{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://basicstack.de/schemas/ds/per_diem/v1.0.0.json",
  "title": "DataSource Response: ds:per-diem-rates /rates v1.0.0",
  "description": "Rückgabe-Schema für den Lesezugriff auf versionierte Verpflegungsmehraufwands-Pauschalen (z.B. BMF-Sätze für Deutschland, analog für andere Länder). Query-Filter kombinieren country (Pflicht), optional city und valid_on (Pflicht); Rückgabe listet alle am Stichtag gültigen passenden Rates (meistens eine, bei großen Städten mit abweichenden Sätzen gelegentlich mehrere).",
  "type": "object",
  "additionalProperties": false,
  "required": ["schema", "data_source", "resource", "filters", "rates", "returned_at"],
  "properties": {
    "schema": {
      "type": "object",
      "additionalProperties": false,
      "required": ["name", "version"],
      "properties": {
        "name":    { "const": "ds.per_diem.rate" },
        "version": { "const": "1.0.0" }
      }
    },
    "data_source": { "const": "ds:per-diem-rates" },
    "resource":    { "const": "rates" },
    "filters": {
      "type": "object",
      "additionalProperties": false,
      "required": ["country", "valid_on"],
      "properties": {
        "country":  { "type": "string", "pattern": "^[A-Z]{2}$", "description": "ISO 3166-1 alpha-2." },
        "city":     { "type": "string", "minLength": 1, "maxLength": 100 },
        "valid_on": { "type": "string", "format": "date" }
      }
    },
    "returned_at": { "type": "string", "format": "date-time" },
    "rates": {
      "type": "array",
      "minItems": 1,
      "maxItems": 50,
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": [
          "rate_id",
          "country",
          "currency",
          "full_day",
          "partial_day_min8h",
          "arrival_day",
          "departure_day",
          "valid_from",
          "source_regulation"
        ],
        "properties": {
          "rate_id":  { "type": "string", "pattern": "^PDR-[0-9]+$" },
          "country":  { "type": "string", "pattern": "^[A-Z]{2}$" },
          "city":     { "type": ["string", "null"], "maxLength": 100 },
          "currency": { "type": "string", "pattern": "^[A-Z]{3}$" },
          "full_day": {
            "type": "string",
            "pattern": "^[0-9]+\\.[0-9]{2}$",
            "description": "Pauschale für vollen Reisetag (24h Abwesenheit)."
          },
          "partial_day_min8h": {
            "type": "string",
            "pattern": "^[0-9]+\\.[0-9]{2}$",
            "description": "Pauschale bei >8h bis <24h Abwesenheit (sofern anwendbar)."
          },
          "arrival_day": {
            "type": "string",
            "pattern": "^[0-9]+\\.[0-9]{2}$",
            "description": "Pauschale Anreisetag (unabhängig von der Abwesenheitsdauer)."
          },
          "departure_day": {
            "type": "string",
            "pattern": "^[0-9]+\\.[0-9]{2}$",
            "description": "Pauschale Abreisetag (unabhängig von der Abwesenheitsdauer)."
          },
          "valid_from": { "type": "string", "format": "date" },
          "valid_to":   { "type": ["string", "null"], "format": "date" },
          "source_regulation": {
            "type": "string",
            "minLength": 1,
            "maxLength": 500,
            "description": "Freitext-Zitierung der Rechtsquelle, z.B. 'BMF-Schreiben 2026-11-15 Az. IV C 5 - S 2353/19/10011 :005'."
          }
        }
      }
    }
  }
}