"""YakPanel - Site service"""
import os
import re
from datetime import datetime, timezone
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select

from app.models.site import Site, Domain
from app.models.redirect import SiteRedirect
from app.core.config import get_runtime_config, get_settings
from app.core.utils import path_safe_check, write_file, read_file, exec_shell_sync, nginx_reload_all_known


DOMAIN_REGEX = re.compile(r"^([\w\-\*]{1,100}\.){1,8}([\w\-]{1,24}|[\w\-]{1,24}\.[\w\-]{1,24})$")

LETSENCRYPT_LIVE = "/etc/letsencrypt/live"
SSL_EXPIRING_DAYS = 14
_SAN_CACHE: dict[str, tuple[float, frozenset[str]]] = {}


def _normalize_hostname(h: str) -> str:
    return (h or "").strip().lower().split(":")[0]


def _iter_le_pairs_sorted() -> list[tuple[str, str]]:
    if not os.path.isdir(LETSENCRYPT_LIVE):
        return []
    try:
        names = sorted(os.listdir(LETSENCRYPT_LIVE))
    except OSError:
        return []
    out: list[tuple[str, str]] = []
    for entry in names:
        if entry.startswith(".") or ".." in entry:
            continue
        fc = os.path.join(LETSENCRYPT_LIVE, entry, "fullchain.pem")
        pk = os.path.join(LETSENCRYPT_LIVE, entry, "privkey.pem")
        if os.path.isfile(fc) and os.path.isfile(pk):
            out.append((fc, pk))
    return out


def _cert_san_names(fullchain: str) -> frozenset[str]:
    try:
        st = os.stat(fullchain)
        mtime = st.st_mtime
    except OSError:
        return frozenset()
    hit = _SAN_CACHE.get(fullchain)
    if hit is not None and hit[0] == mtime:
        return hit[1]
    out, _err = exec_shell_sync(f'openssl x509 -in "{fullchain}" -noout -text', timeout=8)
    names: set[str] = set()
    if out:
        for m in re.finditer(r"DNS:([^,\s\n]+)", out, flags=re.IGNORECASE):
            names.add(m.group(1).strip().lower())
    froz = frozenset(names)
    _SAN_CACHE[fullchain] = (mtime, froz)
    return froz


def _nginx_site_template_path() -> str | None:
    """
    Resolve webserver/templates/nginx_site.conf.
    Order: YAKPANEL_NGINX_TEMPLATE env, repo root (parent of backend/), Settings.panel_path.
    """
    candidates: list[str] = []
    env_override = (os.environ.get("YAKPANEL_NGINX_TEMPLATE") or "").strip()
    if env_override:
        candidates.append(env_override)
    # site_service.py -> services -> app -> backend -> YakPanel-server (repo root)
    here = os.path.abspath(__file__)
    repo_root = os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(here))))
    candidates.append(os.path.join(repo_root, "webserver", "templates", "nginx_site.conf"))
    try:
        s = get_settings()
        pp = (s.panel_path or "").strip()
        if pp:
            candidates.append(os.path.join(os.path.abspath(pp), "webserver", "templates", "nginx_site.conf"))
        sp = (s.setup_path or "").strip()
        if sp:
            candidates.append(
                os.path.join(os.path.abspath(sp), "YakPanel-server", "webserver", "templates", "nginx_site.conf")
            )
    except Exception:
        pass
    for path in candidates:
        if path and os.path.isfile(path):
            return path
    return None


def _backup_count(site_name: str, backup_dir: str) -> int:
    if not backup_dir or not os.path.isdir(backup_dir):
        return 0
    prefix = f"{site_name}_"
    n = 0
    try:
        for f in os.listdir(backup_dir):
            if f.startswith(prefix) and f.endswith(".tar.gz"):
                n += 1
    except OSError:
        return 0
    return n


