{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://schemas.driftframe.org/site-reading-governance/v2.0/database-migration-plan.schema.json",
  "title": "Database Migration Plan",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "migration_plan_id",
    "version",
    "data_contract_id",
    "purpose",
    "source_schema_digest",
    "target_schema_digest",
    "engine_compatibility",
    "tool_binding",
    "script",
    "dependency_migration_ids",
    "phase_sequence",
    "execution_policy",
    "compatibility_window",
    "destructive_change",
    "approval_ids",
    "recovery",
    "verification_criteria",
    "evidence_mode",
    "assurance_stage",
    "metadata"
  ],
  "properties": {
    "migration_plan_id": {
      "$ref": "common.schema.json#/$defs/identifier"
    },
    "version": {
      "$ref": "common.schema.json#/$defs/semver"
    },
    "data_contract_id": {
      "$ref": "common.schema.json#/$defs/identifier"
    },
    "purpose": {
      "type": "string",
      "minLength": 20,
      "maxLength": 1200
    },
    "source_schema_digest": {
      "$ref": "common.schema.json#/$defs/digest"
    },
    "target_schema_digest": {
      "$ref": "common.schema.json#/$defs/digest"
    },
    "engine_compatibility": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "engine_family",
        "minimum_version",
        "maximum_version",
        "required_extensions"
      ],
      "properties": {
        "engine_family": {
          "type": "string",
          "enum": [
            "postgresql",
            "mysql",
            "mariadb",
            "oracle",
            "sqlserver",
            "sqlite",
            "other"
          ]
        },
        "minimum_version": {
          "type": "string",
          "minLength": 1,
          "maxLength": 80
        },
        "maximum_version": {
          "type": "string",
          "minLength": 1,
          "maxLength": 80
        },
        "required_extensions": {
          "type": "array",
          "uniqueItems": true,
          "items": {
            "type": "string",
            "pattern": "^[A-Za-z0-9][A-Za-z0-9_.-]*$",
            "maxLength": 120
          }
        }
      }
    },
    "tool_binding": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "tool_name",
        "tool_version",
        "implementation_digest"
      ],
      "properties": {
        "tool_name": {
          "type": "string",
          "minLength": 1,
          "maxLength": 120
        },
        "tool_version": {
          "type": "string",
          "minLength": 1,
          "maxLength": 80
        },
        "implementation_digest": {
          "$ref": "common.schema.json#/$defs/digest"
        }
      }
    },
    "script": {
      "$ref": "common.schema.json#/$defs/artifact"
    },
    "dependency_migration_ids": {
      "type": "array",
      "uniqueItems": true,
      "items": {
        "$ref": "common.schema.json#/$defs/identifier"
      }
    },
    "phase_sequence": {
      "type": "array",
      "minItems": 1,
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": [
          "phase_id",
          "phase_type",
          "sequence",
          "purpose",
          "dependency_phase_ids",
          "transaction_mode",
          "online_mode",
          "lock_budget_milliseconds",
          "statement_budget_milliseconds",
          "checkpoint_strategy",
          "preconditions",
          "success_criteria"
        ],
        "properties": {
          "phase_id": {
            "$ref": "common.schema.json#/$defs/identifier"
          },
          "phase_type": {
            "type": "string",
            "enum": [
              "expand",
              "backfill",
              "validate",
              "cutover",
              "contract"
            ]
          },
          "sequence": {
            "type": "integer",
            "minimum": 1
          },
          "purpose": {
            "type": "string",
            "minLength": 10,
            "maxLength": 700
          },
          "dependency_phase_ids": {
            "type": "array",
            "uniqueItems": true,
            "items": {
              "$ref": "common.schema.json#/$defs/identifier"
            }
          },
          "transaction_mode": {
            "type": "string",
            "enum": [
              "single_transaction",
              "transaction_per_batch",
              "autocommit_required"
            ]
          },
          "online_mode": {
            "type": "string",
            "enum": [
              "fully_online",
              "bounded_write_pause",
              "maintenance_window"
            ]
          },
          "lock_budget_milliseconds": {
            "type": "integer",
            "minimum": 1,
            "maximum": 3600000
          },
          "statement_budget_milliseconds": {
            "type": "integer",
            "minimum": 1,
            "maximum": 86400000
          },
          "checkpoint_strategy": {
            "type": "string",
            "enum": [
              "atomic_completion",
              "durable_batch_checkpoint",
              "concurrent_build_status",
              "constraint_validation_status",
              "routing_marker"
            ]
          },
          "batch_size": {
            "type": "integer",
            "minimum": 1,
            "maximum": 1000000
          },
          "preconditions": {
            "type": "array",
            "minItems": 1,
            "items": {
              "type": "string",
              "minLength": 5,
              "maxLength": 500
            }
          },
          "success_criteria": {
            "type": "array",
            "minItems": 1,
            "items": {
              "type": "string",
              "minLength": 5,
              "maxLength": 500
