import { useEffect, useMemo, useRef, useState } from 'react';
import { useTranslation } from 'react-i18next';
import { toast } from 'sonner';
import {
  AlertCircle,
  ChevronDown,
  CircleHelp,
  LoaderCircle,
  Play,
  RotateCcw,
} from 'lucide-react';
import { httpClient } from '@/app/infra/http/HttpClient';
import { Badge } from '@/components/ui/badge';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import {
  Select,
  SelectContent,
  SelectGroup,
  SelectItem,
  SelectLabel,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select';
import { Textarea } from '@/components/ui/textarea';
import { Alert, AlertDescription, AlertTitle } from '@/components/ui/alert';
import {
  Collapsible,
  CollapsibleContent,
  CollapsibleTrigger,
} from '@/components/ui/collapsible';
import {
  eventGroupLabel,
  eventPatternDescription,
  eventPatternLabel,
  groupEventPatterns,
} from '@/app/home/components/event-patterns/event-pattern-groups';
import EventSelectOptionContent from '@/app/home/components/event-patterns/EventSelectOptionContent';

interface AgentDebugPanelProps {
  agentId: string;
  availableEventTypes: string[];
  supportedEventPatterns?: string[];
  beforeRun?: () => Promise<boolean>;
  hasUnsavedChanges?: boolean;
  onOpenRunnerConfig?: () => void;
}

interface DebugEntry {
  id: string;
  direction: 'input' | 'output' | 'error';
  eventType: string;
  text: string;
  errorCode?: string;
  detail?: string;
}

const EVENT_PRESET_DATA: Record<
  string,
  { text: string; data: Record<string, unknown> }
> = {
  'message.received': {
    text: '',
    data: {},
  },
  'group.member_joined': {
    text: 'A new member joined the group.',
    data: {
      group_id: 'debug-group',
      member_id: 'debug-user',
      member_name: 'Debug User',
    },
  },
  'group.member_left': {
    text: 'A member left the group.',
    data: {
      group_id: 'debug-group',
      member_id: 'debug-user',
      member_name: 'Debug User',
    },
  },
  'friend.request_received': {
    text: 'A user sent a friend request.',
    data: {
      requester_id: 'debug-user',
      requester_name: 'Debug User',
      message: 'Hello',
    },
  },
  'feedback.received': {
    text: 'The user submitted feedback.',
    data: {
      rating: 5,
      content: 'Debug feedback',
    },
  },
};

function createDebugSessionId(agentId: string) {
  const nonce = globalThis.crypto?.randomUUID?.() ?? String(Date.now());
  return `webui:${agentId}:${nonce}`;
}

function matchesEventPattern(pattern: string, eventType: string) {
  const escaped = pattern.replace(/[.+?^${}()|[\]\\]/g, '\\$&');
  return new RegExp(`^${escaped.replaceAll('*', '.*')}$`).test(eventType);
}

export default function AgentDebugPanel({
  agentId,
  availableEventTypes,
  supportedEventPatterns = ['*'],
  beforeRun,
  hasUnsavedChanges = false,
  onOpenRunnerConfig,
}: AgentDebugPanelProps) {
  const { t } = useTranslation();
  const [preset, setPreset] = useState('message.received');
  const [customEventType, setCustomEventType] = useState('custom.event');
  const [inputText, setInputText] = useState('');
  const [eventDataText, setEventDataText] = useState('{}');
  const [running, setRunning] = useState(false);
  const [entries, setEntries] = useState<DebugEntry[]>([]);
  const sessionIdRef = useRef(createDebugSessionId(agentId));

  const eventType = preset === 'custom' ? customEventType.trim() : preset;
  const isMessageEvent = eventType.startsWith('message.');
  const supportedLabel = useMemo(
    () => supportedEventPatterns.join(', '),
    [supportedEventPatterns],
  );
  const availableEvents = useMemo(() => {
    const concretePatterns = supportedEventPatterns.filter(
      (pattern) => pattern !== '*' && !pattern.endsWith('.*'),
    );
    return Array.from(new Set([...availableEventTypes, ...concretePatterns]))
      .filter((candidate) =>
        supportedEventPatterns.some((pattern) =>
          matchesEventPattern(pattern, candidate),
        ),
      )
      .sort();
  }, [availableEventTypes, supportedEventPatterns]);
  const eventGroups = useMemo(
    () => groupEventPatterns(availableEvents),
    [availableEvents],
  );
  const supportsCustomEvent = supportedEventPatterns.some(
    (pattern) => pattern === '*' || pattern.endsWith('.*'),
  );

  useEffect(() => {
    if (
      availableEvents.includes(preset) ||
      (preset === 'custom' && supportsCustomEvent)
    ) {
      return;
    }
    selectPreset(availableEvents[0] ?? 'custom');
  }, [availableEvents, preset, supportsCustomEvent]);

