-- Durable per-address registry, decoupled from ip_queue's lifecycle: today
-- deleting an address from ip_queue (DeleteIP/DeleteIPs/ClearQueue) cascades
-- to a hard DELETE of its checks/events, so history is lost forever if an
-- address is removed and later re-added. ip_registry gives every address
-- ever submitted a durable identity that check/event history attaches to
-- instead, surviving ip_queue row deletion and recreation.

CREATE TABLE ip_registry (
  id            INTEGER PRIMARY KEY AUTOINCREMENT,
  ip_address    TEXT NOT NULL UNIQUE,
  first_seen_at TIMESTAMP NOT NULL,
  last_seen_at  TIMESTAMP NOT NULL,
  next_cycle    INTEGER NOT NULL DEFAULT 1,
  created_at    TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  updated_at    TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
);

-- Backfill: one registry row per address currently (or ever) in ip_queue.
-- ip_queue.ip_address is already UNIQUE, so this is a straight 1:1 copy.
-- next_cycle starts past the current attempt_number so the first future
-- resubmission of an address gets a cycle_id that has never been used
-- before, even though it's seeded from attempt_number here.
INSERT INTO ip_registry (ip_address, first_seen_at, last_seen_at, next_cycle, created_at, updated_at)
SELECT ip_address, created_at, updated_at, attempt_number + 1, created_at, updated_at FROM ip_queue;

ALTER TABLE ip_queue ADD COLUMN registry_id INTEGER REFERENCES ip_registry(id);
ALTER TABLE ip_queue ADD COLUMN cycle_id    INTEGER NOT NULL DEFAULT 1;
UPDATE ip_queue SET
  registry_id = (SELECT id FROM ip_registry r WHERE r.ip_address = ip_queue.ip_address),
  cycle_id    = attempt_number;

-- checks.ip_id is today NOT NULL + REFERENCES ip_queue(id), which is exactly
-- what forces the cascading DELETE on ip_queue row removal (foreign_keys=ON
-- would otherwise block the delete once ip_queue's row disappears out from
-- under a referencing row). To let history outlive its ip_queue row, ip_id
-- must become nullable and checks must carry their own durable registry_id.
-- SQLite has no ALTER to relax a column's NOT NULL/REFERENCES, so the table
-- is rebuilt.
CREATE TABLE checks_new (
  id             INTEGER PRIMARY KEY AUTOINCREMENT,
  registry_id    INTEGER NOT NULL REFERENCES ip_registry(id),
  cycle_id       INTEGER NOT NULL,
  ip_id          INTEGER REFERENCES ip_queue(id),
  ip_address     TEXT NOT NULL,
  attempt_number INTEGER NOT NULL,
  validator_id   TEXT NOT NULL DEFAULT '',
  source         TEXT NOT NULL,
  check_type     TEXT NOT NULL,
  target         TEXT NOT NULL DEFAULT '',
  success        BOOLEAN NOT NULL,
  latency_ms     INTEGER NOT NULL DEFAULT 0,
  detail         TEXT NOT NULL DEFAULT '',
  checked_at     TIMESTAMP NOT NULL,
  created_at     TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  UNIQUE(registry_id, cycle_id, source, check_type, target)
);
INSERT INTO checks_new (id, registry_id, cycle_id, ip_id, ip_address, attempt_number, validator_id,
                         source, check_type, target, success, latency_ms, detail, checked_at, created_at)
SELECT c.id, iq.registry_id, iq.cycle_id, c.ip_id, c.ip_address, c.attempt_number, c.validator_id,
       c.source, c.check_type, c.target, c.success, c.latency_ms, c.detail, c.checked_at, c.created_at
FROM checks c JOIN ip_queue iq ON iq.id = c.ip_id;
DROP TABLE checks;
ALTER TABLE checks_new RENAME TO checks;
CREATE INDEX idx_checks_registry_cycle ON checks(registry_id, cycle_id);
CREATE INDEX idx_checks_ip_attempt ON checks(ip_id, attempt_number);

-- events.ip_id is already nullable, so no rebuild is needed there — just
-- add the durable registry_id (plus cycle_id, so retention pruning can cut
-- events at the same cycle boundary as checks) alongside it.
ALTER TABLE events ADD COLUMN registry_id INTEGER REFERENCES ip_registry(id);
ALTER TABLE events ADD COLUMN cycle_id INTEGER NOT NULL DEFAULT 0;
UPDATE events SET
  registry_id = (SELECT registry_id FROM ip_queue WHERE ip_queue.id = events.ip_id),
  cycle_id    = (SELECT cycle_id FROM ip_queue WHERE ip_queue.id = events.ip_id)
WHERE ip_id IS NOT NULL;
CREATE INDEX idx_events_registry ON events(registry_id, cycle_id);

-- Configurable history retention depth, in check cycles per address. 0 (the
-- default, matching today's unbounded behavior) means keep everything.
ALTER TABLE settings ADD COLUMN history_retention_cycles INTEGER NOT NULL DEFAULT 0;