{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://a.skh.am/pi-daemon/extension-view.schema.json",
  "title": "Pi declarative extension view v1",
  "description": "Bounded code-free declarative extension views transported across Pi RPC, TUI fallback, and Dash Rich renderers.",
  "oneOf": [
    { "$ref": "#/$defs/view" },
    { "$ref": "#/$defs/response" }
  ],
  "$defs": {
    "identifier": {
      "type": "string",
      "minLength": 1,
      "maxLength": 128,
      "pattern": "^[A-Za-z0-9][A-Za-z0-9._:-]*$"
    },
    "boundedText": {
      "type": "string",
      "minLength": 1,
      "maxLength": 65536
    },
    "negotiationCapability": {
      "type": "object",
      "required": ["protocol", "version", "source", "renderers", "browserCodeExecution", "imageSources", "limits"],
      "properties": {
        "protocol": { "const": "pi-declarative-view" },
        "version": { "const": "1.0" },
        "source": { "const": "pi-rpc-proposal" },
        "renderers": {
          "type": "object",
          "required": ["rich", "tui", "rpc"],
          "properties": {
            "rich": { "const": "native" },
            "tui": { "const": "fallback" },
            "rpc": { "const": "transport" }
          },
          "additionalProperties": false
        },
        "browserCodeExecution": { "const": false },
        "imageSources": { "const": "authorized-blob-only" },
        "limits": {
          "type": "object",
          "required": ["maxViewBytes", "maxNodes", "maxDepth", "maxTextBytes", "maxActions", "maxFields", "maxOptions", "maxImages"],
          "properties": {
            "maxViewBytes": { "type": "integer", "minimum": 1, "maximum": 1048576 },
            "maxNodes": { "type": "integer", "minimum": 1, "maximum": 1024 },
            "maxDepth": { "type": "integer", "minimum": 1, "maximum": 32 },
            "maxTextBytes": { "type": "integer", "minimum": 1, "maximum": 1048576 },
            "maxActions": { "type": "integer", "minimum": 1, "maximum": 128 },
            "maxFields": { "type": "integer", "minimum": 1, "maximum": 128 },
            "maxOptions": { "type": "integer", "minimum": 1, "maximum": 512 },
            "maxImages": { "type": "integer", "minimum": 1, "maximum": 64 }
          },
          "additionalProperties": false
        }
      },
      "additionalProperties": false
    },
    "capabilities": {
      "type": "object",
      "required": ["actions", "links", "images"],
      "properties": {
        "actions": {
          "type": "array",
          "maxItems": 32,
          "uniqueItems": true,
          "items": { "$ref": "#/$defs/identifier" }
        },
        "links": { "const": "none" },
        "images": { "const": "authorized-blob-only" }
      },
      "additionalProperties": false
    },
    "textNode": {
      "type": "object",
      "required": ["type", "text"],
      "properties": {
        "type": { "const": "text" },
        "text": { "$ref": "#/$defs/boundedText" }
      },
      "additionalProperties": false
    },
    "markdownNode": {
      "type": "object",
      "required": ["type", "text"],
      "properties": {
        "type": { "const": "markdown" },
        "text": { "$ref": "#/$defs/boundedText" }
      },
      "additionalProperties": false
    },
    "codeNode": {
      "type": "object",
      "required": ["type", "code"],
      "properties": {
        "type": { "const": "code" },
        "code": { "type": "string", "maxLength": 65536 },
        "language": { "type": "string", "minLength": 1, "maxLength": 64, "pattern": "^[A-Za-z0-9][A-Za-z0-9_+.-]*$" },
        "filename": { "type": "string", "maxLength": 512 }
      },
      "additionalProperties": false
    },
    "diffNode": {
      "type": "object",
      "required": ["type", "diff"],
      "properties": {
        "type": { "const": "diff" },
        "diff": { "type": "string", "maxLength": 65536 },
        "language": { "type": "string", "minLength": 1, "maxLength": 64, "pattern": "^[A-Za-z0-9][A-Za-z0-9_+.-]*$" }
      },
      "additionalProperties": false
    },
    "imageNode": {
      "type": "object",
      "required": ["type", "blobRef", "mediaType", "alt"],
      "properties": {
        "type": { "const": "image" },
        "blobRef": { "type": "string", "minLength": 6, "maxLength": 256, "pattern": "^blob:[A-Za-z0-9][A-Za-z0-9._:-]*$" },
        "mediaType": { "enum": ["image/png", "image/jpeg", "image/gif", "image/webp"] },
        "alt": { "type": "string", "maxLength": 1024 },
        "width": { "type": "integer", "minimum": 1, "maximum": 16384 },
        "height": { "type": "integer", "minimum": 1, "maximum": 16384 }
      },
      "additionalProperties": false
    },
    "keyValueNode": {
      "type": "object",
      "required": ["type", "entries"],
      "properties": {
        "type": { "const": "key-value" },
        "entries": {
          "type": "array",
          "maxItems": 64,
          "items": {
            "type": "object",
            "required": ["key", "value"],
            "properties": {
              "key": { "type": "string", "minLength": 1, "maxLength": 256 },
              "value": { "type": "string", "maxLength": 4096 }
            },
            "additionalProperties": false
          }
        }
      },
      "additionalProperties": false
    },
    "statusNode": {
      "type": "object",
      "required": ["type", "tone", "label"],
      "properties": {
        "type": { "const": "status" },
        "tone": { "enum": ["neutral", "info", "success", "warning", "error"] },
        "label": { "type": "string", "minLength": 1, "maxLength": 512 },
        "detail": { "type": "string", "maxLength": 4096 }
