import { useState, useMemo, useEffect } from 'react';
import { useNavigate } from 'react-router';
import {
  DataTable, Badge, MonoText, DetailPanel, SectionHeader, Button, Toggle, Spinner, useToast,
} from '@cameleer/design-system';
import type { Column } from '@cameleer/design-system';
import { useAllApplicationConfigs, useApplicationConfig, useUpdateApplicationConfig, useProcessorRouteMapping } from '../../api/queries/commands';
import type { ApplicationConfig, TapDefinition } from '../../api/queries/commands';
import { useRouteCatalog } from '../../api/queries/catalog';
import type { AppCatalogEntry, RouteSummary } from '../../api/types';
import styles from './AppConfigPage.module.css';

type ConfigRow = ApplicationConfig & { id: string };
type BadgeColor = 'primary' | 'success' | 'warning' | 'error' | 'running' | 'auto';

interface TracedTapRow { id: string; processorId: string; captureMode: string | null; taps: TapDefinition[]; }
interface RouteRecordingRow { id: string; routeId: string; recording: boolean; }

function timeAgo(iso?: string): string {
  if (!iso) return '\u2014';
  const diff = Date.now() - new Date(iso).getTime();
  const secs = Math.floor(diff / 1000);
  if (secs < 60) return `${secs}s ago`;
  const mins = Math.floor(secs / 60);
  if (mins < 60) return `${mins}m ago`;
  const hours = Math.floor(mins / 60);
  if (hours < 24) return `${hours}h ago`;
  return `${Math.floor(hours / 24)}d ago`;
}

function logLevelColor(level?: string): BadgeColor {
  switch (level?.toUpperCase()) {
    case 'ERROR': return 'error'; case 'WARN': return 'warning'; case 'DEBUG': return 'running'; default: return 'success';
  }
}
function engineLevelColor(level?: string): BadgeColor {
  switch (level?.toUpperCase()) {
    case 'NONE': return 'error'; case 'MINIMAL': return 'warning'; case 'COMPLETE': return 'running'; default: return 'success';
  }
}
function payloadColor(mode?: string): BadgeColor {
  switch (mode?.toUpperCase()) {
    case 'INPUT': case 'OUTPUT': return 'warning'; case 'BOTH': return 'running'; default: return 'auto';
  }
}
function captureColor(mode: string): BadgeColor {
  switch (mode?.toUpperCase()) {
    case 'INPUT': case 'OUTPUT': return 'warning'; case 'BOTH': return 'running'; default: return 'auto';
  }
}

// ── Table columns (overview) ─────────────────────────────────────────────────

function buildColumns(): Column<ConfigRow>[] {
  return [
    { key: 'application', header: 'Application', sortable: true, render: (_v, row) => <MonoText size="sm">{row.application}</MonoText> },
    { key: 'logForwardingLevel', header: 'Log Level', render: (_v, row) => { const val = row.logForwardingLevel ?? 'INFO'; return <Badge label={val} color={logLevelColor(val)} variant="filled" />; } },
    { key: 'engineLevel', header: 'Engine Level', render: (_v, row) => { const val = row.engineLevel ?? 'REGULAR'; return <Badge label={val} color={engineLevelColor(val)} variant="filled" />; } },
    { key: 'payloadCaptureMode', header: 'Payload Capture', render: (_v, row) => { const val = row.payloadCaptureMode ?? 'NONE'; return <Badge label={val} color={payloadColor(val)} variant="filled" />; } },
    { key: 'metricsEnabled', header: 'Metrics', width: '80px', render: (_v, row) => <Badge label={row.metricsEnabled ? 'On' : 'Off'} color={row.metricsEnabled ? 'success' : 'error'} variant="filled" /> },
    { key: 'tracedProcessors', header: 'Traced', width: '70px', render: (_v, row) => { const c = row.tracedProcessors ? Object.keys(row.tracedProcessors).length : 0; return c > 0 ? <Badge label={`${c}`} color="running" variant="filled" /> : <MonoText size="xs">0</MonoText>; } },
    { key: 'taps', header: 'Taps', width: '70px', render: (_v, row) => { const t = row.taps?.length ?? 0; const e = row.taps?.filter(x => x.enabled).length ?? 0; return t === 0 ? <MonoText size="xs">0</MonoText> : <Badge label={`${e}/${t}`} color="running" variant="filled" />; } },
    { key: 'version', header: 'v', width: '40px', render: (_v, row) => <MonoText size="xs">{row.version}</MonoText> },
    { key: 'updatedAt', header: 'Updated', render: (_v, row) => <MonoText size="xs">{timeAgo(row.updatedAt)}</MonoText> },
  ];
}

