from __future__ import annotations

from urllib.parse import urlencode

from ..ddns_models import DdnsSettings
from ..ddns_security import admin_csrf_token
from ..ddns_service import DdnsService
from .html_utils import SafeHtml, attr, escape, trusted
from .templates import _page, _top_nav
from .templates_admin_tables import (
    _account_row,
    _admin_table_pagination,
    _admin_table_toolbar,
    _domain_claim_row,
    _event_row,
)


def _admin_secret_panel(title: str, rows: list[SafeHtml]) -> SafeHtml:
    return trusted(f"""
    <section class="section success-section">
      <div class="container">
        <p class="eyebrow">Admin action</p>
        <h2>{escape(title)}</h2>
        <p class="section-copy">Copy these values now. Secret values are only shown once.</p>
        <div class="d-grid gap-2">
          {"".join(rows)}
        </div>
      </div>
    </section>
    """)

def _render_admin_page(
    service: DdnsService,
    settings: DdnsSettings,
    accounts: list[dict[str, str | int | None]],
    domain_challenges: list[dict[str, str | None]],
    cleanup_runs: list[dict[str, str | int]],
    scheduled_tasks: list[dict[str, str | int | None]],
    update_events: list[dict[str, str | int | None]],
    service_metrics: dict[str, float],
    table_counts: dict[str, int],
    table_offsets: dict[str, int],
    table_limit: int,
    notice_html: SafeHtml | None,
) -> str:
    csrf = attr(admin_csrf_token(settings))
    admin_path = settings.admin_path
    safe_admin_path = attr(admin_path)
    safe_records_path = attr(f"{admin_path}/records")
    safe_events_path = attr(f"{admin_path}/events")
    rows = "\n".join(_account_row(account, csrf=csrf, admin_path=admin_path) for account in accounts) or """
      <tr class="empty-row"><td colspan="7" class="empty">No hostnames yet.</td></tr>
    """
    domain_rows = "\n".join(_domain_claim_row(challenge) for challenge in domain_challenges) or """
      <tr class="empty-row"><td colspan="5" class="empty">No domain claims yet.</td></tr>
    """
    event_rows = "\n".join(_event_row(event) for event in update_events) or """
      <tr class="empty-row"><td colspan="7" class="empty">No update events yet.</td></tr>
    """
    accounts_count = escape(table_counts.get("accounts", len(accounts)))
    domain_count = escape(table_counts.get("domain_challenges", len(domain_challenges)))
    event_count = escape(table_counts.get("update_events", len(update_events)))
    metrics_html = _metrics_panel(service_metrics)
    account_pager = _server_page_links(admin_path, "accounts_offset", table_offsets.get("accounts", 0), table_limit, table_counts.get("accounts", 0))
    domain_pager = _server_page_links(
        admin_path,
        "domain_claims_offset",
        table_offsets.get("domain_challenges", 0),
        table_limit,
        table_counts.get("domain_challenges", 0),
    )
    event_pager = _server_page_links(admin_path, "update_events_offset", table_offsets.get("update_events", 0), table_limit, table_counts.get("update_events", 0))
    cleanup_panel = _cleanup_panel(settings, cleanup_runs, scheduled_tasks, safe_admin_path, csrf)
    return _page(
        "KarlDNS Admin",
        trusted(f"""
        <main id="main">
          {_top_nav("Operator", trusted(f'<a class="nav-link px-0" href="{safe_records_path}">Records</a><a class="nav-link px-0" href="{safe_events_path}">Events</a>'))}
          <section class="section admin-heading">
            <div class="container">
              <p class="eyebrow">KarlDNS</p>
              <h1>Operator console</h1>
              <p class="lead">Review hostnames, domain checks, updates, cleanup, and secret changes.</p>
            </div>
          </section>

          {notice_html or ""}

          <section class="section">
            <div class="container">
              <div class="d-flex align-items-md-center justify-content-between gap-4 flex-column flex-md-row mb-4">
                <div>
                  <p class="eyebrow">Service health</p>
                  <h2>Service status</h2>
                </div>
              </div>
              {cleanup_panel}
              <div class="mt-4">
                {metrics_html}
              </div>
            </div>
          </section>

