/**
 * Anthropic canonical content block types
 * Per constraint #6: Anthropic canonical content blocks
 *
 * @module packages/contracts/src/content-block
 */

/**
 * Text content block
 */
export interface TextBlock {
  type: 'text'
  text: string
}

/**
 * Thinking/reasoning block (for models that support it)
 */
export interface ThinkingBlock {
  type: 'thinking'
  thinking: string
}

/**
 * Tool use block - represents a tool call request
 */
export interface ToolUseBlock {
  type: 'tool_use'
  id: string
  name: string
  input: Record<string, unknown>
}

/**
 * Tool result block - represents the result of a tool execution
 */
export interface ToolResultBlock {
  type: 'tool_result'
  tool_use_id: string
  content: string | ContentBlock[]
  is_error?: boolean
}

/**
 * Union of all canonical content block types
 */
export type ContentBlock = TextBlock | ThinkingBlock | ToolUseBlock | ToolResultBlock

/**
 * Canonical message format using content blocks
 */
export interface CanonicalMessage {
  role: 'user' | 'assistant' | 'system'
  content: string | ContentBlock[]
  // Optional thinking for assistant messages
  thinking?: string
}

/**
 * Tool definition for tool use blocks
 */
export interface ToolDefinitionBlock {
  name: string
  description: string
  input_schema: Record<string, unknown>
}

/**
 * Tool choice specification
 */
export type ToolChoice =
  | { type: 'auto' }
  | { type: 'any' }
  | { type: 'tool'; name: string }