{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://yovision.local/contracts/event-v0.1.schema.json",
  "title": "YoVision Event Instance v0.1",
  "description": "推理侧 → 平台侧的唯一契约。冻结于 2026-08-03。所有顶层键必须存在（可为 null），不允许省略——省略与显式 null 无法区分，是这类系统最常见的排查陷阱。",
  "type": "object",
  "additionalProperties": false,

  "required": [
    "schema_version",
    "id",
    "source_event_id",
    "tenant_id",
    "site_id",
    "device_id",
    "sensors",
    "kind",
    "severity",
    "confidence",
    "occurred_at",
    "detected_at",
    "latency_seconds",
    "config_version",
    "rule",
    "subject",
    "observation",
    "evidence",
    "dedup_key",
    "aggregated_into",
    "outcome",
    "outcome_source",
    "outcome_reason",
    "diagnostics",
    "ext"
  ],

  "properties": {
    "schema_version": {
      "description": "契约版本。破坏性变更必须递增主版本。",
      "const": "0.1"
    },

    "id": {
      "description": "平台侧生成的全局唯一事件 ID（ULID）。推理侧不得自行生成。",
      "type": "string",
      "pattern": "^evt_[0-9A-HJKMNP-TV-Z]{26}$"
    },

    "source_event_id": {
      "description": "推理侧原始事件 ID，如 silver_pose 的 FALL-<session>-000001。用于回溯本地截图文件名（截图即按它命名）。会话内唯一，全局不保证唯一——不得用作主键。",
      "type": "string",
      "pattern": "^[A-Za-z0-9_-]{1,128}$"
    },

    "tenant_id": { "type": "integer", "minimum": 1 },
    "site_id": { "type": "integer", "minimum": 1 },
    "device_id": {
      "description": "主传感器的平台设备实体主键。由推理侧的 source_id 经平台映射表解析得到。事件中不得冗余 RTSP 地址或任何凭据。多传感器融合事件的完整来源见 sensors。",
      "type": "integer",
      "minimum": 1
    },

    "sensors": {
      "description": "参与本次判定的全部传感器。单摄像头事件为单元素数组。恰好一个元素的 role 为 primary，且其 device_id 必须等于顶层 device_id。",
      "type": "array",
      "minItems": 1,
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": ["device_id", "modality", "role"],
        "properties": {
          "device_id": { "type": "integer", "minimum": 1 },
          "modality": {
            "description": "设备模态。决定隐私区域准入：privacy_flag 为真的区域只允许非成像模态。",
            "type": "string",
            "enum": ["video", "radar", "contact", "button", "wearable", "other"]
          },
          "role": {
            "description": "primary=判定主依据；corroborating=佐证（如雷达判跌倒、门磁佐证无人离开）。",
            "type": "string",
            "enum": ["primary", "corroborating"]
          }
        }
      }
    },

    "kind": {
      "description": "事件类型。取值登记在 contracts/README.md 的类型注册表中，新增类型不需要升 schema 版本。v0.1 已登记：fall。",
      "type": "string",
      "pattern": "^[a-z][a-z0-9_]{2,63}$"
    },

    "severity": {
      "type": "string",
      "enum": ["low", "medium", "high", "critical"]
    },

    "confidence": {
      "description": "模型置信度。几何+状态机判定链路没有天然来源，必须填 null——不得用任意常量或阈值余量伪造。",
      "type": ["number", "null"],
      "minimum": 0,
      "maximum": 1
    },

    "occurred_at": {
      "description": "事发时刻（墙钟 UTC）。决定证据回捞窗口。推理侧若只有单调时钟，按 detected_at - latency_seconds 换算。",
      "type": "string",
      "format": "date-time"
    },

    "detected_at": {
      "description": "判定成立时刻（墙钟 UTC）。决定 SLA 计算。必须 >= occurred_at。",
      "type": "string",
      "format": "date-time"
    },

    "latency_seconds": {
      "description": "从可疑到确认的耗时。可由两时间戳相减，但显式存储：它是判定质量的直接指标——贴近确认窗口下限说明证据干脆，贴近上限是误报高发区，为误报排查的首选排序键。",
      "type": "number",
      "minimum": 0
    },

    "config_version": {
      "description": "产出本事件时整套判定配置的版本。粒度高于 rule.version（阈值往往是全局的），用于调参后的回归对比。不得为空串。",
      "type": "string",
      "minLength": 1,
      "maxLength": 128
    },

    "rule": {
      "description": "命中的规则实体。推理侧无规则引擎时为 null，由平台侧按 kind 反查补全。",
      "type": ["object", "null"],
      "additionalProperties": false,
      "required": ["id", "version", "code"],
      "properties": {
        "id": { "type": "string" },
        "version": { "type": "integer", "minimum": 1 },
        "code": { "type": "string" }
      }
    },

