import SwiftUI

struct FilterSheet: View {
    let selectedTab: WatchView.WatchTab
    @Binding var selectedSpeaker: String
    @Binding var selectedDateRange: String
    @Binding var selectedDuration: String
    @Environment(\.dismiss) private var dismiss
    @Environment(\.horizontalSizeClass) private var horizontalSizeClass
    @Environment(ChurchDataService.self) private var dataService
    
    @State private var selectedYear: String = "All Time"
    @State private var selectedMonth: String = "All Months"
    
    private var availableSpeakers: [String] {
        let currentContent = selectedTab == .sermons ? dataService.sermons : dataService.livestreamArchives
        let cleanedSpeakers = currentContent.compactMap { sermon -> String? in
            let speaker = sermon.speaker.trimmingCharacters(in: .whitespacesAndNewlines)
            return speaker.isEmpty ? nil : speaker
        }
        let uniqueSpeakers = Set(cleanedSpeakers)
        return ["All Speakers"] + Array(uniqueSpeakers).sorted()
    }
    
    private var availableYears: [String] {
        var years = ["All Time"]
        let calendar = Calendar.current
        
        // Use proper date formatter for your date format: "August 02, 2025"
        let formatter = DateFormatter()
        formatter.dateFormat = "MMMM dd, yyyy"
        formatter.locale = Locale(identifier: "en_US")
        
        let currentContent = selectedTab == .sermons ? dataService.sermons : dataService.livestreamArchives
        
        // Extract all unique years from content
        var yearSet: Set<Int> = []
        
        for item in currentContent {
            guard let dateString = item.date, 
                  !dateString.isEmpty,
                  let date = formatter.date(from: dateString) else { continue }
            
            let year = calendar.component(.year, from: date)
            yearSet.insert(year)
        }
        
        // Add years in descending order
        let sortedYears = yearSet.sorted(by: >)
        for year in sortedYears {
            years.append(String(year))
        }
        
        return years
    }
    
    private var availableMonths: [String] {
        guard selectedYear != "All Time", let targetYear = Int(selectedYear) else {
            return ["All Months"]
        }
        
        var months = ["All Months"]
        let calendar = Calendar.current
        
        // Use proper date formatter for your date format: "August 02, 2025"
        let formatter = DateFormatter()
        formatter.dateFormat = "MMMM dd, yyyy"
        formatter.locale = Locale(identifier: "en_US")
        
        let currentContent = selectedTab == .sermons ? dataService.sermons : dataService.livestreamArchives
        
        // Extract months for the selected year
        var monthSet: Set<Int> = []
        
        for item in currentContent {
            guard let dateString = item.date, 
                  !dateString.isEmpty,
                  let date = formatter.date(from: dateString) else { continue }
            
            let year = calendar.component(.year, from: date)
            let month = calendar.component(.month, from: date)
            
            if year == targetYear {
                monthSet.insert(month)
            }
        }
        
        // Add months in descending order (most recent first)
        let monthNames = ["January", "February", "March", "April", "May", "June",
                        "July", "August", "September", "October", "November", "December"]
        
        let sortedMonths = monthSet.sorted(by: >)
        for month in sortedMonths {
            if month >= 1 && month <= 12 {
                months.append(monthNames[month-1])
            }
        }
        
        print("🔍 DEBUG: availableMonths for year \(targetYear): \(months)")
        return months
    }
    private let durations = ["Any Duration", "Under 30 min", "30-60 min", "Over 60 min"]
    
    var body: some View {
        NavigationStack {
            Form {
                Section {
                    Text("Filter \(selectedTab.rawValue)")
                        .font(.headline)
                        .foregroundColor(.primary)
                } header: {
                    EmptyView()
                }
                
                Section("Speaker") {
                    Picker("Speaker", selection: $selectedSpeaker) {
                        ForEach(availableSpeakers, id: \.self) { speaker in
                            Text(speaker).tag(speaker)
                        }
                    }
                    .pickerStyle(.menu)
                }
                
                Section("Date Range") {
                    Picker("Year", selection: $selectedYear) {
                        ForEach(availableYears, id: \.self) { year in
                            Text(year).tag(year)
                        }
                    }
                    .pickerStyle(.menu)
                    .onChange(of: selectedYear) { _, newYear in
                        // Don't auto-reset month when year changes during initialization
                        // Only reset if it's a user-initiated change
                        if selectedMonth != "All Months" && !availableMonths.contains(selectedMonth) {
                            selectedMonth = "All Months"
                        }
                    }
                    
                    // Only show month picker if a specific year is selected
                    if selectedYear != "All Time" {
                        Picker("Month", selection: $selectedMonth) {
                            ForEach(availableMonths, id: \.self) { month in
                                Text(month).tag(month)
                            }
                        }
                        .pickerStyle(.menu)
                    }
                }
                
                Section("Duration") {
                    Picker("Duration", selection: $selectedDuration) {
                        ForEach(durations, id: \.self) { duration in
                            Text(duration).tag(duration)
                        }
                    }
                    .pickerStyle(.menu)
                }
                
                Section {
                    Button("Reset Filters") {
                        selectedSpeaker = "All Speakers"
                        selectedYear = "All Time"
                        selectedMonth = "All Months"
                        selectedDuration = "Any Duration"
                    }
                    .foregroundColor(.red)
                }
            }
            .navigationTitle("Filters")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Cancel") {
                        dismiss()
                    }
                }
                
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Apply") {
                        // Convert year/month selection to selectedDateRange format
                        if selectedYear == "All Time" {
                            selectedDateRange = "All Time"
                        } else if selectedMonth == "All Months" {
                            selectedDateRange = selectedYear
                        } else {
                            selectedDateRange = "\(selectedMonth) \(selectedYear)"
                        }
                        dismiss()
                    }
                    .fontWeight(.semibold)
                    .foregroundColor(Color(hex: "fb8b23"))
                }
            }
        }
        .presentationDetents([.medium, .large])
        .presentationDragIndicator(.visible)
        .onAppear {
            // Initialize year/month from current selectedDateRange
            print("🔍 DEBUG: Initializing filter sheet with selectedDateRange: '\(selectedDateRange)'")
            
            if selectedDateRange == "All Time" {
                selectedYear = "All Time"
                selectedMonth = "All Months"
            } else {
                // Check if it's a year-only filter (e.g., "2024")
                if let _ = Int(selectedDateRange) {
                    selectedYear = selectedDateRange
                    selectedMonth = "All Months"
                    print("🔍 DEBUG: Set year-only filter - Year: \(selectedYear), Month: \(selectedMonth)")
                } else {
                    // It's a month-year filter (e.g., "January 2024")
                    let components = selectedDateRange.components(separatedBy: " ")
                    if components.count == 2 {
                        selectedYear = components[1]
                        selectedMonth = components[0]
                        print("🔍 DEBUG: Set month-year filter - Year: \(selectedYear), Month: \(selectedMonth)")
                        
                        // Force a small delay to ensure availableMonths is computed before validation
                        DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
                            if !availableMonths.contains(selectedMonth) {
                                print("🔍 DEBUG: Month '\(selectedMonth)' not found in available months, resetting")
                                selectedMonth = "All Months"
                            } else {
                                print("🔍 DEBUG: Month '\(selectedMonth)' validated successfully")
                            }
                        }
                    } else {
                        selectedYear = "All Time"
                        selectedMonth = "All Months"
                        print("🔍 DEBUG: Failed to parse, defaulting to All Time")
                    }
                }
            }
        }
    }
}