def _parse_cert_not_after(cert_path: str) -> datetime | None:
    if not os.path.isfile(cert_path):
        return None
    out, _err = exec_shell_sync(f'openssl x509 -in "{cert_path}" -noout -enddate', timeout=5)
    if not out or "notAfter=" not in out:
        return None
    val = out.strip().split("=", 1)[1].strip()
    try:
        dt = datetime.strptime(val, "%b %d %H:%M:%S %Y GMT")
        return dt.replace(tzinfo=timezone.utc)
    except ValueError:
        return None


def _best_ssl_for_hostnames(hostnames: list[str]) -> dict:
    """Pick the LE cert (live/ or SAN) that covers site hostnames with longest validity."""
    none = {"status": "none", "days_left": None, "cert_name": None}
    seen: set[str] = set()
    want_list: list[str] = []
    for host in hostnames:
        n = _normalize_hostname(host)
        if n and ".." not in n and n not in seen:
            seen.add(n)
            want_list.append(n)
    if not want_list:
        return none
    want = set(want_list)
    try:
        if not os.path.isdir(LETSENCRYPT_LIVE):
            return none
        best_days: int | None = None
        best_name: str | None = None
        for fc, _pk in _iter_le_pairs_sorted():
            live_name = os.path.basename(os.path.dirname(fc)).lower()
            if live_name in want:
                match_names = {live_name}
            else:
                match_names = want & _cert_san_names(fc)
            if not match_names:
                continue
            end = _parse_cert_not_after(fc)
            if end is None:
                continue
            now = datetime.now(timezone.utc)
            days = int((end - now).total_seconds() // 86400)
            pick = min(match_names)
            if best_days is None or days > best_days:
                best_days = days
                best_name = pick
        if best_days is None:
            return none
        if best_days < 0:
            status = "expired"
        elif best_days <= SSL_EXPIRING_DAYS:
            status = "expiring"
        else:
            status = "active"
        return {"status": status, "days_left": best_days, "cert_name": best_name}
    except OSError:
        return none


def _letsencrypt_paths(hostname: str) -> tuple[str, str] | None:
    """Return (fullchain, privkey) if Let's Encrypt files exist for this hostname."""
    h = (hostname or "").strip().lower().split(":")[0]
    if not h or ".." in h:
        return None
    base = os.path.join(LETSENCRYPT_LIVE, h)
    fc = os.path.join(base, "fullchain.pem")
    pk = os.path.join(base, "privkey.pem")
    if os.path.isfile(fc) and os.path.isfile(pk):
        return fc, pk
    return None


def _letsencrypt_paths_any(hostnames: list[str]) -> tuple[str, str] | None:
    """First matching LE cert: exact live/<host>/, then live dir name, then SAN match."""
    seen: set[str] = set()
    want_ordered: list[str] = []
    for h in hostnames:
        n = _normalize_hostname(h)
        if n and ".." not in n and n not in seen:
            seen.add(n)
            want_ordered.append(n)
    if not want_ordered:
        return None
    want = set(want_ordered)
    for n in want_ordered:
        p = _letsencrypt_paths(n)
        if p:
            return p
    for fc, pk in _iter_le_pairs_sorted():
        live_name = os.path.basename(os.path.dirname(fc)).lower()
        if live_name in want:
            return fc, pk
        if want & _cert_san_names(fc):
            return fc, pk
    return None


