{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "document_metadata_schema.json",
  "title": "Document Metadata Schema",
  "description": "Schema for document metadata following the World Bank Metadata Standards for Improved Data Discoverability (Chapter 5 - Documents). Reference: https://worldbank.github.io/schema-guide/chapter05.html",
  "type": "object",
  "required": ["type", "metadata_information", "document_description"],
  "additionalProperties": true,
  "properties": {
    "type": {
      "type": "string",
      "description": "Resource type identifier.",
      "const": "document"
    },
    "metadata_information": {
      "$ref": "#/$defs/metadata_information"
    },
    "document_description": {
      "$ref": "#/$defs/document_description"
    },
    "provenance": {
      "type": "array",
      "description": "Provenance information describing the origin and harvest history of the metadata.",
      "items": {
        "$ref": "#/$defs/provenance_entry"
      }
    },
    "tags": {
      "type": "array",
      "description": "Tags for classification and filtering.",
      "items": {
        "$ref": "#/$defs/tag"
      }
    },
    "schematype": {
      "type": "string",
      "description": "Schema type identifier.",
      "const": "document"
    },
    "additional": {
      "type": "object",
      "description": "Additional fields not covered by the core schema. Keys follow the 'additional.<namespace>_<field>' convention. Used for source-specific metadata preservation.",
      "additionalProperties": true
    }
  },

  "$defs": {
    "metadata_information": {
      "type": "object",
      "description": "Information about the metadata record itself (who created it, when, etc.).",
      "required": ["title", "idno", "producers", "production_date"],
      "additionalProperties": false,
      "properties": {
        "title": {
          "type": "string",
          "description": "Title of the metadata record."
        },
        "idno": {
          "type": "string",
          "description": "Unique identifier for the metadata record."
        },
        "producers": {
          "type": "array",
          "description": "Organizations or individuals that produced or contributed to the metadata.",
          "items": {
            "$ref": "#/$defs/producer"
          }
        },
        "production_date": {
          "type": "string",
          "description": "Date the metadata was produced. ISO 8601 format: YYYY-MM-DD.",
          "pattern": "^[0-9]{4}-[0-9]{2}-[0-9]{2}$"
        },
        "version": {
          "type": "string",
          "description": "Version or description of the metadata record."
        }
      }
    },

    "producer": {
      "type": "object",
      "description": "An organization or individual that produced metadata.",
      "additionalProperties": false,
      "properties": {
        "name": {
          "type": "string",
          "description": "Name of the producing organization or individual."
        },
        "abbr": {
          "type": "string",
          "description": "Abbreviation of the producer name."
        },
        "affiliation": {
          "type": "string",
          "description": "Institutional affiliation of the producer."
        },
        "role": {
          "type": "string",
          "description": "Role of the producer (e.g., 'Source', 'Compiler')."
        }
      }
    },

