"""FlowDeck — Dashboard : helpers partagés des modules de routes (A28).

Les 15 helpers top-level de l'ancien dashboard.py vivent ici (état :
_VERSION, WORKSPACE_COOKIE) — ré-exportés par le package.
"""
from __future__ import annotations

import logging

from fastapi import HTTPException, Request
from fastapi.responses import RedirectResponse

from app.auth.session import SessionManager
from app.config import settings
from app.db import get_conn

logger = logging.getLogger(__name__)

_VERSION = None

WORKSPACE_COOKIE = "flowdeck_workspace"



def _get_app_version() -> str:
    """Read version from VERSION file with caching."""
    global _VERSION
    if _VERSION is not None:
        return _VERSION
    try:
        import os
        version_path = os.path.join(os.path.dirname(__file__), "..", "..", "VERSION")
        if os.path.exists(version_path):
            with open(version_path) as f:
                _VERSION = f.read().strip()
        else:
            # Docker fallback
            version_path = "/app/VERSION"
            if os.path.exists(version_path):
                with open(version_path) as f:
                    _VERSION = f.read().strip()
            else:
                _VERSION = "0.0.0"
    except Exception:
        _VERSION = "0.0.0"
    return _VERSION






def _get_user_or_redirect(request: Request):
    """Return decoded user or a RedirectResponse to login page.
    Skips redirect when DB has no users (fresh install / test env)."""
    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
    if not user:
        # Allow through if no users exist yet (fresh install / tests)
        try:
            with get_conn() as conn:
                count = conn.execute("SELECT COUNT(*) FROM users").fetchone()[0]
                if count == 0:
                    return {"id": 1, "login": "admin", "full_name": "Admin", "is_admin": True}
        except Exception:
            logger.exception("_get_user_or_redirect")
        return RedirectResponse("/auth/login?provider=local&expired=1", status_code=302)
    return user






def _local_workspaces_for_user(user: dict | None, workspace_id: int = 0) -> list[dict]:
    """Return list of local workspaces for a user."""
    if not user:
        return []
    try:
        with get_conn() as conn:
            rows = conn.execute(
                "SELECT id, name FROM workspaces WHERE owner_id = ? ORDER BY name",
                (user["id"],)
            ).fetchall()
            return [{"id": r["id"], "name": r["name"]} for r in rows]
    except Exception:
        return []






def _sidebar_data(request: Request, repos: list[dict], include_workspace: bool = True) -> dict:
    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
    ws = user.get("login", "Bruno") if user else "Bruno"
    initial = ws[0].upper() if ws else "B"

    # Get avatar info from DB
    avatar_url = ""
    avatar_color = "#3A3A3A"
    if user:
        try:
            with get_conn() as conn:
                row = conn.execute("SELECT avatar_url, avatar_color FROM users WHERE id = ?", (user["id"],)).fetchone()
                if row:
                    avatar_url = row["avatar_url"] or ""
                    avatar_color = row["avatar_color"] or "#3A3A3A"
        except Exception:
            logger.exception("_sidebar_data")

    recent_pages = []
    for repo in repos[:10]:
        full_name = repo.get("full_name", "")
        recent_pages.append({
            "id": full_name,
            "name": repo.get("name", full_name),
            "icon": "folder",
            "url": f"/board/{full_name}",
            "active": False,
            "indent": 0,
            "depth": 0,
            "has_children": False,
            "children": [],
        })

    # Active workspace from cookie (skip on pages like /workspaces where no
    # workspace context should be shown)
    from app.routers.board import _load_workspace_pages
    ws_cookie = request.cookies.get("flowdeck_workspace", "")
    active_ws_name = "Workspace"
    workspace_pages = []
    gitea_workspace = False
    gitea_owner = ""
    gitea_repo = ""
    has_active_workspace = False
    local_ws_id = 0