  function selectPreset(value: string) {
    setPreset(value);
    const nextPreset = EVENT_PRESET_DATA[value] ?? { text: '', data: {} };
    setInputText(nextPreset.text);
    setEventDataText(JSON.stringify(nextPreset.data, null, 2));
  }

  function resetSession() {
    sessionIdRef.current = createDebugSessionId(agentId);
    setEntries([]);
  }

  async function runDebugEvent() {
    if (!eventType) {
      toast.error(t('agents.debugEventTypeRequired'));
      return;
    }
    if (isMessageEvent && !inputText.trim()) {
      toast.error(t('agents.debugInputRequired'));
      return;
    }
    if (
      !supportedEventPatterns.some((pattern) =>
        matchesEventPattern(pattern, eventType),
      )
    ) {
      toast.error(t('agents.debugUnsupportedEvent'));
      return;
    }

    let eventData: Record<string, unknown>;
    try {
      const parsed = JSON.parse(eventDataText || '{}');
      if (!parsed || Array.isArray(parsed) || typeof parsed !== 'object') {
        throw new Error('payload must be an object');
      }
      eventData = parsed as Record<string, unknown>;
    } catch {
      toast.error(t('agents.debugInvalidPayload'));
      return;
    }

    setRunning(true);
    if (hasUnsavedChanges && beforeRun && !(await beforeRun())) {
      setRunning(false);
      return;
    }

    const requestId = globalThis.crypto?.randomUUID?.() ?? String(Date.now());
    setEntries((current) => [
      ...current,
      {
        id: `input:${requestId}`,
        direction: 'input',
        eventType,
        text: inputText.trim() || JSON.stringify(eventData, null, 2),
      },
    ]);
    try {
      const result = await httpClient.debugAgent(agentId, {
        event_type: eventType,
        text: inputText.trim(),
        data: eventData,
        conversation_id: sessionIdRef.current,
      });
      setEntries((current) => [
        ...current,
        {
          id: `output:${result.event_id}`,
          direction: 'output',
          eventType,
          text: result.final_text || t('agents.debugNoTextOutput'),
        },
      ]);
      if (isMessageEvent) setInputText('');
    } catch (error) {
      const errorCode =
        typeof error === 'object' && error && 'code' in error
          ? String((error as { code?: string }).code || '')
          : '';
      const message =
        typeof error === 'object' && error && 'msg' in error
          ? String((error as { msg?: string }).msg || '')
          : t('agents.debugRunFailed');
      const isConfigError = errorCode.endsWith('.config_invalid');
      const isExecutionError = errorCode === 'runner_execution_failed';
      const isTimeout = errorCode === 'runner.timeout';
      const friendlyMessage = isConfigError
        ? t('agents.debugRunnerConfigInvalidDescription', {
            message:
              message === 'api-key is required'
                ? t('agents.debugApiKeyRequired')
                : message,
          })
        : isExecutionError
          ? t('agents.debugRunnerExecutionFailedDescription')
          : isTimeout
            ? t('agents.debugRunnerTimeoutDescription')
            : message || t('agents.debugRunFailed');
      setEntries((current) => [
        ...current,
        {
          id: `error:${requestId}`,
          direction: 'error',
          eventType,
          text: friendlyMessage,
          errorCode,
          detail:
            isExecutionError || isTimeout
              ? message || t('agents.debugRunFailed')
              : undefined,
        },
      ]);
    } finally {
      setRunning(false);
    }
  }

  return (
    <div className="flex h-full min-h-0 min-w-0 flex-col">
      <div className="min-h-0 flex-1 overflow-y-auto p-3">
        <div className="mb-3">
          <p className="text-sm font-medium">{t('agents.debugTranscript')}</p>
          <p className="text-xs text-muted-foreground">
            {t('agents.debugTranscriptDescription')}
          </p>
        </div>
        {entries.length === 0 ? (
          <Alert className="my-4 bg-muted/20">
            <CircleHelp className="size-4" />
            <AlertTitle>{t('agents.debugEmptyTitle')}</AlertTitle>
            <AlertDescription>
              {t('agents.debugEmptyTranscript')}
            </AlertDescription>
          </Alert>
        ) : (
          <div className="space-y-3">
            {entries.map((entry) => (
              <Alert
                key={entry.id}
                variant={
                  entry.direction === 'error' ? 'destructive' : 'default'
                }
                className={
                  entry.direction === 'output'
                    ? 'border-primary/20 bg-primary/5'
                    : entry.direction === 'input'
                      ? 'bg-muted/40'
                      : undefined
                }
              >
                {entry.direction === 'error' && <AlertCircle />}
                <div className="mb-2 flex items-center justify-between gap-2">
                  <Badge variant="outline">{entry.eventType}</Badge>
                  <span className="text-xs text-muted-foreground">
                    {entry.direction === 'output'
                      ? t('agents.debugAgentOutput')
                      : entry.direction === 'error'
                        ? t('common.error')
                        : t('agents.debugTestInput')}
                  </span>
                </div>
                <pre className="min-w-0 whitespace-pre-wrap break-words font-sans text-sm leading-relaxed">
                  {entry.text}
                </pre>
                {entry.detail && (
                  <Collapsible className="mt-3">
                    <CollapsibleTrigger asChild>
                      <Button type="button" variant="ghost" size="sm">
                        {t('agents.debugErrorDetails')}
                        <ChevronDown className="size-3.5" />
                      </Button>
                    </CollapsibleTrigger>
                    <CollapsibleContent>
                      <pre className="mt-2 max-h-32 overflow-auto whitespace-pre-wrap break-words rounded-md bg-muted p-2 font-mono text-xs text-muted-foreground">
                        {entry.detail}
                      </pre>
                    </CollapsibleContent>
                  </Collapsible>
                )}
                {(entry.errorCode?.endsWith('.config_invalid') ||
                  entry.errorCode === 'runner_execution_failed' ||
                  entry.errorCode === 'runner.timeout') &&
                  onOpenRunnerConfig && (
                    <Button
                      type="button"
                      variant="outline"
                      size="sm"
                      className="mt-3"
                      onClick={onOpenRunnerConfig}
                    >
                      {t('agents.debugReviewRunnerConfig')}
                    </Button>
                  )}
              </Alert>
            ))}
          </div>
        )}
      </div>

