import SwiftUI

struct SettingsView: View {
  @Bindable var settings: SettingsStore

  var body: some View {
    Form {
      Section("Backend") {
        TextField("Backend URL", text: $settings.backendURLString)
          .onSubmit {
            settings.saveBackendURL()
          }
          .platformCredentialField()

        Button("Apply Backend URL") {
          settings.saveBackendURL()
        }
      }

      Section("Session") {
        if let user = settings.currentUser {
          LabeledContent("Signed in as", value: user.displayName)
          LabeledContent("Username", value: user.username)

          Button("Sign out", role: .destructive) {
            Task {
              await settings.signOut()
            }
          }
        } else {
          Picker("Mode", selection: $settings.authMode) {
            ForEach(SettingsStore.AuthMode.allCases) { mode in
              Text(mode == .login ? "Log in" : "Register").tag(mode)
            }
          }
          .pickerStyle(.segmented)

          if settings.authMode == .register {
            TextField("Display name", text: $settings.displayName)
          }

          TextField("Username", text: $settings.username)
            .platformCredentialField()

          SecureField("Password", text: $settings.password)

          Button(settings.authMode == .login ? "Authenticate" : "Create account") {
            Task {
              await settings.authenticate()
            }
          }
          .disabled(settings.isBusy)

          Button("Use access key") {
            Task {
              await settings.signInWithAccessKey()
            }
          }
          .disabled(settings.isBusy)
        }
      }

      Section("Access Keys") {
        if settings.currentUser == nil {
          Text("Sign in before registering or listing access keys.")
            .foregroundStyle(.secondary)
        } else {
          TextField("New access key label", text: $settings.accessKeyLabel)
          Button("Register access key") {
            Task {
              await settings.registerAccessKey()
            }
          }
          .disabled(settings.isBusy)

          if settings.accessKeys.isEmpty {
            Text("No access keys registered yet.")
              .foregroundStyle(.secondary)
          } else {
            ForEach(settings.accessKeys) { key in
              VStack(alignment: .leading, spacing: 4) {
                Text(key.label)
                  .font(.headline)
                Text("Device: \(key.deviceType)\(key.backedUp ? " / backed up" : "")")
                  .font(.subheadline)
                  .foregroundStyle(.secondary)
                Text("Transports: \(key.transports.isEmpty ? "unspecified" : key.transports.joined(separator: ", "))")
                  .font(.footnote)
                  .foregroundStyle(.secondary)
              }
              .padding(.vertical, 4)
            }
          }
        }
      }

      if let infoMessage = settings.infoMessage {
        Section("Status") {
          Text(infoMessage)
            .foregroundStyle(.secondary)
        }
      }

      if let errorMessage = settings.errorMessage {
        Section("Error") {
          Text(errorMessage)
            .foregroundStyle(.red)
        }
      }
    }
    .formStyle(.grouped)
    .padding()
    .frame(minWidth: 420, minHeight: 520)
  }
}

private extension View {
  @ViewBuilder
  func platformCredentialField() -> some View {
    #if os(iOS)
    textInputAutocapitalization(.never)
      .autocorrectionDisabled()
    #else
    self
    #endif
  }
}