"""Web App 站点产物 API：能力探测 / 站点列表 / 构建 / 预览签名 / dist 静态托管。

设计要点（降级优先）：
- 所有线程级接口先做 capability 闸门，不可用时返回结构化 ``{"available": false}``
  （HTTP 200），绝不抛 5xx，绝不影响既有功能；
- 静态托管是**唯一**允许 HTML inline 的出口：签名令牌 + dist/ 根限定 +
  CSP（按请求真实 origin 显式声明，兼容 iframe sandbox 不透明 origin）+
  X-Content-Type-Options 三重边界；artifacts 接口既有的强制 attachment 不受影响。
"""

from __future__ import annotations

import asyncio
import logging

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

from app.gateway.authz import require_permission
from app.gateway.path_utils import aresolve_thread_virtual_path
from deerflow.config import get_app_config
from deerflow.config.paths import get_paths
from deerflow.runtime.thread_paths import aresolve_path_user_id
from deerflow.webapp.builder import get_site_build_runner
from deerflow.webapp.engine import (
    SITE_NAME_RE_OK,
    capability_status,
    find_sites,
    guess_site_mime,
)
from deerflow.webapp.security import mint_preview_token, verify_preview_token

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api", tags=["web-app-sites"])

_VIRTUAL_OUTPUTS = "mnt/user-data/outputs"

# CSP 用显式 origin 而非 'self'：iframe sandbox（无 allow-same-origin）下文档
# origin 为 null，'self' 匹配不到任何资源；显式 URL 源按字面匹配不受影响。
# img/connect 放开 http(s) 供内网 GeoServer 瓦片 / PMTiles 之用；脚本严格同源。
_CSP_TEMPLATE = (
    "default-src {origin} data: blob:; "
    "script-src {origin}; "
    "style-src {origin} 'unsafe-inline'; "
    "img-src {origin} data: blob: https: http:; "
    "font-src {origin} data:; "
    "connect-src {origin} data: blob: https: http:; "
    "worker-src {origin} blob:; "
    "object-src 'none'; "
    "base-uri {origin}"
)


def _unavailable_payload() -> dict:
    cap = capability_status()
    reasons = [f"{name}: {item.get('detail', '')}" for name, item in cap.checks.items() if not item.get("ok")]
    return {"available": False, "enabled": cap.enabled, "reasons": reasons, "checks": cap.checks}


def _validate_site_name(site_name: str) -> str:
    if not SITE_NAME_RE_OK.match(site_name):
        raise HTTPException(status_code=400, detail=f"非法站点目录名: {site_name!r}")
    return site_name


@router.get(
    "/web-app/capability",
    summary="Web App Capability",
    description="探测站点产物模式是否可用（配置开关 / 模板 / 预置依赖 / node）。",
)
async def web_app_capability() -> dict:
    cap = capability_status()
    return {
        "available": cap.available,
        "enabled": cap.enabled,
        "template_dir": cap.template_dir,
        "node_bin": cap.node_bin,
        "checks": cap.checks,
    }


@router.get(
    "/threads/{thread_id}/sites",
    summary="List Web App Sites",
    description="列出该对话 outputs/ 下带 site.json 的站点及构建状态。",
)
@require_permission("threads", "read", owner_check=True)
async def list_sites(thread_id: str, request: Request) -> dict:
    if not capability_status().available:
        return _unavailable_payload()
    outputs_dir = await aresolve_thread_virtual_path(thread_id, _VIRTUAL_OUTPUTS)
    runner = get_site_build_runner()
    sites = find_sites(outputs_dir)
    for site in sites:
        job = runner.get_job(thread_id, site["name"])
        if job is not None:
            site["build_job"] = {
                "job_id": job.job_id,
                "status": job.status,
                "started_at": job.started_at,
                "finished_at": job.finished_at,
                "error": job.error,
            }
    return {"available": True, "sites": sites}


