//
//  UnlockView.swift
//  KeeVault
//

import SwiftUI
import UniformTypeIdentifiers
import KeeVaultCore

struct UnlockView: View {
    @ObservedObject var vm: UnlockViewModel

    var body: some View {
        VStack(spacing: 24) {
            Spacer()
            Image("AppIconImage")
                .resizable()
                .frame(width: 88, height: 88)
                .clipShape(RoundedRectangle(cornerRadius: 20, style: .continuous))
            Text("KeeVault")
                .font(.largeTitle.bold())

            if vm.hasVault {
                vaultUnlockSection
            } else {
                openFileSection
            }

            if let msg = vm.errorMessage {
                Text(msg)
                    .foregroundStyle(.red)
                    .font(.caption)
                    .multilineTextAlignment(.center)
            }
            Spacer()
        }
        .padding(32)
        .fileImporter(
            isPresented: $vm.showFilePicker,
            allowedContentTypes: [.init(filenameExtension: "kdbx")!],
            onCompletion: { result in
                if let url = try? result.get() { vm.openFile(url: url) }
            }
        )
    }

    @ViewBuilder
    private var vaultUnlockSection: some View {
        VStack(spacing: 16) {
            if vm.canUseBiometrics {
                Button(action: vm.unlockWithBiometrics) {
                    Label("Use Face ID / Touch ID", systemImage: "faceid")
                        .frame(maxWidth: .infinity)
                }
                .buttonStyle(.borderedProminent)
                .disabled(vm.isUnlocking)

                Text("or enter password")
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }

            PasswordField(text: $vm.password, onSubmit: vm.unlockWithPassword)

            Button("Unlock", action: vm.unlockWithPassword)
                .buttonStyle(.bordered)
                .disabled(vm.password.isEmpty || vm.isUnlocking)

            Button("Choose different file…") { vm.showFilePicker = true }
                .font(.caption)
                .foregroundStyle(.secondary)
        }
    }

    @ViewBuilder
    private var openFileSection: some View {
        VStack(spacing: 16) {
            Text("No vault selected. Open a .kdbx file to get started.")
                .multilineTextAlignment(.center)
                .foregroundStyle(.secondary)
            Button(action: { vm.showFilePicker = true }) {
                Label("Open KDBX File…", systemImage: "doc.badge.plus")
                    .frame(maxWidth: .infinity)
            }
            .buttonStyle(.borderedProminent)
        }
    }
}

/// A password field with a trailing eye button to reveal/hide the typed value.
private struct PasswordField: View {
    @Binding var text: String
    var onSubmit: () -> Void

    @State private var isRevealed = false

    var body: some View {
        HStack {
            Group {
                if isRevealed {
                    TextField("Master Password", text: $text)
                } else {
                    SecureField("Master Password", text: $text)
                }
            }
            .textFieldStyle(.plain)
            .autocorrectionDisabled()
            #if os(iOS)
            .textInputAutocapitalization(.never)
            #endif
            .onSubmit(onSubmit)

            Button {
                isRevealed.toggle()
            } label: {
                Image(systemName: isRevealed ? "eye.slash" : "eye")
                    .foregroundStyle(.secondary)
            }
            .buttonStyle(.plain)
        }
        .padding(8)
        .overlay(
            RoundedRectangle(cornerRadius: 6)
                .stroke(Color.secondary.opacity(0.3), lineWidth: 1)
        )
    }
}