{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "book-schema-v1",
  "title": "Book Module Schema",
  "description": "Schema for long-form books and other chapter-based publications. Content is organized as hierarchical sections and supports annotations, scripture references, footnotes, images, and audio.",

  "definitions": {
    "verseRef": {
      "type": "integer",
      "minimum": 1001001,
      "description": "Numeric verse reference in BBCCCVVV format (for example, 40001001 for Matthew 1:1)."
    },

    "verseRange": {
      "type": "object",
      "properties": {
        "sv": { "$ref": "#/definitions/verseRef", "description": "Start verse reference" },
        "ev": { "$ref": "#/definitions/verseRef", "description": "Optional end verse reference" },
        "label": { "type": "string", "description": "Optional human-readable reference" }
      },
      "required": ["sv"]
    },

    "mediaReference": {
      "type": "object",
      "description": "Reference to an image or audio file packaged with the module.",
      "properties": {
        "id": { "type": "string", "minLength": 1, "description": "Unique media identifier" },
        "type": { "type": "string", "enum": ["image", "audio"] },
        "filename": { "type": "string", "minLength": 1 },
        "mimeType": { "type": "string", "minLength": 1 },
        "size": { "type": "integer", "minimum": 0, "description": "File size in bytes" },
        "width": { "type": "integer", "minimum": 1, "description": "Image width in pixels" },
        "height": { "type": "integer", "minimum": 1, "description": "Image height in pixels" },
        "duration": { "type": "number", "minimum": 0, "description": "Audio duration in seconds" },
        "waveform": {
          "type": "array",
          "items": { "type": "number", "minimum": 0, "maximum": 1 },
          "description": "Normalized audio waveform samples"
        },
        "transcription": { "type": "string" },
        "alt": { "type": "string", "description": "Accessible alternative text for an image" },
        "created": { "type": "integer", "description": "Unix timestamp when the media was added" }
      },
      "required": ["id", "type", "filename", "mimeType"]
    },

    "annotation": {
      "type": "object",
      "description": "An inline annotation using character offsets in its annotated text.",
      "properties": {
        "type": {
          "type": "string",
          "enum": ["scripture", "strongs", "greek", "hebrew", "link", "emphasis", "quote", "footnote", "page", "media"]
        },
        "start": { "type": "integer", "minimum": 0 },
        "end": { "type": "integer", "minimum": 0 },
        "text": { "type": "string" },
        "data": {
          "type": "object",
          "properties": {
            "sv": { "$ref": "#/definitions/verseRef" },
            "ev": { "$ref": "#/definitions/verseRef" },
            "refs": {
              "type": "array",
              "items": { "$ref": "#/definitions/verseRange" }
            },
            "strongs": { "type": "string" },
            "url": { "type": "string", "format": "uri" },
            "style": { "type": "string", "enum": ["bold", "italic", "underline"] },
            "source": { "type": "string" },
            "footnoteId": { "type": "string" },
            "pageNum": { "type": ["string", "integer"] },
            "mediaId": { "type": "string" },
            "mediaType": { "type": "string", "enum": ["image", "audio"] }
          }
        }
      },
      "required": ["type", "start", "end"]
    },

    "footnoteReference": {
      "type": "object",
      "properties": {
        "id": { "type": "string", "minLength": 1 },
        "offset": { "type": "integer", "minimum": 0 }
      },
      "required": ["id", "offset"]
    },

    "annotatedText": {
      "type": "object",
      "description": "Plain text plus offset-based annotations and footnote markers.",
      "properties": {
        "text": { "type": "string" },
        "annotations": {
          "type": "array",
          "items": { "$ref": "#/definitions/annotation" }
        },
        "footnote_refs": {
          "type": "array",
          "items": { "$ref": "#/definitions/footnoteReference" }
        }
      },
      "required": ["text"]
    },

    "textValue": {
      "oneOf": [
        { "type": "string" },
        { "$ref": "#/definitions/annotatedText" }
      ]
    },

    "footnote": {
      "type": "object",
      "properties": {
        "id": { "type": "string", "minLength": 1 },
        "content": { "$ref": "#/definitions/textValue" }
      },
      "required": ["id", "content"]
    },

    "listItem": {
      "type": "object",
      "properties": {
        "content": { "$ref": "#/definitions/annotatedText" },
        "children": {
          "type": "array",
          "items": { "$ref": "#/definitions/listItem" }
        }
      },
      "required": ["content"]
    },

    "tableCell": {
      "type": "object",
      "description": "One cell in a table, positioned by its zero-based column index.",
      "properties": {
        "content": { "$ref": "#/definitions/annotatedText" },
        "column": { "type": "integer", "minimum": 0 },
        "header": { "type": "boolean", "default": false },
        "colSpan": { "type": "integer", "minimum": 1, "default": 1 },
        "rowSpan": { "type": "integer", "minimum": 1, "default": 1 }
      },
      "required": ["content", "column"]
    },

    "tableRow": {
      "type": "object",
      "properties": {
        "cells": {
          "type": "array",
          "items": { "$ref": "#/definitions/tableCell" }
        }
      },
      "required": ["cells"]
    },