    if ws_cookie and ws_cookie.startswith("gitea:"):
        # Gitea workspace: set owner/repo for client-side tree loading
        # AND open the local workspace mirror of the same name in the
        # sidebar's top "My Workspaces" section, in parallel with the
        # Gitea repository tree.
        parts = ws_cookie.split(":", 2)
        if len(parts) >= 3:
            gitea_owner = parts[1]
            gitea_repo = parts[2]
            active_ws_name = f"{gitea_owner}/{gitea_repo}"
            gitea_workspace = True
            has_active_workspace = True
            # Load the local mirror workspace tree so it appears in "My
            # Workspaces" alongside the Gitea repository section.
            if user:
                try:
                    with get_conn() as conn:
                        row = conn.execute(
                            "SELECT id FROM workspaces WHERE owner_id=? AND name=? AND settings_json LIKE ?",
                            (user["id"], f"{gitea_owner}/{gitea_repo}", "%gitea_repo%")
                        ).fetchone()
                        if row:
                            local_ws_id = row["id"]
                            workspace_pages = _load_workspace_pages(str(local_ws_id))
                except (ValueError, Exception):
                    pass
    elif include_workspace and ws_cookie and user:
        try:
            wsi = int(ws_cookie)
            with get_conn() as conn:
                # Verify this workspace belongs to the current user
                row = conn.execute(
                    "SELECT id, name, owner_id FROM workspaces WHERE id=? AND owner_id=?",
                    (wsi, user["id"])
                ).fetchone()
                if row:
                    active_ws_name = row["name"]
                    workspace_pages = _load_workspace_pages(ws_cookie)
                    has_active_workspace = True
                    # v7.46.0 : exposer l'ID de l'espace ACTIF. Avant, le sidebar
                    # ne fournissait que son nom et le bouton Home de la sidebar
                    # retombait sur ``local_workspaces[0]`` (premier espace TRIE
                    # PAR NOM) → clic sur Home = changement d'espace surprise.
                    local_ws_id = wsi
                # else: stale cookie from another user — ignore
        except (ValueError, Exception):
            pass

    # Auth method & OAuth badge data
    auth_method = "local"
    gitea_linked = False
    github_linked = False
    if user and user.get("id"):
        try:
            with get_conn() as conn:
                am_row = conn.execute("SELECT auth_method FROM users WHERE id=?", (user["id"],)).fetchone()
                if am_row and am_row["auth_method"]:
                    auth_method = am_row["auth_method"]
                tokens = conn.execute(
                    "SELECT provider FROM user_oauth_tokens WHERE user_id=?", (user["id"],)
                ).fetchall()
                for t in tokens:
                    if t["provider"] == "gitea":
                        gitea_linked = True
                    elif t["provider"] == "github":
                        github_linked = True
        except Exception:
            logger.exception("_sidebar_data")

    # Get local workspace ID for Gitea workspace mirror (le miroir Gitea est un
    # espace DISTINCT : on ne doit pas écraser ``local_ws_id`` (espace actif).
    gitea_mirror_ws_id = 0
    if gitea_workspace and gitea_owner and gitea_repo:
        try:
            with get_conn() as conn:
                row = conn.execute(
                    "SELECT id FROM workspaces WHERE owner_id=? AND name=? AND settings_json LIKE ?",
                    (user["id"], f"{gitea_owner}/{gitea_repo}", "%gitea_repo%")
                ).fetchone()
                if row:
                    gitea_mirror_ws_id = row["id"]
        except Exception:
            logger.exception("_sidebar_data")

    # Private pages for mirror workspace (when Gitea remote active)
    private_pages = []
    if gitea_workspace and gitea_mirror_ws_id:
        try:
            with get_conn() as conn:
                pp_rows = conn.execute(
                    "SELECT id, title FROM pages WHERE parent_section='Private' AND workspace_id=? AND deleted_at IS NULL ORDER BY updated_at DESC LIMIT 20",
                    (gitea_mirror_ws_id,)
                ).fetchall()
                private_pages = [{"id": r[0], "title": r[1] or "Untitled"} for r in pp_rows]
        except Exception:
            logger.exception("_sidebar_data")

