#!/usr/bin/env python3
"""Obsidian TODO Scanner

Scan a project directory for TODO / FIXME / HACK / XXX comments and
emit a Markdown note into an Obsidian vault.

Usage:
    python main.py /path/to/project
    python main.py /path/to/project --vault ~/Obsidian/MyVault
    python main.py /path/to/project --name "My Project"
"""

import argparse
import sys
from datetime import datetime
from pathlib import Path
from typing import List

from utils.config import ensure_unique_path, get_vault_path, sanitize_filename
from utils.scanner import TodoItem, count_tags, group_by_file, scan_directory


def generate_markdown(project_name: str, todos: List[TodoItem]) -> str:
    lines = []
    lines.append(f"# TODOs – {project_name}")
    lines.append("")
    lines.append(f"_Scanned on {datetime.now().strftime('%Y-%m-%d %H:%M')}_")
    lines.append("")

    if not todos:
        lines.append("No TODO comments found. 🎉")
        return "\n".join(lines)

    tag_counts = count_tags(todos)
    lines.append("## Summary")
    for tag, count in sorted(tag_counts.items()):
        lines.append(f"- **{tag}**: {count}")
    lines.append("")

    groups = group_by_file(todos)
    lines.append("## By File")
    lines.append("")

    for file_path, items in sorted(groups.items(), key=lambda x: str(x[0])):
        lines.append(f"### `{file_path}`")
        for item in items:
            # Obsidian checkbox + link to line in backticks
            lines.append(f"- [ ] **{item.tag}** (line {item.line}) – {item.text}")
        lines.append("")

    return "\n".join(lines)


def main():
    parser = argparse.ArgumentParser(
        description="Scan a project for TODOs and write them to an Obsidian vault."
    )
    parser.add_argument("project", help="Path to the project directory to scan.")
    parser.add_argument(
        "--vault",
        dest="vault",
        default=None,
        help="Path to the Obsidian vault. Overrides OBSIDIAN_VAULT env var.",
    )
    parser.add_argument(
        "--name",
        dest="name",
        default=None,
        help="Project name for the note title. Defaults to the directory name.",
    )
    parser.add_argument(
        "--output-dir",
        dest="output_dir",
        default="Todos",
        help="Subdirectory inside the vault where the note is created (default: Todos).",
    )
    args = parser.parse_args()

    project_path = Path(args.project).expanduser().resolve()
    if not project_path.exists():
        print(f"Error: project path does not exist: {project_path}", file=sys.stderr)
        sys.exit(1)
    if not project_path.is_dir():
        print(f"Error: not a directory: {project_path}", file=sys.stderr)
        sys.exit(1)

    try:
        vault_path = get_vault_path(args.vault)
    except Exception as e:
        print(f"Error: {e}", file=sys.stderr)
        sys.exit(1)

    project_name = args.name or project_path.name
    print(f"🔍 Scanning {project_path} ...")
    todos = scan_directory(project_path)
    print(f"   Found {len(todos)} item(s).")

    md_content = generate_markdown(project_name, todos)

    note_dir = vault_path / args.output_dir
    note_dir.mkdir(parents=True, exist_ok=True)

    safe_name = sanitize_filename(f"TODOs {project_name}")
    note_path = note_dir / f"{safe_name}.md"
    note_path = ensure_unique_path(note_path)

    try:
        note_path.write_text(md_content, encoding="utf-8")
        print(f"✅ Note written to: {note_path}")
    except OSError as e:
        print(f"Error writing note: {e}", file=sys.stderr)
        sys.exit(1)


if __name__ == "__main__":
    main()