import html
import json
import math
from urllib.parse import quote, urlencode

from fastapi import APIRouter, Depends, HTTPException, Query, Request
from fastapi.responses import HTMLResponse

from app.auth import require_user
from app.db.audit import log_audit_event
from app.db.workers import get_worker, get_workers
from app.templates.layout import page

router = APIRouter()
DEFAULT_PAGE_SIZE = 20


def render_worker_badge(online: bool) -> str:
    if online:
        return '<span class="pill pill-success">online</span>'
    return '<span class="pill pill-danger">offline</span>'


def pretty_json(value: str | None) -> str:
    if not value:
        return "{}"

    try:
        return json.dumps(json.loads(value), ensure_ascii=False, indent=2, sort_keys=True)
    except (TypeError, ValueError):
        return value


@router.get("/workers", response_class=HTMLResponse)
def workers_page(
    request: Request,
    status: str = Query(""),
    q: str = Query(""),
    page_number: int = Query(1, alias="page", ge=1),
    user=Depends(require_user),
):
    all_workers = get_workers()
    selected_status = status.strip().lower()
    query = q.strip()
    online_count = sum(1 for worker in all_workers if worker.get("online"))
    total_count = len(all_workers)
    offline_count = total_count - online_count
    workers = all_workers
    if selected_status == "online":
        workers = [worker for worker in workers if worker.get("online")]
    elif selected_status == "offline":
        workers = [worker for worker in workers if not worker.get("online")]
    else:
        selected_status = ""
    if query:
        workers = [worker for worker in workers if query.lower() in (worker.get("id", "") or "").lower()]

    total_filtered = len(workers)
    total_pages = max(1, math.ceil(total_filtered / DEFAULT_PAGE_SIZE))
    if page_number > total_pages:
        page_number = total_pages
    offset = (page_number - 1) * DEFAULT_PAGE_SIZE
    workers = workers[offset : offset + DEFAULT_PAGE_SIZE]

    log_audit_event(
        user,
        action="workers.view",
        target_type="workers",
        metadata={
            "online": online_count,
            "offline": offline_count,
            "total": total_count,
        },
    )

    rows = ""
    for worker in workers:
        worker_id_raw = worker.get("id", "") or ""
        worker_id = html.escape(worker_id_raw)
        worker_url_id = quote(worker_id_raw, safe="")
        status = html.escape(worker.get("status", "") or "")
        last_seen_at = html.escape(worker.get("last_seen_at", "") or "")
        started_at = html.escape(worker.get("started_at", "") or "")
        badge = render_worker_badge(bool(worker.get("online")))
        current_job_id = worker.get("current_job_id")
        current_job = ""
        if current_job_id is not None:
            current_job_label = html.escape(str(current_job_id))
            current_job = f'<a href="/portal/jobs/{current_job_label}">#{current_job_label}</a>'

        rows += f"""
        <tr data-worker-id="{worker_id}">
            <td>
                <strong><a href="/portal/workers/{worker_url_id}">{worker_id}</a></strong>
            </td>
            <td data-worker-field="status">{badge}<br><span class="muted">{status}</span></td>
            <td data-worker-field="last_seen_at">{last_seen_at}</td>
            <td data-worker-field="current_job">{current_job}</td>
            <td>{started_at}</td>
            <td class="actions-cell"><a class="btn" href="/portal/workers/{worker_url_id}">Detail</a></td>
        </tr>
        """

    if not rows:
        rows = '<tr><td colspan="6">Zatím nejsou evidovaní žádní workeři.</td></tr>'
    live_table_attr = ' data-live-table="workers.recent"' if not selected_status and not query and page_number == 1 else ""
    first_item = offset + 1 if total_filtered else 0
    last_item = min(offset + len(workers), total_filtered)

    def page_url(page: int) -> str:
        params = {"page": page}
        if selected_status:
            params["status"] = selected_status
        if query:
            params["q"] = query
        return f"/portal/workers?{urlencode(params)}"

