-- Yealink/PBX call IDs are reused after a phone or PBX lifecycle.
-- Keep historical calls and require uniqueness only while a call is active.

DROP INDEX IF EXISTS ux_telefoni_opkald_callid;

CREATE UNIQUE INDEX IF NOT EXISTS ux_telefoni_opkald_active_callid
    ON telefoni_opkald(callid)
    WHERE ended_at IS NULL;

-- Recover calls that were previously merged into an older row with the same
-- reused call ID. System events are written from the successful callback and
-- retain the callback metadata required for a read-safe reconstruction.
INSERT INTO telefoni_opkald (
    callid, bruger_id, direction, ekstern_nummer, intern_extension,
    started_at, ended_at, duration_sec, raw_payload,
    lifecycle_status, termination_source, last_event_at
)
SELECT
    established.correlation_id,
    established.user_id,
    COALESCE(NULLIF(established.details->'payload'->>'direction', ''), 'inbound'),
    NULLIF(established.details->>'external_number', ''),
    NULLIF(established.details->>'extension', ''),
    established.occurred_at AT TIME ZONE 'UTC',
    terminated.occurred_at AT TIME ZONE 'UTC',
    CASE
        WHEN NULLIF(terminated.details->>'duration_sec', '') ~ '^[0-9]+$'
        THEN (terminated.details->>'duration_sec')::INTEGER
        WHEN terminated.occurred_at IS NOT NULL
        THEN GREATEST(EXTRACT(EPOCH FROM (terminated.occurred_at - established.occurred_at))::INTEGER, 0)
        ELSE NULL
    END,
    COALESCE(established.details->'payload', '{}'::jsonb),
    CASE WHEN terminated.id IS NULL THEN 'active' ELSE 'completed' END,
    CASE WHEN terminated.id IS NULL THEN NULL ELSE 'system_log_recovery' END,
    COALESCE(terminated.occurred_at, established.occurred_at)
FROM system_event_log established
LEFT JOIN LATERAL (
    SELECT term.id, term.occurred_at, term.details
    FROM system_event_log term
    WHERE term.source = 'voip'
      AND term.event_type = 'voip.terminated'
      AND term.correlation_id = established.correlation_id
      AND term.occurred_at >= established.occurred_at
    ORDER BY term.occurred_at ASC, term.id ASC
    LIMIT 1
) terminated ON TRUE
WHERE established.source = 'voip'
  AND established.event_type = 'voip.established'
  AND NULLIF(TRIM(established.correlation_id), '') IS NOT NULL
  AND NOT EXISTS (
      SELECT 1
      FROM telefoni_opkald current_call
      WHERE current_call.callid = established.correlation_id
        AND current_call.started_at BETWEEN
            (established.occurred_at AT TIME ZONE 'UTC') - INTERVAL '5 minutes'
            AND (established.occurred_at AT TIME ZONE 'UTC') + INTERVAL '5 minutes'
  );

CREATE INDEX IF NOT EXISTS idx_telefoni_opkald_callid_started
    ON telefoni_opkald(callid, started_at DESC);