extract HomeModel from ContentView

huge refactor

Signed-off-by: William Casarin <jb55@jb55.com>

damus/Views/LoginView.swift

@@ -0,0 +1,195 @@
+//
+//  LoginView.swift
+//  damus
+//
+//  Created by William Casarin on 2022-05-22.
+//
+
+import SwiftUI
+
+enum ParsedKey {
+    case pub(String)
+    case priv(String)
+    case hex(String)
+    
+    var is_pub: Bool {
+        if case .pub = self {
+            return true
+        }
+        return false
+    }
+    
+    var is_hex: Bool {
+        if case .hex = self {
+            return true
+        }
+        return false
+    }
+}
+
+struct LoginView: View {
+    @State var key: String = ""
+    @State var is_pubkey: Bool = false
+    @State var error: String? = nil
+    
+    func get_error(parsed_key: ParsedKey?) -> String? {
+        if self.error != nil {
+            return self.error
+        }
+        
+        if !key.isEmpty && parsed_key == nil {
+            return "Invalid key"
+        }
+        
+        return nil
+    }
+    
+    var body: some View {
+        ZStack(alignment: .top) {
+            DamusGradient()
+            VStack {
+                Text("Login")
+                    .foregroundColor(.white)
+                    .font(.title)
+                    .padding()
+                
+                Text("Enter your account key to login:")
+                    .foregroundColor(.white)
+                    .padding()
+                
+                KeyInput("nsec1...", key: $key)
+                
+                let parsed = parse_key(key)
+                
+                if parsed?.is_hex ?? false {
+                    Text("This is an old-style nostr key. We're not sure if it's a pubkey or private key. Please toggle the button below if this a public key.")
+                        .font(.subheadline.bold())
+                        .foregroundColor(.white)
+                    PubkeySwitch(isOn: $is_pubkey)
+                        .padding()
+                }
+                
+                if let error = get_error(parsed_key: parsed) {
+                    Text(error)
+                        .foregroundColor(.red)
+                        .padding()
+                }
+                
+                if parsed?.is_pub ?? false {
+                    Text("This is a public key, you will not be able to make posts or interact in any way. This is used for viewing accounts from their perspective.")
+                        .foregroundColor(.white)
+                        .padding()
+                }
+                
+                if let p = parsed {
+                    DamusWhiteButton("Login") {
+                        if !process_login(p, is_pubkey: self.is_pubkey) {
+                            self.error = "Invalid key"
+                        }
+                    }
+                }
+            }
+            .padding()
+        }
+        .navigationBarBackButtonHidden(true)
+        .navigationBarItems(leading: BackNav())
+    }
+}
+
+struct PubkeySwitch: View {
+    @Binding var isOn: Bool
+    var body: some View {
+        HStack {
+            Toggle(isOn: $isOn) {
+                Text("Public Key?")
+                    .foregroundColor(.white)
+            }
+        }
+    }
+}
+
+func parse_key(_ thekey: String) -> ParsedKey? {
+    var key = thekey
+    if key.count > 0 && key.first! == "@" {
+        key = String(key.dropFirst())
+    }
+    if hex_decode(key) != nil {
+        return .hex(key)
+    }
+    
+    if let bech_key = decode_bech32_key(key) {
+        switch bech_key {
+        case .pub(let pk):
+            return .pub(pk)
+        case .sec(let sec):
+            return .priv(sec)
+        }
+    }
+    
+    return nil
+}
+
+func process_login(_ key: ParsedKey, is_pubkey: Bool) -> Bool {
+    switch key {
+    case .priv(let priv):
+        save_privkey(privkey: priv)
+        guard let pk = privkey_to_pubkey(privkey: priv) else {
+            return false
+        }
+        save_pubkey(pubkey: pk)
+        
+    case .pub(let pub):
+        clear_privkey()
+        save_pubkey(pubkey: pub)
+    
+    case .hex(let hexstr):
+        if is_pubkey {
+            clear_privkey()
+            save_pubkey(pubkey: hexstr)
+        } else {
+            save_privkey(privkey: hexstr)
+            guard let pk = privkey_to_pubkey(privkey: hexstr) else {
+                return false
+            }
+            save_pubkey(pubkey: pk)
+        }
+    }
+    
+    notify(.login, ())
+    return true
+}
+
+struct KeyInput: View {
+    let title: String
+    let key: Binding<String>
+    
+    init(_ title: String, key: Binding<String>) {
+        self.title = title
+        self.key = key
+    }
+    
+    var body: some View {
+        TextField("", text: key)
+            .placeholder(when: key.wrappedValue.isEmpty) {
+                Text(title).foregroundColor(.white.opacity(0.6))
+            }
+            .padding()
+            .background {
+                RoundedRectangle(cornerRadius: 4.0).opacity(0.2)
+            }
+            .autocapitalization(.none)
+            .foregroundColor(.white)
+            .font(.body.monospaced())
+    }
+}
+
+struct LoginView_Previews: PreviewProvider {
+    static var previews: some View {
+        let pubkey = "3efdaebb1d8923ebd99c9e7ace3b4194ab45512e2be79c1b7d68d9243e0d2681"
+        let bech32_pubkey = "KeyInput"
+        Group {
+            LoginView(key: pubkey)
+            LoginView(key: bech32_pubkey)
+        }
+    }
+}