SpeakHomeView.swift

//
//  SpeakHomeView.swift
//  InstantEnglish
//
//  ホーム画面（スピーキング特化）
//

import SwiftUI

struct SpeakHomeView: View {
    @EnvironmentObject var conversationManager: ConversationManager
    @EnvironmentObject var progressManager: ProgressManager
    @State private var selectedCategory: ConversationScenario.ScenarioCategory? = nil
    @State private var selectedDifficulty: ConversationScenario.Difficulty? = nil
    
    var body: some View {
        NavigationView {
            ZStack {
                // 背景
                LinearGradient(
                    colors: [Color.blue.opacity(0.1), Color.purple.opacity(0.1)],
                    startPoint: .topLeading,
                    endPoint: .bottomTrailing
                )
                .ignoresSafeArea()
                
                ScrollView {
                    VStack(spacing: 24) {
                        // ヘッダー
                        headerView
                            .padding(.top, 20)
                        
                        // 統計カード
                        statsView
                            .padding(.horizontal)
                        
                        // カテゴリ選択
                        categoryView
                            .padding(.horizontal)
                        
                        // 難易度選択
                        difficultyView
                            .padding(.horizontal)
                        
                        // シナリオリスト
                        scenarioListView
                            .padding(.horizontal)
                            .padding(.bottom, 20)
                    }
                }
            }
            .navigationTitle("Speak English")
            .sheet(isPresented: Binding(
                get: { conversationManager.currentScenario != nil },
                set: { if !$0 { conversationManager.endConversation() } }
            )) {
                NavigationView {
                    ConversationView()
                        .environmentObject(conversationManager)
                }
            }
        }
    }
    
    // MARK: - Header
    private var headerView: some View {
        VStack(spacing: 12) {
            Image(systemName: "mic.circle.fill")
                .font(.system(size: 60))
                .foregroundColor(.blue)
            
            Text("英語で会話を始めましょう")
                .font(.title2)
                .fontWeight(.bold)
            
            Text("AIとリアルタイムで会話練習")
                .font(.subheadline)
                .foregroundColor(.secondary)
        }
    }
    
    // MARK: - Stats
    private var statsView: some View {
        HStack(spacing: 16) {
            StatCard(
                icon: "message.fill",
                title: "会話数",
                value: "\(conversationManager.conversationHistory.count)",
                color: .blue
            )
            
            StatCard(
                icon: "star.fill",
                title: "平均スコア",
                value: String(format: "%.0f%%", averageScore),
                color: .yellow
            )
            
            StatCard(
                icon: "clock.fill",
                title: "練習時間",
                value: "\(totalPracticeMinutes)分",
                color: .green
            )
        }
    }
    
    private var averageScore: Double {
        let scores = conversationManager.conversationHistory.map { $0.finalScore }
        guard !scores.isEmpty else { return 0 }
        return scores.reduce(0, +) / Double(scores.count) * 100
    }
    
    private var totalPracticeMinutes: Int {
        conversationManager.conversationHistory.compactMap { session in
            guard let endTime = session.endTime else { return nil }
            return Int(endTime.timeIntervalSince(session.startTime) / 60)
        }.reduce(0, +)
    }
    
    // MARK: - Category
    private var categoryView: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("カテゴリ")
                .font(.headline)
            
            ScrollView(.horizontal, showsIndicators: false) {
                HStack(spacing: 12) {
                    ForEach(ConversationScenario.ScenarioCategory.allCases, id: \.self) { category in
                        CategoryButton(
                            category: category,
                            isSelected: selectedCategory == category
                        ) {
                            selectedCategory = selectedCategory == category ? nil : category
                        }
                    }
                }
            }
        }
    }
    
    // MARK: - Difficulty
    private var difficultyView: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("難易度")
                .font(.headline)
            
            HStack(spacing: 12) {
                ForEach(ConversationScenario.Difficulty.allCases, id: \.self) { difficulty in
                    DifficultyButton(
                        difficulty: difficulty,
                        isSelected: selectedDifficulty == difficulty
                    ) {
                        selectedDifficulty = selectedDifficulty == difficulty ? nil : difficulty
                    }
                }
            }
        }
    }
    
