//
//  ContentView.swift
//  ChatMasterMind
//
//  Created by Oleksandr Kozachuk on 2023-06-24.
//

import SwiftUI
import SwiftData
import MarkdownView

struct ContentView: View {
    @Environment(\.modelContext) private var modelContext
    @Query private var chatHistoryList: [ChatHistory]
    
    var body: some View {
        NavigationView {
            List {
                ForEach(chatHistoryList) { chatHistory in
                    NavigationLink(destination: ChatHistoryDetailView(chatHistory: chatHistory)) {
                        Text(chatHistory.name)
                    }
                }
                .onDelete(perform: deleteItems)
            }
            .toolbar {
#if os(iOS)
                ToolbarItem(placement: .navigationBarTrailing) {
                    EditButton()
                }
#endif
                ToolbarItem {
                    Button(action: newChat) {
                        Label("New chat", systemImage: "plus")
                    }
                }
            }
            Text("Select an chat")
        }
    }

    private func newChat() {
        withAnimation {
            let newChatHistory = ChatHistory(name: "test1")
            modelContext.insert(newChatHistory)
        }
    }

    private func deleteItems(offsets: IndexSet) {
        withAnimation {
            for index in offsets {
                modelContext.delete(chatHistoryList[index])
            }
        }
    }
}

struct ChatHistoryDetailView: View {
    @Environment(\.modelContext) private var modelContext
    var chatHistory: ChatHistory
    @State private var newQuestion: String = ""
    @State private var pairToEdit: ChatPair? = nil
    @State private var newAnswer: String = ""

    var body: some View {
        VStack {
            List {
                ForEach(chatHistory.chatPairs) { chatPair in
                    VStack(alignment: .leading) {
                        MarkdownView(text: chatPair.question)
                        if let answer = chatPair.answer {
                            MarkdownView(text: answer)
                                .tint(.secondary)
                        }
                        Button(action: {
                            pairToEdit = chatPair
                            newAnswer = chatPair.answer ?? ""
                        }) {
                            Text("Edit")
                                .foregroundColor(.blue)
                        }
                    }
                    Text("Timestamp: \(chatPair.timestamp)")
                        .foregroundColor(.secondary)
                        .font(.footnote)
                }
            }
            HStack {
                TextEditor(text: $newQuestion)
                    .frame(height: 100)
                    .overlay(RoundedRectangle(cornerRadius: 5).stroke(Color.gray))
                Button(action: {
                    addChatPair()
                }) {
                    Text("Add")
                }
                Button(action: {
                    cancelEdit()
                }) {
                    Text("Cancel")
                }
            }
            .padding()
        }
        .navigationTitle(chatHistory.name)
        .sheet(item: $pairToEdit) { pairToEdit in
            VStack {
                Text(pairToEdit.question)
                TextEditor(text: $newAnswer)
                    .overlay(RoundedRectangle(cornerRadius: 5).stroke(Color.gray))
                    .frame(maxHeight: .infinity)
                Button(action: {
                    editChatPair(pairToEdit)
                }) {
                    Text("Save")
                }
            }
            .padding()
        }
    }
    
    private func addChatPair() {
        guard !newQuestion.isEmpty else { return }
        withAnimation {
            let newPair = ChatPair(question: newQuestion)
            chatHistory.chatPairs.append(newPair)
            newQuestion = ""
            do {
                try modelContext.save()
            } catch {
                print("Error saving model context: \(error)")
            }
        }
    }

    private func editChatPair(_ chatPair: ChatPair) {
        guard !newAnswer.isEmpty else { return }
        withAnimation {
            chatHistory.editChatPair(withId: chatPair.id, question: nil, answer: newAnswer)
            newAnswer = ""
            pairToEdit = nil
            do {
                try modelContext.save()
            } catch {
                print("Error saving model context: \(error)")
            }
        }
    }
    
    private func cancelEdit() {
        newAnswer = ""
        pairToEdit = nil
    }
}

#Preview {
    ContentView()
        .modelContainer(for: ChatHistory.self, inMemory: true)
}