            }
          }
        },
        "allOf": [
          {
            "if": {
              "properties": {
                "phase_type": {
                  "const": "backfill"
                }
              },
              "required": [
                "phase_type"
              ]
            },
            "then": {
              "required": [
                "batch_size"
              ],
              "properties": {
                "transaction_mode": {
                  "const": "transaction_per_batch"
                },
                "checkpoint_strategy": {
                  "const": "durable_batch_checkpoint"
                }
              }
            }
          }
        ]
      }
    },
    "execution_policy": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "migration_concurrency",
        "writer_coordination",
        "migrator_role",
        "application_role",
        "schema_drift_check",
        "applied_checksum_policy"
      ],
      "properties": {
        "migration_concurrency": {
          "type": "string",
          "const": "single_migration_writer"
        },
        "writer_coordination": {
          "type": "object",
          "additionalProperties": false,
          "required": [
            "owner",
            "strategy",
            "evidence"
          ],
          "properties": {
            "owner": {
              "type": "string",
              "enum": [
                "migration_tool",
                "deployment_orchestrator",
                "database_platform"
              ]
            },
            "strategy": {
              "type": "string",
              "minLength": 10,
              "maxLength": 500
            },
            "evidence": {
              "type": "string",
              "minLength": 10,
              "maxLength": 700
            }
          }
        },
        "migrator_role": {
          "type": "string",
          "minLength": 2,
          "maxLength": 120
        },
        "application_role": {
          "type": "string",
          "minLength": 2,
          "maxLength": 120
        },
        "schema_drift_check": {
          "type": "string",
          "minLength": 10,
          "maxLength": 700
        },
        "applied_checksum_policy": {
          "type": "string",
          "const": "immutable_after_application"
        }
      }
    },
    "compatibility_window": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "supported_application_releases",
        "minimum_observation_seconds",
        "contract_phase_entry_criteria"
      ],
      "properties": {
        "supported_application_releases": {
          "type": "array",
          "minItems": 1,
          "uniqueItems": true,
          "items": {
            "type": "string",
            "minLength": 1,
            "maxLength": 120
          }
        },
        "minimum_observation_seconds": {
          "type": "integer",
          "minimum": 0,
          "maximum": 31536000
        },
        "contract_phase_entry_criteria": {
          "type": "array",
          "minItems": 1,
          "items": {
            "type": "string",
            "minLength": 10,
            "maxLength": 700
          }
        }
      }
    },
    "destructive_change": {
      "type": "boolean"
    },
    "approval_ids": {
      "type": "array",
      "uniqueItems": true,
      "items": {
        "$ref": "common.schema.json#/$defs/identifier"
      }
    },
    "recovery": {
      "type": "object",
      "additionalProperties": false,
      "required": [
        "strategy",
        "rollback_boundary_phase_id",
        "backup_receipt_required",
        "point_in_time_recovery_required",
        "owner_role",
        "containment",
        "replacement_behavior",
        "verification"
      ],
      "properties": {
        "strategy": {
          "type": "string",
          "enum": [
            "roll_forward_preferred",
            "rollback_supported",
            "restore_checkpoint"
          ]
        },
        "rollback_boundary_phase_id": {
          "$ref": "common.schema.json#/$defs/identifier"
        },
        "backup_receipt_required": {
          "type": "boolean"
        },
        "point_in_time_recovery_required": {
          "type": "boolean"
        },
        "owner_role": {
          "type": "string",
          "minLength": 2,
          "maxLength": 120
        },
        "containment": {
          "type": "string",
          "minLength": 10,
          "maxLength": 700
        },
        "replacement_behavior": {
          "type": "string",
          "minLength": 10,
          "maxLength": 700
        },
        "verification": {
          "type": "string",
          "minLength": 10,
          "maxLength": 700
        }
      }
    },
    "verification_criteria": {
      "type": "array",
      "minItems": 1,
      "uniqueItems": true,
      "items": {
        "$ref": "common.schema.json#/$defs/identifier"
      }
    },
    "evidence_mode": {
      "$ref": "common.schema.json#/$defs/evidenceMode"
    },
    "assurance_stage": {
      "$ref": "common.schema.json#/$defs/assuranceStage"
    },
    "metadata": {
      "$ref": "common.schema.json#/$defs/recordMetadata"
    }
  },
  "allOf": [
    {
      "if": {
        "properties": {
          "destructive_change": {
            "const": true
          }
        },
        "required": [
          "destructive_change"
        ]
      },
      "then": {
        "properties": {
          "approval_ids": {
            "minItems": 1
          },
          "compatibility_window": {
            "type": "object",
            "properties": {
              "minimum_observation_seconds": {
                "minimum": 1
              }
            }
          }
        }
      }
    }
  ]
}