    previous_link = (
        f'<a class="btn btn-secondary" href="{page_url(page_number - 1)}">Předchozí</a>'
        if page_number > 1
        else ""
    )
    next_link = (
        f'<a class="btn btn-secondary" href="{page_url(page_number + 1)}">Další</a>'
        if page_number < total_pages
        else ""
    )
    pagination = ""
    if total_pages > 1:
        pagination = f"""
            <div class="pagination">
                <span>Zobrazeno {first_item}-{last_item} z {total_filtered}</span>
                <div class="pagination-actions">
                    {previous_link}
                    <span class="page-indicator">Strana {page_number} / {total_pages}</span>
                    {next_link}
                </div>
            </div>
        """
    status_options = "".join(
        f'<option value="{value}"{" selected" if selected_status == value else ""}>{label}</option>'
        for value, label in [("", "Všichni workeři"), ("online", "Online"), ("offline", "Offline")]
    )

    return page(
        "Workery",
        f"""
        <div class="card">
            <h2>Workery</h2>
            <p class="muted">Přehled worker procesů obsluhujících úlohy portálu.</p>
        </div>

        <div class="stats-grid">
            <div class="stat-card stat-success"><span>Online workery</span><strong data-live-count="workers.online">{online_count}</strong></div>
            <div class="stat-card stat-danger"><span>Offline workery</span><strong data-live-count="workers.offline">{offline_count}</strong></div>
            <div class="stat-card stat-total"><span>Celkem workerů</span><strong data-live-count="workers.total">{total_count}</strong></div>
        </div>

        <div class="card">
            <h2>Filtry</h2>
            <form method="get" action="/portal/workers" class="filter-form">
                <select name="status">{status_options}</select>
                <input name="q" value="{html.escape(query)}" placeholder="ID workeru">
                <input type="hidden" name="page" value="1">
                <button type="submit">Filtrovat</button>
                <a class="btn btn-secondary" href="/portal/workers">Reset</a>
            </form>
        </div>

        <div class="card">
            <h2>Workery</h2>
            {pagination}
            <table>
                <tr>
                    <th>ID workeru</th>
                    <th>Status</th>
                    <th>Naposledy viděn</th>
                    <th>Aktuální úloha</th>
                    <th>Spuštěn</th>
                    <th>Akce</th>
                </tr>
                <tbody{live_table_attr}>{rows}</tbody>
            </table>
            {pagination}
        </div>
        <script src="/portal/static/operations-live.js"></script>
        """,
        user=user,
    )


@router.get("/workers/{worker_id}", response_class=HTMLResponse)
def worker_detail_page(worker_id: str, request: Request, user=Depends(require_user)):
    worker = get_worker(worker_id)
    if not worker:
        raise HTTPException(status_code=404, detail="Worker not found")

    log_audit_event(
        user,
        action="workers.view",
        target_type="worker",
        target_id=worker_id,
    )

    worker_id_html = html.escape(worker.get("id", "") or "")
    status = html.escape(worker.get("status", "") or "")
    last_seen_at = html.escape(worker.get("last_seen_at", "") or "")
    started_at = html.escape(worker.get("started_at", "") or "")
    badge = render_worker_badge(bool(worker.get("online")))
    current_job_id = worker.get("current_job_id")
    current_job = ""
    if current_job_id is not None:
        current_job_label = html.escape(str(current_job_id))
        current_job = f'<a href="/portal/jobs/{current_job_label}">#{current_job_label}</a>'

    metadata = html.escape(pretty_json(worker.get("metadata_json")))
    metadata_block = ""
    if worker.get("metadata_json"):
        metadata_block = f"""
        <div class="card">
            <h2>Metadata</h2>
            <pre class="log-viewer log-stdout">{metadata}</pre>
        </div>
        """

    return page(
        f"Worker {worker_id_html}",
        f"""
        <div class="card">
            <h2>Worker {worker_id_html}</h2>
            <p>
                <a class="btn" href="/portal/workers">&larr; Zpět na workery</a>
            </p>
        </div>

        <div class="card">
            <h2>Souhrn</h2>
            <table>
                <tr><th>ID workeru</th><td>{worker_id_html}</td></tr>
                <tr><th>Status</th><td>{badge}<br><span class="muted">{status}</span></td></tr>
                <tr><th>Naposledy viděn</th><td>{last_seen_at}</td></tr>
                <tr><th>Aktuální úloha</th><td>{current_job}</td></tr>
                <tr><th>Spuštěn</th><td>{started_at}</td></tr>
            </table>
        </div>

        {metadata_block}
        """,
        user=user,
    )