"""Assemble LaTeX project from markdown (pipeline 1: MD → LaTeX)."""

from __future__ import annotations

import shutil
from pathlib import Path

from .emitter import emit_document


def package_template_dir() -> Path:
    return Path(__file__).resolve().parent.parent / "latex" / "mirea"


def convert_md_to_latex_project(
    md_path: str | Path,
    out_dir: str | Path,
    *,
    titlepage: str | Path | None = None,
) -> Path:
    """
    Copy MIREA template into out_dir, write content.tex from markdown.

    Returns path to main.tex
    """
    md_path = Path(md_path).resolve()
    out_dir = Path(out_dir).resolve()
    tpl = package_template_dir()
    if not tpl.is_dir():
        raise FileNotFoundError(f"LaTeX template not found: {tpl}")

    out_dir.mkdir(parents=True, exist_ok=True)

    # sync template files (keep user Images/content if regenerating)
    for item in tpl.iterdir():
        dest = out_dir / item.name
        if item.name == "content.tex":
            continue
        if item.is_dir():
            if dest.exists():
                # merge Settings etc.
                for sub in item.rglob("*"):
                    if sub.is_file():
                        rel = sub.relative_to(item)
                        target = dest / rel
                        target.parent.mkdir(parents=True, exist_ok=True)
                        shutil.copy2(sub, target)
            else:
                shutil.copytree(item, dest)
        else:
            shutil.copy2(item, dest)

    images_dir = out_dir / "Images"
    images_dir.mkdir(exist_ok=True)

    md_text = md_path.read_text(encoding="utf-8")
    body = emit_document(
        md_text,
        work_dir=md_path.parent,
        images_dir=images_dir,
    )
    (out_dir / "content.tex").write_text(body, encoding="utf-8")

    if titlepage:
        tp = Path(titlepage)
        if tp.is_file():
            shutil.copy2(tp, out_dir / "titlepage.pdf")

    return out_dir / "main.tex"