    "document_description": {
      "type": "object",
      "description": "Core descriptive metadata about the document.",
      "required": ["title_statement"],
      "additionalProperties": false,
      "properties": {
        "title_statement": {
          "$ref": "#/$defs/title_statement"
        },
        "authors": {
          "type": "array",
          "description": "List of document authors.",
          "items": {
            "$ref": "#/$defs/author"
          }
        },
        "date_created": {
          "type": "string",
          "description": "Date the document was created. ISO 8601 format: YYYY-MM-DD."
        },
        "date_available": {
          "type": "string",
          "description": "Date the document was made available. ISO 8601 format: YYYY-MM-DD."
        },
        "date_modified": {
          "type": "string",
          "description": "Date the document was last modified. ISO 8601 format: YYYY-MM-DD."
        },
        "date_published": {
          "type": "string",
          "description": "Date the document was published. ISO 8601 format: YYYY-MM-DD."
        },
        "identifiers": {
          "type": "array",
          "description": "External identifiers (DOI, ISBN, ISSN, etc.).",
          "items": {
            "$ref": "#/$defs/identifier"
          }
        },
        "type": {
          "type": "string",
          "description": "Document type (e.g., 'Working Paper', 'Report')."
        },
        "abstract": {
          "type": "string",
          "description": "Abstract or summary of the document."
        },
        "ref_country": {
          "type": "array",
          "description": "Countries referenced in the document.",
          "items": {
            "$ref": "#/$defs/country"
          }
        },
        "geographic_units": {
          "type": "array",
          "description": "Geographic units or regions referenced.",
          "items": {
            "$ref": "#/$defs/geographic_unit"
          }
        },
        "spatial_coverage": {
          "type": "string",
          "description": "Free-text description of spatial coverage."
        },
        "languages": {
          "type": "array",
          "description": "Languages of the document.",
          "items": {
            "$ref": "#/$defs/language"
          }
        },
        "volume": {
          "type": "string",
          "description": "Volume number."
        },
        "number": {
          "type": "string",
          "description": "Issue or report number."
        },
        "series": {
          "type": "string",
          "description": "Series or collection name."
        },
        "publisher_address": {
          "type": "string",
          "description": "Publisher address or place of production."
        },
        "organization": {
          "type": "string",
          "description": "Publishing or sponsoring organization."
        },
        "url": {
          "type": "string",
          "description": "URL to the document."
        },
        "keywords": {
          "type": "array",
          "description": "Keywords associated with the document.",
          "items": {
            "$ref": "#/$defs/keyword"
          }
        },
        "themes": {
          "type": "array",
          "description": "Thematic classifications.",
          "items": {
            "$ref": "#/$defs/theme"
          }
        },
        "topics": {
          "type": "array",
          "description": "Topic classifications.",
          "items": {
            "$ref": "#/$defs/topic"
          }
        },
        "relations": {
          "type": "array",
          "description": "Related resources (alternate formats, parent collections).",
          "items": {
            "$ref": "#/$defs/relation"
          }
        },
        "security_classification": {
          "type": "string",
          "description": "Security classification level."
        },
        "access_restrictions": {
          "type": "string",
          "description": "Access restrictions or disclosure status."
        },
        "edition": {
          "type": "string",
          "description": "Edition or version type."
        },
        "contacts": {
          "type": "array",
          "description": "Contact information for inquiries.",
          "items": {
            "$ref": "#/$defs/contact"
          }
        },
        "usage_terms": {
          "type": "string",
          "description": "Terms of use for the document."
        },
        "notes": {
          "type": "array",
          "description": "Additional notes about the document.",
          "items": {
            "$ref": "#/$defs/note"
          }
        },
        "disclaimer": {
          "type": "string",
          "description": "Disclaimer text associated with the document."
        },
        "pricing": {
          "type": "string",
          "description": "Pricing or availability information."
        },
        "reproducibility": {
          "$ref": "#/$defs/reproducibility"
        }
      }
    },

    "title_statement": {
      "type": "object",
      "description": "Title information for the document.",
      "additionalProperties": false,
      "properties": {
        "idno": {
          "type": "string",
          "description": "Document identifier."
        },
        "title": {
          "type": "string",
          "description": "Primary title of the document."
        },
        "sub_title": {
          "type": "string",
          "description": "Subtitle of the document."
        },
        "alternate_title": {
          "type": "string",
          "description": "Alternate title."
        },
        "translated_title": {
          "type": "string",
          "description": "Translated title."
        }
      }
    },

    "author": {
      "type": "object",
      "description": "Document author information.",
      "additionalProperties": false,
      "properties": {
        "first_name": {
          "type": "string",
          "description": "Author's first name."
        },
        "initial": {
          "type": "string",
          "description": "Author's middle initial."
        },
        "last_name": {
          "type": "string",
          "description": "Author's last name."
        },
        "affiliation": {
          "type": "string",
          "description": "Author's institutional affiliation."
        },
        "full_name": {
          "type": "string",
          "description": "Author's full name (used when individual name parts are unavailable)."
        }
      }
    },

    "identifier": {
      "type": "object",
      "description": "External identifier for the document.",
      "additionalProperties": false,
      "properties": {
        "type": {
          "type": "string",
          "description": "Identifier type (e.g., 'DOI', 'ISBN', 'ISSN')."
        },
        "identifier": {
          "type": "string",
          "description": "Identifier value."
        }
      }
    },

    "country": {
      "type": "object",
      "description": "Country reference.",
      "additionalProperties": false,
      "properties": {
        "name": {
          "type": "string",
          "description": "Country name."
        },
        "code": {
          "type": "string",
          "description": "ISO 3166-1 alpha-3 country code."
        }
      }
    },

    "geographic_unit": {
      "type": "object",
      "description": "Geographic unit or region.",
      "additionalProperties": false,
      "properties": {
        "name": {
          "type": "string",
          "description": "Name of the geographic unit."
        },
        "code": {
          "type": "string",
          "description": "Code for the geographic unit."
        },
        "type": {
          "type": "string",
          "description": "Type of geographic unit (e.g., 'region')."
        }
      }
    },

    "language": {
      "type": "object",
      "description": "Language information.",
      "additionalProperties": false,
      "properties": {
        "name": {
          "type": "string",
          "description": "Language name (e.g., 'English')."
        },
        "code": {
          "type": "string",
          "description": "ISO 639 language code (e.g., 'en')."
        }
      }
    },

