// OpenAI helper functions for translator

// Valid OpenAI content block types
export const VALID_OPENAI_CONTENT_TYPES = ["text", "image_url", "image"];
export const VALID_OPENAI_MESSAGE_TYPES = ["text", "image_url", "image", "tool_calls", "tool_result"];

// Filter messages to OpenAI standard format
// Remove: thinking, redacted_thinking, signature, and other non-OpenAI blocks
export function filterToOpenAIFormat(body) {
  if (!body.messages || !Array.isArray(body.messages)) return body;
  
  body.messages = body.messages.map(msg => {
    // Keep tool messages as-is (OpenAI format)
    if (msg.role === "tool") return msg;
    
    // Keep assistant messages with tool_calls as-is
    if (msg.role === "assistant" && msg.tool_calls) return msg;
    
    // Handle string content
    if (typeof msg.content === "string") return msg;
    
    // Handle array content
    if (Array.isArray(msg.content)) {
      const filteredContent = [];
      
      for (const block of msg.content) {
        // Skip thinking blocks
        if (block.type === "thinking" || block.type === "redacted_thinking") continue;
        
        // Only keep valid OpenAI content types
        if (VALID_OPENAI_CONTENT_TYPES.includes(block.type)) {
          // Remove signature field if exists
          const { signature, cache_control, ...cleanBlock } = block;
          filteredContent.push(cleanBlock);
        } else if (block.type === "tool_use") {
          // Convert tool_use to tool_calls format (handled separately)
          continue;
        } else if (block.type === "tool_result") {
          // Keep tool_result but clean it
          const { signature, cache_control, ...cleanBlock } = block;
          filteredContent.push(cleanBlock);
        }
      }
      
      // If all content was filtered, add empty text
      if (filteredContent.length === 0) {
        filteredContent.push({ type: "text", text: "" });
      }
      
      return { ...msg, content: filteredContent };
    }
    
    return msg;
  });
  
  // Filter out messages with only empty text (but NEVER filter tool messages)
  body.messages = body.messages.filter(msg => {
    // Always keep tool messages
    if (msg.role === "tool") return true;
    // Always keep assistant messages with tool_calls
    if (msg.role === "assistant" && msg.tool_calls) return true;
    
    if (typeof msg.content === "string") return msg.content.trim() !== "";
    if (Array.isArray(msg.content)) {
      return msg.content.some(b => 
        (b.type === "text" && b.text?.trim()) ||
        b.type !== "text"
      );
    }
    return true;
  });

  // Remove empty tools array (some providers like QWEN reject it)
  if (body.tools && Array.isArray(body.tools) && body.tools.length === 0) {
    delete body.tools;
  }

  return body;
}