// ── Detail Panel Content ─────────────────────────────────────────────────────

function AppConfigDetail({ appId, onClose }: { appId: string; onClose: () => void }) {
  const { toast } = useToast();
  const navigate = useNavigate();
  const { data: config, isLoading } = useApplicationConfig(appId);
  const updateConfig = useUpdateApplicationConfig();
  const { data: catalog } = useRouteCatalog();

  const [editing, setEditing] = useState(false);
  const [form, setForm] = useState<Partial<ApplicationConfig> | null>(null);
  const [tracedDraft, setTracedDraft] = useState<Record<string, string>>({});
  const [routeRecordingDraft, setRouteRecordingDraft] = useState<Record<string, boolean>>({});

  const appRoutes: RouteSummary[] = useMemo(() => {
    if (!catalog || !appId) return [];
    const entry = (catalog as AppCatalogEntry[]).find((e) => e.appId === appId);
    return entry?.routes ?? [];
  }, [catalog, appId]);

  // processorId → routeId mapping from backend
  const { data: processorToRoute = {} } = useProcessorRouteMapping(appId);

  useEffect(() => {
    if (config) {
      setForm({
        logForwardingLevel: config.logForwardingLevel ?? 'INFO',
        engineLevel: config.engineLevel ?? 'REGULAR',
        payloadCaptureMode: config.payloadCaptureMode ?? 'NONE',
        metricsEnabled: config.metricsEnabled,
        samplingRate: config.samplingRate,
        compressSuccess: config.compressSuccess,
      });
      setTracedDraft({ ...config.tracedProcessors });
      setRouteRecordingDraft({ ...config.routeRecording });
    }
  }, [config]);

  function startEditing() {
    if (!config) return;
    setForm({
      logForwardingLevel: config.logForwardingLevel ?? 'INFO',
      engineLevel: config.engineLevel ?? 'REGULAR',
      payloadCaptureMode: config.payloadCaptureMode ?? 'NONE',
      metricsEnabled: config.metricsEnabled,
      samplingRate: config.samplingRate,
      compressSuccess: config.compressSuccess,
    });
    setTracedDraft({ ...config.tracedProcessors });
    setRouteRecordingDraft({ ...config.routeRecording });
    setEditing(true);
  }

  function updateField<K extends keyof ApplicationConfig>(key: K, value: ApplicationConfig[K]) {
    setForm((prev) => prev ? { ...prev, [key]: value } : prev);
  }

  function updateTracedProcessor(processorId: string, mode: string) {
    setTracedDraft((prev) => {
      if (mode === 'REMOVE') { const next = { ...prev }; delete next[processorId]; return next; }
      return { ...prev, [processorId]: mode };
    });
  }

  function updateRouteRecording(routeId: string, recording: boolean) {
    setRouteRecordingDraft((prev) => ({ ...prev, [routeId]: recording }));
  }

  function handleSave() {
    if (!config || !form) return;
    const updated = { ...config, ...form, tracedProcessors: tracedDraft, routeRecording: routeRecordingDraft } as ApplicationConfig;
    updateConfig.mutate(updated, {
      onSuccess: (saved) => { setEditing(false); toast({ title: 'Config saved', description: `${appId} updated to v${saved.version}`, variant: 'success' }); },
      onError: () => { toast({ title: 'Save failed', description: 'Could not update configuration', variant: 'error' }); },
    });
  }

  function navigateToTaps(processorId: string) {
    const routeId = processorToRoute[processorId];
    onClose();
    if (routeId) {
      navigate(`/routes/${appId}/${routeId}?tab=taps`);
    } else {
      navigate(`/routes/${appId}`);
    }
  }

  // ── Traces & Taps merged rows
  const tracedTapRows: TracedTapRow[] = useMemo(() => {
    const traced = editing ? tracedDraft : (config?.tracedProcessors ?? {});
    const taps = config?.taps ?? [];
    const pids = new Set<string>([...Object.keys(traced), ...taps.map(t => t.processorId)]);
    return Array.from(pids).sort().map(pid => ({ id: pid, processorId: pid, captureMode: traced[pid] ?? null, taps: taps.filter(t => t.processorId === pid) }));
  }, [editing, tracedDraft, config?.tracedProcessors, config?.taps]);

  const tracedCount = useMemo(() => Object.keys(editing ? tracedDraft : (config?.tracedProcessors ?? {})).length, [editing, tracedDraft, config?.tracedProcessors]);
  const tapCount = config?.taps?.length ?? 0;

