API Reference
=============

Complete API documentation for vein.

Core Modules
-----------

.. toctree::
   :maxdepth: 2
   
   vein
   vein.config
   vein.default

Configuration Sources
--------------------

.. toctree::
   :maxdepth: 2
   
   vein.sources
   vein.sources.memory
   vein.sources.files
   vein.sources.remote
   vein.sources.aws

Validation
----------

.. toctree::
   :maxdepth: 2
   
   vein.validation

Caching
-------

.. toctree::
   :maxdepth: 2
   
   vein.cache

Retry & Backoff
--------------

.. toctree::
   :maxdepth: 2
   
   vein.backoff

Quick Reference
--------------

Common Imports
~~~~~~~~~~~~~

.. code-block:: python

    # Core
    from vein import config, Config
    
    # Sources
    from vein.sources import from_env, from_dict
    from vein.sources.files import from_yaml, from_json, from_ini
    from vein.sources.aws import (
        from_appconfig,
        from_parameter_store,
        from_secrets_manager
    )
    
    # Validation
    from vein.validation.policies import (
        RangeValidator,
        RegexValidator,
        TypeValidator,
        PydanticValidator
    )
    
    # Caching
    from vein.cache import Cache
    from vein.cache.strategies import TTLCacheStrategy, LRUCacheStrategy

Config Methods
~~~~~~~~~~~~~

.. code-block:: python

    # Assignment
    config.key = value
    config["key"] = value
    config.nested.key = value
    
    # Access
    value = config.key
    value = config["key"]
    value = config.get("key", default)
    
    # Update
    config.update(dict_or_source)
    config.update({"key": "value"})
    config.update(from_env())
    
    # Validation
    config.key.add_validator(validator)
    config.key.remove_validator(validator)
    
    # Events
    config.on_change("key", handler)
    config.off_change("key", handler)
    
    # State tracking
    config.enable_state_tracking()
    history = config.key.get_history()
    config.key.rollback(steps=1)

Value Methods
~~~~~~~~~~~~

When working with configuration values:

.. code-block:: python

    # Get raw value (for external libraries)
    raw_value = config.key.value
    
    # Type checking
    if isinstance(config.port, int):
        print("Port is an integer")
    
    # All Python operators work
    result = config.timeout * config.retries
    message = config.prefix + " " + config.suffix
    
    # Comparison
    if config.count > 10:
        print("Count exceeds limit")

Source Options
~~~~~~~~~~~~~

Common options for configuration sources:

.. code-block:: python

    # Environment variables
    from_env(prefix="APP_", lowercase=True, strip_prefix=True)
    
    # Files
    from_yaml("config.yml", encoding="utf-8")
    from_json("config.json", parse_dates=True)
    
    # AWS
    from_appconfig(
        application="my-app",
        environment="prod",
        profile="config",
        poll_interval=30,
        cache=Cache(TTLCacheStrategy(minutes=5))
    )
    
    from_parameter_store(
        prefix="/myapp/prod/",
        recursive=True,
        decrypt=True,
        cache=Cache(LRUCacheStrategy(100))
    )