView(summaryLab, offset: 4)
            .centerY(summaryLab)
            .width(22)
            .height(22)

        summaryTailLab.layoutChain
            .leftToRightOfView(placeCountLab, offset: 4)
            .centerY(summaryLab)

        tagLab.layoutChain
            .topToBottomOfView(summaryLab, offset: 12)
            .right(14)
            .bottom(14)
            .height(20)
    }

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

    private lazy var cardView: UIView = {
        let v = UIView()
        v.backgroundColor = .white
        v.cornerRadius = 16
        return v
    }()

    private lazy var avatarImg: UIImageView = {
        let iv = UIImageView()
        iv.contentMode = .scaleAspectFill
        iv.cornerRadius = 18
        iv.clipsToBounds = true
        return iv
    }()

    private lazy var nameLab: UILabel = {
        let label = UILabel()
        label.font = .systemFont(ofSize: 14, weight: .semibold)
        label.textColor = UIColor(hexStr: "#353B4F")
        return label
    }()

    private lazy var statusLab: PaddingLabel = {
        let label = PaddingLabel()
        label.font = .systemFont(ofSize: 11, weight: .medium)
        label.textAlignment = .center
        label.cornerRadius = 6
        label.clipsToBounds = true
        label.insets = UIEdgeInsets(top: 2, left: 8, bottom: 2, right: 8)
        return label
    }()

    private lazy var summaryLab: UILabel = {
        let label = UILabel()
        label.text = "今天停留了"
        label.font = .systemFont(ofSize: 14, weight: .medium)
        label.textColor = UIColor(hexStr: "#353B4F")
        return label
    }()

    private lazy var placeCountLab: UILabel = {
        let label = UILabel()
        label.font = FontManager.youSheBiaoTiHei(12)
        label.textColor = .white
        label.textAlignment = .center
        label.backgroundColor = UIColor(hexStr: "#353B4F")
        label.cornerRadius = 11
        label.clipsToBounds = true
        return label
    }()

    private lazy var summaryTailLab: UILabel = {
        let label = UILabel()
        label.text = "个地方"
        label.font = .systemFont(ofSize: 14, weight: .medium)
        label.textColor = UIColor(hexStr: "#353B4F")
        return label
    }()

    private lazy var tagLab: UILabel = {
        let label = UILabel()
        label.font = .systemFont(ofSize: 10, weight: .medium)
        label.textColor = UIColor(hexStr: "#FF8A3D")
        label.backgroundColor = UIColor(hexStr: "#FFE8D6")
        label.cornerRadius = 4
        label.clipsToBounds = true
        label.textAlignment = .center
        return label
    }()
}

private final class PaddingLabel: UILabel {
    var insets = UIEdgeInsets.zero

    override func drawText(in rect: CGRect) {
        super.drawText(in: rect.inset(by: insets))
    }

    override var intrinsicContentSize: CGSize {
        let size = super.intrinsicContentSize
        return CGSize(width: size.width + insets.left + insets.right,
                      height: size.height + insets.top + insets.bottom)
    }
}