├── README.md
└── main.py


/README.md:
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1 | # diagrams-as-code


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/main.py:
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  1 | import logging
  2 | from logging.config import fileConfig
  3 | from typing import Optional
  4 | 
  5 | from flask import current_app
  6 | from alembic import context
  7 | from sqlalchemy.engine import Engine
  8 | 
  9 | # Get Alembic configuration
 10 | config = context.config
 11 | 
 12 | # Configure logging if a config file is specified
 13 | if config.config_file_name:
 14 |     fileConfig(config.config_file_name)
 15 | 
 16 | logger = logging.getLogger("alembic.env")
 17 | 
 18 | 
 19 | def get_engine() -> Optional[Engine]:
 20 |     """Returns the database engine."""
 21 |     try:
 22 |         migrate_ext = current_app.extensions.get("migrate")
 23 |         if not migrate_ext or not hasattr(migrate_ext, "db"):
 24 |             logger.error("Flask-Migrate extension not found.")
 25 |             return None
 26 |         return migrate_ext.db.get_engine()
 27 |     except (AttributeError, KeyError, TypeError) as e:
 28 |         logger.error(f"Error retrieving the database engine: {e}")
 29 |         return None
 30 | 
 31 | 
 32 | def get_engine_url() -> str:
 33 |     """Returns the database URL."""
 34 |     engine = get_engine()
 35 |     if not engine:
 36 |         raise RuntimeError("Failed to retrieve the database engine.")
 37 | 
 38 |     try:
 39 |         return engine.url.render_as_string(hide_password=False).replace("%", "%%")
 40 |     except AttributeError:
 41 |         return str(engine.url).replace("%", "%%")
 42 | 
 43 | 
 44 | # Set the database URL for Alembic
 45 | config.set_main_option("sqlalchemy.url", get_engine_url())
 46 | 
 47 | # Retrieve the database object
 48 | target_db = current_app.extensions["migrate"].db
 49 | 
 50 | 
 51 | def get_metadata():
 52 |     """Returns the database metadata for autogeneration."""
 53 |     return getattr(target_db, "metadatas", {}).get(None, target_db.metadata)
 54 | 
 55 | 
 56 | def run_migrations_offline():
 57 |     """Runs migrations in offline mode."""
 58 |     url = config.get_main_option("sqlalchemy.url")
 59 |     if not url:
 60 |         raise RuntimeError("Database URL is not set.")
 61 | 
 62 |     context.configure(url=url, target_metadata=get_metadata(), literal_binds=True)
 63 | 
 64 |     with context.begin_transaction():
 65 |         context.run_migrations()
 66 | 
 67 | 
 68 | def run_migrations_online():
 69 |     """Runs migrations in online mode."""
 70 | 
 71 |     def process_revision_directives(context, revision, directives):
 72 |         """Prevents empty migrations from being generated."""
 73 |         cmd_opts = getattr(config, "cmd_opts", None)
 74 |         if cmd_opts and getattr(cmd_opts, "autogenerate", False):
 75 |             script = directives[0]
 76 |             if script.upgrade_ops.is_empty():
 77 |                 directives[:] = []
 78 |                 logger.info("No schema changes detected. Migration not created.")
 79 | 
 80 |     # Retrieve Alembic configuration arguments
 81 |     conf_args = getattr(current_app.extensions["migrate"], "configure_args", {})
 82 |     conf_args.setdefault("process_revision_directives", process_revision_directives)
 83 | 
 84 |     # Get the database engine
 85 |     connectable = get_engine()
 86 |     if not connectable:
 87 |         raise RuntimeError("Failed to connect to the database.")
 88 | 
 89 |     with connectable.connect() as connection:
 90 |         context.configure(connection=connection, target_metadata=get_metadata(), **conf_args)
 91 | 
 92 |         with context.begin_transaction():
 93 |             context.run_migrations()
 94 | 
 95 | 
 96 | # Determine the migration mode
 97 | if context.is_offline_mode():
 98 |     run_migrations_offline()
 99 | else:
100 |     run_migrations_online()
101 | 


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