    "keyword": {
      "type": "object",
      "description": "Keyword entry.",
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Keyword identifier."
        },
        "name": {
          "type": "string",
          "description": "Keyword text."
        },
        "vocabulary": {
          "type": "string",
          "description": "Source vocabulary or controlled list."
        },
        "uri": {
          "type": "string",
          "description": "URI for the keyword in its vocabulary."
        }
      }
    },

    "theme": {
      "type": "object",
      "description": "Thematic classification entry.",
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Theme identifier."
        },
        "name": {
          "type": "string",
          "description": "Theme name."
        },
        "parent_id": {
          "type": "string",
          "description": "Parent theme identifier (for hierarchical themes)."
        },
        "vocabulary": {
          "type": "string",
          "description": "Source vocabulary (e.g., 'World Bank - theme')."
        },
        "uri": {
          "type": "string",
          "description": "URI for the theme."
        }
      }
    },

    "topic": {
      "type": "object",
      "description": "Topic classification entry.",
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Topic identifier."
        },
        "name": {
          "type": "string",
          "description": "Topic name."
        },
        "parent_id": {
          "type": "string",
          "description": "Parent topic identifier."
        },
        "vocabulary": {
          "type": "string",
          "description": "Source vocabulary."
        },
        "uri": {
          "type": "string",
          "description": "URI for the topic."
        }
      }
    },

    "relation": {
      "type": "object",
      "description": "Related resource entry.",
      "additionalProperties": false,
      "properties": {
        "name": {
          "type": "string",
          "description": "Name or URL of the related resource."
        },
        "type": {
          "type": "string",
          "description": "Relationship type (e.g., 'hasFormat', 'isPartOf')."
        }
      }
    },

    "contact": {
      "type": "object",
      "description": "Contact information.",
      "additionalProperties": false,
      "properties": {
        "name": {
          "type": "string",
          "description": "Contact name."
        },
        "affiliation": {
          "type": "string",
          "description": "Contact's institutional affiliation."
        },
        "email": {
          "type": "string",
          "description": "Contact email address."
        },
        "uri": {
          "type": "string",
          "description": "Contact URI or URL."
        }
      }
    },

    "note": {
      "type": "object",
      "description": "A free-text note.",
      "additionalProperties": false,
      "properties": {
        "note": {
          "type": "string",
          "description": "Note text."
        }
      }
    },

    "tag": {
      "type": "object",
      "description": "A tag entry for classification.",
      "additionalProperties": false,
      "properties": {
        "tag": {
          "type": "string",
          "description": "Tag value."
        },
        "tag_group": {
          "type": "string",
          "description": "Tag group or category."
        }
      }
    },

    "provenance_entry": {
      "type": "object",
      "description": "A provenance record.",
      "additionalProperties": false,
      "properties": {
        "origin_description": {
          "$ref": "#/$defs/origin_description"
        }
      }
    },

    "origin_description": {
      "type": "object",
      "description": "Description of the metadata's origin and harvest details.",
      "additionalProperties": false,
      "properties": {
        "harvest_date": {
          "type": "string",
          "description": "Date/time the metadata was harvested. ISO 8601 format."
        },
        "altered": {
          "type": "boolean",
          "description": "Whether the metadata was altered after harvest."
        },
        "base_url": {
          "type": "string",
          "description": "Base URL of the metadata source."
        },
        "identifier": {
          "type": "string",
          "description": "Identifier for the source record."
        },
        "date_stamp": {
          "type": "string",
          "description": "Timestamp of the source record. ISO 8601 format."
        },
        "metadata_namespace": {
          "type": "string",
          "description": "Namespace identifier for the metadata source."
        }
      }
    },

    "reproducibility": {
      "type": "object",
      "description": "Reproducibility information for the document.",
      "additionalProperties": false,
      "properties": {
        "statement": {
          "type": "string",
          "description": "Reproducibility statement."
        },
        "links": {
          "type": "array",
          "description": "Links to reproducibility resources (code, data).",
          "items": {
            "$ref": "#/$defs/reproducibility_link"
          }
        }
      }
    },

    "reproducibility_link": {
      "type": "object",
      "description": "A link to a reproducibility resource.",
      "additionalProperties": false,
      "properties": {
        "uri": {
          "type": "string",
          "description": "URI of the reproducibility resource."
        },
        "description": {
          "type": "string",
          "description": "Description of the linked resource."
        }
      }
    }
  }
}