import { useQuery } from '@tanstack/react-query';
import { config } from '../../config';
import { useAuthStore } from '../../auth/auth-store';
import { useRefreshInterval } from './use-refresh-interval';
import { useGlobalFilters } from '@cameleer/design-system';
import { useEnvironmentStore } from '../environment-store';
import { useInfiniteStream, type UseInfiniteStreamResult } from '../../hooks/useInfiniteStream';

export interface LogEntryResponse {
  timestamp: string;
  level: string;
  loggerName: string | null;
  message: string;
  threadName: string | null;
  stackTrace: string | null;
  exchangeId: string | null;
  instanceId: string | null;
  application: string | null;
  mdc: Record<string, string> | null;
  source: string | null;
}

export interface LogSearchPageResponse {
  data: LogEntryResponse[];
  nextCursor: string | null;
  hasMore: boolean;
  levelCounts: Record<string, number>;
}

export interface LogSearchParams {
  q?: string;
  level?: string;
  application?: string;
  agentId?: string;
  source?: string;
  /** Required: env in path */
  environment: string;
  exchangeId?: string;
  logger?: string;
  from?: string;
  to?: string;
  cursor?: string;
  limit?: number;
  sort?: 'asc' | 'desc';
}

async function fetchLogs(params: LogSearchParams): Promise<LogSearchPageResponse> {
  const token = useAuthStore.getState().accessToken;
  const urlParams = new URLSearchParams();
  if (params.q) urlParams.set('q', params.q);
  if (params.level) urlParams.set('level', params.level);
  if (params.application) urlParams.set('application', params.application);
  if (params.agentId) urlParams.set('agentId', params.agentId);
  if (params.source) urlParams.set('source', params.source);
  if (params.exchangeId) urlParams.set('exchangeId', params.exchangeId);
  if (params.logger) urlParams.set('logger', params.logger);
  if (params.from) urlParams.set('from', params.from);
  if (params.to) urlParams.set('to', params.to);
  if (params.cursor) urlParams.set('cursor', params.cursor);
  if (params.limit) urlParams.set('limit', String(params.limit));
  if (params.sort) urlParams.set('sort', params.sort);

  const res = await fetch(
    `${config.apiBaseUrl}/environments/${encodeURIComponent(params.environment)}/logs?${urlParams}`, {
    headers: {
      Authorization: `Bearer ${token}`,
      'X-Cameleer-Protocol-Version': '1',
    },
  });
  if (!res.ok) throw new Error('Failed to load logs');
  return res.json() as Promise<LogSearchPageResponse>;
}

/**
 * Primary log search hook with cursor pagination and level counts.
 */
export function useLogs(
  params: LogSearchParams,
  options?: { enabled?: boolean; refetchInterval?: number | false },
) {
  const defaultRefetch = useRefreshInterval(15_000);

  return useQuery({
    queryKey: ['logs', params],
    queryFn: () => fetchLogs(params),
    enabled: (options?.enabled ?? true) && !!params.environment,
    placeholderData: (prev) => prev,
    refetchInterval: options?.refetchInterval ?? defaultRefetch,
    staleTime: 300,
  });
}

/**
 * Backward-compatible wrapper for existing consumers (LogTab, AgentHealth, AgentInstance).
 * Returns the same shape they expect: data is the LogEntryResponse[] (unwrapped from the page response).
 */
export function useApplicationLogs(
  application?: string,
  agentId?: string,
  options?: { limit?: number; toOverride?: string; exchangeId?: string; source?: string },
) {
  const refetchInterval = useRefreshInterval(15_000);
  const { timeRange } = useGlobalFilters();
  const selectedEnv = useEnvironmentStore((s) => s.environment);
  const to = options?.toOverride ?? timeRange.end.toISOString();
  const useTimeRange = !options?.exchangeId;

  const params: LogSearchParams = {
    application: application || undefined,
    agentId: agentId || undefined,
    source: options?.source || undefined,
    environment: selectedEnv ?? '',
    exchangeId: options?.exchangeId || undefined,
    from: useTimeRange ? timeRange.start.toISOString() : undefined,
    to: useTimeRange ? to : undefined,
    limit: options?.limit,
  };

  const query = useQuery({
    queryKey: ['logs', 'compat', application, agentId, selectedEnv,
      useTimeRange ? timeRange.start.toISOString() : null,
      useTimeRange ? to : null,
      options?.limit, options?.exchangeId, options?.source],
    queryFn: () => fetchLogs(params),
    enabled: !!application && !!selectedEnv,
    placeholderData: (prev) => prev,
    refetchInterval,
  });

