/**
 * Protocol types and limits defined in CONTRACTS.md Revision 1
 */

export const PROTOCOL_VERSION = 1;

// Size limits in bytes
export const KIB = 1024;
export const MIB = 1024 * 1024;

/**
 * Protocol maximum for one query in milliseconds. The backend sets
 * CONFLUENCE_WEB_MAX_DEADLINE_SECONDS on the container; the supervisor forwards
 * it. Invalid or absent values fall back to 900 s (15 minutes).
 */
function maxDeadlineMs(): number {
  const raw = typeof process !== 'undefined' ? process.env.CONFLUENCE_WEB_MAX_DEADLINE_SECONDS : undefined;
  const seconds = raw === undefined || raw === '' ? NaN : Number(raw);
  return Number.isInteger(seconds) && seconds >= 60 && seconds <= 3600 ? seconds * 1000 : 900_000;
}

export const LIMITS = {
  USER_PROMPT_MAX_BYTES: 16 * MIB,
  FINAL_MARKDOWN_MAX_BYTES: 128 * MIB,
  TOOL_REQUEST_PAYLOAD_MAX_BYTES: 16 * MIB,
  TOOL_RESULT_PAYLOAD_MAX_BYTES: 128 * MIB,
  MODEL_REQUEST_PAYLOAD_MAX_BYTES: 128 * MIB,
  MODEL_RESULT_PAYLOAD_MAX_BYTES: 128 * MIB,
  ENVELOPE_ALLOWANCE_BYTES: 64 * KIB,
  START_FRAME_MAX_BYTES: 6 * (16 * MIB) + 64 * KIB,
  COLLECTION_START_FRAME_MAX_BYTES: 6 * (128 * MIB) + 64 * KIB,
  ORDINARY_FRAME_MAX_BYTES: 128 * MIB + 64 * KIB,
  ARTIFACT_CHUNK_MAX_DECODED_BYTES: 64 * KIB,
  ARTIFACT_MAX_FILES: 20,
  ARTIFACT_MAX_FILE_BYTES: 10 * MIB,
  ARTIFACT_MAX_TOTAL_BYTES: 50 * MIB,
  MAX_DEADLINE_MS: maxDeadlineMs(),
  MAX_REMOTE_CONCURRENCY: 4,
  MAX_WARNINGS: 100,
  MAX_ERROR_MESSAGE_BYTES: 1024,
  MAX_PATH_BYTES: 1024
} as const;

export interface ErrorShape {
  code: string;
  message: string;
}

export interface Warning {
  code: string;
  message: string;
  tool_call_id?: string;
  name?: string;
}

export interface Page {
  page_id: string;
  title: string;
  space: string;
  url: string;
}

export interface Pagination {
  offset: number;
  limit: number;
  has_more: boolean;
}

export interface ModelDescriptor {
  id: string;
  context_window_tokens: number;
  max_output_tokens: number;
}

// Model Protocol
export type TextContentBlock = {
  type: "text";
  text: string;
};

export type ToolCallContentBlock = {
  type: "tool_call";
  id: string;
  name: string;
  arguments: Record<string, any>;
};

export type ContentBlock = TextContentBlock | ToolCallContentBlock;

export interface UserMessageContract {
  role: "user";
  content: Array<{ type: "text"; text: string }>;
}

export interface AssistantMessageContract {
  role: "assistant";
  content: ContentBlock[];
  provider_state?: string;
}

export interface ToolMessageContract {
  role: "tool";
  tool_call_id: string;
  name: string;
  content: string;
  is_error: boolean;
}

export type MessageContract =
  | UserMessageContract
  | AssistantMessageContract
  | ToolMessageContract;

export interface ToolDeclaration {
  name: string;
  description: string;
  input_schema: Record<string, any>;
}

export interface ModelRequest {
  messages: MessageContract[];
  tools: ToolDeclaration[];
}

export interface ModelResponse {
  content: ContentBlock[];
  stop_reason: "stop" | "tool_calls" | "length";
  usage: {
    input_tokens: number;
    output_tokens: number;
  };
  provider_state?: string;
}

// Bridge Protocol Frames
export interface BridgeBaseMessage {
  v: number;
  type: string;
  id: string;
  reply_to?: string;
  payload: any;
}

export interface StartMessage extends BridgeBaseMessage {
  type: "start";
  payload: {
    prompt: string;
    system_instruction: string;
    remaining_ms: number;
    model: ModelDescriptor;
  };
}

export interface ToolRequestMessage extends BridgeBaseMessage {
  type: "tool_request";
  payload: {
    tool: string;
    parameters: Record<string, any>;
  };
}

export interface ToolResponseMessage extends BridgeBaseMessage {
  type: "tool_response";
  reply_to: string;
  payload: {
    result: any;
    error: ErrorShape | null;
  };
}

export interface ModelRequestMessage extends BridgeBaseMessage {
  type: "model_request";
  payload: ModelRequest;
}

export interface ModelResponseMessage extends BridgeBaseMessage {
  type: "model_response";
  reply_to: string;
  payload: {
    result: ModelResponse | null;
    error: ErrorShape | null;
  };
}

export interface CollectionStartMessage extends BridgeBaseMessage {
  type: "collection_start";
  payload: {
    markdown: string;
    warnings: Warning[];
  };
}

export interface CollectionReadyMessage extends BridgeBaseMessage {
  type: "collection_ready";
  reply_to: string;
  payload: Record<string, never>;
}

export interface ArtifactBeginMessage extends BridgeBaseMessage {
  type: "artifact_begin";
  payload: {
    transfer_id: string;
    name: string;
    size_bytes: number;
  };
}

export interface ArtifactAckMessage extends BridgeBaseMessage {
  type: "artifact_ack";
  reply_to: string;
  payload: {
    transfer_id: string;
    decision: "accept" | "skip" | "stored";
    warning: Warning | null;
  };
}

export interface ArtifactChunkMessage extends BridgeBaseMessage {
  type: "artifact_chunk";
  payload: {
    transfer_id: string;
    index: number;
    data_base64: string;
  };
}

export interface ArtifactEndMessage extends BridgeBaseMessage {
  type: "artifact_end";
  payload: {
    transfer_id: string;
    size_bytes: number;
    chunks: number;
  };
}

export interface CompleteMessage extends BridgeBaseMessage {
  type: "complete";
  payload: {
    accepted_transfer_count: number;
  };
}

export interface ErrorMessage extends BridgeBaseMessage {
  type: "error";
  payload: ErrorShape;
}

export type BridgeInboundMessage =
  | StartMessage
  | ToolResponseMessage
  | ModelResponseMessage
  | CollectionReadyMessage
  | ArtifactAckMessage;

export type BridgeOutboundMessage =
  | ToolRequestMessage
  | ModelRequestMessage
  | CollectionStartMessage
  | ArtifactBeginMessage
  | ArtifactChunkMessage
  | ArtifactEndMessage
  | CompleteMessage
  | ErrorMessage;