import AppKit
import SwiftUI

struct OAuthSetupView: View {
    @State private var tokenManager = TokenManager.shared
    @State private var statusMessage: String?

    var body: some View {
        VStack(spacing: 16) {
            Image(systemName: "link.circle")
                .font(.system(size: 40))
                .foregroundStyle(.blue)

            Text("Connect Feishu")
                .font(.headline)

            Text("Authorize Bugger to read bugs assigned to you from your Feishu Bitable.")
                .font(.caption)
                .foregroundStyle(.secondary)
                .multilineTextAlignment(.center)

            if case .authenticating = tokenManager.state {
                ProgressView("Completing sign-in...")
            } else if tokenManager.authorizeURL == nil {
                Text("Set FEISHU_APP_ID and FEISHU_APP_SECRET in the Xcode build settings before connecting.")
                    .font(.caption)
                    .foregroundStyle(.orange)
                    .multilineTextAlignment(.center)
            } else {
                Button("Connect Feishu") {
                    connectFeishu()
                }
                .buttonStyle(.borderedProminent)
                .disabled(statusMessage != nil)
            }

            if case .error(let message) = tokenManager.state {
                VStack(spacing: 4) {
                    Text("Authorization failed")
                        .font(.caption)
                        .fontWeight(.medium)
                        .foregroundStyle(.red)
                    Text(message)
                        .font(.caption2)
                        .foregroundStyle(.secondary)
                        .multilineTextAlignment(.center)
                    Button("Try again") {
                        tokenManager.clearTokens()
                        statusMessage = nil
                    }
                    .font(.caption)
                }
            }

            if let statusMessage, !statusMessage.isEmpty,
               tokenManager.state != .authenticating {
                Text(statusMessage)
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }
        }
        .padding(24)
        .frame(maxWidth: .infinity, maxHeight: .infinity)
    }

    private func connectFeishu() {
        statusMessage = "Starting..."
        Task {
            let server = LocalOAuthServer(port: 18_923)
            tokenManager.authService.redirectURI = server.redirectURI

            guard let url = tokenManager.authorizeURL else {
                statusMessage = nil
                tokenManager.setError("Missing credentials. Check FEISHU_APP_ID.")
                return
            }

            statusMessage = "Complete authorization in your browser..."
            NSWorkspace.shared.open(url)

            do {
                let code = try await server.receiveCode()
                statusMessage = "Completing sign-in..."
                try await tokenManager.handleCallback(code: code)
                statusMessage = nil
                await PollerService.shared.startIfConfigured()
                await PollerService.shared.fetchNow()
            } catch {
                statusMessage = nil
                tokenManager.setError(error.localizedDescription)
            }
        }
    }
}