#!/usr/bin/env python3
# SPDX-License-Identifier: Apache-2.0
# Copyright 2024-2026 Lukasz Krzemien (biuro@softspark.eu)
# Source: https://github.com/softspark/ai-toolkit

"""Generate ``.cursor/agents/ai-toolkit-*.md`` files for Cursor IDE.

Each ai-toolkit agent is mirrored as a Cursor custom agent. Per Cursor's
subagent docs (cursor.com/docs/subagents) the frontmatter schema documents
only these fields:

    ---
    name: <slug>              # lowercase letters and hyphens
    description: "<one-line summary shown in the Task picker>"
    model: inherit            # `inherit` (default) or a specific model id
    ---

    <system prompt body>

Design choices:

* ``model: inherit`` is emitted — the documented default value. Our agents
  store short aliases (``opus``/``sonnet``/``haiku``) that do not map to
  Cursor's provider-qualified model ids, so we use the literal ``inherit``.
* ``tools`` and ``color`` are NOT emitted — the current Cursor schema documents
  only name/description/model/readonly/is_background (tools/color were dropped).
* Files are prefixed ``ai-toolkit-`` so install/uninstall can identify ours.
* Regeneration removes stale ``ai-toolkit-*.md`` files whose source agent
  no longer exists, but leaves user-authored agents untouched.

Usage:
  python3 scripts/generate_cursor_agents.py [target-dir]

Writes files to ``target-dir/.cursor/agents/``.
"""
from __future__ import annotations

import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parent))
from emission import agents_dir
from frontmatter import frontmatter_field

AGENT_PREFIX = "ai-toolkit-"


def _agent_body(agent_file: Path) -> str:
    """Return the markdown body of an agent file (content after frontmatter)."""
    text = agent_file.read_text(encoding="utf-8")
    if not text.startswith("---"):
        return text.strip() + "\n"
    parts = text.split("---", 2)
    if len(parts) < 3:
        return text.strip() + "\n"
    return parts[2].lstrip("\n")


def _render_cursor_agent(agent_file: Path) -> str:
    """Render a single Cursor custom agent .md file."""
    name = frontmatter_field(agent_file, "name")
    description = frontmatter_field(agent_file, "description")

    safe_desc = description.replace('"', "'")

    lines: list[str] = ["---"]
    lines.append(f"name: {name}")
    lines.append(f'description: "{safe_desc}"')
    # `inherit` is the documented default model value; our short aliases do not
    # map to Cursor's provider-qualified model ids.
    lines.append("model: inherit")
    lines.append("---")
    lines.append("")
    body = _agent_body(agent_file).rstrip()
    if body:
        lines.append(body)
    lines.append("")
    return "\n".join(lines)


def _cleanup_stale(agents_out: Path) -> int:
    """Remove stale ai-toolkit-* agent files whose source no longer exists."""
    if not agents_out.is_dir():
        return 0
    removed = 0
    for f in sorted(agents_out.glob(f"{AGENT_PREFIX}*.md")):
        source_name = f.stem[len(AGENT_PREFIX):]
        source = agents_dir / f"{source_name}.md"
        if not source.is_file():
            f.unlink()
            removed += 1
    return removed


def generate(
    target_dir: Path, config_root: Path | None = None
) -> tuple[int, int]:
    """Write Cursor agent files and return (written, removed_stale).

    By default writes to ``target_dir/.cursor/agents/`` (project-local).
    Pass ``config_root=~/.cursor`` for the global layout.
    """
    base = config_root if config_root is not None else target_dir / ".cursor"
    agents_out = base / "agents"
    agents_out.mkdir(parents=True, exist_ok=True)

    written = 0
    for agent_file in sorted(agents_dir.glob("*.md")):
        name = frontmatter_field(agent_file, "name")
        description = frontmatter_field(agent_file, "description")
        if not name or not description:
            continue
        out_path = agents_out / f"{AGENT_PREFIX}{name}.md"
        out_path.write_text(_render_cursor_agent(agent_file), encoding="utf-8")
        written += 1

    removed = _cleanup_stale(agents_out)
    return written, removed


def main() -> None:
    target = Path(sys.argv[1]) if len(sys.argv) > 1 else Path.cwd()
    written, removed = generate(target)
    msg = f"Generated: .cursor/agents/ ({written} agents"
    if removed:
        msg += f", {removed} stale removed"
    msg += ")"
    print(msg)


if __name__ == "__main__":
    main()