def _build_ssl_server_block(
    server_names: str,
    root_path: str,
    logs_path: str,
    site_name: str,
    php_version: str,
    fullchain: str,
    privkey: str,
    redirects: list[tuple[str, str, int]] | None,
) -> str:
    """Second server {} for HTTPS when LE certs exist."""
    pv = php_version or "74"
    redirect_lines: list[str] = []
    for src, tgt, code in (redirects or []):
        if src and tgt:
            redirect_lines.append(f"    location = {src} {{ return {code} {tgt}; }}")
    redirect_block = ("\n" + "\n".join(redirect_lines)) if redirect_lines else ""
    q_fc = fullchain.replace("\\", "\\\\").replace('"', '\\"')
    q_pk = privkey.replace("\\", "\\\\").replace('"', '\\"')
    return (
        f"server {{\n"
        f"    listen 443 ssl;\n"
        f"    server_name {server_names};\n"
        f'    ssl_certificate "{q_fc}";\n'
        f'    ssl_certificate_key "{q_pk}";\n'
        f"    index index.php index.html index.htm default.php default.htm default.html;\n"
        f"    root {root_path};\n"
        f"    error_page 404 /404.html;\n"
        f"    error_page 502 /502.html;\n"
        f"    location ^~ /.well-known/acme-challenge/ {{\n"
        f"        root {root_path};\n"
        f'        default_type "text/plain";\n'
        f"        allow all;\n"
        f"        access_log off;\n"
        f"    }}\n"
        f"{redirect_block}\n"
        r"    location ~ .*\.(gif|jpg|jpeg|png|bmp|swf)$ {" + "\n"
        f"        expires 30d;\n"
        f"        access_log off;\n"
        f"    }}\n"
        r"    location ~ .*\.(js|css)?$ {" + "\n"
        f"        expires 12h;\n"
        f"        access_log off;\n"
        f"    }}\n"
        r"    location ~ \.php$ {" + "\n"
        f"        fastcgi_pass unix:/tmp/php-cgi-{pv}.sock;\n"
        f"        fastcgi_index index.php;\n"
        f"        include fastcgi.conf;\n"
        f"    }}\n"
        f"    access_log {logs_path}/{site_name}.log;\n"
        f"    error_log {logs_path}/{site_name}.error.log;\n"
        f"}}\n"
    )


def _render_vhost(
    template: str,
    server_names: str,
    root_path: str,
    logs_path: str,
    site_name: str,
    php_version: str,
    force_https: int,
    redirects: list[tuple[str, str, int]] | None = None,
    le_hostnames: list[str] | None = None,
) -> str:
    """Render nginx vhost template. redirects: [(source, target, code), ...]"""
    if force_https:
        force_block = (
            '    if ($request_uri !~ "^/.well-known/acme-challenge/") {\n'
            "        return 301 https://$host$request_uri;\n"
            "    }"
        )
    else:
        force_block = ""
    redirect_lines = []
    for src, tgt, code in (redirects or []):
        if src and tgt:
            redirect_lines.append(f"    location = {src} {{ return {code} {tgt}; }}")
    redirect_block = "\n".join(redirect_lines) if redirect_lines else ""
    hosts = le_hostnames if le_hostnames is not None else [p for p in server_names.split() if p]
    ssl_block = ""
    for h in hosts:
        le = _letsencrypt_paths(h)
        if le:
            fc, pk = le
            ssl_block = _build_ssl_server_block(
                server_names, root_path, logs_path, site_name, php_version, fc, pk, redirects
            )
            break
    content = template.replace("{SERVER_NAMES}", server_names)
    content = content.replace("{ROOT_PATH}", root_path)
    content = content.replace("{LOGS_PATH}", logs_path)
    content = content.replace("{SITE_NAME}", site_name)
    content = content.replace("{PHP_VERSION}", php_version or "74")
    content = content.replace("{FORCE_HTTPS_BLOCK}", force_block)
    content = content.replace("{REDIRECTS_BLOCK}", redirect_block)
    content = content.replace("{SSL_SERVER_BLOCK}", ssl_block)
    return content


async def domain_format(domains: list[str]) -> str | None:
    """Validate domain format. Returns first invalid domain or None."""
    for d in domains:
        if not DOMAIN_REGEX.match(d):
            return d
    return None


async def domain_exists(db: AsyncSession, domains: list[str], exclude_site_id: int | None = None) -> str | None:
    """Check if domain already exists. Returns first existing domain or None."""
    for d in domains:
        parts = d.split(":")
        name, port = parts[0], parts[1] if len(parts) > 1 else "80"
        q = select(Domain).where(Domain.name == name, Domain.port == port)
        if exclude_site_id is not None:
            q = q.where(Domain.pid != exclude_site_id)
        result = await db.execute(q)
        if result.scalar_one_or_none():
            return d
    return None


