//
//  AddItemSheet.swift
//  SportsTime
//
//  Sheet for adding/editing custom itinerary items
//

import SwiftUI
import MapKit

struct AddItemSheet: View {
    @Environment(\.dismiss) private var dismiss
    @Environment(\.colorScheme) private var colorScheme

    let tripId: UUID
    let day: Int
    let existingItem: CustomItineraryItem?
    var onSave: (CustomItineraryItem) -> Void

    // Entry mode
    enum EntryMode: String, CaseIterable {
        case searchPlaces = "Search Places"
        case custom = "Custom"
    }

    @State private var entryMode: EntryMode = .searchPlaces
    @State private var selectedCategory: CustomItineraryItem.ItemCategory = .restaurant
    @State private var title: String = ""
    @State private var isSaving = false

    // MapKit search state
    @State private var searchQuery = ""
    @State private var searchResults: [MKMapItem] = []
    @State private var selectedPlace: MKMapItem?
    @State private var isSearching = false

    private var isEditing: Bool { existingItem != nil }

    var body: some View {
        NavigationStack {
            VStack(spacing: Theme.Spacing.lg) {
                // Category picker
                categoryPicker

                // Entry mode picker (only for new items)
                if !isEditing {
                    Picker("Entry Mode", selection: $entryMode) {
                        ForEach(EntryMode.allCases, id: \.self) { mode in
                            Text(mode.rawValue).tag(mode)
                        }
                    }
                    .pickerStyle(.segmented)
                }

                if entryMode == .searchPlaces && !isEditing {
                    // MapKit search UI
                    searchPlacesView
                } else {
                    // Custom text entry
                    TextField("What's the plan?", text: $title)
                        .textFieldStyle(.roundedBorder)
                        .font(.body)
                }

                Spacer()
            }
            .padding()
            .background(Theme.backgroundGradient(colorScheme))
            .navigationTitle(isEditing ? "Edit Item" : "Add Item")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Cancel") { dismiss() }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button(isEditing ? "Save" : "Add") {
                        saveItem()
                    }
                    .disabled(!canSave || isSaving)
                }
            }
            .onAppear {
                if let existing = existingItem {
                    selectedCategory = existing.category
                    title = existing.title
                    // If editing a mappable item, switch to custom mode
                    entryMode = .custom
                }
            }
        }
    }

    private var canSave: Bool {
        if entryMode == .searchPlaces && !isEditing {
            return selectedPlace != nil
        } else {
            return !title.trimmingCharacters(in: .whitespaces).isEmpty
        }
    }

    @ViewBuilder
    private var searchPlacesView: some View {
        VStack(spacing: Theme.Spacing.md) {
            // Search field
            HStack {
                Image(systemName: "magnifyingglass")
                    .foregroundStyle(.secondary)
                TextField("Search for a place...", text: $searchQuery)
                    .textFieldStyle(.plain)
                    .autocorrectionDisabled()
                    .onSubmit {
                        performSearch()
                    }
                if isSearching {
                    ProgressView()
                        .scaleEffect(0.8)
                } else if !searchQuery.isEmpty {
                    Button {
                        searchQuery = ""
                        searchResults = []
                        selectedPlace = nil
                    } label: {
                        Image(systemName: "xmark.circle.fill")
                            .foregroundStyle(.secondary)
                    }
                }
            }
            .padding(10)
            .background(Color(.systemGray6))
            .cornerRadius(10)

            // Search results
            if !searchResults.isEmpty {
                ScrollView {
                    LazyVStack(spacing: 0) {
                        ForEach(searchResults, id: \.self) { item in
                            PlaceResultRow(
                                item: item,
                                isSelected: selectedPlace == item
                            ) {
                                selectedPlace = item
                            }
                            Divider()
                        }
                    }
                }
                .frame(maxHeight: 300)
                .background(Color(.systemBackground))
                .cornerRadius(10)
            } else if !searchQuery.isEmpty && !isSearching {
                Text("No results found")
                    .foregroundStyle(.secondary)
                    .font(.subheadline)
                    .padding()
            }

            // Selected place preview
            if let place = selectedPlace {
                selectedPlacePreview(place)
            }
        }
    }

    @ViewBuilder
    private func selectedPlacePreview(_ place: MKMapItem) -> some View {
        VStack(alignment: .leading, spacing: 4) {
            HStack {
                Image(systemName: "checkmark.circle.fill")
                    .foregroundStyle(.green)
                Text(place.name ?? "Unknown Place")
                    .font(.headline)
                Spacer()
            }
            if let address = formatAddress(for: place) {
                Text(address)
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }
        }
        .padding()
        .background(Color.green.opacity(0.1))
        .cornerRadius(10)
        .overlay(
            RoundedRectangle(cornerRadius: 10)
                .stroke(Color.green.opacity(0.3), lineWidth: 1)
        )
    }

    private func performSearch() {
        let trimmedQuery = searchQuery.trimmingCharacters(in: .whitespaces)
        guard !trimmedQuery.isEmpty else { return }

        isSearching = true
        selectedPlace = nil

        let request = MKLocalSearch.Request()
        request.naturalLanguageQuery = trimmedQuery