    "subject": {
      "type": "object",
      "additionalProperties": false,
      "required": ["class", "track_id", "attributes", "anon_id", "identity", "identity_status"],
      "properties": {
        "class": { "type": "string", "enum": ["person", "vehicle", "object"] },
        "track_id": {
          "description": "跟踪器内的短期标识，跨会话不保证稳定。",
          "type": "string",
          "minLength": 1
        },
        "attributes": {
          "description": "A 类属性（年龄段、着装等）。未启用时为空对象，不是 null。",
          "type": "object"
        },
        "anon_id": {
          "description": "B+ 类 ReID 匿名标识，站点内会话级有效（≤30min），不做跨日长期关联。未启用为 null。",
          "type": ["string", "null"]
        },
        "identity": {
          "description": "C 类人脸身份。仅在租户已授权且比对命中时非 null。",
          "type": ["object", "null"],
          "additionalProperties": false,
          "required": ["person_id", "library_id", "score"],
          "properties": {
            "person_id": { "type": "string" },
            "library_id": { "type": "string" },
            "score": { "type": "number", "minimum": 0, "maximum": 1 }
          }
        },
        "identity_status": {
          "description": "必须显式。只写 null 无法区分「没开这功能」与「比对失败」，后者是需要排查的故障。",
          "type": "string",
          "enum": ["not_enabled", "pending", "matched", "below_threshold", "no_candidate", "timeout"]
        }
      }
    },

    "observation": {
      "description": "结构化观测。bbox/keypoint 序列是数据闭环的唯一原料——只有视频与截图无法用于训练。",
      "type": ["object", "null"],
      "additionalProperties": false,
      "required": ["zone", "dwell_sec", "bbox_seq_uri", "keypoint_seq_uri", "signal_seq_uri"],
      "properties": {
        "zone": { "type": ["string", "null"] },
        "dwell_sec": { "type": ["number", "null"], "minimum": 0 },
        "bbox_seq_uri": {
          "description": "视觉模态专用。非视觉事件为 null。",
          "type": ["string", "null"],
          "format": "uri"
        },
        "keypoint_seq_uri": {
          "description": "COCO-17 关键点逐帧序列（JSONL）。视觉模态专用，P1 必补项。",
          "type": ["string", "null"],
          "format": "uri"
        },
        "signal_seq_uri": {
          "description": "非视觉模态的结构化序列（雷达点云轨迹与多普勒、门磁状态变迁等，JSONL）。与 keypoint_seq_uri 平级——两者是各自模态的数据闭环原料，缺任一模态的序列，该模态就无法参与模型迭代。",
          "type": ["string", "null"],
          "format": "uri"
        }
      }
    },

    "evidence": {
      "type": "object",
      "additionalProperties": false,
      "required": ["snapshot_uris", "clip_uri", "clip_range"],
      "properties": {
        "snapshot_uris": {
          "description": "证据截图。**允许为空数组**：非成像模态（雷达、门磁）产出的事件本就没有画面，隐私区域更是禁止成像。不得据此假设每个事件都有图可看——值班台 UI 必须能渲染无画面事件。文件命名只允许包含事件 ID 与日期目录，绝不得含 RTSP 地址、凭据或客户名称，文件名会出现在日志、URL 与工单中。",
          "type": "array",
          "minItems": 0,
          "items": { "type": "string", "format": "uri" }
        },
        "clip_uri": {
          "description": "含 pre-roll 的证据片段。仅有截图不足以让值班员判断真假，是误报反馈闭环的前置条件。P1 必补项。",
          "type": ["string", "null"],
          "format": "uri"
        },
        "clip_range": {
          "type": ["array", "null"],
          "minItems": 2,
          "maxItems": 2,
          "items": { "type": "string", "format": "date-time" }
        }
      }
    },

    "dedup_key": {
      "description": "跨机位/跨时间去重键，由平台侧构造。推理侧进程内按 source_event_id 的去重仍保留——它防的是同帧重复写盘，属不同层次。",
      "type": ["string", "null"]
    },

    "aggregated_into": {
      "description": "被合并入的事件 ID。非 null 时本事件不独立触发告警。",
      "type": ["string", "null"],
      "pattern": "^evt_[0-9A-HJKMNP-TV-Z]{26}$"
    },

    "outcome": {
      "description": "处置结果。事件不可变，误判只能通过本字段标记，不得删改。subject_recovered 由推理侧状态机自动回传（确认后自行起身），无需等人工。",
      "type": "string",
      "enum": [
        "unknown",
        "true_positive",
        "false_positive",
        "subject_recovered",
        "duplicate",
        "test"
      ]
    },

    "outcome_source": {
      "type": ["string", "null"],
      "enum": ["auto", "manual", null]
    },

    "outcome_reason": { "type": ["string", "null"] },

    "diagnostics": {
      "description": "推理侧内部诊断量，仅用于排查，平台不得依赖其语义。单调时钟跨进程无意义，不得用于任何时间计算。",
      "type": ["object", "null"],
      "additionalProperties": true,
      "properties": {
        "fsm_state": {
          "type": "string",
          "enum": ["NORMAL", "SUSPECT", "CONFIRMED", "RECOVERING"]
        },
        "suspected_at_monotonic": { "type": "number" },
        "confirmed_at_monotonic": { "type": "number" },
        "horizontal_angle_degrees": { "type": ["number", "null"] },
        "visible_joint_count": { "type": ["integer", "null"], "minimum": 0, "maximum": 17 }
      }
    },

    "ext": {
      "description": "厂商/场景扩展位。根对象 additionalProperties=false，任何未登记字段一律放这里，避免为实验性字段升版本。",
      "type": "object"
    }
  }
}