import type {
  ConversationSummary,
  ConversationDetail,
  UsageInfo,
} from "./types";

export class ApiError extends Error {
  public constructor(
    public readonly status: number,
    message: string,
  ) {
    super(message);
  }
}

function getConfig(): { apiUrl: string; apiKey: string } {
  return window.flexibleChatHistory;
}

function getApiUrl(endpoint: string): string {
  const config = getConfig();
  return `${config.apiUrl}${endpoint}`;
}

function getHeaders(): HeadersInit {
  const config = getConfig();
  return {
    "Content-Type": "application/json",
    Authorization: `Bearer ${config.apiKey}`,
  };
}

export async function fetchConversations(): Promise<ConversationSummary[]> {
  const response = await fetch(getApiUrl("/conversations"), {
    headers: getHeaders(),
  });

  if (!response.ok) {
    throw new ApiError(response.status, "Failed to fetch conversations");
  }

  return response.json();
}

export async function fetchConversation(
  id: string,
): Promise<ConversationDetail> {
  const response = await fetch(getApiUrl(`/conversations/${id}`), {
    headers: getHeaders(),
  });

  if (!response.ok) {
    throw new ApiError(response.status, "Failed to fetch conversation");
  }

  return response.json();
}

export async function fetchUsage(): Promise<UsageInfo> {
  const response = await fetch(getApiUrl("/usage"), {
    headers: getHeaders(),
  });

  if (!response.ok) {
    throw new ApiError(response.status, "Failed to fetch usage");
  }

  return response.json();
}