# Limits

A limit is a constraint on the aggregated value of a subset of
holdings. Limits live under a client and can be hierarchical via
`parentLimit`. A `limit-group` limit imposes no constraint itself —
it just groups child limits. `proportional` limits express bounds as
a fraction of the parent limit's value (so they're only meaningful
when `parentLimit` is set). `absolute` limits express bounds as a
fixed amount in `ccyCode`.

## Endpoints

POST /v2/limits
  Create a new limit.

GET /v2/limits/:id
  Fetch one limit.

DELETE /v2/limits/:id
  Delete the limit. Cascades to its children.

GET /v2/limits/:id/status
  Current status of a single limit (date-parameterized).

GET /v2/clients/:id/limits
  List all limits owned by a client.

GET /v2/clients/:id/limits-status
  Current status of every limit on a client (date-parameterized).

## Path params (collection / by-id endpoints)

  id (required) — Limit identifier (UUID) on /v2/limits/:id endpoints,
                   client identifier (Mongo ObjectID) on /v2/clients/:id endpoints.

## Limit data model (`type: limit`)

  name        (string)            — Human-readable name.
  ccyCode     (string)            — ISO 4217 currency for the limit's expressed value.
  startDate   (string, ISO 8601)  — Start date.
  limitFilter (object)            — Recursive filter (and / or / condition). See below.
  limitType   (object)            — One of:
                                      { "type": "limit-group" }
                                      { "type": "proportional", "values": { "min": <0..1>?, "max": <0..1>? } }
                                      { "type": "absolute",     "values": { "min": <number>?, "max": <number>? } }

## limitFilter shapes

  Logical:
    { "type": "and", "filters": [ <filter>, ... ] }
    { "type": "or",  "filters": [ <filter>, ... ] }
  Condition:
    { "type": "condition", "condition": <condition> }

## Condition types

Each condition has `type` plus a value field whose name depends on type.

  country-code-is / country-code-is-not                     → country-code (ISO 3166-1 alpha-2)
  instrument-class-is / instrument-class-is-not             → instrument-class-id
  detailed-instrument-class-is / detailed-instrument-class-is-not → detailed-instrument-class-id
  currency-code-is / currency-code-is-not                   → currency-code (ISO 4217)
  security-identifier-is / security-identifier-is-not       → security-identifier
  reporting-entity-is / reporting-entity-is-not             → reporting-entity-id
  reporting-portfolio-is / reporting-portfolio-is-not       → reporting-portfolio-id

## Relationships

  client       — Owning client.
  parentLimit  — Optional parent limit (forms a tree).