from __future__ import annotations

from datetime import datetime, timezone
from pathlib import Path

from jinja2 import Environment, FileSystemLoader, select_autoescape

from .chapters import Section


def format_timestamp(seconds: float) -> str:
    total = int(seconds)
    hours, remainder = divmod(total, 3600)
    minutes, secs = divmod(remainder, 60)
    if hours > 0:
        return f"{hours:02d}:{minutes:02d}:{secs:02d}"
    return f"{minutes:02d}:{secs:02d}"


def quote_yaml(value: str | None) -> str:
    if value is None:
        return '""'
    needs_quote = any(c in value for c in [':', '#', '{', '}', '[', ']', ',', '&', '*', '!', '|', '>', "'", '"', '%', '@', '`', '\n'])
    if needs_quote:
        escaped = value.replace('"', '\\"')
        return f'"{escaped}"'
    return value


def to_json(value) -> str:
    import json
    return json.dumps(value, ensure_ascii=False)


def _make_env(template_dir: Path) -> Environment:
    env = Environment(
        loader=FileSystemLoader(str(template_dir)),
        autoescape=select_autoescape(disabled_extensions=("j2", "txt")),
        trim_blocks=True,
        lstrip_blocks=True,
    )
    env.filters["format_timestamp"] = format_timestamp
    env.filters["quote_yaml"] = quote_yaml
    env.filters["to_json"] = to_json
    return env


def render_markdown(
    template_path: str | Path,
    output_dir: str | Path,
    filename_stem: str,
    context: dict,
) -> Path:
    tpl_path = Path(template_path).resolve()
    env = _make_env(tpl_path.parent)
    template = env.get_template(tpl_path.name)
    rendered = template.render(**context)

    out_dir = Path(output_dir)
    out_dir.mkdir(parents=True, exist_ok=True)
    out_file = out_dir / f"{filename_stem}.md"
    out_file.write_text(rendered, encoding="utf-8")
    return out_file


def build_filename_stem(upload_date: str | None, title: str, template: str = "{upload_date}_{slug}") -> str:
    from slugify import slugify
    date_part = upload_date or "unknown-date"
    slug = slugify(title, max_length=60) or "untitled"
    stem = template.format(upload_date=date_part, slug=slug, title=title)
    safe = "".join(c for c in stem if c not in r'\/:*?"<>|')
    return safe.strip().strip(".")