Andromida/Andromida/App/Views/History/HistoryView.swift

//
//  HistoryView.swift
//  Andromida
//
//  A scrollable calendar history view showing daily habit completion.
//

import SwiftUI
import Bedrock

/// Main history view with scrollable months and ritual filtering.
/// Wrapper struct to make Date identifiable for sheet presentation
struct IdentifiableDate: Identifiable {
    let id = UUID()
    let date: Date
}

struct HistoryView: View {
    @Bindable var store: RitualStore
    @State private var selectedRitual: Ritual?
    @State private var selectedDateItem: IdentifiableDate?
    @State private var showingExpandedHistory = false
    
    private let calendar = Calendar.current
    
    /// Generate months based on expanded state
    /// - Collapsed: Last month + current month (2 months)
    /// - Expanded: Up to 12 months of history
    /// Months are ordered oldest first, newest last (chronological order)
    private var months: [Date] {
        let today = Date()
        let currentMonth = calendar.date(from: calendar.dateComponents([.year, .month], from: today)) ?? today
        
        // Determine how far back to go
        let monthsBack = showingExpandedHistory ? 11 : 1 // 12 months or 2 months total
        guard let startMonth = calendar.date(byAdding: .month, value: -monthsBack, to: currentMonth) else {
            return [currentMonth]
        }
        
        // Build list of months in chronological order (oldest first)
        var result: [Date] = []
        var current = startMonth
        
        while current <= currentMonth {
            result.append(current)
            current = calendar.date(byAdding: .month, value: 1, to: current) ?? current
        }
        
        return result
    }
    
    /// Check if there's more history available beyond what's shown
    private var hasMoreHistory: Bool {
        guard let earliestActivity = store.earliestActivityDate() else { return false }
        let today = Date()
        guard let twoMonthsAgo = calendar.date(byAdding: .month, value: -1, to: today) else { return false }
        return earliestActivity < twoMonthsAgo
    }
    
    var body: some View {
        ScrollView(.vertical, showsIndicators: false) {
            VStack(alignment: .leading, spacing: Design.Spacing.large) {
                // Header with Show More/Less button
                headerSection
                
                // Ritual filter picker
                ritualPicker
                
                // Month calendars
                ForEach(months, id: \.self) { month in
                    HistoryMonthView(
                        month: month,
                        selectedRitual: selectedRitual,
                        completionRate: { date, ritual in
                            store.completionRate(for: date, ritual: ritual)
                        },
                        onDayTapped: { date in
                            selectedDateItem = IdentifiableDate(date: date)
                        }
                    )
                }
            }
            .padding(Design.Spacing.large)
        }
        .background(LinearGradient(
            colors: [AppSurface.primary, AppSurface.secondary],
            startPoint: .topLeading,
            endPoint: .bottomTrailing
        ))
        .sheet(item: $selectedDateItem) { item in
            HistoryDayDetailSheet(
                date: item.date,
                completions: store.habitCompletions(for: item.date, ritual: selectedRitual),
                store: store
            )
        }
    }
    
    private var headerSection: some View {
        HStack(alignment: .top) {
            SectionHeaderView(
                title: String(localized: "History"),
                subtitle: String(localized: "Your journey over time")
            )
            
            Spacer()
            
            if hasMoreHistory || showingExpandedHistory {
                Button {
                    withAnimation(.easeInOut(duration: Design.Animation.standard)) {
                        showingExpandedHistory.toggle()
                    }
                } label: {
                    HStack(spacing: Design.Spacing.xSmall) {
                        Text(showingExpandedHistory ? String(localized: "Show less") : String(localized: "Show more"))
                            .font(.subheadline)
                        Image(systemName: showingExpandedHistory ? "chevron.up" : "chevron.down")
                            .font(.caption)
                    }
                    .foregroundStyle(AppAccent.primary)
                }
                .buttonStyle(.plain)
            }
        }
    }
    
    private var ritualPicker: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            HStack(spacing: Design.Spacing.small) {
                // "All" option
                filterChip(
                    title: String(localized: "All"),
                    isSelected: selectedRitual == nil,
                    action: { selectedRitual = nil }
                )
                
                // Individual rituals
                ForEach(store.rituals) { ritual in
                    filterChip(
                        title: ritual.title,
                        isSelected: selectedRitual?.id == ritual.id,
                        action: { selectedRitual = ritual }
                    )
                }
            }
        }
    }
    
    private func filterChip(title: String, isSelected: Bool, action: @escaping () -> Void) -> some View {
        Button(action: action) {
            Text(title)
                .font(.subheadline)
                .fontWeight(isSelected ? .semibold : .regular)
                .foregroundStyle(isSelected ? AppTextColors.inverse : AppTextColors.primary)
                .padding(.horizontal, Design.Spacing.medium)
                .padding(.vertical, Design.Spacing.small)
                .background(isSelected ? AppAccent.primary : AppSurface.card)
                .clipShape(.capsule)
        }
        .buttonStyle(.plain)
        .accessibilityAddTraits(isSelected ? .isSelected : [])
    }
}

#Preview {
    HistoryView(store: RitualStore.preview)
}