# app/services/changelog_loader.py
from __future__ import annotations
from dataclasses import dataclass
from pathlib import Path
from typing import Any, List, Optional, Dict
import yaml

from flask import Blueprint, current_app, render_template

@dataclass
class ChangeItem:
    title: str
    details: List[str]

@dataclass
class VersionLog:
    version: str
    features: List[ChangeItem]
    refactors: List[ChangeItem]
    fixes: List[ChangeItem]
    notes: List[str]

@dataclass
class Changelog:
    unreleased: Dict[str, List[ChangeItem]]
    versions: List[VersionLog]

def _coerce_items(items: Optional[List[Dict[str, Any]]]) -> List[ChangeItem]:
    out: List[ChangeItem] = []
    for it in items or []:
        title = str(it.get("title", "")).strip()
        details = [str(d) for d in (it.get("details") or [])]
        out.append(ChangeItem(title=title, details=details))
    return out

def load_changelog(path: Path) -> Changelog:
    """
    Load changelog.yaml and coerce into dataclasses.
    """
    data = yaml.safe_load(path.read_text(encoding="utf-8"))

    unreleased = {
        "features": _coerce_items(data.get("unreleased", {}).get("features")),
        "refactors": _coerce_items(data.get("unreleased", {}).get("refactors")),
        "fixes": _coerce_items(data.get("unreleased", {}).get("fixes")),
    }

    versions: List[VersionLog] = []
    for v in data.get("versions", []):
        versions.append(
            VersionLog(
                version=str(v.get("version")),
                features=_coerce_items(v.get("features")),
                refactors=_coerce_items(v.get("refactors")),
                fixes=_coerce_items(v.get("fixes")),
                notes=[str(n) for n in (v.get("notes") or [])],
            )
        )

    return Changelog(unreleased=unreleased, versions=versions)


bp = Blueprint("changelog", __name__)

@bp.route("/changelog")
def view_changelog():
    # Configurable path with sensible default at project root
    cfg_path = current_app.config.get("CHANGELOG_FILE")
    path = Path(cfg_path) if cfg_path else (Path(current_app.root_path).parent / "changelog.yaml")
    changelog = load_changelog(path)
    return render_template("changelog.html", changelog=changelog)