"""
This module implements the MkDocsRenderer, which generates Markdown source files
compatible with the MkDocs 'material' theme and 'mkdocstrings' extension.
"""

from pathlib import Path

from docforge.models import Project


class MkDocsRenderer:
    """
    Renderer that generates Markdown source files formatted for the MkDocs
    'mkdocstrings' plugin.
    """

    name = "mkdocs"

    def generate_sources(self, project: Project, out_dir: Path) -> None:
        """
        Produce a set of Markdown files in the output directory based on the
        provided Project models.

        Args:
            project: The project models to render.
            out_dir: Target directory for documentation files.
        """
        modules = list(project.get_all_modules())
        paths = {m.path for m in modules}

        # Package detection (level-agnostic)
        packages = {
            p for p in paths
            if any(other.startswith(p + ".") for other in paths)
        }

        for module in modules:
            self._write_module(module, packages, out_dir)

    # -------------------------
    # Internal helpers
    # -------------------------
    def _write_module(self, module, packages: set[str], out_dir: Path) -> None:
        """
        Write a single module's documentation file. Packages are written as
        'index.md' inside their respective directories.

        Args:
            module: The module to write.
            packages: A set of module paths that are identified as packages.
            out_dir: The base output directory.
        """
        parts = module.path.split(".")

        if module.path in packages:
            # package → index.md
            dir_path = out_dir.joinpath(*parts)
            dir_path.mkdir(parents=True, exist_ok=True)

            md_path = dir_path / "index.md"
            title = parts[-1].replace("_", " ").title()
        else:
            # leaf module → <name>.md
            dir_path = out_dir.joinpath(*parts[:-1])
            dir_path.mkdir(parents=True, exist_ok=True)

            md_path = dir_path / f"{parts[-1]}.md"
            title = parts[-1].replace("_", " ").title()

        content = self._render_markdown(title, module.path)

        if md_path.exists() and md_path.read_text(encoding="utf-8") == content:
            return

        md_path.write_text(content, encoding="utf-8")

    def _render_markdown(self, title: str, module_path: str) -> str:
        """
        Generate the Markdown content for a module file.

        Args:
            title: The display title for the page.
            module_path: The dotted path of the module to document.

        Returns:
            A string containing the Markdown source.
        """
        return (
            f"# {title}\n\n"
            f"::: {module_path}\n"
        )