    # Shared / received / published pages for the sidebar (Par moi / Avec moi)
    shared_made_pages = []
    shared_received_pages = []
    published_pages = []
    shared_pages = []
    if user and user.get("id"):
        from app.routers.board import _load_shared_sidebar_pages
        shared_made_pages, shared_received_pages, published_pages, shared_pages = _load_shared_sidebar_pages(user["id"])

    sidebar = {
        "workspace_name": ws, "workspace_initial": initial,
        "active_ws_name": active_ws_name,
        "workspace_key": f"{gitea_owner}/{gitea_repo}" if gitea_workspace else "",
        "gitea_workspace": gitea_workspace,
        "gitea_owner": gitea_owner,
        "gitea_repo": gitea_repo,
        "local_ws_id": local_ws_id,
        "workspace_pages": workspace_pages,
        "current_page": "Dashboard", "last_edited": "now",
        "recent_pages": recent_pages,
        "private_pages": private_pages,
        "favorite_pages": [],
        "shared_pages": shared_pages,
        "shared_made_pages": shared_made_pages,
        "shared_received_pages": shared_received_pages,
        "published_pages": published_pages,
        "user": user,
        "avatar_url": avatar_url,
        "avatar_color": avatar_color,
        "auth_method": auth_method,
        "gitea_linked": gitea_linked,
        "github_linked": github_linked,
        "has_active_workspace": has_active_workspace,
        "app_version": _get_app_version(),
    }

    sidebar["local_workspaces"] = _local_workspaces_for_user(user)

    return sidebar






# ═══════════ User API endpoints ═══════════

def _get_user_id(request: Request) -> int:
    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
    return user["id"] if user and user.get("id") else 1






def _require_user_id(request: Request) -> int:
    """A3/A4 — 401 sans session (les routes qui mutent un compte ne tolèrent
    plus le fallback « legacy single-user » → id 1 = l'admin seedé)."""
    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
    if not user or not user.get("id"):
        raise HTTPException(401, "Authentication required")
    return user["id"]






def _file_page_disk_path(page: dict):
    """Resolve the on-disk file behind a ``content_format == 'file'`` page.

    Returns ``(abs_path: Path, filename: str, mime: str, size: int)`` or None
    when the row is not a file page, references a non-textual/missing file, or
    the path escapes the data root (path-traversal guard).
    """
    if (page.get("content_format") or "") != "file":
        return None
    import json as _json
    try:
        meta = _json.loads(page.get("content", "{}"))
    except (_json.JSONDecodeError, TypeError):
        meta = {}
    if not isinstance(meta, dict):
        return None
    rel = (meta.get("file_path") or "").replace("\\", "/").strip()
    if not rel or not rel.startswith("uploads/"):
        return None
    parts = rel.split("/")
    if ".." in parts or "." in parts:
        return None
    from pathlib import Path
    root = Path(settings.data_dir).resolve()
    full = (root / rel).resolve()
    try:
        full.relative_to(root)
    except ValueError:
        return None
    if not full.exists() or not full.is_file():
        return None
    filename = parts[-1] or page.get("title", "file")
    mime = meta.get("mime_type") or "application/octet-stream"
    size = meta.get("size") or 0
    return (full, filename, mime, size)






def _require_page_view(request: Request, page_id: int) -> None:
    """A16 : lecture d'une pièce jointe = session + `can_view_page` (404 sinon)."""
    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
    if not user or not user.get("id"):
        raise HTTPException(401, "Authentication required")
    from app.services.permission_manager import PermissionManager

    if not PermissionManager(user["id"], bool(user.get("is_admin"))).can_view_page(page_id):
        raise HTTPException(404, "Page not found")






def _build_tree_children(conn, parent_id: int | None, ws_id: int, uid: int | None = None) -> list:
    """Recursively build the tree of children for a node."""
    if parent_id is None:
        rows = conn.execute(
            "SELECT id, title, parent_section, content_format, content, page_icon, "
            "(is_shared OR share_mode != 'private' OR COALESCE(published,0)) as is_shared, "
            "created_at, updated_at FROM pages "
            "WHERE parent_id IS NULL AND workspace_id=? AND deleted_at IS NULL AND collection_row_id IS NULL "
            "ORDER BY created_at DESC",
            (ws_id,),
        ).fetchall()
    else:
        rows = conn.execute(
            "SELECT id, title, parent_section, content_format, content, page_icon, "
            "(is_shared OR share_mode != 'private' OR COALESCE(published,0)) as is_shared, "
            "created_at, updated_at FROM pages "
            "WHERE parent_id=? AND workspace_id=? AND deleted_at IS NULL "
            "ORDER BY created_at DESC",
            (parent_id, ws_id),
        ).fetchall()

