{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "edu-content source registry",
  "description": "机器可读的 L1 资源清单。一个 YAML 文件 = 一个域，内含多条 source。source 是四层血缘链的根 id。",
  "type": "object",
  "required": [
    "sources"
  ],
  "additionalProperties": false,
  "properties": {
    "sources": {
      "type": "array",
      "items": {
        "$ref": "#/definitions/source"
      }
    }
  },
  "definitions": {
    "source": {
      "type": "object",
      "required": [
        "id",
        "title",
        "publisher",
        "type",
        "license",
        "status",
        "subjects"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "pattern": "^[a-z0-9][a-z0-9-]*$",
          "description": "全局唯一 kebab-case，血缘链根 id"
        },
        "title": {
          "type": "string"
        },
        "publisher": {
          "type": "string"
        },
        "type": {
          "type": "string",
          "enum": [
            "dataset",
            "website",
            "book",
            "internal",
            "tool"
          ]
        },
        "url": {
          "type": [
            "string",
            "null"
          ],
          "description": "internal 可为 null"
        },
        "license": {
          "type": "string",
          "enum": [
            "official-free",
            "mit",
            "cc-by",
            "cc-by-sa",
            "cc-nc-education",
            "restricted",
            "internal-only",
            "llm-generated",
            "unknown"
          ]
        },
        "license_note": {
          "type": "string"
        },
        "fetch_method": {
          "type": "string",
          "enum": [
            "curl",
            "git-clone",
            "manual-download",
            "manual-export",
            "generated"
          ],
          "description": "unknown 允许暂存"
        },
        "status": {
          "type": "string",
          "enum": [
            "planned",
            "fetching",
            "fetched",
            "failed",
            "archived"
          ]
        },
        "fetched_at": {
          "type": [
            "string",
            "null"
          ],
          "pattern": "^\\d{4}-\\d{2}-\\d{2}$|^$"
        },
        "items": {
          "type": "array",
          "items": {
            "$ref": "#/definitions/item"
          }
        },
        "subjects": {
          "type": "array",
          "items": {
            "type": "string",
            "enum": [
              "chinese",
              "math",
              "english",
              "science",
              "morality",
              "physics",
              "chemistry",
              "biology",
              "history",
              "geography",
              "it",
              "ket",
              "pet",
              "fce",
              "amc8",
              "cspj"
            ]
          },
          "description": "该来源覆盖的学科/考试域，取值与 structured/ 目录名一致；用于回答『某学科有哪些来源』"
        },
        "stages": {
          "type": "array",
          "items": {
            "type": "string",
            "enum": [
              "primary",
              "junior"
            ]
          },
          "description": "覆盖学段：primary=小学，junior=初中"
        },
        "url_template": {
          "type": [
            "string",
            "null"
          ],
          "description": "fetch_method=curl 时的下载模板，{item_id} 占位；item.url 优先级更高。例：https://host/sims/{item_id}/{item_id}_zh_CN.html"
        }
      }
    },
    "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"
        },
        "url": {
          "type": [
            "string",
            "null"
          ],
          "description": "该条目的直接下载地址；缺省时由 source.url_template 渲染"
        },
        "src_path": {
          "type": [
            "string",
            "null"
          ],
          "description": "fetch_method=git-clone 时，条目在仓库内的相对路径（打包为 oss_key 指向的归档）"
        }
      }
    }
  }
}