---
apiVersion: v1
kind: ConfigMap
metadata:
  name: postgresql-connection-metrics
  namespace: postgresql-system
  labels:
    cnpg.io/reload: ""  # Enable automatic reload
data:
  custom-queries: |
    pg_application_connections:
      query: "SELECT 
                COALESCE(NULLIF(application_name, ''), 'unknown') AS app_name,
                state,
                COUNT(*) AS connection_count
              FROM pg_stat_activity 
              WHERE state IS NOT NULL 
                AND pid != pg_backend_pid()
              GROUP BY COALESCE(NULLIF(application_name, ''), 'unknown'), state"
      metrics:
        - app_name:
            usage: "LABEL"
            description: "Application name from connection"
        - state:
            usage: "LABEL" 
            description: "Connection state (active, idle, idle_in_transaction, etc)"
        - connection_count:
            usage: "GAUGE"
            description: "Number of connections per application and state"
    
    pg_database_connections:
      query: "SELECT 
                datname AS database_name,
                COALESCE(NULLIF(application_name, ''), 'unknown') AS app_name,
                COUNT(*) AS connection_count
              FROM pg_stat_activity 
              WHERE datname IS NOT NULL
                AND pid != pg_backend_pid()
              GROUP BY datname, COALESCE(NULLIF(application_name, ''), 'unknown')"
      metrics:
        - database_name:
            usage: "LABEL"
            description: "Database name"
        - app_name:
            usage: "LABEL"
            description: "Application name from connection"
        - connection_count:
            usage: "GAUGE"
            description: "Number of connections per database and application"

    pg_connection_states:
      query: "SELECT 
                state,
                COUNT(*) AS connection_count,
                COUNT(*) FILTER (WHERE COALESCE(NULLIF(application_name, ''), 'unknown') != 'unknown') AS named_connections,
                COUNT(*) FILTER (WHERE COALESCE(NULLIF(application_name, ''), 'unknown') = 'unknown') AS unnamed_connections
              FROM pg_stat_activity 
              WHERE state IS NOT NULL 
                AND pid != pg_backend_pid()
              GROUP BY state"
      metrics:
        - state:
            usage: "LABEL"
            description: "Connection state"
        - connection_count:
            usage: "GAUGE"
            description: "Total connections in this state"
        - named_connections:
            usage: "GAUGE"
            description: "Connections with application_name set"
        - unnamed_connections:
            usage: "GAUGE"
            description: "Connections without application_name"

    pg_user_connections:
      query: "SELECT 
                usename AS username,
                COUNT(*) AS connection_count
              FROM pg_stat_activity 
              WHERE usename IS NOT NULL
                AND pid != pg_backend_pid()
              GROUP BY usename"
      metrics:
        - username:
            usage: "LABEL"
            description: "PostgreSQL username"
        - connection_count:
            usage: "GAUGE"
            description: "Number of connections per user"
    
    pg_long_running_queries:
      query: "SELECT 
                datname AS database_name,
                usename AS username,
                COALESCE(NULLIF(application_name, ''), 'unknown') AS app_name,
                state,
                COALESCE(EXTRACT(EPOCH FROM (now() - query_start))::numeric, 0) AS query_duration_seconds,
                COALESCE(EXTRACT(EPOCH FROM (now() - state_change))::numeric, 0) AS state_duration_seconds,
                CASE 
                  WHEN state_change IS NOT NULL AND query_start IS NOT NULL THEN
                    COALESCE(EXTRACT(EPOCH FROM (state_change - query_start))::numeric, 0)
                  ELSE 0
                END AS execution_time_seconds,
                COALESCE(wait_event_type, 'none') AS wait_event_type,
                CASE 
                  WHEN query LIKE 'SELECT%' THEN 'SELECT'
                  WHEN query LIKE 'INSERT%' THEN 'INSERT'
                  WHEN query LIKE 'UPDATE%' THEN 'UPDATE'
                  WHEN query LIKE 'DELETE%' THEN 'DELETE'
                  WHEN query LIKE 'CREATE%' THEN 'CREATE'
                  WHEN query LIKE 'ALTER%' THEN 'ALTER'
                  WHEN query LIKE 'DROP%' THEN 'DROP'
                  ELSE 'OTHER'
                END AS query_type,
                LEFT(
                  CASE 
                    WHEN query ILIKE 'SELECT%' AND position('FROM' in UPPER(query)) > 0 THEN 
                      'SELECT (...) ' || SUBSTRING(query FROM position('FROM' in UPPER(query)))
                    WHEN query ILIKE 'UPDATE%' AND position('UPDATE' in UPPER(query)) > 0 THEN 
                      SUBSTRING(query FROM position('UPDATE' in UPPER(query)))
                    WHEN query ILIKE 'INSERT%' AND position('INTO' in UPPER(query)) > 0 THEN 
                      SUBSTRING(query FROM position('INTO' in UPPER(query)))
                    WHEN query ILIKE 'DELETE%' AND position('FROM' in UPPER(query)) > 0 THEN
                      'DELETE (...) ' || SUBSTRING(query FROM position('FROM' in UPPER(query)))
                    ELSE query
                  END,
                  8000
                ) AS query_context
              FROM pg_stat_activity 
              WHERE state != 'idle' 
                AND pid != pg_backend_pid()
                AND query_start IS NOT NULL
                AND EXTRACT(EPOCH FROM (now() - query_start)) > 5.0
              ORDER BY query_start ASC"
      metrics:
        - database_name:
            usage: "LABEL"
            description: "Database name"
        - username:
            usage: "LABEL"
            description: "PostgreSQL username"
        - app_name:
            usage: "LABEL"
            description: "Application name"
        - state:
            usage: "LABEL"
            description: "Query state (active, idle_in_transaction, etc)"
        - query_duration_seconds:
            usage: "GAUGE"
            description: "Time in seconds since query started"
        - state_duration_seconds:
            usage: "GAUGE"
            description: "Time in seconds since last state change (client wait time for 'Client' wait events)"
        - execution_time_seconds:
            usage: "GAUGE"
            description: "Actual query execution time in seconds (state_change - query_start)"
        - wait_event_type:
            usage: "LABEL"
            description: "Type of event the backend is waiting for"
        - query_type:
            usage: "LABEL"
            description: "Type of SQL query (SELECT, INSERT, UPDATE, etc)"
        - query_context:
            usage: "LABEL"
            description: "Query clause after SELECT (FROM/WHERE/etc)"
    
    pg_active_query_stats:
      query: "SELECT 
                state,
                COUNT(*) AS query_count,
                MAX(COALESCE(EXTRACT(EPOCH FROM (now() - query_start))::numeric, 0)) AS max_duration_seconds,
                AVG(COALESCE(EXTRACT(EPOCH FROM (now() - query_start))::numeric, 0)) AS avg_duration_seconds
              FROM pg_stat_activity 
              WHERE state != 'idle' 
                AND pid != pg_backend_pid()
                AND query_start IS NOT NULL
              GROUP BY state"
      metrics:
        - state:
            usage: "LABEL"
            description: "Query state"
        - query_count:
            usage: "GAUGE"
            description: "Number of queries in this state"
        - max_duration_seconds:
            usage: "GAUGE"
            description: "Maximum query duration in seconds"
        - avg_duration_seconds:
            usage: "GAUGE"
            description: "Average query duration in seconds"