//
//  ContentView.swift
//  Gemini-iOS
//
//  Created by Shadowfacts on 7/15/20.
//

import SwiftUI
import BrowserCore

struct ContentView: View {
    @ObservedObject private var navigator: NavigationManager
    @State private var urlFieldContents: String
    @State private var showPreferencesSheet = false
    
    init(navigator: NavigationManager) {
        self.navigator = navigator
        self._urlFieldContents = State(initialValue: navigator.currentURL.absoluteString)
    }
    
    var body: some View {
        VStack(spacing: 0) {
            urlBar
            
            barBorder
            
            Spacer()
            BrowserView(navigator: navigator)
            Spacer()
            
            barBorder
            
            bottomBar
        }
        .onReceive(navigator.$currentURL, perform: { (new) in
            urlFieldContents = new.absoluteString
        })
        .sheet(isPresented: $showPreferencesSheet, content: {
            PreferencesView(presented: $showPreferencesSheet)
        })
    }
    
    private var barBorder: some View {
        Rectangle()
            .frame(height: 1)
            .foregroundColor(Color(white: 0.75))
    }
    
    private var urlBar: some View {
        TextField("URL", text: $urlFieldContents, onCommit: commitURL)
            .keyboardType(.URL)
            .textFieldStyle(RoundedBorderTextFieldStyle())
            .padding([.leading, .trailing, .bottom])
    }
    
    private var bottomBar: some View {
        HStack {
            Spacer()
            
            Button(action: navigator.back, label: {
                Image(systemName: "arrow.left")
                    .font(.system(size: 24))
            })
            .disabled(navigator.backStack.isEmpty)
            
            Spacer()
            
            Button(action: navigator.forward, label: {
                Image(systemName: "arrow.right")
                    .font(.system(size: 24))
            })
            .disabled(navigator.forwardStack.isEmpty)
            
            Spacer()
            
            Button(action: navigator.reload, label: {
                Image(systemName: "arrow.clockwise")
                    .font(.system(size: 24))
            })
            
            Spacer()
            
            Button(action: {
                showPreferencesSheet = true
            }, label: {
                Image(systemName: "gear")
                    .font(.system(size: 24))
            })
            
            Spacer()
        }
        .padding(.top, 4)
    }
    
    private func commitURL() {
        guard let url = URL(string: urlFieldContents) else { return }
        navigator.changeURL(url)
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView(navigator: NavigationManager(url: URL(string: "gemini://localhost/overview.gmi")!))
    }
}