        let search = MKLocalSearch(request: request)
        search.start { response, error in
            isSearching = false
            if let response = response {
                searchResults = response.mapItems
            } else {
                searchResults = []
            }
        }
    }

    private func formatAddress(for item: MKMapItem) -> String? {
        let placemark = item.placemark
        var components: [String] = []

        if let thoroughfare = placemark.thoroughfare {
            if let subThoroughfare = placemark.subThoroughfare {
                components.append("\(subThoroughfare) \(thoroughfare)")
            } else {
                components.append(thoroughfare)
            }
        }
        if let locality = placemark.locality {
            components.append(locality)
        }
        if let administrativeArea = placemark.administrativeArea {
            components.append(administrativeArea)
        }

        return components.isEmpty ? nil : components.joined(separator: ", ")
    }

    @ViewBuilder
    private var categoryPicker: some View {
        HStack(spacing: Theme.Spacing.md) {
            ForEach(CustomItineraryItem.ItemCategory.allCases, id: \.self) { category in
                CategoryButton(
                    category: category,
                    isSelected: selectedCategory == category
                ) {
                    selectedCategory = category
                }
            }
        }
    }

    private func saveItem() {
        isSaving = true

        let item: CustomItineraryItem

        if let existing = existingItem {
            // Editing existing item - preserve day and sortOrder
            let trimmedTitle = title.trimmingCharacters(in: .whitespaces)
            guard !trimmedTitle.isEmpty else { return }

            item = CustomItineraryItem(
                id: existing.id,
                tripId: existing.tripId,
                category: selectedCategory,
                title: trimmedTitle,
                day: existing.day,
                sortOrder: existing.sortOrder,
                createdAt: existing.createdAt,
                modifiedAt: Date(),
                latitude: existing.latitude,
                longitude: existing.longitude,
                address: existing.address
            )
        } else if entryMode == .searchPlaces, let place = selectedPlace {
            // Creating from MapKit search
            let placeName = place.name ?? "Unknown Place"
            let coordinate = place.placemark.coordinate

            // New items get sortOrder 0 (will be placed at beginning, caller can adjust)
            item = CustomItineraryItem(
                tripId: tripId,
                category: selectedCategory,
                title: placeName,
                day: day,
                sortOrder: 0.0,
                latitude: coordinate.latitude,
                longitude: coordinate.longitude,
                address: formatAddress(for: place)
            )
        } else {
            // Creating custom item (no location)
            let trimmedTitle = title.trimmingCharacters(in: .whitespaces)
            guard !trimmedTitle.isEmpty else { return }

            // New items get sortOrder 0 (will be placed at beginning, caller can adjust)
            item = CustomItineraryItem(
                tripId: tripId,
                category: selectedCategory,
                title: trimmedTitle,
                day: day,
                sortOrder: 0.0
            )
        }

        onSave(item)
        dismiss()
    }
}

// MARK: - Place Result Row

private struct PlaceResultRow: View {
    let item: MKMapItem
    let isSelected: Bool
    let onTap: () -> Void

    var body: some View {
        Button(action: onTap) {
            HStack {
                VStack(alignment: .leading, spacing: 2) {
                    Text(item.name ?? "Unknown")
                        .font(.subheadline)
                        .foregroundStyle(.primary)
                    if let address = formattedAddress {
                        Text(address)
                            .font(.caption)
                            .foregroundStyle(.secondary)
                            .lineLimit(1)
                    }
                }
                Spacer()
                if isSelected {
                    Image(systemName: "checkmark.circle.fill")
                        .foregroundStyle(.green)
                }
            }
            .padding(.vertical, 10)
            .padding(.horizontal, 12)
            .background(isSelected ? Color.green.opacity(0.1) : Color.clear)
        }
        .buttonStyle(.plain)
    }

    private var formattedAddress: String? {
        let placemark = item.placemark
        var components: [String] = []

        if let locality = placemark.locality {
            components.append(locality)
        }
        if let administrativeArea = placemark.administrativeArea {
            components.append(administrativeArea)
        }

        return components.isEmpty ? nil : components.joined(separator: ", ")
    }
}

// MARK: - Category Button

private struct CategoryButton: View {
    let category: CustomItineraryItem.ItemCategory
    let isSelected: Bool
    let action: () -> Void

    var body: some View {
        Button(action: action) {
            VStack(spacing: 4) {
                Text(category.icon)
                    .font(.title2)
                Text(category.label)
                    .font(.caption2)
            }
            .frame(maxWidth: .infinity)
            .padding(.vertical, 12)
            .background(isSelected ? Theme.warmOrange.opacity(0.2) : Color.clear)
            .cornerRadius(8)
            .overlay(
                RoundedRectangle(cornerRadius: 8)
                    .stroke(isSelected ? Theme.warmOrange : Color.secondary.opacity(0.3), lineWidth: isSelected ? 2 : 1)
            )
        }
        .buttonStyle(.plain)
    }
}

#Preview {
    AddItemSheet(
        tripId: UUID(),
        day: 1,
        existingItem: nil
    ) { _ in }
}