{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "doc_id": {"type": "string", "pattern": "^sha256:[0-9a-f]{12}$"},
    "receipt_mode": {"type": "string", "enum": ["text", "image-transcription"]},
    "doc_type": {
      "type": "string",
      "enum": ["agreement", "amendment", "sow", "schedule", "exhibit", "guaranty", "other"]
    },
    "title": {"type": ["string", "null"], "minLength": 1},
    "parties": {
      "type": "array",
      "uniqueItems": true,
      "items": {"type": "string", "minLength": 1}
    },
    "dated": {"type": ["string", "null"], "format": "date"},
    "references": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "kind": {
            "type": "string",
            "enum": ["parent-agreement", "amendment", "sow", "schedule", "exhibit", "guaranty", "other"]
          },
          "text": {"type": "string", "minLength": 1},
          "quote": {"type": "string", "minLength": 1},
          "page": {"type": ["integer", "null"], "minimum": 1},
          "gap_eligible": {"type": "boolean"}
        },
        "required": ["kind", "text", "quote", "page", "gap_eligible"],
        "additionalProperties": false
      }
    },
    "evidence": {
      "type": "object",
      "properties": {
        "doc_type": {"$ref": "#/$defs/evidenceOrNull"},
        "title": {"$ref": "#/$defs/evidenceOrNull"},
        "dated": {"$ref": "#/$defs/evidenceOrNull"},
        "parties": {
          "type": "array",
          "items": {
            "type": "object",
            "properties": {
              "value": {"type": "string", "minLength": 1},
              "quote": {"type": "string", "minLength": 1},
              "page": {"type": ["integer", "null"], "minimum": 1}
            },
            "required": ["value", "quote", "page"],
            "additionalProperties": false
          }
        }
      },
      "required": ["doc_type", "title", "dated", "parties"],
      "additionalProperties": false
    }
  },
  "required": [
    "doc_id", "receipt_mode", "doc_type", "title", "parties", "dated",
    "references", "evidence"
  ],
  "additionalProperties": false,
  "$defs": {
    "evidenceOrNull": {
      "anyOf": [
        {
          "type": "object",
          "properties": {
            "quote": {"type": "string", "minLength": 1},
            "page": {"type": ["integer", "null"], "minimum": 1}
          },
          "required": ["quote", "page"],
          "additionalProperties": false
        },
        {"type": "null"}
      ]
    }
  }
}