"""Message formatting and system prompt construction."""

from __future__ import annotations

from pathlib import Path


def build_system_prompt(
    identity_dir: Path,
    memory_context: str = "",
    tools_description: str = "",
) -> str:
    """Build the system prompt from identity files + memory + tools."""
    parts = []

    # 1. Identity: SOUL.md
    soul_path = identity_dir / "SOUL.md"
    if soul_path.exists():
        parts.append(soul_path.read_text(encoding="utf-8").strip())

    # 2. Identity: USER.md
    user_path = identity_dir / "USER.md"
    if user_path.exists():
        parts.append(user_path.read_text(encoding="utf-8").strip())

    # 3. Memory context (injected by memory system)
    if memory_context:
        parts.append(f"# Relevant Memory\n{memory_context}")

    # 4. Available tools
    if tools_description:
        parts.append(f"# Available Tools\n{tools_description}")

    # 5. Core instructions
    parts.append(
        "# Instructions\n"
        "- Use tools when they would help answer the user's request.\n"
        "- If you learn something important about the user, save it to memory.\n"
        "- Be concise but thorough. Don't pad responses unnecessarily.\n"
        "- When uncertain, ask for clarification.\n"
        "- Reference memories naturally when relevant.\n"
        "- IMPORTANT: Do NOT call the same tool twice with the same arguments. "
        "If a tool already returned a result, use that result — do not re-call it.\n"
        "- After using tools, always respond to the user with a final answer. "
        "Do not end your turn with only tool calls and no text.\n"
        "- For tasks requiring shell commands, file edits, or system access, "
        "use the delegate_task tool instead of trying to do it yourself."
    )

    return "\n\n---\n\n".join(parts)


def format_messages_for_llm(
    system_prompt: str,
    history: list[dict],
    max_messages: int = 50,
) -> list[dict]:
    """Format conversation history into LLM message format."""
    messages = [{"role": "system", "content": system_prompt}]

    # Take the most recent messages up to the limit
    recent = history[-max_messages:] if len(history) > max_messages else history

    for msg in recent:
        role = msg.get("role", "user")
        content = msg.get("content", "")
        if role in ("user", "assistant", "system"):
            messages.append({"role": role, "content": content})
        elif role == "tool":
            # Tool results go as a user message with context
            tool_name = msg.get("tool_result", "unknown")
            messages.append({"role": "user", "content": f'[Tool "{tool_name}" result]\n{content}'})

    return messages