import html
import math
from urllib.parse import urlencode

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

from app.auth import require_user
from app.db.jobs import count_job_logs, search_job_logs
from app.routes.jobs import render_job_status
from app.templates.layout import page

router = APIRouter()

STREAM_FILTERS = ("stdout", "stderr", "system")
PAGE_SIZE = 100


def _can_view_logs(user: dict) -> bool:
    return (user.get("role") or "").lower() in ("admin", "developer")


def render_stream_pill(stream: str | None) -> str:
    value = (stream or "system").lower()
    if value == "stderr":
        return '<span class="pill pill-danger">stderr</span>'
    if value == "stdout":
        return '<span class="pill pill-success">stdout</span>'
    return '<span class="pill pill-muted">system</span>'


def render_stream_options(selected: str) -> str:
    options = ['<option value="">Všechny streamy</option>']
    for value in STREAM_FILTERS:
        selected_attr = " selected" if selected == value else ""
        options.append(f'<option value="{value}"{selected_attr}>{value}</option>')
    return "".join(options)


@router.get("/logs", response_class=HTMLResponse)
def logs_page(
    request: Request,
    q: str = Query(""),
    stream: str = Query(""),
    job: str = Query(""),
    page_number: int = Query(1, alias="page", ge=1),
    user=Depends(require_user),
):
    if not _can_view_logs(user):
        raise HTTPException(status_code=403, detail="Logy mohou číst jen developer nebo admin")

    query = q.strip()
    selected_stream = stream.strip().lower()
    if selected_stream not in STREAM_FILTERS:
        selected_stream = ""

    job_id: int | None = None
    job_value = job.strip()
    if job_value.isdigit():
        job_id = int(job_value)

    total = count_job_logs(query=query or None, stream=selected_stream or None, job_id=job_id)
    total_pages = max(1, math.ceil(total / PAGE_SIZE))
    if page_number > total_pages:
        page_number = total_pages
    offset = (page_number - 1) * PAGE_SIZE

    logs = search_job_logs(
        query=query or None,
        stream=selected_stream or None,
        job_id=job_id,
        limit=PAGE_SIZE,
        offset=offset,
    )

    rows = ""
    for log in logs:
        log_id = html.escape(str(log.get("id", "")))
        job_id_html = html.escape(str(log.get("job_id", "")))
        created_at = html.escape(log.get("created_at", "") or "")
        job_type = html.escape(log.get("job_type", "") or "")
        target_type = html.escape(log.get("target_type", "") or "")
        target_id = html.escape(log.get("target_id", "") or "")
        message = log.get("message", "") or ""
        # Náhled zprávy ať tabulka nepřeteče; plný text je po prokliku na úlohu.
        preview = message if len(message) <= 400 else f"{message[:397]}..."
        message_html = html.escape(preview)
        # Proklik míří přímo na konkrétní řádek logu v detailu úlohy (kotva #log-{id}).
        deep_link = f"/portal/jobs/{job_id_html}#log-{log_id}"
        rows += f"""
        <tr>
            <td>{created_at}</td>
            <td><strong><a href="/portal/jobs/{job_id_html}">#{job_id_html}</a></strong><br><span class="muted">{job_type}</span></td>
            <td>{render_stream_pill(log.get("stream"))}</td>
            <td>{render_job_status(log.get("job_status"))}<br><span class="muted">{target_type}: {target_id}</span></td>
            <td><pre class="log-viewer log-inline">{message_html}</pre></td>
            <td class="actions-cell"><a class="icon-action" href="{deep_link}" title="Zobrazit v úloze" aria-label="Zobrazit v úloze"><i class="fa-solid fa-up-right-from-square" aria-hidden="true"></i></a></td>
        </tr>
        """

    if not rows:
        rows = '<tr><td colspan="6">Žádné logy neodpovídají filtru.</td></tr>'

    def page_url(target_page: int) -> str:
        params = {"page": target_page}
        if query:
            params["q"] = query
        if selected_stream:
            params["stream"] = selected_stream
        if job_value:
            params["job"] = job_value
        return f"/portal/logs?{urlencode(params)}"

    first_item = offset + 1 if total else 0
    last_item = min(offset + len(logs), total)
    previous_link = (
        f'<a class="btn btn-secondary" href="{page_url(page_number - 1)}"><i class="fa-solid fa-chevron-left" aria-hidden="true"></i> Předchozí</a>'
        if page_number > 1
        else ""
    )
    next_link = (
        f'<a class="btn btn-secondary" href="{page_url(page_number + 1)}">Další <i class="fa-solid fa-chevron-right" aria-hidden="true"></i></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}</span>
                <div class="pagination-actions">
                    {previous_link}
                    <span class="page-indicator">Strana {page_number} / {total_pages}</span>
                    {next_link}
                </div>
            </div>
        """

    return page(
        "Logy",
        f"""
        <div class="card">
            <h2><i class="fa-solid fa-file-lines" aria-hidden="true"></i> Logy</h2>
            <p class="muted">
                Souhrnné čtení logů napříč všemi úlohami. Vyfiltrujte si chyby (stream <strong>stderr</strong>)
                nebo hledejte text a proklikněte se přímo na problematický řádek konkrétní úlohy.
            </p>
            <form method="get" action="/portal/logs" class="filter-form">
                <input name="q" value="{html.escape(query)}" placeholder="Hledat v textu logu">
                <select name="stream">{render_stream_options(selected_stream)}</select>
                <input name="job" value="{html.escape(job_value)}" placeholder="ID úlohy" inputmode="numeric">
                <input type="hidden" name="page" value="1">
                <button type="submit"><i class="fa-solid fa-filter" aria-hidden="true"></i> Filtrovat</button>
                <a class="btn btn-secondary" href="/portal/logs?stream=stderr"><i class="fa-solid fa-triangle-exclamation" aria-hidden="true"></i> Jen chyby</a>
                <a class="btn btn-secondary" href="/portal/logs"><i class="fa-solid fa-arrow-rotate-left" aria-hidden="true"></i> Reset</a>
            </form>
        </div>

        <div class="card">
            <h2>Záznamy</h2>
            {pagination}
            <table>
                <tr>
                    <th>Čas</th>
                    <th>Úloha</th>
                    <th>Stream</th>
                    <th>Stav / cíl</th>
                    <th>Zpráva</th>
                    <th>Akce</th>
                </tr>
                {rows}
            </table>
            {pagination}
        </div>
        """,
        user=user,
    )