    "contentBlock": {
      "type": "object",
      "description": "A display block within a section.",
      "properties": {
        "type": {
          "type": "string",
          "enum": ["paragraph", "list", "blockquote", "heading", "table", "image", "audio", "thematic-break"]
        },
        "content": { "$ref": "#/definitions/annotatedText" },
        "level": { "type": "integer", "minimum": 1, "maximum": 6 },
        "listType": { "type": "string", "enum": ["bullet", "numbered"] },
        "items": {
          "type": "array",
          "items": { "$ref": "#/definitions/listItem" }
        },
        "columnCount": { "type": "integer", "minimum": 1 },
        "rows": {
          "type": "array",
          "items": { "$ref": "#/definitions/tableRow" }
        },
        "mediaId": { "type": "string", "description": "ID of an item in the top-level media array" },
        "caption": { "$ref": "#/definitions/textValue" },
        "alignment": { "type": "string", "enum": ["left", "center", "right", "full"] },
        "showWaveform": { "type": "boolean" },
        "autoplay": { "type": "boolean" }
      },
      "required": ["type"],
      "allOf": [
        {
          "if": { "properties": { "type": { "enum": ["paragraph", "blockquote", "heading"] } } },
          "then": { "required": ["content"] }
        },
        {
          "if": { "properties": { "type": { "const": "list" } } },
          "then": { "required": ["listType", "items"] }
        },
        {
          "if": { "properties": { "type": { "const": "table" } } },
          "then": { "required": ["columnCount", "rows"] }
        },
        {
          "if": { "properties": { "type": { "enum": ["image", "audio"] } } },
          "then": { "required": ["mediaId"] }
        },
        {
          "if": { "properties": { "type": { "const": "heading" } } },
          "then": { "required": ["level"] }
        }
      ]
    },

    "section": {
      "type": "object",
      "description": "A hierarchical book unit such as a preface, part, chapter, or appendix.",
      "properties": {
        "id": { "type": "string", "minLength": 1, "description": "Identifier unique within this book" },
        "type": {
          "type": "string",
          "enum": ["front-matter", "part", "chapter", "section", "appendix", "back-matter", "other"]
        },
        "number": {
          "type": ["string", "integer"],
          "description": "Optional displayed number or label, such as 3, IV, or Appendix A"
        },
        "title": { "type": "string", "minLength": 1 },
        "subtitle": { "type": "string" },
        "order": { "type": "integer", "minimum": 0, "description": "Optional explicit sibling sort order; array order is used when omitted" },
        "keyScriptures": {
          "type": "array",
          "items": { "$ref": "#/definitions/verseRange" }
        },
        "content": {
          "type": "array",
          "items": { "$ref": "#/definitions/contentBlock" }
        },
        "sections": {
          "type": "array",
          "items": { "$ref": "#/definitions/section" }
        }
      },
      "required": ["id", "type", "title"],
      "anyOf": [
        { "required": ["content"] },
        { "required": ["sections"] }
      ]
    }
  },

  "type": "object",
  "properties": {
    "meta": {
      "type": "object",
      "description": "Book and publication metadata.",
      "properties": {
        "schemaVersion": { "type": "string", "const": "1.0" },
        "id": { "type": "string", "minLength": 1, "description": "Unique module identifier" },
        "type": { "type": "string", "const": "book" },
        "title": { "type": "string", "minLength": 1 },
        "subtitle": { "type": "string" },
        "description": { "type": "string" },
        "author": { "type": "string" },
        "editor": { "type": "string" },
        "publisher": { "type": "string" },
        "year": { "type": "integer", "minimum": 0 },
        "edition": { "type": "string" },
        "isbn": { "type": "string" },
        "language": { "type": "string", "minLength": 2, "description": "BCP 47 language tag, such as en" },
        "textDirection": { "type": "string", "enum": ["ltr", "rtl"] },
        "copyright": { "type": "string" },
        "license": { "type": "string" },
        "version": { "type": "string", "description": "Version of this module's content" },
        "tags": {
          "type": "array",
          "items": { "type": "string" }
        },
        "coverMediaId": { "type": "string", "description": "ID of the cover image in the top-level media array" },
        "isEditable": { "type": "boolean", "default": false },
        "created": { "type": "integer", "description": "Unix timestamp when the module was created" },
        "lastModified": { "type": "integer", "description": "Unix timestamp of the last modification" }
      },
      "required": ["schemaVersion", "id", "type", "title", "language"]
    },

    "sections": {
      "type": "array",
      "minItems": 1,
      "items": { "$ref": "#/definitions/section" },
      "description": "The book's ordered, hierarchical contents."
    },

    "footnotes": {
      "type": "array",
      "items": { "$ref": "#/definitions/footnote" },
      "description": "Footnotes shared by all sections in the book."
    },

    "media": {
      "type": "array",
      "items": { "$ref": "#/definitions/mediaReference" },
      "description": "Media referenced by the cover or content blocks."
    }
  },
  "required": ["meta", "sections"]
}