# Phase 0: Container Runtime Validation Tests

## Overview
This directory contains the test files used to validate Snowflake Container Runtime capabilities for the Spark POC (TikTok music analytics proof of concept).

## Test Results Summary

### ✅ **PASSED Tests**

#### Test 1: Basic Streamlit Functionality (`test_1_basic.py`)
- **Purpose**: Validate core Streamlit functionality in Container Runtime
- **Result**: ✅ PASSED - All UI components, session state, and st.rerun() work perfectly
- **Key Finding**: Original simple code works best; avoid over-engineering "fixes"

#### Test 3: External API Connectivity (`test_3_api.py`)
- **Purpose**: Test external API calls needed for Apify integration
- **Result**: ✅ PASSED - HTTP requests to httpbin.org and api.apify.com work
- **Key Finding**: Network rules must be specific (no wildcards like `*:443`)

#### Test 4: Package Management (`test_4_packages.py`)
- **Purpose**: Validate required Python packages are available
- **Result**: ✅ PASSED - All essential packages available (pandas, numpy, requests, snowflake-connector-python)
- **Key Finding**: Core packages sufficient for POC; optional packages like plotly missing but not critical

### ⏭️ **SKIPPED Tests**

#### Test 2: Database Connectivity (`test_2_database.py`)
- **Purpose**: Test Snowflake database access
- **Result**: ⏭️ SKIPPED - Database connectivity is inherent in Container Runtime via Snowpark
- **Key Finding**: Use `get_active_session()` pattern, not `st.connection()`

### ❌ **FAILED Tests**

#### Test 5: Multi-file Module Structure (`test_5_*` files)
- **Purpose**: Test multi-file Python application support
- **Result**: ❌ FAILED - Container Runtime doesn't support custom module imports
- **Key Finding**: Files stored compressed in stage; Python can't import them
- **Impact**: Must use single-file architecture with class-based organization

## Architecture Decision

Based on test results, the Spark POC will use a **single-file architecture** with class-based modular organization:

```python
# spark_poc.py
class ChartmetricModule:
    # Snowflake data access and song-to-URL mapping
    
class ApifyModule:  
    # TikTok video scraping via external API
    
class AnalyticsModule:
    # Video data processing and insights generation
    
class DashboardModule:
    # Streamlit UI components and visualization
```

## Key Container Runtime Patterns

### ✅ Working Patterns
```python
# Snowpark integration
from snowflake.snowpark.context import get_active_session
session = get_active_session()
data = session.sql("SELECT * FROM table").to_pandas()

# Caching
@st.cache_data(ttl=300)
def expensive_query():
    return session.sql("...").to_pandas()

# API calls with proper error handling
response = requests.get(url, timeout=30)
```

### ❌ Patterns to Avoid
```python
# Don't use st.connection() - use Snowpark session
data = st.connection("snowflake").query("SELECT ...")  # ❌

# Don't try to import custom modules
import my_custom_module  # ❌ Will fail

# Don't use overly broad network rules
# VALUE_LIST = ('*:443', '*:80')  # ❌ Security risk
```

## Files in This Directory

### Working Test Files
- `test_1_basic.py` - Basic Streamlit functionality (PASSED)
- `test_1_basic_fixed.py` - Over-engineered version (caused issues)
- `test_3_api.py` - External API connectivity (PASSED)  
- `test_4_packages.py` - Package management (PASSED)
- `test_7_simple_logging.py` - Hello world baseline (PASSED)
- `test_8_simple_import.py` + `simple_utils.py` - Module imports (PASSED) ✅

### Archive Files (Failed with Old Deployment Syntax)
- `test_2_database.py` - Database test (skipped as unnecessary)
- `test_5_*` - Various multi-file attempts (failed due to deployment syntax issues)
- `utils/` - Utility modules that couldn't be imported (deployment syntax issues)
- **Note**: These failures were due to incorrect deployment syntax, not Container Runtime limitations

### Configuration
- Container Runtime setup: `../container_runtime_setup.sql`
- Network rules configured for PyPI and Apify API access
- Compute pool: `spark_streamlit_pool` (CPU_X64_XS)

## Next Steps

1. **Clean up test artifacts** using `../Phase0_Cleanup_Commands.md`
2. **Begin POC development** with validated single-file architecture
3. **Use established patterns** for Snowpark integration and API calls
4. **Reference this validation** for troubleshooting and best practices

## Key Lessons for POC Development

1. **Keep it simple** - Container Runtime works well with straightforward code
2. **Modular architecture supported** - Can use multiple files with correct deployment syntax ✅
3. **Specific network rules** - Be explicit about external endpoints needed  
4. **Use Snowpark session** - `get_active_session()` is the correct pattern
5. **Deployment syntax critical** - `AUTO_COMPRESS=FALSE` and `FROM '@stage/'` required
5. **Cache appropriately** - Use `@st.cache_data` for expensive operations
6. **Test incrementally** - Start simple, add complexity gradually