  const tracedTapColumns: Column<TracedTapRow>[] = useMemo(() => [
    { key: 'route' as any, header: 'Route', render: (_v, row) => {
      const routeId = processorToRoute[row.processorId];
      return routeId ? <span className={styles.routeLabel}>{routeId}</span> : <span className={styles.hint}>&mdash;</span>;
    }},
    { key: 'processorId', header: 'Processor', render: (_v, row) => <MonoText size="xs">{row.processorId}</MonoText> },
    {
      key: 'captureMode', header: 'Capture',
      render: (_v, row) => {
        if (row.captureMode === null) return <span className={styles.hint}>&mdash;</span>;
        if (editing) return (
          <select className={styles.select} value={row.captureMode} onChange={(e) => updateTracedProcessor(row.processorId, e.target.value)}>
            <option value="NONE">None</option><option value="INPUT">Input</option><option value="OUTPUT">Output</option><option value="BOTH">Both</option>
          </select>
        );
        return <Badge label={row.captureMode} color={captureColor(row.captureMode)} variant="filled" />;
      },
    },
    {
      key: 'taps', header: 'Taps',
      render: (_v, row) => row.taps.length === 0
        ? <span className={styles.hint}>&mdash;</span>
        : <div className={styles.tapBadges}>{row.taps.map(t => (
            <button key={t.tapId} className={styles.tapBadgeLink} onClick={() => navigateToTaps(row.processorId)} title={`Manage on route page${processorToRoute[row.processorId] ? ` (${processorToRoute[row.processorId]})` : ''}`}>
              <Badge label={t.attributeName} color={t.enabled ? 'success' : 'auto'} variant="filled" />
            </button>
          ))}</div>,
    },
    ...(editing ? [{
      key: '_remove' as const, header: '', width: '36px',
      render: (_v: unknown, row: TracedTapRow) => row.captureMode === null ? null : (
        <button className={styles.removeBtn} title="Remove" onClick={() => updateTracedProcessor(row.processorId, 'REMOVE')}>&times;</button>
      ),
    }] : []),
  ], [editing, processorToRoute]);

  // ── Route Recording rows
  const routeRecordingRows: RouteRecordingRow[] = useMemo(() => {
    const rec = editing ? routeRecordingDraft : (config?.routeRecording ?? {});
    return appRoutes.map(r => ({ id: r.routeId, routeId: r.routeId, recording: rec[r.routeId] !== false }));
  }, [editing, routeRecordingDraft, config?.routeRecording, appRoutes]);

  const recordingCount = routeRecordingRows.filter(r => r.recording).length;

  const routeRecordingColumns: Column<RouteRecordingRow>[] = useMemo(() => [
    { key: 'routeId', header: 'Route', render: (_v, row) => <MonoText size="xs">{row.routeId}</MonoText> },
    { key: 'recording', header: 'Recording', width: '100px', render: (_v, row) => <Toggle checked={row.recording} onChange={() => { if (editing) updateRouteRecording(row.routeId, !row.recording); }} disabled={!editing} /> },
  ], [editing, routeRecordingDraft]);

  if (isLoading) return <div style={{ padding: 24, textAlign: 'center' }}><Spinner size="sm" /></div>;
  if (!config || !form) return <div style={{ padding: 16 }}>No configuration found.</div>;

  return (
    <>
      <div className={styles.panelToolbar}>
        <div className={styles.panelMeta}>
          Version <MonoText size="xs">{config.version}</MonoText>
          {config.updatedAt && <> &middot; Updated <MonoText size="xs">{timeAgo(config.updatedAt)}</MonoText></>}
        </div>
        {editing ? (
          <div className={styles.panelActions}>
            <Button variant="secondary" size="sm" onClick={() => setEditing(false)}>Cancel</Button>
            <Button size="sm" onClick={handleSave} disabled={updateConfig.isPending}>
              {updateConfig.isPending ? 'Saving\u2026' : 'Save'}
            </Button>
          </div>
        ) : (
          <button className={styles.editBtn} onClick={startEditing} title="Edit configuration">&#x270E;</button>
        )}
      </div>