          <section class="section">
            <div class="container">
              <div class="d-flex align-items-md-center justify-content-between gap-4 flex-column flex-md-row">
                <div>
                  <p class="eyebrow">Hostnames</p>
                  <h2>Hostnames</h2>
                  <p class="section-copy mb-0">Showing {escape(len(accounts))} of {accounts_count}.</p>
                </div>
              </div>
              {_admin_table_toolbar("hostnames", "Search hostnames")}
              <div class="table-responsive border rounded admin-table-scroll">
                <table class="table mb-0">
                  <thead>
                    <tr><th scope="col">Domain</th><th scope="col">User</th><th scope="col">IPv4</th><th scope="col">IPv6</th><th scope="col">Updated</th><th scope="col">Links</th><th scope="col">Actions</th></tr>
                  </thead>
                  <tbody>{rows}</tbody>
                </table>
              </div>
              {_admin_table_pagination()}
              {account_pager}
            </div>
          </section>

          <section class="section">
            <div class="container">
              <div class="d-flex align-items-md-center justify-content-between gap-4 flex-column flex-md-row">
                <div>
                  <p class="eyebrow">Domain claims</p>
                  <h2>Domain verification</h2>
                  <p class="section-copy mb-0">Showing {escape(len(domain_challenges))} of {domain_count}.</p>
                </div>
              </div>
              {_admin_table_toolbar("domain-claims", "Search domain claims")}
              <div class="table-responsive border rounded admin-table-scroll">
                <table class="table mb-0">
                  <thead><tr><th scope="col">Domain</th><th scope="col">Owner dashboard</th><th scope="col">Status</th><th scope="col">Created</th><th scope="col">Verified</th></tr></thead>
                  <tbody>{domain_rows}</tbody>
                </table>
              </div>
              {_admin_table_pagination()}
              {domain_pager}
            </div>
          </section>

          <section class="section">
            <div class="container">
              <div class="d-flex align-items-md-center justify-content-between gap-4 flex-column flex-md-row">
                <div>
                  <p class="eyebrow">Updates</p>
                  <h2>Update events</h2>
                  <p class="section-copy mb-0">Showing {escape(len(update_events))} of {event_count}. Repeated checks with no IP change are grouped.</p>
                </div>
              </div>
              {_admin_table_toolbar("update-events", "Search update events")}
              <div class="table-responsive border rounded admin-table-scroll">
                <table class="table mb-0">
                  <thead><tr><th scope="col">Time</th><th scope="col">Domain</th><th scope="col">Status</th><th scope="col">IPv4</th><th scope="col">IPv6</th><th scope="col">Count</th><th scope="col">Detail</th></tr></thead>
                  <tbody>{event_rows}</tbody>
                </table>
              </div>
              {_admin_table_pagination()}
              {event_pager}
            </div>
          </section>
        </main>
        """),
        extra_styles=trusted('<link href="/admin.css?v=2" rel="stylesheet">'),
        extra_scripts=trusted('<script src="/admin-tables.js?v=2" defer></script>'),
    )


def _server_page_links(admin_path: str, offset_name: str, offset: int, limit: int, total: int) -> SafeHtml:
    if total <= limit:
        return trusted("")
    previous_offset = max(0, offset - limit)
    next_offset = offset + limit
    previous_disabled = " disabled" if offset <= 0 else ""
    next_disabled = " disabled" if next_offset >= total else ""
    previous_href = attr(f"{admin_path}?{urlencode({offset_name: previous_offset})}")
    next_href = attr(f"{admin_path}?{urlencode({offset_name: next_offset})}")
    start = min(offset + 1, total)
    end = min(offset + limit, total)
    return trusted(f"""
      <nav class="d-flex align-items-center justify-content-end gap-2 mt-3" aria-label="Server-side table pages">
        <span class="small text-secondary">{escape(start)}-{escape(end)} of {escape(total)}</span>
        <a class="btn btn-sm btn-light rounded-pill{previous_disabled}" href="{previous_href}" aria-disabled="{str(offset <= 0).lower()}">Previous</a>
        <a class="btn btn-sm btn-light rounded-pill{next_disabled}" href="{next_href}" aria-disabled="{str(next_offset >= total).lower()}">Next</a>
      </nav>
    """)


