#!/usr/bin/env python3
"""
Script to update all remaining apps to use core models.
Updates patient, encounter, and facility FK references.
"""

import re
import sys
from pathlib import Path

# Apps to update with their specific changes needed
APPS_TO_UPDATE = {
    'billing': {
        'patient_fk': True,
        'encounter_fk': True,
        'facility_fk': False,
    },
    'pharmacy': {
        'patient_fk': True,
        'encounter_fk': True,
        'facility_fk': False,
    },
    'laboratory': {
        'patient_fk': True,
        'encounter_fk': True,
        'facility_fk': False,
    },
    'radiology': {
        'patient_fk': True,
        'encounter_fk': True,
        'facility_fk': False,
    },
    'operating_theatre': {
        'patient_fk': True,
        'encounter_fk': True,
        'facility_fk': True,
    },
    'inpatients': {
        'patient_fk': True,
        'encounter_fk': True,
        'facility_fk': False,
    },
    'blood_bank': {
        'patient_fk': True,
        'encounter_fk': False,
        'facility_fk': False,
    },
    'appointments': {
        'patient_fk': True,
        'encounter_fk': False,
        'facility_fk': False,
    },
    'facility_management': {
        'patient_fk': False,
        'encounter_fk': False,
        'facility_fk': True,
    },
}

def update_app_models(app_name, changes_needed):
    """Update a single app's models.py file."""
    
    models_path = Path(f'{app_name}/models.py')
    
    if not models_path.exists():
        print(f"⚠️  {app_name}/models.py not found, skipping...")
        return False
    
    print(f"\n📝 Processing {app_name}/models.py...")
    content = models_path.read_text(encoding='utf-8')
    
    # Track if any changes were made
    changes_made = False
    
    # Step 1: Check if imports already exist
    has_core_imports = 'from core.models import' in content
    
    if not has_core_imports:
        print(f"  ➕ Adding core imports...")
        
        # Build import list based on what's needed
        imports = []
        if changes_needed['patient_fk']:
            imports.append('Patient')
        if changes_needed['encounter_fk']:
            imports.append('Encounter')
        if changes_needed['facility_fk']:
            imports.append('Facility')
        imports.append('TenantScopedModel')
        
        import_line = f"\n# Import core models\nfrom core.models import {', '.join(imports)}\n"
        
        # Find a good place to insert (after other imports, before first class)
        # Look for the last import statement
        import_pattern = r'((?:from|import)\s+[\w.]+.*\n)+'
        match = re.search(import_pattern, content)
        
        if match:
            insert_pos = match.end()
            content = content[:insert_pos] + import_line + content[insert_pos:]
            changes_made = True
        else:
            # Fallback: insert after docstring
            docstring_pattern = r'"""[\s\S]*?"""'
            match = re.search(docstring_pattern, content)
            if match:
                insert_pos = match.end()
                content = content[:insert_pos] + "\n" + import_line + content[insert_pos:]
                changes_made = True
    
    # Step 2: Update patient FK references
    if changes_needed['patient_fk']:
        old_patient_refs = content.count("'patients.PatientProfile'")
        if old_patient_refs > 0:
            print(f"  🔄 Updating {old_patient_refs} patient FK reference(s)...")
            content = content.replace("'patients.PatientProfile'", "'core.Patient'")
            changes_made = True
    
    # Step 3: Update encounter FK references
    if changes_needed['encounter_fk']:
        old_encounter_refs = content.count("'emr.Encounter'")
        if old_encounter_refs > 0:
            print(f"  🔄 Updating {old_encounter_refs} encounter FK reference(s)...")
            content = content.replace("'emr.Encounter'", "'core.Encounter'")
            changes_made = True
    
    # Step 4: Update facility FK references (if app has local Facility model)
    if changes_needed['facility_fk']:
        # This is more complex - need to check if app has its own Facility model
        if 'class Facility(models.Model)' in content or 'class Facility(TenantScopedModel)' in content:
            print(f"  ⚠️  {app_name} has local Facility model - manual review needed!")
        
        old_facility_refs = content.count(f"'{app_name}.Facility'")
        if old_facility_refs > 0:
            print(f"  🔄 Updating {old_facility_refs} facility FK reference(s)...")
            content = content.replace(f"'{app_name}.Facility'", "'core.Facility'")
            changes_made = True
    
    # Step 5: Write changes if any were made
    if changes_made:
        models_path.write_text(content, encoding='utf-8')
        print(f"  ✅ {app_name}/models.py updated successfully!")
        return True
    else:
        print(f"  ℹ️  No changes needed for {app_name}/models.py")
        return False

def main():
    """Main function to update all apps."""
    
    print("=" * 70)
    print("UPDATING ALL APPS TO USE CORE MODELS")
    print("=" * 70)
    
    updated_count = 0
    skipped_count = 0
    
    for app_name, changes_needed in APPS_TO_UPDATE.items():
        result = update_app_models(app_name, changes_needed)
        if result:
            updated_count += 1
        else:
            skipped_count += 1
    
    print("\n" + "=" * 70)
    print("SUMMARY")
    print("=" * 70)
    print(f"✅ Apps updated: {updated_count}")
    print(f"ℹ️  Apps skipped: {skipped_count}")
    print(f"📊 Total apps processed: {len(APPS_TO_UPDATE)}")
    
    print("\n" + "=" * 70)
    print("NEXT STEPS")
    print("=" * 70)
    print("1. Review the changes in each app's models.py")
    print("2. Check for any manual adjustments needed")
    print("3. Delete db.sqlite3")
    print("4. Delete all migration files (keep __init__.py)")
    print("5. Run: python manage.py makemigrations")
    print("6. Run: python manage.py migrate")
    print("7. Create superuser")
    print("8. Reseed data")
    print("=" * 70)
    
    return True

if __name__ == '__main__':
    success = main()
    sys.exit(0 if success else 1)