async def create_site(
    db: AsyncSession,
    name: str,
    path: str,
    domains: list[str],
    project_type: str = "PHP",
    ps: str = "",
    php_version: str = "74",
    force_https: int = 0,
) -> dict:
    """Create a new site with vhost config."""
    if not path_safe_check(name) or not path_safe_check(path):
        return {"status": False, "msg": "Invalid site name or path"}

    invalid = await domain_format(domains)
    if invalid:
        return {"status": False, "msg": f"Invalid domain format: {invalid}"}

    existing = await domain_exists(db, domains)
    if existing:
        return {"status": False, "msg": f"Domain already exists: {existing}"}

    cfg = get_runtime_config()
    setup_path = cfg["setup_path"]
    www_root = cfg["www_root"]
    www_logs = cfg["www_logs"]
    vhost_path = os.path.join(setup_path, "panel", "vhost", "nginx")

    site_path = os.path.join(www_root, name)
    if not os.path.exists(site_path):
        os.makedirs(site_path, 0o755)

    site = Site(name=name, path=site_path, ps=ps, project_type=project_type, php_version=php_version or "74", force_https=force_https or 0)
    db.add(site)
    await db.flush()

    for d in domains:
        parts = d.split(":")
        domain_name, port = parts[0], parts[1] if len(parts) > 1 else "80"
        db.add(Domain(pid=site.id, name=domain_name, port=port))

    await db.flush()

    # Generate Nginx vhost
    conf_path = os.path.join(vhost_path, f"{name}.conf")
    panel_root = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
    template_path = os.path.join(panel_root, "webserver", "templates", "nginx_site.conf")

    if os.path.exists(template_path):
        template = read_file(template_path) or ""
        server_names = " ".join(d.split(":")[0] for d in domains)
        le_hosts = [d.split(":")[0] for d in domains]
        content = _render_vhost(
            template, server_names, site_path, www_logs, name, php_version or "74", force_https or 0, [], le_hosts
        )
        write_file(conf_path, content)

    reload_ok, reload_err = nginx_reload_all_known()

    await db.commit()
    if reload_ok:
        return {"status": True, "msg": "Site created", "id": site.id}
    return {
        "status": True,
        "msg": f"Site created but nginx reload failed (HTTPS may not work): {reload_err}",
        "id": site.id,
    }


async def list_sites(db: AsyncSession) -> list[dict]:
    """List all sites with domain count, primary domain, backup count, SSL summary."""
    cfg = get_runtime_config()
    backup_dir = cfg.get("backup_path") or ""
    result = await db.execute(select(Site).order_by(Site.id))
    sites = result.scalars().all()
    out = []
    for s in sites:
        domain_result = await db.execute(select(Domain).where(Domain.pid == s.id).order_by(Domain.id))
        domain_rows = domain_result.scalars().all()
        domain_list = [f"{d.name}:{d.port}" if d.port != "80" else d.name for d in domain_rows]
        hostnames = [d.name for d in domain_rows]
        primary = hostnames[0] if hostnames else ""
        php_ver = getattr(s, "php_version", None) or "74"
        out.append({
            "id": s.id,
            "name": s.name,
            "path": s.path,
            "status": s.status,
            "ps": s.ps,
            "project_type": s.project_type,
            "domain_count": len(domain_rows),
            "addtime": s.addtime.isoformat() if s.addtime else None,
            "php_version": php_ver,
            "primary_domain": primary,
            "domains": domain_list,
            "backup_count": _backup_count(s.name, backup_dir),
            "ssl": _best_ssl_for_hostnames(hostnames),
        })
    return out


async def delete_site(db: AsyncSession, site_id: int) -> dict:
    """Delete a site and its vhost config."""
    result = await db.execute(select(Site).where(Site.id == site_id))
    site = result.scalar_one_or_none()
    if not site:
        return {"status": False, "msg": "Site not found"}

    await db.execute(Domain.__table__.delete().where(Domain.pid == site_id))
    await db.execute(SiteRedirect.__table__.delete().where(SiteRedirect.site_id == site_id))
    await db.delete(site)

