import type { ChannelId } from "../channels/plugins/types.js";
import {
  CHANNEL_IDS,
  getChatChannelMeta,
  getRegisteredChannelPluginMeta,
  listRegisteredChannelPluginAliases,
  listRegisteredChannelPluginIds,
  listChatChannelAliases,
  normalizeChatChannelId,
  normalizeAnyChannelId,
} from "../channels/registry.js";
import {
  GATEWAY_CLIENT_MODES,
  GATEWAY_CLIENT_NAMES,
  type GatewayClientMode,
  type GatewayClientName,
  normalizeGatewayClientMode,
  normalizeGatewayClientName,
} from "../gateway/protocol/client-info.js";

export const INTERNAL_MESSAGE_CHANNEL = "webchat" as const;
export type InternalMessageChannel = typeof INTERNAL_MESSAGE_CHANNEL;

export { GATEWAY_CLIENT_NAMES, GATEWAY_CLIENT_MODES };
export type { GatewayClientName, GatewayClientMode };
export { normalizeGatewayClientName, normalizeGatewayClientMode };

type GatewayClientInfoLike = {
  mode?: string | null;
  id?: string | null;
};

export function isGatewayCliClient(client?: GatewayClientInfoLike | null): boolean {
  return normalizeGatewayClientMode(client?.mode) === GATEWAY_CLIENT_MODES.CLI;
}

export function isOperatorUiClient(client?: GatewayClientInfoLike | null): boolean {
  const clientId = normalizeGatewayClientName(client?.id);
  return clientId === GATEWAY_CLIENT_NAMES.CONTROL_UI || clientId === GATEWAY_CLIENT_NAMES.TUI;
}

export function isBrowserOperatorUiClient(client?: GatewayClientInfoLike | null): boolean {
  const clientId = normalizeGatewayClientName(client?.id);
  return clientId === GATEWAY_CLIENT_NAMES.CONTROL_UI;
}

export function isInternalMessageChannel(raw?: string | null): raw is InternalMessageChannel {
  return normalizeMessageChannel(raw) === INTERNAL_MESSAGE_CHANNEL;
}

export function isWebchatClient(client?: GatewayClientInfoLike | null): boolean {
  const mode = normalizeGatewayClientMode(client?.mode);
  if (mode === GATEWAY_CLIENT_MODES.WEBCHAT) {
    return true;
  }
  return normalizeGatewayClientName(client?.id) === GATEWAY_CLIENT_NAMES.WEBCHAT_UI;
}

export function normalizeMessageChannel(raw?: string | null): string | undefined {
  const normalized = raw?.trim().toLowerCase();
  if (!normalized) {
    return undefined;
  }
  if (normalized === INTERNAL_MESSAGE_CHANNEL) {
    return INTERNAL_MESSAGE_CHANNEL;
  }
  const builtIn = normalizeChatChannelId(normalized);
  if (builtIn) {
    return builtIn;
  }
  return normalizeAnyChannelId(normalized) ?? normalized;
}

const listPluginChannelIds = (): string[] => {
  return listRegisteredChannelPluginIds();
};

const listPluginChannelAliases = (): string[] => {
  return listRegisteredChannelPluginAliases();
};

export const listDeliverableMessageChannels = (): ChannelId[] =>
  Array.from(new Set([...CHANNEL_IDS, ...listPluginChannelIds()]));

export type DeliverableMessageChannel = ChannelId;

export type GatewayMessageChannel = DeliverableMessageChannel | InternalMessageChannel;

export const listGatewayMessageChannels = (): GatewayMessageChannel[] => [
  ...listDeliverableMessageChannels(),
  INTERNAL_MESSAGE_CHANNEL,
];

export const listGatewayAgentChannelAliases = (): string[] =>
  Array.from(new Set([...listChatChannelAliases(), ...listPluginChannelAliases()]));

export type GatewayAgentChannelHint = GatewayMessageChannel | "last";

export const listGatewayAgentChannelValues = (): string[] =>
  Array.from(
    new Set([...listGatewayMessageChannels(), "last", ...listGatewayAgentChannelAliases()]),
  );

export function isGatewayMessageChannel(value: string): value is GatewayMessageChannel {
  return listGatewayMessageChannels().includes(value as GatewayMessageChannel);
}

export function isDeliverableMessageChannel(value: string): value is DeliverableMessageChannel {
  return listDeliverableMessageChannels().includes(value as DeliverableMessageChannel);
}

export function resolveGatewayMessageChannel(
  raw?: string | null,
): GatewayMessageChannel | undefined {
  const normalized = normalizeMessageChannel(raw);
  if (!normalized) {
    return undefined;
  }
  return isGatewayMessageChannel(normalized) ? normalized : undefined;
}

export function resolveMessageChannel(
  primary?: string | null,
  fallback?: string | null,
): string | undefined {
  return normalizeMessageChannel(primary) ?? normalizeMessageChannel(fallback);
}

export function isMarkdownCapableMessageChannel(raw?: string | null): boolean {
  const channel = normalizeMessageChannel(raw);
  if (!channel) {
    return false;
  }
  if (channel === INTERNAL_MESSAGE_CHANNEL || channel === "tui") {
    return true;
  }
  const builtInChannel = normalizeChatChannelId(channel);
  if (builtInChannel) {
    return getChatChannelMeta(builtInChannel).markdownCapable === true;
  }
  return getRegisteredChannelPluginMeta(channel)?.markdownCapable === true;
}