    # Get workspace owner name for author display
    ws_owner = conn.execute(
        "SELECT u.full_name, u.login FROM workspaces w JOIN users u ON u.id=w.owner_id WHERE w.id=?",
        (ws_id,),
    ).fetchone()
    author = ws_owner["full_name"] or ws_owner["login"] if ws_owner else "—"

    # Collect all page IDs to fetch tags in one query
    all_ids = [r["id"] for r in rows]
    tags_map = {}
    favorited_ids = set()
    if all_ids:
        placeholders = ",".join("?" for _ in all_ids)
        tag_rows = conn.execute(
            f"SELECT pt.page_id, t.id, t.name, t.color FROM page_tags pt "
            f"JOIN tags t ON t.id=pt.tag_id WHERE pt.page_id IN ({placeholders})",
            all_ids,
        ).fetchall()
        for tr in tag_rows:
            tags_map.setdefault(tr["page_id"], []).append({
                "id": tr["id"], "name": tr["name"], "color": tr["color"],
            })
        if uid is not None:
            fav_rows = conn.execute(
                f"SELECT page_id FROM favorites WHERE user_id=? AND page_id IN ({placeholders})",
                [uid, *all_ids],
            ).fetchall()
            favorited_ids = {fr["page_id"] for fr in fav_rows}

    tree = []
    for r in rows:
        is_folder = r["parent_section"] == "Workspace"
        children = _build_tree_children(conn, r["id"], ws_id, uid)

        # Compute size
        size = 0
        if r["content_format"] == "file":
            import json as _json
            try:
                meta = _json.loads(r["content"])
                size = meta.get("size", 0)
            except Exception:
                size = len(r["content"] or "")
        else:
            size = len(r["content"] or "")

        tree.append({
            "id": r["id"],
            "name": r["title"] or "Untitled",
            "type": "folder" if is_folder else "page",
            "is_folder": is_folder,
            "content_format": r["content_format"] if not is_folder else None,
            "page_icon": r["page_icon"] or "",
            "children": children,
            "has_children": len(children) > 0,
            "child_count": len(children),
            "size": size,
            "size_display": _format_size(size),
            "created_at": r["created_at"],
            "updated_at": r["updated_at"],
            "author": author,
            "tags": tags_map.get(r["id"], []),
            "is_shared": bool(r["is_shared"]),
            "favorited": r["id"] in favorited_ids,
        })
    return tree






def _format_size(size_bytes: int) -> str:
    """Human-readable file size."""
    if size_bytes < 1024:
        return f"{size_bytes} B"
    elif size_bytes < 1024 * 1024:
        return f"{size_bytes / 1024:.1f} KB"
    elif size_bytes < 1024 * 1024 * 1024:
        return f"{size_bytes / (1024 * 1024):.1f} MB"
    return f"{size_bytes / (1024 * 1024 * 1024):.2f} GB"






def _build_breadcrumb(conn, folder_id: int) -> list:
    """Build breadcrumb trail from root to folder_id."""
    breadcrumb = []
    current = folder_id
    seen = set()
    while current and current not in seen:
        seen.add(current)
        row = conn.execute(
            "SELECT id, title, parent_id, parent_section FROM pages WHERE id=?",
            (current,),
        ).fetchone()
        if row:
            breadcrumb.insert(0, {
                "id": row["id"],
                "name": row["title"] or "Untitled",
                "is_folder": row["parent_section"] == "Workspace",
            })
            current = row["parent_id"]
        else:
            break
    return breadcrumb






def _nav_breadcrumb(conn, page_id: int) -> list:
    """Build a Notion-style breadcrumb chain (root -> page) for the header.