    cfg = get_runtime_config()
    conf_path = os.path.join(cfg["setup_path"], "panel", "vhost", "nginx", f"{site.name}.conf")
    if os.path.exists(conf_path):
        os.remove(conf_path)

    reload_ok, reload_err = nginx_reload_all_known()

    await db.commit()
    if reload_ok:
        return {"status": True, "msg": "Site deleted"}
    return {"status": True, "msg": f"Site deleted but nginx reload failed: {reload_err}"}


async def get_site_count(db: AsyncSession) -> int:
    """Get total site count."""
    from sqlalchemy import func
    result = await db.execute(select(func.count()).select_from(Site))
    return result.scalar() or 0


async def get_site_with_domains(db: AsyncSession, site_id: int) -> dict | None:
    """Get site with domain list for editing."""
    result = await db.execute(select(Site).where(Site.id == site_id))
    site = result.scalar_one_or_none()
    if not site:
        return None
    domain_result = await db.execute(select(Domain).where(Domain.pid == site.id))
    domains = domain_result.scalars().all()
    domain_list = [f"{d.name}:{d.port}" if d.port != "80" else d.name for d in domains]
    return {
        "id": site.id,
        "name": site.name,
        "path": site.path,
        "status": site.status,
        "ps": site.ps,
        "project_type": site.project_type,
        "php_version": getattr(site, "php_version", None) or "74",
        "force_https": getattr(site, "force_https", 0) or 0,
        "domains": domain_list,
    }


async def update_site(
    db: AsyncSession,
    site_id: int,
    path: str | None = None,
    domains: list[str] | None = None,
    ps: str | None = None,
    php_version: str | None = None,
    force_https: int | None = None,
) -> dict:
    """Update site domains, path, or note."""
    result = await db.execute(select(Site).where(Site.id == site_id))
    site = result.scalar_one_or_none()
    if not site:
        return {"status": False, "msg": "Site not found"}

    if domains is not None:
        invalid = await domain_format(domains)
        if invalid:
            return {"status": False, "msg": f"Invalid domain format: {invalid}"}
        existing = await domain_exists(db, domains, exclude_site_id=site_id)
        if existing:
            return {"status": False, "msg": f"Domain already exists: {existing}"}
        await db.execute(Domain.__table__.delete().where(Domain.pid == site_id))
        for d in domains:
            parts = d.split(":")
            domain_name, port = parts[0], parts[1] if len(parts) > 1 else "80"
            db.add(Domain(pid=site.id, name=domain_name, port=port))

    if path is not None and path_safe_check(path):
        site.path = path

    if ps is not None:
        site.ps = ps
    if php_version is not None:
        site.php_version = php_version or "74"
    if force_https is not None:
        site.force_https = 1 if force_https else 0

    await db.flush()

    # Regenerate Nginx vhost if domains, php_version, or force_https changed
    if domains is not None or php_version is not None or force_https is not None:
        cfg = get_runtime_config()
        vhost_path = os.path.join(cfg["setup_path"], "panel", "vhost", "nginx")
        conf_path = os.path.join(vhost_path, f"{site.name}.conf")
        template_path = _nginx_site_template_path()
        if template_path:
            template = read_file(template_path) or ""
            domain_result = await db.execute(select(Domain).where(Domain.pid == site.id))
            domain_rows = domain_result.scalars().all()
            domain_list = [f"{d.name}:{d.port}" if d.port != "80" else d.name for d in domain_rows]
            server_names = " ".join(d.split(":")[0] for d in domain_list) if domain_list else site.name
            php_ver = getattr(site, "php_version", None) or "74"
            fhttps = getattr(site, "force_https", 0) or 0
            redir_result = await db.execute(select(SiteRedirect).where(SiteRedirect.site_id == site.id))
            redirects = [(r.source, r.target, r.code or 301) for r in redir_result.scalars().all()]
            le_hosts = [d.name for d in domain_rows]
            content = _render_vhost(
                template, server_names, site.path, cfg["www_logs"], site.name, php_ver, fhttps, redirects, le_hosts
            )
            write_file(conf_path, content)
        reload_ok, reload_err = nginx_reload_all_known()
        if not reload_ok:
            await db.commit()
            return {"status": False, "msg": f"Vhost updated but nginx test/reload failed: {reload_err}"}

