"""FlowDeck — Export endpoints (v4.7.0).

Routes /api/export/* — generate Markdown, HTML, PDF and static-site (zip)
exports server-side for a given page.
"""
from __future__ import annotations

import logging
import re

from fastapi import APIRouter, HTTPException, Request
from fastapi.responses import Response

from app.db import get_conn
from app.services.export import (
    build_static_site_bytes,
    page_to_markdown,
    page_to_pdf_bytes,
    page_to_standalone_html,
)

logger = logging.getLogger(__name__)
router = APIRouter(tags=["export"], prefix="/api/export")


def _load_page_or_404(page_id: int) -> dict:
    with get_conn() as conn:
        row = conn.execute(
            "SELECT * FROM pages WHERE id=? AND deleted_at IS NULL",
            (page_id,),
        ).fetchone()
    if not row:
        raise HTTPException(status_code=404, detail="Page not found")
    return dict(row)


def _download_header(filename: str, media_type: str) -> dict:
    ascii_name = re.sub(r"[^\x00-\x7F]", "_", filename)
    quoted = filename.replace('"', '')
    return {
        "Content-Disposition": f'attachment; filename="{ascii_name}"; filename*=UTF-8\'\'{quoted}',
        "Cache-Control": "no-store",
        "Content-Type": media_type,
    }


def _safe_filename(page: dict, ext: str) -> str:
    title = (page.get("title") or "Untitled").strip() or "Untitled"
    title = re.sub(r'[\\/:*?"<>|]+', "_", title)
    return f"{title}.{ext}"


@router.get("/markdown/{page_id}")
async def export_markdown(page_id: int, request: Request):
    page = _load_page_or_404(page_id)
    md = page_to_markdown(page)
    filename = _safe_filename(page, "md")
    headers = _download_header(filename, "text/markdown")
    return Response(content=md.encode("utf-8"), status_code=200, headers=headers)


@router.get("/html/{page_id}")
async def export_html(page_id: int, request: Request):
    page = _load_page_or_404(page_id)
    html = page_to_standalone_html(page)
    filename = _safe_filename(page, "html")
    headers = _download_header(filename, "text/html")
    return Response(content=html.encode("utf-8"), status_code=200, headers=headers)


@router.get("/pdf/{page_id}")
async def export_pdf(page_id: int, request: Request):
    page = _load_page_or_404(page_id)
    try:
        pdf_bytes = page_to_pdf_bytes(page)
    except ImportError:
        raise HTTPException(status_code=501, detail="PDF export requires 'weasyprint' or 'xhtml2pdf'") from None
    except Exception as exc:  # noqa: BLE001
        logger.error("PDF export failed for page %s: %s", page_id, exc)
        raise HTTPException(status_code=500, detail="PDF generation failed") from exc
    filename = _safe_filename(page, "pdf")
    headers = _download_header(filename, "application/pdf")
    return Response(content=pdf_bytes, status_code=200, headers=headers)


@router.get("/site/{page_id}")
async def export_site(page_id: int, request: Request):
    page = _load_page_or_404(page_id)
    site_bytes = build_static_site_bytes(page)
    title = _safe_filename(page, "site").replace(".site", "") or "flowdeck-site"
    filename = f"{title}_site.zip"
    headers = _download_header(filename, "application/zip")
    return Response(content=site_bytes, status_code=200, headers=headers)