    Returns a list of dicts: {id, label, url, icon, menu}. The last item is the
    current page (url = None). Every item has ``menu: True`` so the header can
    open a sibling-navigation dropdown for it.
    """
    from app.routers.board import _file_icon
    chain = []
    current = page_id
    seen = set()
    while current and current not in seen:
        seen.add(current)
        row = conn.execute(
            "SELECT id, title, parent_id, parent_section, content_format "
            "FROM pages WHERE id=? AND deleted_at IS NULL",
            (current,),
        ).fetchone()
        if not row:
            break
        is_folder = row["parent_section"] == "Workspace"
        title = row["title"] or "Untitled"
        chain.insert(0, {
            "id": row["id"],
            "label": title,
            "url": None,
            "icon": "folder" if is_folder else _file_icon(title, row["content_format"]),
            "menu": True,
        })
        current = row["parent_id"]
    # All items except the current page are navigable links.
    for i, item in enumerate(chain):
        if i < len(chain) - 1:
            item["url"] = f"/pages/{item['id']}"
    return chain






def _get_active_workspace(request: Request, user_id: int = None) -> dict | None:
    """Get the active workspace ID from the cookie (verified for current user), or first user workspace, or None."""
    ws_id = request.cookies.get(WORKSPACE_COOKIE)
    if ws_id:
        try:
            with get_conn() as conn:
                ws = conn.execute("SELECT * FROM workspaces WHERE id=?",
                                  (int(ws_id),)).fetchone()
                if ws:
                    ws_dict = dict(ws)
                    # Verify ownership — only return if it belongs to the current user
                    if user_id is None or ws_dict.get("owner_id") == user_id:
                        return ws_dict
        except (ValueError, Exception):
            pass
    # Fallback: first workspace owned by this user
    if user_id:
        with get_conn() as conn:
            ws = conn.execute(
                "SELECT * FROM workspaces WHERE owner_id=? ORDER BY id LIMIT 1",
                (user_id,)
            ).fetchone()
            if ws:
                return dict(ws)
    return None






def _sanitize_id(block_id: str) -> str:
    """Sanitize a block id for use as an HTML anchor (only alnum kept)."""
    if not block_id:
        return ""
    return "".join(ch for ch in str(block_id) if ch.isalnum())






def _render_blocks_public(blocks: list, titles: dict | None = None) -> str:
    """Render FlowDeck blocks as plain HTML for public pages.

    v5.11.0: ``titles`` (token → label, see app.services.wiki_links) turns
    ``[[fdpage:ID]]`` / ``[[fddate:...]]`` tokens into chips/links.
    """
    html_parts = []

    def _wiki(c: str) -> str:
        if titles and ("[[fdpage:" in c or "[[fddate:" in c):
            from app.services.wiki_links import resolve_tokens_html
            return resolve_tokens_html(c, titles)
        return c

