{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "edu-content source registry",
  "description": "机器可读的 L1 资源清单。一个 YAML 文件 = 一个域，内含多条 source。source 是四层血缘链的根 id。",
  "type": "object",
  "required": ["sources"],
  "additionalProperties": false,
  "properties": {
    "sources": {
      "type": "array",
      "items": { "$ref": "#/definitions/source" }
    }
  },
  "definitions": {
    "source": {
      "type": "object",
      "required": ["id", "title", "publisher", "type", "license", "status"],
      "additionalProperties": false,
      "properties": {
        "id": { "type": "string", "pattern": "^[a-z0-9][a-z0-9-]*$", "description": "全局唯一 kebab-case，血缘链根 id" },
        "title": { "type": "string" },
        "publisher": { "type": "string" },
        "type": { "type": "string", "enum": ["dataset", "website", "book", "internal", "tool"] },
        "url": { "type": ["string", "null"], "description": "internal 可为 null" },
        "license": { "type": "string", "enum": ["official-free", "cc-by", "cc-by-sa", "cc-nc-education", "restricted", "internal-only", "llm-generated", "unknown"] },
        "license_note": { "type": "string" },
        "fetch_method": { "type": "string", "enum": ["curl", "git-clone", "manual-download", "manual-export", "generated"], "description": "unknown 允许暂存" },
        "status": { "type": "string", "enum": ["planned", "fetching", "fetched", "failed", "archived"] },
        "fetched_at": { "type": ["string", "null"], "pattern": "^\\d{4}-\\d{2}-\\d{2}$|^$" },
        "items": { "type": "array", "items": { "$ref": "#/definitions/item" } }
      }
    },
    "item": {
      "type": "object",
      "required": ["id", "title"],
      "additionalProperties": false,
      "properties": {
        "id": { "type": "string", "pattern": "^[a-z0-9][a-z0-9-]*$", "description": "source 内唯一" },
        "title": { "type": "string" },
        "oss_key": { "type": ["string", "null"], "description": "fetched 后必填，形如 edu-raw/exams/ket/vocab/cambridge-official/a2-key-vocab.pdf" },
        "sha256": { "type": ["string", "null"], "pattern": "^[a-f0-9]{64}$|^$" },
        "size": { "type": ["integer", "null"], "minimum": 0 },
        "media_type": { "type": "string" },
        "fetch_date": { "type": ["string", "null"], "pattern": "^\\d{4}-\\d{2}-\\d{2}$|^$" },
        "status": { "type": "string", "enum": ["planned", "fetching", "fetched", "failed", "archived"] },
        "note": { "type": "string" }
      }
    }
  }
}