@router.post(
    "/threads/{thread_id}/sites/{site_name}/build",
    status_code=202,
    summary="Build Web App Site",
    description="触发站点 vite build（同一站点并发幂等：运行中则返回当前任务）。",
)
@require_permission("threads", "write", owner_check=True)
async def build_site(thread_id: str, site_name: str, request: Request) -> dict:
    if not capability_status().available:
        return _unavailable_payload()
    _validate_site_name(site_name)
    outputs_dir = await aresolve_thread_virtual_path(thread_id, _VIRTUAL_OUTPUTS)
    site_dir = outputs_dir / site_name
    if not (site_dir / "site.json").is_file():
        raise HTTPException(status_code=404, detail=f"站点不存在: {site_name}")
    job = await get_site_build_runner().start_build(thread_id, site_name, site_dir)
    return {"available": True, "job_id": job.job_id, "status": job.status, "started_at": job.started_at}


@router.get(
    "/threads/{thread_id}/sites/{site_name}/build-status",
    summary="Web App Site Build Status",
    description="查询站点最近一次构建任务状态（内存任务 + 落盘 .build-result.json）。",
)
@require_permission("threads", "read", owner_check=True)
async def site_build_status(thread_id: str, site_name: str, request: Request) -> dict:
    _validate_site_name(site_name)
    outputs_dir = await aresolve_thread_virtual_path(thread_id, _VIRTUAL_OUTPUTS)
    site_dir = outputs_dir / site_name
    job = get_site_build_runner().get_job(thread_id, site_name)
    if job is not None:
        return {
            "available": True,
            "job_id": job.job_id,
            "status": job.status,
            "started_at": job.started_at,
            "finished_at": job.finished_at,
            "error": job.error,
            "result": job.result,
        }
    last_build = None
    result_path = site_dir / ".build-result.json"
    if result_path.is_file():
        import json

        try:
            last_build = json.loads(result_path.read_text(encoding="utf-8"))
        except (OSError, ValueError):
            last_build = None
    return {"available": True, "status": "idle", "last_build": last_build}


@router.post(
    "/threads/{thread_id}/sites/{site_name}/preview-url",
    summary="Mint Web App Preview URL",
    description="签发站点 dist/ 静态托管的短时效签名 URL（iframe 可直接引用）。",
)
@require_permission("threads", "read", owner_check=True)
async def mint_site_preview_url(thread_id: str, site_name: str, request: Request) -> dict:
    if not capability_status().available:
        return _unavailable_payload()
    _validate_site_name(site_name)
    outputs_dir = await aresolve_thread_virtual_path(thread_id, _VIRTUAL_OUTPUTS)
    site_dir = outputs_dir / site_name
    if not (site_dir / "site.json").is_file():
        raise HTTPException(status_code=404, detail=f"站点不存在: {site_name}")
    ttl = get_app_config().web_app.preview_token_ttl_seconds
    token, expires_at = mint_preview_token(thread_id, site_name, ttl)
    return {
        "available": True,
        "url_path": f"/api/public/site-preview/{token}",
        "token": token,
        "expires_at": expires_at,
    }


# ─────────────────────────────────────────────────────────────────────────────
# 跨对话站点 gallery（当前用户所有普通会话的 outputs 扫描；入口页数据源）
# ─────────────────────────────────────────────────────────────────────────────

_GALLERY_THREAD_BATCH = 100
_GALLERY_SCAN_CONCURRENCY = 8


async def _current_user_thread_rows(request: Request) -> list[dict]:
    """分页拉取当前用户的全部普通会话（对齐 artifact-library 的枚举语义）。"""
    from app.gateway.deps import get_thread_store

    store = get_thread_store(request)
    rows: list[dict] = []
    seen: set[str] = set()
    offset = 0
    while True:
        batch = await store.search(limit=_GALLERY_THREAD_BATCH, offset=offset, exclude_system=True)
        if not batch:
            break
        added = 0
        for row in batch:
            thread_id = str(row.get("thread_id") or "")
            if not thread_id or thread_id in seen:
                continue
            seen.add(thread_id)
            rows.append(row)
            added += 1
        if len(batch) < _GALLERY_THREAD_BATCH or added == 0:
            break
        offset += len(batch)
    return rows


async def _scan_user_sites(request: Request) -> list[dict]:
    """扫描当前用户所有会话的 outputs/，返回带 thread 归属的站点列表。"""
    rows = await _current_user_thread_rows(request)
    paths = get_paths()
    semaphore = asyncio.Semaphore(_GALLERY_SCAN_CONCURRENCY)

