{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://basicstack.de/schemas/expense/canonical/v1.2.0.json",
  "title": "Expense (canonical) v1.2.0",
  "description": "Additive gegenüber v1.1.0: (1) pro Item optional receipt_content_hash + receipt_attestation_ref, damit die Belegbindung in die Signatur-Kette eingeht. (2) Neue Item-Typen PER_DIEM_FULL, PER_DIEM_PARTIAL, PER_DIEM_ARRIVAL, PER_DIEM_DEPARTURE für vom per-diem-calculator erzeugte Pauschalen. (3) Pro Item optional computed_from — Rückbindung an die Transform- und Query-Attestationen, aus denen das Item deterministisch gerechnet wurde.",
  "type": "object",
  "additionalProperties": false,
  "required": ["schema", "workflow_id", "employee_id", "trip", "currency", "total_amount", "expense_items"],
  "properties": {
    "schema": {
      "type": "object",
      "additionalProperties": false,
      "required": ["name", "version"],
      "properties": {
        "name":    { "const": "expense.canonical" },
        "version": { "const": "1.2.0" }
      }
    },
    "workflow_id": { "type": "string", "pattern": "^WF-[0-9]{4}-[0-9]{4,}$" },
    "employee_id": { "type": "string", "pattern": "^EMP-[0-9]+$" },
    "trip": {
      "type": "object",
      "additionalProperties": false,
      "required": ["start_date", "end_date", "destination"],
      "properties": {
        "start_date":  { "type": "string", "format": "date" },
        "end_date":    { "type": "string", "format": "date" },
        "destination": { "type": "string", "minLength": 1, "maxLength": 200 },
        "purpose":     { "type": "string", "maxLength": 500 },
        "countries_visited": {
          "type": "array",
          "minItems": 1,
          "maxItems": 20,
          "items": {
            "type": "object",
            "additionalProperties": false,
            "required": ["country", "from_date", "to_date"],
            "properties": {
              "country":   { "type": "string", "pattern": "^[A-Z]{2}$" },
              "city":      { "type": ["string","null"], "maxLength": 100 },
              "from_date": { "type": "string", "format": "date" },
              "to_date":   { "type": "string", "format": "date" }
            }
          }
        }
      }
    },
    "currency": { "type": "string", "pattern": "^[A-Z]{3}$" },
    "total_amount": { "type": "string", "pattern": "^-?[0-9]+\\.[0-9]{2}$" },
    "project_assignment": {
      "type": "object",
      "additionalProperties": false,
      "required": ["project_code", "cost_center", "source_attestation_ref"],
      "properties": {
        "project_code": { "type": "string", "pattern": "^P-[0-9]+$" },
        "cost_center":  { "type": "string", "pattern": "^CC-[0-9]+$" },
        "source_attestation_ref": { "type": "string", "pattern": "^sha256:[0-9a-f]{64}$" }
      }
    },
    "expense_items": {
      "type": "array",
      "minItems": 1,
      "maxItems": 200,
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": ["type", "amount", "incurred_on"],
        "properties": {
          "type": {
            "type": "string",
            "enum": [
              "HOTEL", "MEALS", "TRANSPORT_FLIGHT", "TRANSPORT_RAIL", "TRANSPORT_CAR",
              "PARKING", "COMMUNICATION", "CONFERENCE_FEE", "OTHER",
              "PER_DIEM_FULL", "PER_DIEM_PARTIAL", "PER_DIEM_ARRIVAL", "PER_DIEM_DEPARTURE"
            ]
          },
          "amount":      { "type": "string", "pattern": "^-?[0-9]+\\.[0-9]{2}$" },
          "incurred_on": { "type": "string", "format": "date" },
          "description": { "type": "string", "maxLength": 500 },
          "receipt_ref": { "type": "string", "pattern": "^pii://[A-Za-z0-9/._-]+$" },
          "receipt_content_hash": {
            "type": "string",
            "pattern": "^sha256:[0-9a-f]{64}$",
            "description": "SHA-256 des hochgeladenen Belegs. Wird vom Receipt-Adapter beim Upload geliefert und ins Item eingetragen; vom Approval mit-signiert."
          },
          "receipt_attestation_ref": {
            "type": "string",
            "pattern": "^sha256:[0-9a-f]{64}$",
            "description": "SHA-256 der Receipt Attestation (ingest). Verification kann so prüfen, dass genau dieser Beleg vorlag."
          },
          "computed_from": {
            "type": "object",
            "additionalProperties": false,
            "required": ["transform_attestation_ref"],
            "description": "Nur gesetzt für deterministisch berechnete Items (z.B. PER_DIEM_*). Bindet an die Transform-Attestation, die dieses Item erzeugt hat, und optional an die Rate-Query-Attestation.",
            "properties": {
              "transform_attestation_ref": { "type": "string", "pattern": "^sha256:[0-9a-f]{64}$" },
              "rate_query_attestation_ref": { "type": "string", "pattern": "^sha256:[0-9a-f]{64}$" },
              "rate_id": { "type": "string", "pattern": "^PDR-[0-9]+$" }
            }
          },
          "allocations": {
            "type": "array",
            "minItems": 1,
            "maxItems": 50,
            "items": {
              "type": "object",
              "additionalProperties": false,
              "required": ["project_code", "cost_center", "mode", "source_attestation_ref"],
              "properties": {
                "project_code": { "type": "string", "pattern": "^P-[0-9]+$" },
                "cost_center":  { "type": "string", "pattern": "^CC-[0-9]+$" },
                "mode":         { "enum": ["percentage", "absolute"] },
                "percentage":   { "type": "string", "pattern": "^(100\\.00|[0-9]{1,2}\\.[0-9]{2})$" },
                "amount":       { "type": "string", "pattern": "^-?[0-9]+\\.[0-9]{2}$" },
                "source_attestation_ref": { "type": "string", "pattern": "^sha256:[0-9a-f]{64}$" }
              },
              "allOf": [
                {
                  "if": { "properties": { "mode": { "const": "percentage" } }, "required": ["mode"] },
                  "then": { "required": ["percentage"], "not": { "required": ["amount"] } }
                },
                {
                  "if": { "properties": { "mode": { "const": "absolute" } }, "required": ["mode"] },
                  "then": { "required": ["amount"], "not": { "required": ["percentage"] } }
                }
              ]
            }
          }
        },
        "allOf": [
          {
            "if": {
              "properties": {
                "type": {
                  "enum": ["PER_DIEM_FULL", "PER_DIEM_PARTIAL", "PER_DIEM_ARRIVAL", "PER_DIEM_DEPARTURE"]
                }
              },
              "required": ["type"]
            },
            "then": { "required": ["computed_from"] }
          }
        ]
      }
    }
  }
}