      },
      "additionalProperties": false
    },
    "stackNode": {
      "type": "object",
      "required": ["type", "children"],
      "properties": {
        "type": { "const": "stack" },
        "gap": { "enum": ["compact", "normal", "relaxed"] },
        "children": { "type": "array", "minItems": 1, "maxItems": 256, "items": { "$ref": "#/$defs/node" } }
      },
      "additionalProperties": false
    },
    "gridNode": {
      "type": "object",
      "required": ["type", "columns", "children"],
      "properties": {
        "type": { "const": "grid" },
        "columns": { "type": "integer", "minimum": 1, "maximum": 4 },
        "children": { "type": "array", "minItems": 1, "maxItems": 256, "items": { "$ref": "#/$defs/node" } }
      },
      "additionalProperties": false
    },
    "actionNode": {
      "type": "object",
      "required": ["type", "actionId", "label"],
      "properties": {
        "type": { "const": "action" },
        "actionId": { "$ref": "#/$defs/identifier" },
        "label": { "type": "string", "minLength": 1, "maxLength": 512 },
        "tone": { "enum": ["default", "primary", "danger"] }
      },
      "additionalProperties": false
    },
    "textField": {
      "type": "object",
      "required": ["type", "name", "label"],
      "properties": {
        "type": { "enum": ["text", "multiline"] },
        "name": { "$ref": "#/$defs/identifier" },
        "label": { "type": "string", "minLength": 1, "maxLength": 512 },
        "required": { "type": "boolean" },
        "placeholder": { "type": "string", "maxLength": 1024 },
        "initial": { "type": "string", "maxLength": 8192 }
      },
      "additionalProperties": false
    },
    "selectField": {
      "type": "object",
      "required": ["type", "name", "label", "options"],
      "properties": {
        "type": { "const": "select" },
        "name": { "$ref": "#/$defs/identifier" },
        "label": { "type": "string", "minLength": 1, "maxLength": 512 },
        "required": { "type": "boolean" },
        "options": {
          "type": "array",
          "minItems": 1,
          "maxItems": 128,
          "items": {
            "type": "object",
            "required": ["value", "label"],
            "properties": {
              "value": { "type": "string", "minLength": 1, "maxLength": 512 },
              "label": { "type": "string", "minLength": 1, "maxLength": 512 }
            },
            "additionalProperties": false
          }
        },
        "initial": { "type": "string", "minLength": 1, "maxLength": 512 }
      },
      "additionalProperties": false
    },
    "booleanField": {
      "type": "object",
      "required": ["type", "name", "label"],
      "properties": {
        "type": { "const": "boolean" },
        "name": { "$ref": "#/$defs/identifier" },
        "label": { "type": "string", "minLength": 1, "maxLength": 512 },
        "required": { "type": "boolean" },
        "initial": { "type": "boolean" }
      },
      "additionalProperties": false
    },
    "field": {
      "oneOf": [
        { "$ref": "#/$defs/textField" },
        { "$ref": "#/$defs/selectField" },
        { "$ref": "#/$defs/booleanField" }
      ]
    },
    "formNode": {
      "type": "object",
      "required": ["type", "formId", "submitActionId", "submitLabel", "fields"],
      "properties": {
        "type": { "const": "form" },
        "formId": { "$ref": "#/$defs/identifier" },
        "submitActionId": { "$ref": "#/$defs/identifier" },
        "submitLabel": { "type": "string", "minLength": 1, "maxLength": 512 },
        "fields": { "type": "array", "minItems": 1, "maxItems": 32, "items": { "$ref": "#/$defs/field" } }
      },
      "additionalProperties": false
    },
    "node": {
      "oneOf": [
        { "$ref": "#/$defs/textNode" },
        { "$ref": "#/$defs/markdownNode" },
        { "$ref": "#/$defs/codeNode" },
        { "$ref": "#/$defs/diffNode" },
        { "$ref": "#/$defs/imageNode" },
        { "$ref": "#/$defs/keyValueNode" },
        { "$ref": "#/$defs/statusNode" },
        { "$ref": "#/$defs/stackNode" },
        { "$ref": "#/$defs/gridNode" },
        { "$ref": "#/$defs/actionNode" },
        { "$ref": "#/$defs/formNode" }
      ]
    },
    "view": {
      "type": "object",
      "required": ["protocol", "version", "viewId", "revision", "fallbackText", "capabilities", "root"],
      "properties": {
        "protocol": { "const": "pi-declarative-view" },
        "version": { "const": "1.0" },
        "viewId": { "$ref": "#/$defs/identifier" },
        "revision": { "type": "integer", "minimum": 0 },
        "title": { "type": "string", "maxLength": 512 },
        "fallbackText": { "type": "string", "minLength": 1, "maxLength": 4096 },
        "capabilities": { "$ref": "#/$defs/capabilities" },
        "root": { "$ref": "#/$defs/node" }
      },
      "additionalProperties": false
    },
    "response": {
      "type": "object",
      "required": ["protocol", "version", "viewId", "revision", "actionId"],
      "properties": {
        "protocol": { "const": "pi-declarative-view" },
        "version": { "const": "1.0" },
        "viewId": { "$ref": "#/$defs/identifier" },
        "revision": { "type": "integer", "minimum": 0 },
        "actionId": { "$ref": "#/$defs/identifier" },
        "values": {
          "type": "object",
          "maxProperties": 32,
          "propertyNames": { "$ref": "#/$defs/identifier" },
          "additionalProperties": {
            "oneOf": [
              { "type": "string", "maxLength": 8192 },
              { "type": "boolean" }
            ]
          }
        }
      },
      "additionalProperties": false
    }
  }
}