"""
Prometheus metrics configuration for the OPC Ingestor application.

This module defines all the metrics used for monitoring and observability
of the OPC Ingestor system. It includes metrics for:

- Application health and performance
- OPC server connections and subscriptions
- Data processing and storage operations
- Resource management and load balancing
- Error tracking and notification systems

All metrics follow Prometheus naming conventions and include appropriate
labels for multi-dimensional analysis and alerting.
"""

from prometheus_client import Counter, Gauge, Histogram

# Metric label definitions for consistent labeling across all metrics
POD_ID_LABEL = ["pod_id"]
SERVER_LABELS = ["pod_id", "server_name", "server_url"]
KAFKA_LABELS = ["pod_id", "topic"]
REDIS_LABELS = ["pod_id", "operation"]
NOTIFICATION_LABELS = ["pod_id", "level", "block"]

MAIN_LABELS = ["pod_id"]

# --- Reliability Metrics ---
TAG_WRITTEN_COUNT = Counter(
    "ingestor_tag_written_count",
    "Number of writing process to the collection",
    [*MAIN_LABELS, "tag_name", "collection_name"],
)

# --- General Application Metrics ---
APP_LOOP_COUNT = Counter(
    "app_main_loop_total",
    "Total number of times the application main loop has run",
    POD_ID_LABEL,
)
APP_LOOP_DURATION = Histogram(
    "app_main_loop_duration_seconds",
    "Duration of the application main loop in seconds",
    POD_ID_LABEL,
)
APP_ERRORS_TOTAL = Counter(
    "app_errors_total",
    "Total number of unhandled errors in the main loop",
    POD_ID_LABEL,
)
APP_UP = Gauge(
    "app_up",
    "Indicates if the application is running (1) or shutting down (0)",
    POD_ID_LABEL,
)

# --- Ingestor Manager Metrics ---
ACTIVE_INGESTORS = Gauge(
    "ingestor_active_total",
    "Number of active ingestors reported by Redis",
)
SLOTS_TOTAL = Gauge(
    "ingestor_slots_total",
    "Total number of slots configured in Redis",
)
LEASES_TOTAL = Gauge(
    "ingestor_leases_total",
    "Total number of leases (allocated slots) in Redis",
)
SLOTS_MANAGED = Gauge(
    "ingestor_slots_managed_current",
    "Number of slots currently managed by this ingestor instance",
    POD_ID_LABEL,
)
SLOTS_ACQUIRED = Counter(
    "ingestor_slots_acquired_total",
    "Total number of slots acquired by this instance",
    POD_ID_LABEL,
)
SLOTS_RELEASED = Counter(
    "ingestor_slots_released_total",
    "Total number of slots released by this instance",
    POD_ID_LABEL,
)
OPC_MANAGERS_ACTIVE = Gauge(
    "ingestor_opc_managers_active",
    "Number of active OPC Managers in this instance",
    POD_ID_LABEL,
)
OPC_SUBSCRIPTION_ERRORS = Counter(
    "ingestor_opc_subscription_errors_total",
    "Errors when trying to subscribe to OPC tags",
    ["pod_id", "server", "slot"],
)

# --- OPC Manager Metrics ---
OPC_CONNECTIONS_TOTAL = Counter(
    "opc_connections_initiated_total",
    "Total connection attempts to OPC servers",
    ["pod_id", "server_name"],
)
OPC_CONNECTIONS_FAILED = Counter(
    "opc_connections_failed_total",
    "Total failed connection attempts to OPC servers",
    ["pod_id", "server_name"],
)
OPC_CONNECTION_STATUS = Gauge(
    "opc_connection_status",
    "Connection status with the OPC server (1=connected, 0=disconnected)",
    SERVER_LABELS,
)
OPC_SUBSCRIPTIONS_CREATED = Counter(
    "opc_subscriptions_created_total",
    "Total OPC subscriptions created",
    ["pod_id", "server_name", "slot_name"],
)
OPC_TAGS_SUBSCRIBED = Gauge(
    "opc_tags_subscribed_current",
    "Current number of OPC tags subscribed on a server",
    ["pod_id", "server_name"],
)
OPC_CYCLES_WITHOUT_DATA = Gauge(
    "opc_cycles_without_data",
    "Current number of cycles without receiving data from a server",
    ["pod_id", "server_name"],
)
OPC_RECONNECTIONS_TOTAL = Counter(
    "opc_reconnections_tried_total",
    "Reconnection attempts to an OPC server after a loss",
    ["pod_id", "server_name"],
)

# --- Data Manager (Kafka) Metrics ---
KAFKA_MESSAGES_SENT = Counter(
    "kafka_messages_sent_total", "Total messages sent to Kafka", KAFKA_LABELS
)
KAFKA_MESSAGES_ERRORS = Counter(
    "kafka_messages_errors_total",
    "Total errors sending messages to Kafka",
    KAFKA_LABELS,
)
KAFKA_CONNECTION_STATUS = Gauge(
    "kafka_connection_status",
    "Connection status with Kafka (1=connected, 0=disconnected)",
    POD_ID_LABEL,
)

# --- Resource Manager (Redis) Metrics ---
REDIS_OPERATIONS_TOTAL = Counter(
    "redis_operations_total", "Total number of Redis operations performed", REDIS_LABELS
)
REDIS_OPERATIONS_ERRORS = Counter(
    "redis_operations_errors_total",
    "Total number of errors in Redis operations",
    REDIS_LABELS,
)
REDIS_OPERATIONS_DURATION = Histogram(
    "redis_operations_duration_seconds",
    "Duration of Redis operations in seconds",
    REDIS_LABELS,
)
REDIS_CONNECTION_STATUS = Gauge(
    "redis_connection_status",
    "Connection status with Redis (1=connected, 0=disconnected)",
    POD_ID_LABEL,
)

# --- Notification Metrics ---
NOTIFICATIONS_SENT = Counter(
    "notifications_sent_total",
    "Total number of notifications sent",
    NOTIFICATION_LABELS,
)