    for b in blocks:
        t = b.get("type", "paragraph")
        c = _wiki(b.get("content", "") or "")
        if t == "heading_1":
            html_parts.append(f'<h1 id="h-{_sanitize_id(b.get("id",""))}" style="font-size:2.5rem;font-weight:700;margin:32px 0 8px;">{c}</h1>')
        elif t == "heading_2":
            html_parts.append(f'<h2 id="h-{_sanitize_id(b.get("id",""))}" style="font-size:1.75rem;font-weight:600;margin:28px 0 6px;">{c}</h2>')
        elif t == "heading_3":
            html_parts.append(f'<h3 id="h-{_sanitize_id(b.get("id",""))}" style="font-size:1.35rem;font-weight:600;margin:24px 0 4px;">{c}</h3>')
        elif t == "heading_4":
            html_parts.append(f'<h4 id="h-{_sanitize_id(b.get("id",""))}" style="font-size:1.15rem;font-weight:600;margin:20px 0 4px;">{c}</h4>')
        elif t == "bulleted_list":
            html_parts.append(f'<li style="margin-left:24px;">{c}</li>')
        elif t == "numbered_list":
            html_parts.append(f'<li style="margin-left:24px;list-style:decimal;">{c}</li>')
        elif t == "to_do":
            checked = "checked" if b.get("checked") else ""
            todo_style = "text-decoration:line-through;opacity:.5" if b.get("checked") else ""
            html_parts.append(
                f'<div style="display:flex;align-items:center;gap:8px;margin:4px 0;">'
                f'<input type="checkbox" {checked} disabled>'
                f'<span style="{todo_style}">{c}</span>'
                f'</div>'
            )
        elif t == "toggle":
            children_html = ""
            if b.get("children"):
                children_html = '<div style="margin-left:22px;padding-left:12px;border-left:1px solid rgba(255,255,255,.1);margin-top:4px;">'
                children_html += _render_blocks_public(b["children"], titles)
                children_html += "</div>"
            html_parts.append(
                f'<details style="margin:8px 0;" open><summary style="cursor:pointer;font-weight:500;">{c}</summary>{children_html}</details>'
            )
        elif t == "quote":
            html_parts.append(
                f'<blockquote style="border-left:3px solid var(--accent,#4c9aff);margin:12px 0;padding:4px 16px;opacity:.85;">{c}</blockquote>'
            )
        elif t == "table_of_contents":
            toc = [
                x for x in blocks
                if x.get("type", "").startswith("heading_") and (x.get("content") or "").strip()
            ]
            if toc:
                items = []
                for h in toc:
                    lvl = int(h["type"].split("_")[-1])
                    items.append(
                        f'<div style="margin-left:{max(0, lvl - 1) * 14}px;padding:5px 8px;font-size:14px;">'
                        f'<a href="#h-{_sanitize_id(h.get("id",""))}" style="color:inherit;text-decoration:none;display:block;">{h.get("content","")}</a></div>'
                    )
                html_parts.append(
                    '<div style="border:1px solid rgba(255,255,255,.1);border-radius:8px;padding:16px 20px;margin:4px 0;">'
                    '<div style="font-size:12px;font-weight:600;text-transform:uppercase;letter-spacing:.5px;opacity:.5;margin-bottom:10px;">On this page</div>'
                    + "".join(items) + "</div>"
                )
        elif t == "math":
            tex = c.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
            html_parts.append(
                f'<div data-katex="{tex}" style="margin:12px 0;padding:12px 16px;background:rgba(255,255,255,.04);border-radius:8px;overflow-x:auto;"></div>'
            )
        elif t == "columns":
            cols_html = ""
            for child in b.get("children") or []:
                cols_html += (
                    '<div style="flex:1;min-width:0;padding:10px 12px;background:rgba(255,255,255,.05);'
                    'border-radius:8px;box-sizing:border-box;">'
                    + _render_blocks_public([child], titles) + "</div>"
                )
            html_parts.append(
                f'<div style="display:flex;gap:12px;margin:8px 0 16px;align-items:stretch;">{cols_html}</div>'
            )
        elif t == "callout":
            icon = b.get("icon", "💡")
            bg = (b.get("style") or {}).get("bgColor", "rgba(76,154,255,.1)")
            html_parts.append(
                f'<div style="display:flex;gap:10px;padding:14px 18px;margin:12px 0;border-radius:8px;'
                f'background:{bg};align-items:flex-start;">'
                f'<span style="font-size:20px;flex-shrink:0;">{icon}</span>'
                f'<span>{c}</span></div>'
            )
        elif t == "code":
            lang = b.get("language", "")
            lang_label = f"<div style='font-size:11px;opacity:.4;margin-bottom:8px;'>{lang}</div>" if lang else ""
            html_parts.append(
                f'<pre style="background:rgba(255,255,255,.05);padding:16px 20px;border-radius:8px;'
                f'overflow-x:auto;font-size:14px;line-height:1.5;margin:12px 0;">'
                f'{lang_label}'
                f'<code>{c}</code></pre>'
            )
        elif t == "divider":
            html_parts.append('<hr style="border:none;border-top:1px solid rgba(255,255,255,.1);margin:16px 0;">')
