# Server Setup Feature - Implementation Summary

## Overview
Added a mandatory server setup screen on first app startup with endpoint validation to ensure users configure a valid server URL before using the app.

## Features Added

### 1. First-Run Server Setup Screen
- **File**: `ServerSetupScreen.kt`
- Mandatory setup screen shown on first app launch
- User-friendly interface with clear instructions
- Real-time validation feedback with visual indicators
- Cannot be skipped - must validate successfully to proceed
- Tips card with connection examples for emulator and physical devices

### 2. Server Endpoint Validation
- **File**: `ServerSetupViewModel.kt`
- Validates URL format (must start with http:// or https://)
- Tests server connectivity by calling the `/health` endpoint
- Shows specific error messages:
  - Connection failures
  - Timeout errors
  - Invalid URL format
  - Server error codes
- Loading states with progress indicators
- Success confirmation before proceeding

### 3. First-Run Detection
- **Updated**: `PreferencesManager.kt`
- Added `isFirstRun()` method to check if app has been configured
- Added `setIsFirstRun(Boolean)` method to mark setup as complete
- Persists across app restarts using SharedPreferences

### 4. Updated Navigation Flow
- **Updated**: `AppNavigation.kt`
- Dynamically determines start destination based on first-run status
- Shows `server_setup` screen on first run
- Shows `lists` screen on subsequent runs
- Prevents navigation back to setup after completion

## User Experience Flow

### First App Launch:
1. User opens app for the first time
2. Server Setup screen is displayed automatically
3. User enters server URL
4. App validates the endpoint:
   - Shows loading indicator during validation
   - Displays success checkmark if valid
   - Shows error message if invalid
5. On successful validation:
   - Server URL is saved
   - First-run flag is set to false
   - User is navigated to Lists screen
6. User can now use the app normally

### Subsequent Launches:
1. User opens app
2. App checks first-run status
3. Directly shows Lists screen (normal flow)
4. User can still change server URL via Settings

## Validation Process

The validation performs these checks:
1. **URL Format**: Ensures URL starts with http:// or https://
2. **Normalization**: Adds trailing slash if missing
3. **Health Check**: Calls `/health` endpoint (converted from `/api/` path)
4. **Timeout**: 10-second timeout for connection attempts
5. **Error Handling**: User-friendly error messages for common issues

## Error Messages

- "URL must start with http:// or https://"
- "Cannot connect to server. Check URL and network."
- "Connection timeout. Server might be offline."
- "Server returned error: [code]"
- "Invalid URL format"
- "Error: [specific error message]"

## Settings Integration

Users can still:
- Change server URL later via Settings screen
- Test new URLs at any time
- View connection tips in Settings

## Technical Details

### Dependencies Used:
- OkHttp for HTTP requests
- Kotlin Coroutines for async operations
- StateFlow for reactive state management
- SharedPreferences for persistence

### Network Configuration:
- Connection timeout: 10 seconds
- Read timeout: 10 seconds
- Validates against `/health` endpoint
- Supports both HTTP and HTTPS

## Testing Recommendations

1. **First Run Test**:
   - Clear app data
   - Launch app
   - Verify server setup screen appears

2. **Validation Test**:
   - Test with valid URL (should succeed)
   - Test with invalid URL (should show error)
   - Test with unreachable server (should show connection error)
   - Test with malformed URL (should show format error)

3. **Subsequent Launch Test**:
   - After successful setup, close and reopen app
   - Verify Lists screen appears directly

4. **Settings Test**:
   - Navigate to Settings
   - Change server URL
   - Verify changes persist

## Files Modified/Created

### New Files:
- `app/src/main/java/com/collabtable/app/ui/screens/ServerSetupScreen.kt`
- `app/src/main/java/com/collabtable/app/ui/screens/ServerSetupViewModel.kt`

### Modified Files:
- `app/src/main/java/com/collabtable/app/data/preferences/PreferencesManager.kt`
- `app/src/main/java/com/collabtable/app/ui/navigation/AppNavigation.kt`

## Build Status
✅ Build successful with all tests passing
✅ No compilation errors
✅ All dependencies resolved correctly