"""Configuration constants and environment variables for HAProxy MCP Server."""

import os
import re
import logging

# Configure structured logging
log_level = os.getenv("LOG_LEVEL", "INFO").upper()
logging.basicConfig(
    level=getattr(logging, log_level, logging.INFO),
    format='%(asctime)s [%(levelname)s] %(message)s',
    datefmt='%Y-%m-%d %H:%M:%S'
)
logger = logging.getLogger("haproxy_mcp")

# MCP Server configuration
MCP_HOST: str = os.getenv("MCP_HOST", "0.0.0.0")
MCP_PORT: int = int(os.getenv("MCP_PORT", "8000"))

# HAProxy Runtime API configuration
HAPROXY_HOST: str = os.getenv("HAPROXY_HOST", "localhost")
HAPROXY_PORT: int = int(os.getenv("HAPROXY_PORT", "9999"))
HAPROXY_SOCKET: tuple[str, int] = (HAPROXY_HOST, HAPROXY_PORT)

# File paths (configurable via environment)
STATE_FILE: str = os.getenv("HAPROXY_STATE_FILE", "/opt/haproxy/data/servers.state")
MAP_FILE: str = os.getenv("HAPROXY_MAP_FILE", "/opt/haproxy/conf/domains.map")
MAP_FILE_CONTAINER: str = os.getenv("HAPROXY_MAP_FILE_CONTAINER", "/usr/local/etc/haproxy/domains.map")
# Wildcards map for 2-stage matching (map_dom fallback)
WILDCARDS_MAP_FILE: str = os.getenv("HAPROXY_WILDCARDS_MAP_FILE", "/opt/haproxy/conf/wildcards.map")
WILDCARDS_MAP_FILE_CONTAINER: str = os.getenv("HAPROXY_WILDCARDS_MAP_FILE_CONTAINER", "/usr/local/etc/haproxy/wildcards.map")
SERVERS_FILE: str = os.getenv("HAPROXY_SERVERS_FILE", "/opt/haproxy/conf/servers.json")
CERTS_FILE: str = os.getenv("HAPROXY_CERTS_FILE", "/opt/haproxy/conf/certificates.json")

# Pool configuration
POOL_COUNT: int = int(os.getenv("HAPROXY_POOL_COUNT", "100"))
MAX_SLOTS: int = int(os.getenv("HAPROXY_MAX_SLOTS", "10"))

# Container configuration
HAPROXY_CONTAINER: str = os.getenv("HAPROXY_CONTAINER", "haproxy")

# Validation patterns - compiled once for performance
DOMAIN_PATTERN = re.compile(
    r'^[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?'
    r'(\.[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?)*$'
)
# Backend/server names: alphanumeric, underscore, hyphen only
BACKEND_NAME_PATTERN = re.compile(r'^[a-zA-Z0-9_-]+$')
# Pattern for converting domain to backend name
NON_ALNUM_PATTERN = re.compile(r'[^a-zA-Z0-9]')

# Limits
MAX_RESPONSE_SIZE = 10 * 1024 * 1024  # 10 MB max response from HAProxy
SUBPROCESS_TIMEOUT = 30  # seconds
STARTUP_RETRY_COUNT = 10  # HAProxy ready check retries
STATE_MIN_COLUMNS = 19  # Minimum columns in HAProxy server state output
SOCKET_TIMEOUT = 5  # seconds for HAProxy socket connection
SOCKET_RECV_TIMEOUT = 30  # seconds for HAProxy socket recv loop
MAX_BULK_SERVERS = 10  # Max servers per bulk add call
MAX_SERVERS_JSON_SIZE = 10000  # Max size of servers JSON in haproxy_add_servers


# CSV field indices for HAProxy stats (show stat command)
class StatField:
    """HAProxy CSV stat field indices."""
    PXNAME = 0      # Proxy name (frontend/backend)
    SVNAME = 1      # Server name (or FRONTEND/BACKEND)
    SCUR = 4        # Current sessions
    SMAX = 6        # Max sessions
    STATUS = 17     # Status (UP/DOWN/MAINT/etc)
    WEIGHT = 18     # Server weight
    CHECK_STATUS = 36  # Check status


# Field indices for HAProxy server state (show servers state command)
class StateField:
    """HAProxy server state field indices."""
    BE_ID = 0       # Backend ID
    BE_NAME = 1     # Backend name
    SRV_ID = 2      # Server ID
    SRV_NAME = 3    # Server name
    SRV_ADDR = 4    # Server address
    SRV_OP_STATE = 5    # Operational state
    SRV_ADMIN_STATE = 6  # Admin state
    SRV_PORT = 18   # Server port