      {/* Settings */}
      <div className={styles.panelSection}>
        <div className={styles.panelSectionHeader}>Settings</div>
        <div className={styles.settingsGrid}>
          <div className={styles.field}>
            <span className={styles.fieldLabel}>Log Forwarding</span>
            {editing
              ? <select className={styles.select} value={String(form.logForwardingLevel)} onChange={(e) => updateField('logForwardingLevel', e.target.value)}><option value="ERROR">ERROR</option><option value="WARN">WARN</option><option value="INFO">INFO</option><option value="DEBUG">DEBUG</option></select>
              : <Badge label={String(form.logForwardingLevel)} color={logLevelColor(form.logForwardingLevel as string)} variant="filled" />}
          </div>
          <div className={styles.field}>
            <span className={styles.fieldLabel}>Engine Level</span>
            {editing
              ? <select className={styles.select} value={String(form.engineLevel)} onChange={(e) => updateField('engineLevel', e.target.value)}><option value="NONE">None</option><option value="MINIMAL">Minimal</option><option value="REGULAR">Regular</option><option value="COMPLETE">Complete</option></select>
              : <Badge label={String(form.engineLevel)} color={engineLevelColor(form.engineLevel as string)} variant="filled" />}
          </div>
          <div className={styles.field}>
            <span className={styles.fieldLabel}>Payload Capture</span>
            {editing
              ? <select className={styles.select} value={String(form.payloadCaptureMode)} onChange={(e) => updateField('payloadCaptureMode', e.target.value)}><option value="NONE">None</option><option value="INPUT">Input</option><option value="OUTPUT">Output</option><option value="BOTH">Both</option></select>
              : <Badge label={String(form.payloadCaptureMode)} color={payloadColor(form.payloadCaptureMode as string)} variant="filled" />}
          </div>
          <div className={styles.field}>
            <span className={styles.fieldLabel}>Metrics</span>
            {editing
              ? <Toggle checked={Boolean(form.metricsEnabled)} onChange={(e) => updateField('metricsEnabled', (e.target as HTMLInputElement).checked)} />
              : <Badge label={form.metricsEnabled ? 'On' : 'Off'} color={form.metricsEnabled ? 'success' : 'error'} variant="filled" />}
          </div>
          <div className={styles.field}>
            <span className={styles.fieldLabel}>Compress Success</span>
            {editing
              ? <Toggle checked={Boolean(form.compressSuccess)} onChange={(e) => updateField('compressSuccess', (e.target as HTMLInputElement).checked)} />
              : <Badge label={form.compressSuccess ? 'On' : 'Off'} color={form.compressSuccess ? 'success' : 'error'} variant="filled" />}
          </div>
          <div className={styles.field}>
            <span className={styles.fieldLabel}>Sampling Rate</span>
            {editing
              ? <input type="number" className={styles.select} min={0} max={1} step={0.01} value={form.samplingRate ?? 1.0} onChange={(e) => updateField('samplingRate', parseFloat(e.target.value) || 0)} />
              : <MonoText size="xs">{form.samplingRate}</MonoText>}
          </div>
        </div>
      </div>

      {/* Traces & Taps */}
      <div className={styles.panelSection}>
        <div className={styles.panelSectionHeader}>Traces & Taps</div>
        <span className={styles.sectionSummary}>{tracedCount} traced &middot; {tapCount} taps &middot; click tap to manage</span>
        {tracedTapRows.length > 0
          ? <DataTable<TracedTapRow> columns={tracedTapColumns} data={tracedTapRows} pageSize={20} flush />
          : <span className={styles.hint}>No processor traces or taps configured.</span>}
      </div>

      {/* Route Recording */}
      <div className={styles.panelSection}>
        <div className={styles.panelSectionHeader}>Route Recording</div>
        <span className={styles.sectionSummary}>{recordingCount} of {routeRecordingRows.length} routes recording</span>
        {routeRecordingRows.length > 0
          ? <DataTable<RouteRecordingRow> columns={routeRecordingColumns} data={routeRecordingRows} pageSize={20} flush />
          : <span className={styles.hint}>No routes found for this application.</span>}
      </div>
    </>
  );
}

// ── Main Page ────────────────────────────────────────────────────────────────

export default function AppConfigPage() {
  const { data: configs } = useAllApplicationConfigs();
  const [selectedApp, setSelectedApp] = useState<string | null>(null);
  const columns = useMemo(buildColumns, []);

  return (
    <div>
      <DataTable<ConfigRow>
        columns={columns}
        data={(configs ?? []).map(c => ({ ...c, id: c.application }))}
        onRowClick={(row) => setSelectedApp(row.application)}
        selectedId={selectedApp ?? undefined}
        pageSize={50}
      />
      <DetailPanel
        open={!!selectedApp}
        onClose={() => setSelectedApp(null)}
        title={selectedApp ?? ''}
        className={styles.widePanel}
      >
        {selectedApp && <AppConfigDetail appId={selectedApp} onClose={() => setSelectedApp(null)} />}
      </DetailPanel>
    </div>
  );
}