def _cleanup_panel(
    settings: DdnsSettings,
    cleanup_runs: list[dict[str, str | int]],
    scheduled_tasks: list[dict[str, str | int | None]],
    safe_admin_path: str,
    csrf: str,
) -> SafeHtml:
    task = next((item for item in scheduled_tasks if item.get("name") == "cleanup"), scheduled_tasks[0] if scheduled_tasks else {})
    last_run = task.get("last_finished_at") or (cleanup_runs[0].get("created_at") if cleanup_runs else None)
    next_run = task.get("next_run_at")
    status = task.get("last_status") or "pending"
    last_error = task.get("last_error") or ""
    interval = task.get("interval_seconds") or settings.cleanup_interval_seconds
    last_cleanup = cleanup_runs[0] if cleanup_runs else {}
    domains_removed = last_cleanup.get("domain_challenges_deleted", 0)
    accounts_removed = last_cleanup.get("unused_accounts_deleted", 0)
    error_html = (
        trusted(f'<p class="small text-danger mb-0">Last error: {escape(last_error)}</p>')
        if last_error
        else trusted("")
    )
    cards = [
        ("Interval", f"*/{interval}s"),
        ("Last run", str(last_run or "Never")),
        ("Next run", str(next_run or "Pending")),
        ("Status", str(status)),
    ]
    card_html = "\n".join(
        f"""
        <div class="col-12 col-md-6 col-xl-3">
          <div class="metric-card h-100">
            <span>{escape(label)}</span>
            <strong>{escape(value)}</strong>
          </div>
        </div>
        """
        for label, value in cards
    )
    return trusted(f"""
      <div class="card flat-card">
        <div class="card-body p-4">
          <div class="d-flex align-items-start justify-content-between gap-3 flex-column flex-lg-row">
            <div>
              <h3 class="h5 mb-2">Cleanup</h3>
              <p class="section-copy mb-1">Last cleanup removed {escape(domains_removed)} domain claims and {escape(accounts_removed)} unused hostnames.</p>
              {error_html}
            </div>
            <form method="post" action="{safe_admin_path}/cleanup" aria-label="Run cleanup now">
              <input type="hidden" name="csrf" value="{csrf}">
              <button type="submit" class="btn btn-primary rounded-pill">Run now</button>
            </form>
          </div>
          <div class="row g-3 mt-3">
            {card_html}
          </div>
        </div>
      </div>
    """)


def _metrics_panel(metrics: dict[str, float]) -> SafeHtml:
    samples = metrics.get("update_latency_samples_total", 0)
    average_latency = metrics.get("update_latency_ms_total", 0) / samples if samples else 0
    items = [
        ("Updates", _metric_int(metrics.get("update_requests_total", 0))),
        ("Updated", _metric_int(metrics.get("update_success_total", 0))),
        ("DNS failures", _metric_int(metrics.get("dns_failures_total", 0))),
        ("DNS check failures", _metric_int(metrics.get("dns_reconcile_failures_total", 0))),
        ("Blocked requests", _metric_int(metrics.get("rate_limit_hits_total", 0))),
        ("Average update time", f"{average_latency:.1f} ms"),
        ("Last update time", f"{metrics.get('last_update_latency_ms', 0):.1f} ms"),
        ("Cleanup ok/errors", f"{_metric_int(metrics.get('cleanup_success_total', 0))}/{_metric_int(metrics.get('cleanup_errors_total', 0))}"),
    ]
    cards = "\n".join(
        f"""
        <div class="col-6 col-lg-3">
          <div class="metric-card h-100">
            <span>{escape(label)}</span>
            <strong>{escape(value)}</strong>
          </div>
        </div>
        """
        for label, value in items
    )
    return trusted(f"""
      <div class="mt-4">
        <p class="eyebrow">Metrics</p>
        <div class="row g-3 mt-1">{cards}</div>
      </div>
    """)


def _metric_int(value: float) -> str:
    return str(int(value))