from __future__ import annotations

import json
import os
from pathlib import Path
from typing import Any

import frontmatter


PROJECT_ROOT = Path(__file__).resolve().parents[1]
ZPWIKI_ROOT = Path(os.getenv("ZPWIKI_ROOT", str(PROJECT_ROOT.parent / "zpwiki"))).resolve()
PAGES_ROOT = ZPWIKI_ROOT / "pages"

DATA_DIR = PROJECT_ROOT / "data"
DOCUMENTS_FILE = DATA_DIR / "documents.json"
CHUNKS_FILE = DATA_DIR / "chunks.json"
DB_FILE = DATA_DIR / "zp_index.sqlite"


def json_safe(value: Any) -> Any:
    """Prevedie metadata do formátu vhodného pre JSON."""
    if value is None or isinstance(value, (str, int, float, bool)):
        return value

    if isinstance(value, list):
        return [json_safe(item) for item in value]

    if isinstance(value, dict):
        return {str(key): json_safe(item) for key, item in value.items()}

    return str(value)


def normalize_list(value: Any) -> list[str]:
    """Zjednotí hodnotu na čistý zoznam bez duplicít."""
    if value is None:
        return []

    if isinstance(value, list):
        raw_items = [str(item).strip() for item in value]
    elif isinstance(value, str):
        raw_items = [item.strip() for item in value.split(",")]
    else:
        raw_items = [str(value).strip()]

    items = []
    seen = set()

    for item in raw_items:
        if item and item not in seen:
            items.append(item)
            seen.add(item)

    return items


def read_json(path: Path) -> Any:
    if not path.exists():
        raise FileNotFoundError(f"Súbor neexistuje: {path}")

    with path.open("r", encoding="utf-8") as file:
        return json.load(file)


def write_json(path: Path, data: Any) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)

    with path.open("w", encoding="utf-8") as file:
        json.dump(data, file, ensure_ascii=False, indent=2)


def load_zpwiki_page(file_path: Path) -> dict[str, Any]:
    post = frontmatter.load(file_path)

    metadata = {
        key: json_safe(value)
        for key, value in post.metadata.items()
    }

    taxonomy = metadata.get("taxonomy") or {}

    categories = normalize_list(
        metadata.get("category")
        or taxonomy.get("category")
    )

    tags = normalize_list(
        metadata.get("tag")
        or metadata.get("tags")
        or taxonomy.get("tag")
        or taxonomy.get("tags")
    )

    return {
        "path": str(file_path.relative_to(ZPWIKI_ROOT)),
        "title": metadata.get("title"),
        "categories": categories,
        "tags": tags,
        "published": metadata.get("published"),
        "author": metadata.get("author") or taxonomy.get("author"),
        "taxonomy": taxonomy,
        "metadata": metadata,
        "content": post.content.strip(),
    }