from ..paths import get_templates_path
from ..cli import CLI
import shutil
import os

def find_template_conflicts(dest_dir: str) -> list[str]:
    templates_path = get_templates_path() / "project"

    if not os.path.exists(templates_path):
        raise RuntimeError(f"Project template path does not exist: {templates_path}")

    conflicts = []

    for root, _, files in os.walk(templates_path):
        rel = os.path.relpath(root, templates_path)
        target_root = os.path.join(dest_dir, rel) if rel != "." else dest_dir

        for file in files:
            target_file = os.path.join(target_root, file)
            if os.path.exists(target_file):
                conflicts.append(target_file)

    return conflicts

def copy_template_files(dest_dir: str, force: bool = False, checked: bool = False) -> None:
    templates_path = get_templates_path() / "project"

    if not os.path.exists(templates_path):
        raise RuntimeError(f"Project template path does not exist: {templates_path}")

    os.makedirs(dest_dir, exist_ok=True)

    if not checked:
        conflicts = find_template_conflicts(dest_dir)
        if conflicts and not force:
            raise FileExistsError(
                "Refusing to overwrite existing files:\n" +
                "\n".join(conflicts)
            )

    shutil.copytree(
        templates_path,
        dest_dir,
        dirs_exist_ok=True
    )

def main(args, flags) -> int:
    dest_dir = args[0]
    force = flags["force"]

    conflicts = find_template_conflicts(dest_dir)
    if conflicts and not force:
        print("Some files already exist that would be overwritten:")
        for file in conflicts:
            print(f"  {file}")

        print("Use --force to overwrite existing files.")
        return 1
    
    copy_template_files(dest_dir, force=force, checked=True)

    return 0

def setup(cli: CLI):
    cli.command(
        "init",
        help="Create an empty chipnut workspace or reinitialize with --force",
        description=(
            "Initialize a chipnut development workspace by creating a Nutfile and default project files. "
            "If a Nutfile already exists, initialization should fail unless --force is used."
        ),
    ).flag(
        "force",
        "f",
        help="Reinitialize even when a Nutfile already exists",
    ).arg(
        "path",
        nargs="?",
        default=".",
        help="Directory to initialize (default: current directory)",
    ).handle(main)