import type { MSTeamsConfig } from "symi/plugin-sdk";
import { GRAPH_ROOT } from "./attachments/shared.js";
import { loadMSTeamsSdkWithAuth } from "./sdk.js";
import { resolveMSTeamsCredentials } from "./token.js";

export type GraphUser = {
  id?: string;
  displayName?: string;
  userPrincipalName?: string;
  mail?: string;
};

export type GraphGroup = {
  id?: string;
  displayName?: string;
};

export type GraphChannel = {
  id?: string;
  displayName?: string;
};

export type GraphResponse<T> = { value?: T[] };

function readAccessToken(value: unknown): string | null {
  if (typeof value === "string") {
    return value;
  }
  if (value && typeof value === "object") {
    const token =
      (value as { accessToken?: unknown }).accessToken ?? (value as { token?: unknown }).token;
    return typeof token === "string" ? token : null;
  }
  return null;
}

export function normalizeQuery(value?: string | null): string {
  return value?.trim() ?? "";
}

export function escapeOData(value: string): string {
  return value.replace(/'/g, "''");
}

export async function fetchGraphJson<T>(params: {
  token: string;
  path: string;
  headers?: Record<string, string>;
}): Promise<T> {
  const res = await fetch(`${GRAPH_ROOT}${params.path}`, {
    headers: {
      Authorization: `Bearer ${params.token}`,
      ...params.headers,
    },
  });
  if (!res.ok) {
    const text = await res.text().catch(() => "");
    throw new Error(`Graph ${params.path} failed (${res.status}): ${text || "unknown error"}`);
  }
  return (await res.json()) as T;
}

export async function resolveGraphToken(cfg: unknown): Promise<string> {
  const creds = resolveMSTeamsCredentials(
    (cfg as { channels?: { msteams?: unknown } })?.channels?.msteams as MSTeamsConfig | undefined,
  );
  if (!creds) {
    throw new Error("MS Teams credentials missing");
  }
  const { sdk, authConfig } = await loadMSTeamsSdkWithAuth(creds);
  const tokenProvider = new sdk.MsalTokenProvider(authConfig);
  const token = await tokenProvider.getAccessToken("https://graph.microsoft.com");
  const accessToken = readAccessToken(token);
  if (!accessToken) {
    throw new Error("MS Teams graph token unavailable");
  }
  return accessToken;
}

export async function listTeamsByName(token: string, query: string): Promise<GraphGroup[]> {
  const escaped = escapeOData(query);
  const filter = `resourceProvisioningOptions/Any(x:x eq 'Team') and startsWith(displayName,'${escaped}')`;
  const path = `/groups?$filter=${encodeURIComponent(filter)}&$select=id,displayName`;
  const res = await fetchGraphJson<GraphResponse<GraphGroup>>({ token, path });
  return res.value ?? [];
}

export async function listChannelsForTeam(token: string, teamId: string): Promise<GraphChannel[]> {
  const path = `/teams/${encodeURIComponent(teamId)}/channels?$select=id,displayName`;
  const res = await fetchGraphJson<GraphResponse<GraphChannel>>({ token, path });
  return res.value ?? [];
}