    await db.commit()
    return {"status": True, "msg": "Site updated"}


def _vhost_path(site_name: str) -> tuple[str, str]:
    """Return (conf_path, disabled_path) for site vhost."""
    cfg = get_runtime_config()
    vhost_dir = os.path.join(cfg["setup_path"], "panel", "vhost", "nginx")
    disabled_dir = os.path.join(vhost_dir, "disabled")
    return (
        os.path.join(vhost_dir, f"{site_name}.conf"),
        os.path.join(disabled_dir, f"{site_name}.conf"),
    )


async def set_site_status(db: AsyncSession, site_id: int, status: int) -> dict:
    """Enable (1) or disable (0) site by moving vhost config."""
    result = await db.execute(select(Site).where(Site.id == site_id))
    site = result.scalar_one_or_none()
    if not site:
        return {"status": False, "msg": "Site not found"}

    conf_path, disabled_path = _vhost_path(site.name)
    disabled_dir = os.path.dirname(disabled_path)

    if status == 1:  # enable
        if os.path.isfile(disabled_path):
            os.makedirs(os.path.dirname(conf_path), exist_ok=True)
            os.rename(disabled_path, conf_path)
    else:  # disable
        if os.path.isfile(conf_path):
            os.makedirs(disabled_dir, exist_ok=True)
            os.rename(conf_path, disabled_path)

    site.status = status
    await db.commit()

    reload_ok, reload_err = nginx_reload_all_known()
    if not reload_ok:
        return {
            "status": False,
            "msg": f"Site {'enabled' if status == 1 else 'disabled'} but nginx test/reload failed: {reload_err}",
        }

    return {"status": True, "msg": "Site " + ("enabled" if status == 1 else "disabled")}


async def regenerate_site_vhost(db: AsyncSession, site_id: int) -> dict:
    """Regenerate nginx vhost for a site (e.g. after redirect changes or before LE validation)."""
    result = await db.execute(select(Site).where(Site.id == site_id))
    site = result.scalar_one_or_none()
    if not site:
        return {"status": False, "msg": "Site not found"}
    cfg = get_runtime_config()
    conf_path, disabled_path = _vhost_path(site.name)
    if site.status == 1:
        write_path = conf_path
    else:
        write_path = disabled_path if os.path.isfile(disabled_path) else conf_path
    template_path = _nginx_site_template_path()
    if not template_path:
        return {
            "status": False,
            "msg": "Template not found (nginx_site.conf). Expected under panel webserver/templates/ "
            "or set env YAKPANEL_NGINX_TEMPLATE to the full path. Check Settings.panel_path matches the install directory.",
        }
    template = read_file(template_path) or ""
    domain_result = await db.execute(select(Domain).where(Domain.pid == site.id))
    domain_rows = domain_result.scalars().all()
    domain_list = [f"{d.name}:{d.port}" if d.port != "80" else d.name for d in domain_rows]
    server_names = " ".join(d.split(":")[0] for d in domain_list) if domain_list else site.name
    php_ver = getattr(site, "php_version", None) or "74"
    fhttps = getattr(site, "force_https", 0) or 0
    redir_result = await db.execute(select(SiteRedirect).where(SiteRedirect.site_id == site.id))
    redirects = [(r.source, r.target, r.code or 301) for r in redir_result.scalars().all()]
    le_hosts = [d.name for d in domain_rows]
    content = _render_vhost(
        template, server_names, site.path, cfg["www_logs"], site.name, php_ver, fhttps, redirects, le_hosts
    )
    write_file(write_path, content)
    reload_ok, reload_err = nginx_reload_all_known()
    if not reload_ok:
        return {"status": False, "msg": f"Vhost written but nginx test/reload failed: {reload_err}"}
    return {"status": True, "msg": "Vhost regenerated"}