import { listBundledPluginMetadata } from "../plugins/bundled-plugin-metadata.js";
import type { PluginPackageChannel } from "../plugins/manifest.js";
import { CHAT_CHANNEL_ORDER, type ChatChannelId } from "./ids.js";
import type { ChannelMeta } from "./plugins/types.js";

export type ChatChannelMeta = ChannelMeta;

const CHAT_CHANNEL_ID_SET = new Set<string>(CHAT_CHANNEL_ORDER);

function toChatChannelMeta(params: {
  id: ChatChannelId;
  channel: PluginPackageChannel;
}): ChatChannelMeta {
  const label = params.channel.label?.trim();
  if (!label) {
    throw new Error(`Missing label for bundled chat channel "${params.id}"`);
  }

  return {
    id: params.id,
    label,
    selectionLabel: params.channel.selectionLabel?.trim() || label,
    docsPath: params.channel.docsPath?.trim() || `/channels/${params.id}`,
    docsLabel: params.channel.docsLabel?.trim() || undefined,
    blurb: params.channel.blurb?.trim() || "",
    ...(params.channel.aliases?.length ? { aliases: params.channel.aliases } : {}),
    ...(params.channel.order !== undefined ? { order: params.channel.order } : {}),
    ...(params.channel.selectionDocsPrefix !== undefined
      ? { selectionDocsPrefix: params.channel.selectionDocsPrefix }
      : {}),
    ...(params.channel.selectionDocsOmitLabel !== undefined
      ? { selectionDocsOmitLabel: params.channel.selectionDocsOmitLabel }
      : {}),
    ...(params.channel.selectionExtras?.length
      ? { selectionExtras: params.channel.selectionExtras }
      : {}),
    ...(params.channel.detailLabel?.trim()
      ? { detailLabel: params.channel.detailLabel.trim() }
      : {}),
    ...(params.channel.systemImage?.trim()
      ? { systemImage: params.channel.systemImage.trim() }
      : {}),
    ...(params.channel.markdownCapable !== undefined
      ? { markdownCapable: params.channel.markdownCapable }
      : {}),
    ...(params.channel.showConfigured !== undefined
      ? { showConfigured: params.channel.showConfigured }
      : {}),
    ...(params.channel.quickstartAllowFrom !== undefined
      ? { quickstartAllowFrom: params.channel.quickstartAllowFrom }
      : {}),
    ...(params.channel.forceAccountBinding !== undefined
      ? { forceAccountBinding: params.channel.forceAccountBinding }
      : {}),
    ...(params.channel.preferSessionLookupForAnnounceTarget !== undefined
      ? {
          preferSessionLookupForAnnounceTarget: params.channel.preferSessionLookupForAnnounceTarget,
        }
      : {}),
    ...(params.channel.preferOver?.length ? { preferOver: params.channel.preferOver } : {}),
  };
}

function buildChatChannelMetaById(): Record<ChatChannelId, ChatChannelMeta> {
  const entries = new Map<ChatChannelId, ChatChannelMeta>();

  for (const entry of listBundledPluginMetadata({
    includeChannelConfigs: true,
    includeSyntheticChannelConfigs: false,
  })) {
    const channel =
      entry.packageManifest && "channel" in entry.packageManifest
        ? entry.packageManifest.channel
        : undefined;
    if (!channel) {
      continue;
    }
    const rawId = channel?.id?.trim();
    if (!rawId || !CHAT_CHANNEL_ID_SET.has(rawId)) {
      continue;
    }
    const id = rawId as ChatChannelId;
    entries.set(
      id,
      toChatChannelMeta({
        id,
        channel,
      }),
    );
  }

  const missingIds = CHAT_CHANNEL_ORDER.filter((id) => !entries.has(id));
  if (missingIds.length > 0) {
    throw new Error(`Missing bundled chat channel metadata for: ${missingIds.join(", ")}`);
  }

  return Object.freeze(Object.fromEntries(entries)) as Record<ChatChannelId, ChatChannelMeta>;
}

const CHAT_CHANNEL_META = buildChatChannelMetaById();

export const CHAT_CHANNEL_ALIASES: Record<string, ChatChannelId> = Object.freeze(
  Object.fromEntries(
    Object.values(CHAT_CHANNEL_META)
      .flatMap((meta) =>
        (meta.aliases ?? []).map((alias) => [alias.trim().toLowerCase(), meta.id] as const),
      )
      .filter(([alias]) => alias.length > 0)
      .toSorted(([left], [right]) => left.localeCompare(right)),
  ),
) as Record<string, ChatChannelId>;

function normalizeChannelKey(raw?: string | null): string | undefined {
  const normalized = raw?.trim().toLowerCase();
  return normalized || undefined;
}

export function listChatChannels(): ChatChannelMeta[] {
  return CHAT_CHANNEL_ORDER.map((id) => CHAT_CHANNEL_META[id]);
}

export function listChatChannelAliases(): string[] {
  return Object.keys(CHAT_CHANNEL_ALIASES);
}

export function getChatChannelMeta(id: ChatChannelId): ChatChannelMeta {
  return CHAT_CHANNEL_META[id];
}

export function normalizeChatChannelId(raw?: string | null): ChatChannelId | null {
  const normalized = normalizeChannelKey(raw);
  if (!normalized) {
    return null;
  }
  const resolved = CHAT_CHANNEL_ALIASES[normalized] ?? normalized;
  return CHAT_CHANNEL_ORDER.includes(resolved) ? resolved : null;
}