# frozen_string_literal: true

class UpdateVulnerabilityReadsTriggerFunctions < Gitlab::Database::Migration[2.0]
  AGENT_ID_VALUE = "NEW.location->'kubernetes_resource'->>'agent_id'"
  CASTED_AGENT_ID_VALUE = "CAST(#{AGENT_ID_VALUE} AS bigint)"

  def up
    update_insert_or_update_vulnerability_reads_function(with_casted_cluster_agent_id: true)
    update_update_location_from_vulnerability_occurrences_function(with_casted_cluster_agent_id: true)
  end

  def down
    update_insert_or_update_vulnerability_reads_function(with_casted_cluster_agent_id: false)
    update_update_location_from_vulnerability_occurrences_function(with_casted_cluster_agent_id: false)
  end

  private

  def update_insert_or_update_vulnerability_reads_function(with_casted_cluster_agent_id: false)
    insert_fields = with_casted_cluster_agent_id ? 'cluster_agent_id, casted_cluster_agent_id' : 'cluster_agent_id'
    insert_values = with_casted_cluster_agent_id ? [AGENT_ID_VALUE, CASTED_AGENT_ID_VALUE].join(', ') : AGENT_ID_VALUE

    execute(<<~SQL)
      CREATE OR REPLACE FUNCTION insert_or_update_vulnerability_reads()
      RETURNS TRIGGER
      LANGUAGE plpgsql
      AS $$
      DECLARE
        severity smallint;
        state smallint;
        report_type smallint;
        resolved_on_default_branch boolean;
      BEGIN
        IF (NEW.vulnerability_id IS NULL AND (TG_OP = 'INSERT' OR TG_OP = 'UPDATE')) THEN
          RETURN NULL;
        END IF;

        IF (TG_OP = 'UPDATE' AND OLD.vulnerability_id IS NOT NULL AND NEW.vulnerability_id IS NOT NULL) THEN
          RETURN NULL;
        END IF;

        SELECT
          vulnerabilities.severity, vulnerabilities.state, vulnerabilities.report_type, vulnerabilities.resolved_on_default_branch
        INTO
          severity, state, report_type, resolved_on_default_branch
        FROM
           vulnerabilities
        WHERE
          vulnerabilities.id = NEW.vulnerability_id;

        INSERT INTO vulnerability_reads (vulnerability_id, project_id, scanner_id, report_type, severity, state, resolved_on_default_branch, uuid, location_image, #{insert_fields})
          VALUES (NEW.vulnerability_id, NEW.project_id, NEW.scanner_id, report_type, severity, state, resolved_on_default_branch, NEW.uuid::uuid, NEW.location->>'image', #{insert_values})
          ON CONFLICT(vulnerability_id) DO NOTHING;
        RETURN NULL;
      END
      $$;
    SQL
  end

  def update_update_location_from_vulnerability_occurrences_function(with_casted_cluster_agent_id: false)
    execute(<<~SQL)
      CREATE OR REPLACE FUNCTION update_location_from_vulnerability_occurrences()
      RETURNS trigger
      LANGUAGE plpgsql
      AS $$
      BEGIN
      UPDATE
        vulnerability_reads
      SET
        location_image = NEW.location->>'image',
        #{with_casted_cluster_agent_id ? "casted_cluster_agent_id = #{CASTED_AGENT_ID_VALUE}," : ''}
        cluster_agent_id = #{AGENT_ID_VALUE}
      WHERE
        vulnerability_id = NEW.vulnerability_id;
      RETURN NULL;

      END
      $$;
    SQL
  end
end