CREATE TABLE IF NOT EXISTS task_input_attachments (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  organization_id uuid NOT NULL REFERENCES organizations(id) ON DELETE CASCADE,
  task_id uuid NOT NULL REFERENCES tasks(id) ON DELETE CASCADE,
  purpose text NOT NULL DEFAULT 'passenger_list'
    CHECK (purpose = 'passenger_list'),
  source text NOT NULL
    CHECK (source IN ('manual', 'agentbus')),
  file_name_ciphertext text NOT NULL,
  content_type text NOT NULL,
  byte_size integer NOT NULL CHECK (byte_size > 0),
  sha256 text NOT NULL CHECK (sha256 ~ '^[a-f0-9]{64}$'),
  status text NOT NULL
    CHECK (status IN ('normalized', 'rejected', 'superseded')),
  normalizer_version text,
  normalized_text_ciphertext text,
  row_count integer CHECK (row_count IS NULL OR row_count > 0),
  error_code text,
  error_details jsonb NOT NULL DEFAULT '{}'::jsonb,
  created_at timestamptz NOT NULL DEFAULT now(),
  updated_at timestamptz NOT NULL DEFAULT now(),
  CONSTRAINT task_input_attachments_normalized_check CHECK (
    (status = 'normalized' AND normalizer_version IS NOT NULL
      AND normalized_text_ciphertext IS NOT NULL AND row_count IS NOT NULL
      AND error_code IS NULL)
    OR
    (status = 'rejected' AND normalized_text_ciphertext IS NULL
      AND row_count IS NULL AND error_code IS NOT NULL)
    OR
    status = 'superseded'
  ),
  UNIQUE (task_id, purpose, sha256)
);

CREATE UNIQUE INDEX IF NOT EXISTS task_input_attachments_current_idx
  ON task_input_attachments (task_id, purpose)
  WHERE status = 'normalized';

CREATE INDEX IF NOT EXISTS task_input_attachments_task_idx
  ON task_input_attachments (organization_id, task_id, created_at DESC);

CREATE INDEX IF NOT EXISTS tasks_awaiting_attachment_idx
  ON tasks (organization_id, updated_at)
  WHERE status = 'awaiting_attachment';