      <div className="shrink-0 space-y-3 border-t p-3">
        <div className="flex items-end gap-2">
          <div className="min-w-0 flex-1 space-y-1.5">
            <Label>{t('agents.debugEventType')}</Label>
            <Select value={preset} onValueChange={selectPreset}>
              <SelectTrigger
                className="w-full"
                aria-label={t('agents.debugEventType')}
              >
                <SelectValue />
              </SelectTrigger>
              <SelectContent className="w-[var(--radix-select-trigger-width)] max-w-[calc(100vw-2rem)]">
                {eventGroups.map((group) => (
                  <SelectGroup key={group.namespace}>
                    <SelectLabel>
                      {eventGroupLabel(group.namespace, t)}
                    </SelectLabel>
                    {group.patterns.map((event) => (
                      <SelectItem
                        key={event}
                        value={event}
                        description={eventPatternDescription(event, t)}
                        className="py-2"
                      >
                        <EventSelectOptionContent
                          event={event}
                          label={eventPatternLabel(event, t)}
                        />
                      </SelectItem>
                    ))}
                  </SelectGroup>
                ))}
                {supportsCustomEvent && (
                  <SelectGroup>
                    <SelectLabel>{t('agents.debugCustomEvent')}</SelectLabel>
                    <SelectItem
                      value="custom"
                      description={t('bots.eventDescriptions.custom')}
                      className="py-2"
                    >
                      <EventSelectOptionContent
                        event="custom.event"
                        label={t('agents.debugCustomEvent')}
                      />
                    </SelectItem>
                  </SelectGroup>
                )}
              </SelectContent>
            </Select>
          </div>
          <Button
            type="button"
            variant="outline"
            size="icon"
            onClick={resetSession}
            title={t('agents.debugResetSession')}
          >
            <RotateCcw className="size-4" />
          </Button>
        </div>

        {preset === 'custom' && (
          <div className="space-y-1.5">
            <Label htmlFor="agent-debug-custom-event">
              {t('agents.debugCustomEventType')}
            </Label>
            <Input
              id="agent-debug-custom-event"
              value={customEventType}
              onChange={(event) => setCustomEventType(event.target.value)}
              placeholder="custom.event"
            />
          </div>
        )}

        <div className="space-y-1.5">
          <Label htmlFor="agent-debug-input">
            {isMessageEvent
              ? t('agents.debugMessageInput')
              : t('agents.debugEventSummary')}
          </Label>
          <Textarea
            id="agent-debug-input"
            value={inputText}
            onChange={(event) => setInputText(event.target.value)}
            className="min-h-20 resize-y"
            placeholder={t('agents.debugInputPlaceholder')}
          />
        </div>

        <details className="rounded-md border bg-muted/20 px-3 py-2">
          <summary className="cursor-pointer text-xs font-medium">
            {t('agents.debugEventPayload')}
          </summary>
          <div className="mt-2 space-y-2">
            <p className="text-xs text-muted-foreground">
              {t('agents.debugSupportedEvents')}: {supportedLabel}
            </p>
            <Textarea
              id="agent-debug-payload"
              value={eventDataText}
              onChange={(event) => setEventDataText(event.target.value)}
              className="min-h-28 resize-y font-mono text-xs"
              spellCheck={false}
            />
          </div>
        </details>

        <Button
          type="button"
          className="w-full"
          disabled={running}
          onClick={runDebugEvent}
        >
          {running ? (
            <LoaderCircle className="size-4 animate-spin" />
          ) : (
            <Play className="size-4" />
          )}
          {running
            ? t('agents.debugRunning')
            : hasUnsavedChanges
              ? t('agents.debugSaveAndRun')
              : t('agents.debugRun')}
        </Button>
      </div>
    </div>
  );
}