import SwiftUI

struct OrderSourcePicker: View {
    let selection: OrderSourceSelection?
    let people: [OrderSourcePerson]
    let leadsForPerson: (OrderSourcePerson) -> [OrderSourceLead]
    let leadsLoading: Bool
    let onSheetOpen: () -> Void
    let onPersonClick: (OrderSourcePerson) -> Void
    let onSelectionChange: (OrderSourceSelection) -> Void
    let callPhone: (String) -> Void

    @State private var sheetVisible = false
    @State private var navigationPath = NavigationPath()
    @State private var previewImages: [String] = []
    @State private var previewIndex: Int?

    var body: some View {
        VStack(alignment: .leading, spacing: 10) {
            HStack(alignment: .center) {
                VStack(alignment: .leading, spacing: 4) {
                    Text("订单来源")
                        .font(.system(size: 14, weight: .medium))
                        .foregroundStyle(OrderSourceColors.text563)
                    if let selection {
                        HStack(spacing: 10) {
                            Text(selection.person.name)
                                .font(.system(size: 13, weight: .medium))
                                .foregroundStyle(OrderSourceColors.text333)
                            if !selection.person.phone.isEmpty {
                                Text(selection.person.phone)
                                    .font(.system(size: 13))
                                    .foregroundStyle(OrderSourceColors.text666)
                            }
                        }
                    } else {
                        Text("选择获客员及其创建的带客单")
                            .font(.system(size: 13))
                            .foregroundStyle(OrderSourceColors.text666)
                    }
                }
                Spacer(minLength: 0)
                Image(systemName: "chevron.right")
                    .font(.system(size: 12, weight: .semibold))
                    .foregroundStyle(OrderSourceColors.primary)
                    .frame(width: 20, height: 20)
            }

            if let selection {
                Divider().overlay(OrderSourceColors.divider)
                SourceLeadContent(
                    lead: selection.lead,
                    compact: true,
                    enablePhoneCall: false,
                    onCall: callPhone,
                    onImageTap: { images, index in
                        previewImages = images
                        previewIndex = index
                    }
                )
            }
        }
        .padding(12)
        .frame(maxWidth: .infinity, alignment: .leading)
        .background(OrderSourceColors.entryBg, in: RoundedRectangle(cornerRadius: 8))
        .overlay(
            RoundedRectangle(cornerRadius: 8)
                .stroke(OrderSourceColors.border, lineWidth: 1)
        )
        .contentShape(RoundedRectangle(cornerRadius: 8))
        .onTapGesture {
            openSheet()
        }
        .sheet(isPresented: $sheetVisible) {
            sheetContainer
                .presentationDetents([.medium, .large])
                .presentationDragIndicator(.visible)
        }
        .sheet(item: previewBinding) { item in
            SimpleImagePreviewSheet(
                imageUrls: item.urls,
                startIndex: item.index,
                onDismiss: { previewIndex = nil }
            )
        }
    }

    private func openSheet() {
        onSheetOpen()
        navigationPath = NavigationPath()
        sheetVisible = true
    }

    private var previewBinding: Binding<ImagePreviewItem?> {
        Binding(
            get: {
                guard let previewIndex else { return nil }
                return ImagePreviewItem(urls: previewImages, index: previewIndex)
            },
            set: { newValue in
                if newValue == nil { previewIndex = nil }
            }
        )
    }

    private var sheetContainer: some View {
        NavigationStack(path: $navigationPath) {
            personSheetContent
                .navigationDestination(for: OrderSourcePerson.self) { person in
                    leadSheetContent(person: person)
                }
                .navigationDestination(for: OrderSourceImagePreviewRoute.self) { route in
                    SimpleImagePreviewScreen(
                        imageUrls: route.urls,
                        startIndex: route.startIndex
                    )
                }
        }
        .background(Color.white)
    }

    private var personSheetContent: some View {
        ScrollView {
            VStack(alignment: .leading, spacing: 0) {
                Text("选择人员后，再选择该人员创建的带客单")
                    .font(.system(size: 13))
                    .foregroundStyle(OrderSourceColors.text666)
                    .padding(.bottom, 14)

                if people.isEmpty {
                    Text("暂无合作获客员")
                        .font(.system(size: 14))
                        .foregroundStyle(OrderSourceColors.text666)
                        .frame(maxWidth: .infinity)
                        .padding(.vertical, 32)
                } else {
                    LazyVStack(spacing: 10) {
                        ForEach(people) { person in
                            SourcePersonRow(
                                person: person,
                                selected: selection?.person.key == person.key,
                                onCall: callPhone,
                                onTap: {
                                    onPersonClick(person)
                                    navigationPath.append(person)
                                }
                            )
                        }
                    }
                }
            }
            .padding(.horizontal, 16)
            .padding(.top, 8)
            .padding(.bottom, 24)
        }
        .navigationTitle("选择获客员")
        .navigationBarTitleDisplayMode(.inline)
    }

    private func leadSheetContent(person: OrderSourcePerson) -> some View {
        ScrollView {
            VStack(alignment: .leading, spacing: 0) {
                if !person.phone.isEmpty {
                    HStack(spacing: 6) {
                        Text(person.phone)
                            .font(.system(size: 13))
                            .foregroundStyle(OrderSourceColors.primary)
                            .onTapGesture { callPhone(person.phone) }
                        AcquirerCallButton(phone: person.phone, onCall: callPhone)
                    }
                    .padding(.bottom, 14)
                }

                if leadsLoading {
                    ProgressView()
                        .tint(OrderSourceColors.primary)
                        .frame(maxWidth: .infinity)
                        .padding(.top, 32)
                } else {
                    let leads = leadsForPerson(person)
                    if leads.isEmpty {
                        Text("暂无可绑定带客单")
                            .font(.system(size: 14))
                            .foregroundStyle(OrderSourceColors.text666)
                            .frame(maxWidth: .infinity)
                            .padding(.vertical, 24)
                    } else {
                        LazyVStack(spacing: 12) {
                            ForEach(leads) { lead in
                                SourceLeadCard(
                                    lead: lead,
                                    selected: selection?.person.key == person.key && selection?.lead.key == lead.key,
                                    onCall: callPhone,
                                    onImageTap: { images, index in
                                        navigationPath.append(
                                            OrderSourceImagePreviewRoute(urls: images, startIndex: index)
                                        )
                                    },
                                    onSelect: {
                                        onSelectionChange(OrderSourceSelection(person: person, lead: lead))
                                        sheetVisible = false
                                    }
                                )
                            }
                        }
                    }
                }
            }
            .padding(.horizontal, 16)
            .padding(.top, 8)
            .padding(.bottom, 24)
        }
        .navigationTitle("\(person.name)创建的带客单")
        .navigationBarTitleDisplayMode(.inline)
    }
}

private struct ImagePreviewItem: Identifiable {
    let urls: [String]
    let index: Int
    var id: String { "\(index)-\(urls.joined())" }
}

private struct OrderSourceImagePreviewRoute: Hashable {
    let urls: [String]
    let startIndex: Int
}