QR Master automatic billing alarm SQL
=====================================

Run this SQL once in the database.

After it is installed, every database update of "User"."plan" automatically
creates a "UserLifecycleLog" entry.

That means:
- FREE -> PRO or BUSINESS creates reason = subscription_created
- PRO/BUSINESS -> FREE creates reason = subscription_deleted
- PRO -> BUSINESS or BUSINESS -> PRO creates reason = subscription_updated

No customer email needs to be typed into this file.
No manual log insert is needed after this is installed.


CREATE OR REPLACE FUNCTION qrmaster_log_plan_change()
RETURNS trigger AS $$
DECLARE
  next_stage TEXT;
  log_reason TEXT;
BEGIN
  IF NEW."plan" IS NOT DISTINCT FROM OLD."plan" THEN
    RETURN NEW;
  END IF;

  IF NEW."plan"::TEXT IN ('PRO', 'BUSINESS') THEN
    next_stage := 'paid';
  ELSIF COALESCE(NEW."leadScore", 0) >= 70 THEN
    next_stage := 'upgrade_candidate';
  ELSIF COALESCE(NEW."leadScore", 0) >= 55 THEN
    next_stage := 'hot';
  ELSIF COALESCE(NEW."leadScore", 0) >= 30 THEN
    next_stage := 'warm';
  ELSIF NEW."activationAt" IS NOT NULL THEN
    next_stage := 'activated';
  ELSE
    next_stage := 'cold';
  END IF;

  IF OLD."plan"::TEXT = 'FREE' AND NEW."plan"::TEXT IN ('PRO', 'BUSINESS') THEN
    log_reason := 'subscription_created';
  ELSIF OLD."plan"::TEXT IN ('PRO', 'BUSINESS') AND NEW."plan"::TEXT = 'FREE' THEN
    log_reason := 'subscription_deleted';
  ELSE
    log_reason := 'subscription_updated';
  END IF;

  NEW."lifecycleStage" := next_stage;
  NEW."lastScoredAt" := NOW();

  IF next_stage IN ('paid', 'hot', 'upgrade_candidate') THEN
    NEW."lastQualifiedAt" := NOW();
  END IF;

  INSERT INTO "UserLifecycleLog" (
    "id",
    "userId",
    "fromStage",
    "toStage",
    "fitScore",
    "intentScore",
    "leadScore",
    "reason",
    "createdAt"
  )
  VALUES (
    CONCAT('planlog_', MD5(NEW."id" || clock_timestamp()::TEXT || random()::TEXT)),
    NEW."id",
    OLD."lifecycleStage",
    next_stage,
    COALESCE(NEW."fitScore", 0),
    COALESCE(NEW."intentScore", 0),
    COALESCE(NEW."leadScore", 0),
    log_reason,
    NOW()
  );

  RETURN NEW;
END;
$$ LANGUAGE plpgsql;


DROP TRIGGER IF EXISTS qrmaster_user_plan_change_alarm ON "User";

CREATE TRIGGER qrmaster_user_plan_change_alarm
BEFORE UPDATE OF "plan" ON "User"
FOR EACH ROW
EXECUTE FUNCTION qrmaster_log_plan_change();