{
  "type": "object",
  "required": [
    "id",
    "level",
    "domain",
    "skill",
    "rule_id",
    "difficulty",
    "type",
    "instruction",
    "tokens",
    "hint",
    "explanation",
    "review_tags",
    "review_status"
  ],
  "additionalProperties": false,
  "properties": {
    "id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
    "level": { "type": "string", "enum": ["CE1", "CE2", "CM1", "CM2"] },
    "domain": { "type": "string", "enum": ["grammaire", "orthographe"] },
    "skill": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
    "rule_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
    "difficulty": { "type": "integer", "minimum": 1, "maximum": 3 },
    "type": { "type": "string", "const": "sentence_correction" },
    "instruction": { "type": "string", "minLength": 1 },
    "tokens": {
      "type": "array",
      "minItems": 2,
      "items": {
        "type": "object",
        "required": ["text", "correct"],
        "additionalProperties": false,
        "properties": {
          "text": { "type": "string", "minLength": 1 },
          "correct": { "type": "boolean" },
          "expected": { "type": "string", "minLength": 1 },
          "rule_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" }
        }
      }
    },
    "hint": { "type": "string", "minLength": 1 },
    "explanation": { "type": "string", "minLength": 1 },
    "review_tags": { "type": "array", "items": { "type": "string" } },
    "review_status": { "type": "string", "enum": ["draft", "validated"] }
  }
}