    // MARK: - Scenario List
    private var scenarioListView: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("会話シナリオ")
                .font(.headline)
            
            let filteredScenarios = getFilteredScenarios()
            
            if filteredScenarios.isEmpty {
                Text("シナリオが見つかりません")
                    .foregroundColor(.secondary)
                    .padding()
            } else {
                ForEach(filteredScenarios) { scenario in
                    ScenarioCard(scenario: scenario)
                        .onTapGesture {
                            conversationManager.startConversation(scenario: scenario)
                        }
                }
            }
        }
    }
    
    private func getFilteredScenarios() -> [ConversationScenario] {
        var scenarios = ConversationScenarios.defaultScenarios
        
        if let category = selectedCategory {
            scenarios = scenarios.filter { $0.category == category }
        }
        
        if let difficulty = selectedDifficulty {
            scenarios = scenarios.filter { $0.difficulty == difficulty }
        }
        
        return scenarios
    }
}

// MARK: - Stat Card
struct StatCard: View {
    let icon: String
    let title: String
    let value: String
    let color: Color
    
    var body: some View {
        VStack(spacing: 8) {
            Image(systemName: icon)
                .font(.title2)
                .foregroundColor(color)
            
            Text(value)
                .font(.title)
                .fontWeight(.bold)
            
            Text(title)
                .font(.caption)
                .foregroundColor(.secondary)
        }
        .frame(maxWidth: .infinity)
        .padding()
        .background(Color(.systemBackground))
        .cornerRadius(12)
        .shadow(radius: 2)
    }
}

// MARK: - Category Button
struct CategoryButton: View {
    let category: ConversationScenario.ScenarioCategory
    let isSelected: Bool
    let action: () -> Void
    
    var body: some View {
        Button(action: action) {
            Text(category.rawValue)
                .font(.subheadline)
                .fontWeight(.medium)
                .padding(.horizontal, 16)
                .padding(.vertical, 8)
                .background(isSelected ? Color.blue : Color(.systemGray5))
                .foregroundColor(isSelected ? .white : .primary)
                .cornerRadius(20)
        }
    }
}

// MARK: - Difficulty Button
struct DifficultyButton: View {
    let difficulty: ConversationScenario.Difficulty
    let isSelected: Bool
    let action: () -> Void
    
    var body: some View {
        Button(action: action) {
            Text(difficulty.rawValue)
                .font(.subheadline)
                .fontWeight(.medium)
                .padding(.horizontal, 20)
                .padding(.vertical, 10)
                .frame(maxWidth: .infinity)
                .background(isSelected ? Color.blue : Color(.systemGray5))
                .foregroundColor(isSelected ? .white : .primary)
                .cornerRadius(12)
        }
    }
}

// MARK: - Scenario Card
struct ScenarioCard: View {
    let scenario: ConversationScenario
    
    var body: some View {
        VStack(alignment: .leading, spacing: 8) {
            HStack {
                Text(scenario.title)
                    .font(.headline)
                Spacer()
                Text(scenario.difficulty.rawValue)
                    .font(.caption)
                    .padding(.horizontal, 8)
                    .padding(.vertical, 4)
                    .background(difficultyColor)
                    .foregroundColor(.white)
                    .cornerRadius(8)
            }
            
            Text(scenario.description)
                .font(.subheadline)
                .foregroundColor(.secondary)
            
            HStack {
                Label(scenario.category.rawValue, systemImage: "tag.fill")
                    .font(.caption)
                    .foregroundColor(.blue)
                Spacer()
            }
        }
        .padding()
        .background(Color(.systemBackground))
        .cornerRadius(12)
        .shadow(radius: 2)
    }
    
    private var difficultyColor: Color {
        switch scenario.difficulty {
        case .beginner: return .green
        case .intermediate: return .orange
        case .advanced: return .red
        }
    }
}