{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://schemas.driftframe.org/site-reading-governance/v2.0/data-contract.schema.json",
  "title": "Database Data Contract",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "data_contract_id",
    "version",
    "contract_digest",
    "title",
    "purpose",
    "status",
    "database",
    "entities",
    "compatibility",
    "invalidation_triggers",
    "metadata"
  ],
  "properties": {
    "data_contract_id": {
      "$ref": "common.schema.json#/$defs/identifier"
    },
    "version": {
      "$ref": "common.schema.json#/$defs/semver"
    },
    "contract_digest": {
      "$ref": "common.schema.json#/$defs/digest"
    },
    "title": {
      "type": "string",
      "minLength": 5,
      "maxLength": 200
    },
    "purpose": {
      "type": "string",
      "minLength": 20,
      "maxLength": 1200
    },
    "status": {
      "type": "string",
      "enum": [
        "draft",
        "approved",
        "superseded"
      ]
    },
    "database": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "engine_family",
        "engine_version",
        "extensions",
        "collation",
        "database_timezone",
        "settings_digest",
        "migration_history_table"
      ],
      "properties": {
        "engine_family": {
          "type": "string",
          "enum": [
            "postgresql",
            "mysql",
            "mariadb",
            "oracle",
            "sqlserver",
            "sqlite",
            "other"
          ]
        },
        "engine_version": {
          "type": "string",
          "minLength": 1,
          "maxLength": 80
        },
        "extensions": {
          "type": "array",
          "uniqueItems": true,
          "items": {
            "type": "object",
            "additionalProperties": false,
            "required": [
              "name",
              "version"
            ],
            "properties": {
              "name": {
                "type": "string",
                "pattern": "^[A-Za-z0-9][A-Za-z0-9_.-]*$",
                "maxLength": 120
              },
              "version": {
                "type": "string",
                "minLength": 1,
                "maxLength": 80
              }
            }
          }
        },
        "collation": {
          "type": "string",
          "minLength": 1,
          "maxLength": 120
        },
        "database_timezone": {
          "type": "string",
          "minLength": 1,
          "maxLength": 80
        },
        "settings_digest": {
          "$ref": "common.schema.json#/$defs/digest"
        },
        "migration_history_table": {
          "type": "string",
          "pattern": "^[a-z][a-z0-9_]*(?:\\.[a-z][a-z0-9_]*)?$",
          "maxLength": 120
        }
      }
    },
    "entities": {
      "type": "array",
      "minItems": 1,
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": [
          "entity_id",
          "table_name",
          "purpose",
          "data_class",
          "retention_class",
          "fields",
          "primary_key_field_ids",
          "constraints"
        ],
        "properties": {
          "entity_id": {
            "$ref": "common.schema.json#/$defs/identifier"
          },
          "table_name": {
            "type": "string",
            "pattern": "^[a-z][a-z0-9_]*$",
            "maxLength": 120
          },
          "purpose": {
            "type": "string",
            "minLength": 10,
            "maxLength": 700
          },
          "data_class": {
            "type": "string",
            "enum": [
              "synthetic",
              "public",
              "internal",
              "confidential",
              "regulated"
            ]
          },
          "retention_class": {
            "type": "string",
            "minLength": 2,
            "maxLength": 96
          },
          "fields": {
            "type": "array",
            "minItems": 1,
            "items": {
              "type": "object",
              "additionalProperties": false,
              "required": [
                "field_id",
                "column_name",
                "semantic_type",
                "physical_type",
                "nullable",
                "source_of_truth",
                "description"
              ],
              "properties": {
                "field_id": {
                  "$ref": "common.schema.json#/$defs/identifier"
                },
                "column_name": {
                  "type": "string",
                  "pattern": "^[a-z][a-z0-9_]*$",
                  "maxLength": 120
                },
                "semantic_type": {
                  "type": "string",
                  "enum": [
                    "identifier",
                    "instant",
                    "civil_date",
                    "local_date_time",
                    "exact_decimal",
                    "integer",
                    "boolean",
                    "text",
                    "controlled_term",
                    "json_document",
                    "binary_reference"
                  ]
                },
                "physical_type": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 120
                },
                "nullable": {
                  "type": "boolean"
                },
                "source_of_truth": {
                  "type": "string",
                  "enum": [
                    "database",
                    "upstream_system",
                    "derived"
                  ]
                },
                "description": {
                  "type": "string",
                  "minLength": 10,
                  "maxLength": 700
                },
                "default_expression_digest": {
                  "$ref": "common.schema.json#/$defs/digest"
                },
                "generated_expression_digest": {
                  "$ref": "common.schema.json#/$defs/digest"
                },
                "precision": {
                  "type": "integer",
                  "minimum": 1,
                  "maximum": 1000
                },
                "scale": {
                  "type": "integer",
                  "minimum": 0,
                  "maximum": 1000
                },
                "unit": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 80
                },
                "temporal_semantics": {
                  "type": "string",
                  "enum": [
                    "absolute_instant",
                    "civil_date",
                    "civil_local_date_time"
                  ]
                },
                "controlled_vocabulary_id": {
                  "$ref": "common.schema.json#/$defs/identifier"
                }