    async def scan_thread(row: dict) -> list[dict]:
        thread_id = str(row.get("thread_id") or "")
        if not thread_id:
            return []
        async with semaphore:
            try:
                path_user_id = await aresolve_path_user_id(thread_id)
                outputs_dir = paths.sandbox_outputs_dir(thread_id, user_id=path_user_id)
                sites = await asyncio.to_thread(find_sites, outputs_dir)
            except Exception:
                logger.warning("Failed to scan web-app sites for thread %s", thread_id, exc_info=True)
                return []
        title = str(row.get("display_name") or "新对话")
        for site in sites:
            site["thread_id"] = thread_id
            site["thread_title"] = title
        return sites

    nested = await asyncio.gather(*(scan_thread(row) for row in rows))
    items = [site for group in nested for site in group]
    items.sort(key=lambda s: (-(s.get("manifest_mtime") or 0), str(s.get("thread_id") or ""), str(s.get("name") or "")))
    return items


@router.get(
    "/web-app/sites",
    summary="List All Web App Sites",
    description="跨对话扫描当前用户所有会话生成的站点（capability 不可用时返回结构化不可用）。",
)
@require_permission("threads", "read")
async def list_all_sites(request: Request) -> dict:
    if not capability_status().available:
        return _unavailable_payload()
    sites = await _scan_user_sites(request)
    runner = get_site_build_runner()
    for site in sites:
        job = runner.get_job(str(site.get("thread_id") or ""), str(site.get("name") or ""))
        if job is not None:
            site["build_job"] = {
                "job_id": job.job_id,
                "status": job.status,
                "started_at": job.started_at,
                "finished_at": job.finished_at,
                "error": job.error,
            }
    return {"available": True, "sites": sites}


# ─────────────────────────────────────────────────────────────────────────────
# 公开静态托管（/api/public/ 前缀在 AuthMiddleware 白名单内；令牌即授权）
# ─────────────────────────────────────────────────────────────────────────────


@router.get(
    "/public/site-preview/{token}",
    summary="Serve Site Root",
    description="站点 dist/ 根：返回 index.html。",
    include_in_schema=False,
)
async def serve_site_root(token: str, request: Request) -> FileResponse:
    return await _serve_site_file_async(request, token, "index.html")


@router.get(
    "/public/site-preview/{token}/{file_path:path}",
    summary="Serve Site Asset",
    description="签名令牌授权的站点 dist/ 静态文件托管（HTML inline + CSP）。",
)
async def serve_site_asset(token: str, file_path: str, request: Request) -> FileResponse:
    return await _serve_site_file_async(request, token, file_path)


async def _serve_site_file_async(request: Request, token: str, file_path: str) -> FileResponse:
    try:
        thread_id, site_name = verify_preview_token(token)
    except ValueError as exc:
        raise HTTPException(status_code=403, detail=f"预览令牌无效: {exc}") from exc
    _validate_site_name(site_name)

    normalized = file_path.strip().replace("\\", "/")
    if normalized in ("", ".", "/"):
        normalized = "index.html"
    parts = [p for p in normalized.split("/") if p != ""]
    if any(p in ("..", ".") or p.startswith(".") for p in parts):
        raise HTTPException(status_code=400, detail="非法文件路径")

    virtual_path = f"{_VIRTUAL_OUTPUTS}/{site_name}/dist/{'/'.join(parts)}"
    actual_path = await aresolve_thread_virtual_path(thread_id, virtual_path)
    if not actual_path.is_file():
        raise HTTPException(status_code=404, detail="站点文件不存在")

    origin = str(request.base_url).rstrip("/")
    headers = {
        "Cache-Control": "no-cache",
        "X-Content-Type-Options": "nosniff",
    }
    if actual_path.suffix.lower() in (".html", ".htm", ".svg"):
        headers["Content-Security-Policy"] = _CSP_TEMPLATE.format(origin=origin)
    return FileResponse(
        path=actual_path,
        media_type=guess_site_mime(actual_path),
        headers=headers,
    )