        elif t == "image":
            src = b.get("src", "")
            alt = b.get("alt", "")
            html_parts.append(
                f'<figure style="margin:16px 0;text-align:center;">'
                f'<img src="{src}" alt="{alt}" data-full="{src}" style="max-width:100%;border-radius:8px;cursor:zoom-in;">'
                f'</figure>'
            )
        elif t == "video":
            src = b.get("src", "")
            if src:
                html_parts.append(
                    f'<video controls preload="metadata" style="max-width:100%;border-radius:8px;display:block;margin:12px auto;">'
                    f'<source src="{src}"></video>'
                )
        elif t == "audio":
            src = b.get("src", "")
            if src:
                html_parts.append(
                    f'<audio controls preload="metadata" style="width:100%;margin:8px 0;"><source src="{src}"></audio>'
                )
        elif t == "bookmark":
            url = b.get("url") or b.get("src") or ""
            title = b.get("title") or url
            desc = b.get("description") or ""
            img = b.get("image") or ""
            site = b.get("site_name") or ""
            img_html = (
                f'<img src="{img}" alt="" style="width:120px;height:90px;object-fit:cover;border-radius:8px;flex-shrink:0;">' if img else ""
            )
            desc_html = f'<div style="font-size:13px;opacity:.75;margin-top:4px;">{desc}</div>' if desc else ""
            site_html = f'<div style="font-size:11px;opacity:.5;text-transform:uppercase;letter-spacing:.5px;margin-top:6px;">{site}</div>' if site else ""
            html_parts.append(
                f'<a href="{url}" target="_blank" rel="noopener noreferrer" style="text-decoration:none;color:inherit;">'
                f'<div style="display:flex;gap:14px;align-items:center;border:1px solid rgba(255,255,255,.12);border-radius:10px;'
                f'padding:14px 16px;margin:14px 0;background:rgba(255,255,255,.03);">'
                f'<div style="flex:1;min-width:0;"><div style="font-weight:600;font-size:15px;">{title}</div>'
                f'{desc_html}{site_html}</div>{img_html}</div></a>'
            )
        elif t == "embed":
            url = b.get("src", "")
            emb = b.get("embed_type") or ""
            if emb in ("inline_dbs", "collection"):
                html_parts.append('<div>[Embedded content]</div>')
            elif emb == "download":
                html_parts.append(
                    f'<a href="{url}" download style="display:inline-block;margin:12px 0;color:var(--accent,#4c9aff);">⬇ {b.get("file_name") or "Download"}</a>'
                )
            elif emb == "pdf" and url:
                html_parts.append(
                    f'<iframe src="{url}" style="width:100%;height:70vh;border:none;border-radius:8px;margin:12px 0;"></iframe>'
                )
            elif url:
                from app.services.embeds import embed_src
                src = b.get("embed_src") or embed_src(url) or url
                height = b.get("height") or 520
                try:
                    height = int(height)
                except (ValueError, TypeError):
                    height = 520
                html_parts.append(
                    f'<div style="position:relative;width:100%;height:{height}px;border-radius:8px;overflow:hidden;'
                    f'background:#0a0a0a;"><iframe src="{src}" loading="lazy" frameborder="0" '
                    f'style="position:absolute;inset:0;width:100%;height:100%;" allowfullscreen allow="autoplay; encrypted-media; picture-in-picture"></iframe></div>'
                )
        elif t == "synced":
            # v6.5.0: render synced block instances (resolved server-side).
            if b.get("_synced_deleted"):
                html_parts.append(
                    '<div style="margin:8px 0;padding:8px 12px;border-left:3px solid #e05e5e;'
                    'background:rgba(224,94,94,.08);border-radius:4px;font-size:13px;opacity:.8;">'
                    'Deleted synced block</div>'
                )
            else:
                inner = b.get("_synced_content")
                if not isinstance(inner, list) or not inner:
                    try:
                        import json as _sj
                        parsed = _sj.loads(b.get("content") or "[]")
                        inner = parsed if isinstance(parsed, list) else []
                    except (ValueError, TypeError):
                        inner = []
                inner = [{"type": "paragraph", "content": str(x)} if not isinstance(x, dict) else x
                         for x in inner]
                if inner:
                    html_parts.append(
                        '<div style="margin:8px 0;padding-left:12px;'
                        'border-left:3px solid var(--accent,#4c9aff);">'
                        + _render_blocks_public(inner, titles) + '</div>'
                    )
        else:
            html_parts.append(f'<p style="margin:4px 0;line-height:1.7;">{c}</p>')
    return "\n".join(html_parts)


# ═══════════ Library page actions API ═══════════