from pydantic import Field, NonNegativeInt, PositiveFloat, PositiveInt, field_validator
from pydantic_settings import BaseSettings


class RedisConfig(BaseSettings):
    """
    Configuration settings for Redis connection
    """

    REDIS_HOST: str = Field(
        description="Hostname or IP address of the Redis server",
        default="localhost",
    )

    REDIS_PORT: PositiveInt = Field(
        description="Port number on which the Redis server is listening",
        default=6379,
    )

    REDIS_USERNAME: str | None = Field(
        description="Username for Redis authentication (if required)",
        default=None,
    )

    REDIS_PASSWORD: str | None = Field(
        description="Password for Redis authentication (if required)",
        default=None,
    )

    REDIS_DB: NonNegativeInt = Field(
        description="Redis database number to use (0-15)",
        default=0,
    )

    REDIS_KEY_PREFIX: str = Field(
        description="Optional global prefix for Redis keys, topics, and transport artifacts",
        default="",
    )

    REDIS_USE_SSL: bool = Field(
        description="Enable SSL/TLS for the Redis connection",
        default=False,
    )

    REDIS_SSL_CERT_REQS: str = Field(
        description="SSL certificate requirements (CERT_NONE, CERT_OPTIONAL, CERT_REQUIRED)",
        default="CERT_NONE",
    )

    REDIS_SSL_CA_CERTS: str | None = Field(
        description="Path to the CA certificate file for SSL verification",
        default=None,
    )

    REDIS_SSL_CERTFILE: str | None = Field(
        description="Path to the client certificate file for SSL authentication",
        default=None,
    )

    REDIS_SSL_KEYFILE: str | None = Field(
        description="Path to the client private key file for SSL authentication",
        default=None,
    )

    REDIS_USE_SENTINEL: bool | None = Field(
        description="Enable Redis Sentinel mode for high availability",
        default=False,
    )

    REDIS_SENTINELS: str | None = Field(
        description="Comma-separated list of Redis Sentinel nodes (host:port)",
        default=None,
    )

    REDIS_SENTINEL_SERVICE_NAME: str | None = Field(
        description="Name of the Redis Sentinel service to monitor",
        default=None,
    )

    REDIS_SENTINEL_USERNAME: str | None = Field(
        description="Username for Redis Sentinel authentication (if required)",
        default=None,
    )

    REDIS_SENTINEL_PASSWORD: str | None = Field(
        description="Password for Redis Sentinel authentication (if required)",
        default=None,
    )

    REDIS_SENTINEL_SOCKET_TIMEOUT: PositiveFloat | None = Field(
        description="Socket timeout in seconds for Redis Sentinel connections",
        default=0.1,
    )

    REDIS_USE_CLUSTERS: bool = Field(
        description="Enable Redis Clusters mode for high availability",
        default=False,
    )

    REDIS_CLUSTERS: str | None = Field(
        description="Comma-separated list of Redis Clusters nodes (host:port)",
        default=None,
    )

    REDIS_CLUSTERS_PASSWORD: str | None = Field(
        description="Password for Redis Clusters authentication (if required)",
        default=None,
    )

    REDIS_SERIALIZATION_PROTOCOL: int = Field(
        description="Redis serialization protocol (RESP) version",
        default=3,
    )

    REDIS_ENABLE_CLIENT_SIDE_CACHE: bool = Field(
        description="Enable client side cache in redis",
        default=False,
    )

    REDIS_MAX_CONNECTIONS: PositiveInt | None = Field(
        description="Maximum connections in the Redis connection pool (unset for library default)",
        default=None,
    )

    REDIS_RETRY_RETRIES: NonNegativeInt = Field(
        description="Maximum number of retries per Redis command on "
        "transient failures (ConnectionError, TimeoutError, socket.timeout)",
        default=3,
    )

    REDIS_RETRY_BACKOFF_BASE: PositiveFloat = Field(
        description="Base delay in seconds for exponential backoff between retries",
        default=1.0,
    )

    REDIS_RETRY_BACKOFF_CAP: PositiveFloat = Field(
        description="Maximum backoff delay in seconds between retries",
        default=10.0,
    )

    REDIS_SOCKET_TIMEOUT: PositiveFloat | None = Field(
        description="Socket timeout in seconds for Redis read/write operations",
        default=5.0,
    )

    REDIS_SOCKET_CONNECT_TIMEOUT: PositiveFloat | None = Field(
        description="Socket timeout in seconds for Redis connection establishment",
        default=5.0,
    )

    REDIS_HEALTH_CHECK_INTERVAL: NonNegativeInt = Field(
        description="Interval in seconds between Redis connection health checks (0 to disable)",
        default=30,
    )

    @field_validator("REDIS_MAX_CONNECTIONS", mode="before")
    @classmethod
    def _empty_string_to_none_for_max_conns(cls, v):
        """Allow empty string in env/.env to mean 'unset' (None)."""
        if v is None:
            return None
        if isinstance(v, str) and v.strip() == "":
            return None
        return v