#!/usr/bin/env python3

import json
import os
import shutil
from dataclasses import dataclass
from datetime import datetime
from pathlib import Path

import jinja2
from typst import Compiler


@dataclass
class CompiledPage:
    url: str
    title: str
    date: datetime


class Builder:
    def __init__(self, site_dir: Path, static_dir: Path, public_dir: Path) -> None:
        self.site_dir = site_dir
        self.content_dir = site_dir / 'content'
        self.static_dir = static_dir
        self.public_dir = public_dir
        self.compiler = Compiler(root=site_dir)

    def _compile_typst_page(self, path: Path) -> CompiledPage:
        relative_path = path.relative_to(self.content_dir)
        print(f'Typst: {relative_path}')

        output_path = self.public_dir / relative_path.with_suffix('.html')
        output_path.parent.mkdir(parents=True, exist_ok=True)

        self.compiler.compile(input=path, output=output_path)

        metadata = json.loads(
            self.compiler.query(
                selector='<post-meta>',
                field='value',
                one=True,
            )
        )

        return CompiledPage(
            url=str(relative_path.with_suffix('.html')),
            title=metadata['title'],
            date=datetime(
                year=metadata['date_year'],
                month=metadata['date_month'],
                day=metadata['date_day'],
            ),
        )

    def _compile_typst_pages(self) -> list[CompiledPage]:
        return [self._compile_typst_page(path) for path in self.content_dir.rglob('*.typ')]

    def _compile_index_page(self, pages: list[CompiledPage]) -> None:
        pages.sort(key=lambda page: page.date)
        template = jinja2.Template((self.site_dir / 'index.html').read_text())
        (self.public_dir / 'index.html').write_text(template.render(pages=pages))

    def build(self) -> None:
        print(f'Removing {str(self.public_dir)!r}...')
        shutil.rmtree(self.public_dir, ignore_errors=True)
        self.public_dir.mkdir(parents=True, exist_ok=True)

        print('Linking static directory...')
        (self.public_dir / 'static').symlink_to(self.static_dir)

        pages = self._compile_typst_pages()

        print('Building index page...')
        self._compile_index_page(pages)


def main() -> None:
    repo_dir = Path(__file__).parent
    site_dir = repo_dir / 'site'
    public_dir = repo_dir / 'public'
    static_dir = repo_dir / 'static'

    os.environ['TYPST_FEATURES'] = 'html'

    builder = Builder(site_dir=site_dir, static_dir=static_dir, public_dir=public_dir)
    builder.build()


if __name__ == '__main__':
    main()