  // Unwrap: existing consumers expect data to be LogEntryResponse[] directly
  return {
    ...query,
    data: query.data?.data ?? (undefined as LogEntryResponse[] | undefined),
  };
}

/**
 * Fetches container startup logs for a deployment.
 * Polls every 3s while the deployment is STARTING, stops when RUNNING/FAILED.
 */
export function useStartupLogs(
  application: string | undefined,
  environment: string | undefined,
  deployCreatedAt: string | undefined,
  isStarting: boolean,
) {
  const params: LogSearchParams = {
    application: application || undefined,
    environment: environment ?? '',
    source: 'container',
    from: deployCreatedAt || undefined,
    sort: 'asc',
    limit: 500,
  };

  return useLogs(params, {
    enabled: !!application && !!deployCreatedAt && !!environment,
    refetchInterval: isStarting ? 3_000 : false,
  });
}

export interface UseInfiniteApplicationLogsArgs {
  application?: string;
  agentId?: string;
  sources?: string[];   // multi-select, server-side OR
  levels?: string[];    // multi-select, server-side OR
  exchangeId?: string;
  sort?: 'asc' | 'desc';
  isAtTop: boolean;
  pageSize?: number;
}

/**
 * Cursor-paginated log stream. Filters `sources`, `levels`, and the global
 * time range are applied server-side. Free-text search is applied by the
 * caller on top of the flattened items.
 */
export function useInfiniteApplicationLogs(
  args: UseInfiniteApplicationLogsArgs,
): UseInfiniteStreamResult<LogEntryResponse> {
  const { timeRange } = useGlobalFilters();
  const selectedEnv = useEnvironmentStore((s) => s.environment);

  const useTimeRange = !args.exchangeId;
  const fromIso = useTimeRange ? timeRange.start.toISOString() : undefined;
  const toIso = useTimeRange ? timeRange.end.toISOString() : undefined;
  // Relative presets (e.g. "last 1h") should live-tail: each fetch advances
  // `to` to "now" so new rows that arrive after the page was first rendered
  // show up on refetch. Absolute ranges keep their captured `to`.
  const isLiveRange = useTimeRange && !!timeRange.preset;

  const sortedSources = (args.sources ?? []).slice().sort();
  const sortedLevels = (args.levels ?? []).slice().sort();
  const sourcesParam = sortedSources.join(',');
  const levelsParam = sortedLevels.join(',');
  const pageSize = args.pageSize ?? 100;
  const sort = args.sort ?? 'desc';

  return useInfiniteStream<LogEntryResponse>({
    queryKey: [
      'logs', 'infinite',
      selectedEnv ?? '',
      args.application ?? '',
      args.agentId ?? '',
      args.exchangeId ?? '',
      sourcesParam,
      levelsParam,
      fromIso ?? '',
      toIso ?? '',
      pageSize,
      sort,
    ],
    enabled: !!args.application && !!selectedEnv,
    isAtTop: args.isAtTop,
    fetchPage: async (cursor) => {
      const token = useAuthStore.getState().accessToken;
      const qp = new URLSearchParams();
      if (args.application) qp.set('application', args.application);
      if (args.agentId) qp.set('agentId', args.agentId);
      if (args.exchangeId) qp.set('exchangeId', args.exchangeId);
      if (sourcesParam) qp.set('source', sourcesParam);
      if (levelsParam) qp.set('level', levelsParam);
      if (fromIso) qp.set('from', fromIso);
      const effectiveTo = isLiveRange ? new Date().toISOString() : toIso;
      if (effectiveTo) qp.set('to', effectiveTo);
      if (cursor) qp.set('cursor', cursor);
      qp.set('limit', String(pageSize));
      qp.set('sort', sort);

      const res = await fetch(
        `${config.apiBaseUrl}/environments/${encodeURIComponent(selectedEnv ?? '')}/logs?${qp}`,
        {
          headers: {
            Authorization: `Bearer ${token}`,
            'X-Cameleer-Protocol-Version': '1',
          },
        },
      );
      if (!res.ok) throw new Error('Failed to load logs');
      const page: LogSearchPageResponse = await res.json();
      return { data: page.data, nextCursor: page.nextCursor, hasMore: page.hasMore };
    },
  });
}