import type { ChannelAccountCatalogGroup, ChannelConnectionStatus } from '@src/lib/channel-types';

const KNOWN_CHANNEL_STATUSES: ChannelConnectionStatus[] = [
  'connected',
  'connecting',
  'disconnected',
  'error',
  'degraded',
];

export interface ChannelStatusInferenceInput {
  status?: unknown;
  configured?: boolean;
  channelUrl?: string | null;
  lastError?: string | null;
  error?: unknown;
  warnings?: readonly string[] | null;
  warningCount?: number;
  isConnecting?: boolean;
  isLoading?: boolean;
  connectionState?: unknown;
  hasBinding?: boolean;
  degraded?: boolean;
}

export interface ChannelStatusSummary {
  status: ChannelConnectionStatus;
  counts: Record<ChannelConnectionStatus, number>;
  groupCount: number;
  accountCount: number;
}

function isMeaningfulText(value: unknown): boolean {
  return String(value ?? '').trim().length > 0;
}

function isValidUrl(value: string): boolean {
  try {
    new URL(value);
    return true;
  } catch {
    return false;
  }
}

export function normalizeChannelConnectionStatus(value: unknown): ChannelConnectionStatus | null {
  const normalized = String(value ?? '').trim().toLowerCase();
  return KNOWN_CHANNEL_STATUSES.includes(normalized as ChannelConnectionStatus)
    ? (normalized as ChannelConnectionStatus)
    : null;
}

export function inferChannelConnectionStatus(
  input: ChannelStatusInferenceInput = {},
): ChannelConnectionStatus {
  const explicitStatus = normalizeChannelConnectionStatus(input.status);
  const normalizedConnectionState = normalizeChannelConnectionStatus(input.connectionState);
  const channelUrl = String(input.channelUrl ?? '').trim();
  const warningCount = typeof input.warningCount === 'number'
    ? input.warningCount
    : Array.isArray(input.warnings)
      ? input.warnings.filter(isMeaningfulText).length
      : 0;

  if (isMeaningfulText(input.error) || isMeaningfulText(input.lastError)) {
    return 'error';
  }

  if (explicitStatus === 'error' || normalizedConnectionState === 'error') {
    return 'error';
  }

  if (input.configured === false || !channelUrl) {
    return 'disconnected';
  }

  if (!isValidUrl(channelUrl)) {
    return 'error';
  }

  if (
    explicitStatus === 'connecting'
    || normalizedConnectionState === 'connecting'
    || input.isConnecting
    || input.isLoading
  ) {
    return 'connecting';
  }

  if (explicitStatus === 'disconnected' || normalizedConnectionState === 'disconnected') {
    return 'disconnected';
  }

  if (explicitStatus === 'degraded' || normalizedConnectionState === 'degraded') {
    return 'degraded';
  }

  if (warningCount > 0 || input.degraded || input.hasBinding === false) {
    return 'degraded';
  }

  if (explicitStatus === 'connected') {
    return 'connected';
  }

  return 'connected';
}

export function summarizeChannelConnectionStatuses(
  statuses: readonly ChannelConnectionStatus[],
): ChannelConnectionStatus {
  const counts = statuses.reduce<Record<ChannelConnectionStatus, number>>(
    (acc, status) => {
      acc[status] += 1;
      return acc;
    },
    {
      connected: 0,
      connecting: 0,
      disconnected: 0,
      error: 0,
      degraded: 0,
    },
  );

  if (counts.error > 0) {
    return counts.connected > 0 || counts.connecting > 0 || counts.degraded > 0 || counts.disconnected > 0
      ? 'degraded'
      : 'error';
  }

  if (counts.connecting > 0) {
    return 'connecting';
  }

  if (counts.degraded > 0) {
    return 'degraded';
  }

  if (counts.disconnected > 0 && counts.connected === 0) {
    return 'disconnected';
  }

  if (counts.connected > 0 && counts.disconnected > 0) {
    return 'degraded';
  }

  return counts.connected > 0 ? 'connected' : 'disconnected';
}

export function buildChannelStatusSummary(
  groups: readonly ChannelAccountCatalogGroup[],
): ChannelStatusSummary {
  const counts: Record<ChannelConnectionStatus, number> = {
    connected: 0,
    connecting: 0,
    disconnected: 0,
    error: 0,
    degraded: 0,
  };

  let accountCount = 0;

  for (const group of groups) {
    accountCount += group.accounts.length;
    for (const account of group.accounts) {
      counts[account.status] += 1;
    }
  }

  const accountStatuses: ChannelConnectionStatus[] = [];
  for (const group of groups) {
    for (const account of group.accounts) {
      accountStatuses.push(account.status);
    }
  }

  return {
    status: summarizeChannelConnectionStatuses(accountStatuses),
    counts,
    groupCount: groups.length,
    accountCount,
  };
}