              },
              "allOf": [
                {
                  "if": {
                    "properties": {
                      "semantic_type": {
                        "const": "exact_decimal"
                      }
                    },
                    "required": [
                      "semantic_type"
                    ]
                  },
                  "then": {
                    "required": [
                      "precision",
                      "scale",
                      "unit"
                    ]
                  }
                },
                {
                  "if": {
                    "properties": {
                      "semantic_type": {
                        "const": "instant"
                      }
                    },
                    "required": [
                      "semantic_type"
                    ]
                  },
                  "then": {
                    "required": [
                      "temporal_semantics"
                    ],
                    "properties": {
                      "temporal_semantics": {
                        "const": "absolute_instant"
                      }
                    }
                  }
                },
                {
                  "if": {
                    "properties": {
                      "semantic_type": {
                        "const": "civil_date"
                      }
                    },
                    "required": [
                      "semantic_type"
                    ]
                  },
                  "then": {
                    "required": [
                      "temporal_semantics"
                    ],
                    "properties": {
                      "temporal_semantics": {
                        "const": "civil_date"
                      }
                    }
                  }
                },
                {
                  "if": {
                    "properties": {
                      "semantic_type": {
                        "const": "controlled_term"
                      }
                    },
                    "required": [
                      "semantic_type"
                    ]
                  },
                  "then": {
                    "required": [
                      "controlled_vocabulary_id"
                    ]
                  }
                }
              ]
            }
          },
          "primary_key_field_ids": {
            "type": "array",
            "minItems": 1,
            "uniqueItems": true,
            "items": {
              "$ref": "common.schema.json#/$defs/identifier"
            }
          },
          "constraints": {
            "type": "array",
            "items": {
              "type": "object",
              "additionalProperties": false,
              "required": [
                "constraint_id",
                "constraint_type",
                "field_ids",
                "validation_state"
              ],
              "properties": {
                "constraint_id": {
                  "$ref": "common.schema.json#/$defs/identifier"
                },
                "constraint_type": {
                  "type": "string",
                  "enum": [
                    "unique",
                    "foreign_key",
                    "check"
                  ]
                },
                "field_ids": {
                  "type": "array",
                  "minItems": 1,
                  "uniqueItems": true,
                  "items": {
                    "$ref": "common.schema.json#/$defs/identifier"
                  }
                },
                "validation_state": {
                  "type": "string",
                  "enum": [
                    "declared",
                    "enforced",
                    "validated"
                  ]
                },
                "expression_digest": {
                  "$ref": "common.schema.json#/$defs/digest"
                },
                "referenced_entity_id": {
                  "$ref": "common.schema.json#/$defs/identifier"
                },
                "referenced_field_ids": {
                  "type": "array",
                  "minItems": 1,
                  "uniqueItems": true,
                  "items": {
                    "$ref": "common.schema.json#/$defs/identifier"
                  }
                }
              },
              "allOf": [
                {
                  "if": {
                    "properties": {
                      "constraint_type": {
                        "const": "foreign_key"
                      }
                    },
                    "required": [
                      "constraint_type"
                    ]
                  },
                  "then": {
                    "required": [
                      "referenced_entity_id",
                      "referenced_field_ids"
                    ]
                  }
                },
                {
                  "if": {
                    "properties": {
                      "constraint_type": {
                        "const": "check"
                      }
                    },
                    "required": [
                      "constraint_type"
                    ]
                  },
                  "then": {
                    "required": [
                      "expression_digest"
                    ]
                  }
                }
              ]
            }
          }
        }
      }
    },
    "compatibility": {
      "type": "array",
      "minItems": 1,
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": [
          "application_release",
          "minimum_schema_version",
          "maximum_schema_version",
          "verification_receipt_ids"
        ],
        "properties": {
          "application_release": {
            "type": "string",
            "minLength": 1,
            "maxLength": 120
          },
          "minimum_schema_version": {
            "$ref": "common.schema.json#/$defs/semver"
          },
          "maximum_schema_version": {
            "$ref": "common.schema.json#/$defs/semver"
          },
          "verification_receipt_ids": {
            "type": "array",
            "uniqueItems": true,
            "items": {
              "$ref": "common.schema.json#/$defs/identifier"
            }
          }
        }
      }
    },
    "invalidation_triggers": {
      "type": "array",
      "minItems": 1,
      "uniqueItems": true,
      "items": {
        "type": "string",
        "minLength": 5,
        "maxLength": 300
      }
    },
    "metadata": {
      "$ref": "common.schema.json#/$defs/recordMetadata"
    }
  }
}