const API_BASE = "https://api.dongfeng-systems.org";

// ── Response types ───────────────────────────────────────────────────────────
interface UserInterestResponse {
  items: string[];
}

interface SymbolCheckResponse {
  found: boolean;
  message: string;
}

interface AddInterestResponse {
  success: boolean;
  message: string;
}

// ── Fetch user symbols ───────────────────────────────────────────────────────
export async function getUserSymbols(user: string = "frontend"): Promise<string[]> {
  const res = await fetch(
    `${API_BASE}/api/user-interest/fetch?user=${encodeURIComponent(user)}&type=symbol`,
    { cache: "no-store" }
  );
  if (!res.ok) throw new Error("Failed to fetch user symbols");
  const data: UserInterestResponse = await res.json();
  return data.items;
}

// ── Fetch user topics ────────────────────────────────────────────────────────
export async function getUserTopics(user: string = "frontend"): Promise<string[]> {
  const res = await fetch(
    `${API_BASE}/api/user-interest/fetch?user=${encodeURIComponent(user)}&type=topic`,
    { cache: "no-store" }
  );
  if (!res.ok) throw new Error("Failed to fetch user topics");
  const data: UserInterestResponse = await res.json();
  return data.items;
}

// ── Check if symbol is valid ─────────────────────────────────────────────────
export async function checkSymbol(symbol: string): Promise<SymbolCheckResponse> {
  const normalized = symbol.trim().toUpperCase();

  if (!normalized) {
    return {
      found: false,
      message: "Symbol cannot be empty",
    };
  }

  try {
    const res = await fetch(
      `${API_BASE}/api/market/symbol-check/${encodeURIComponent(normalized)}`,
      { cache: "no-store" }
    );

    const raw = await res.text();

    let data: any = null;
    try {
      data = raw ? JSON.parse(raw) : null;
    } catch {
      data = null;
    }

    if (!res.ok) {
      return {
        found: false,
        message:
          data?.message ||
          raw ||
          "Unable to verify this symbol right now. Please try again.",
      };
    }

    return {
      found: Boolean(data?.found),
      message:
        data?.message ||
        (data?.found ? "Symbol found." : "This symbol is invalid."),
    };
  } catch {
    return {
      found: false,
      message: "Unable to verify this symbol right now. Please try again.",
    };
  }
}

// ── Delete a user interest (symbol or topic) ─────────────────────────────────
export async function deleteUserInterest(
  type: "symbol" | "topic",
  value: string,
  user: string = "frontend"
): Promise<AddInterestResponse> {
  const normalized = value.trim();
  if (!normalized) throw new Error(`${type} cannot be empty`);

  const body = {
    user,
    type,
    value: type === "symbol" ? normalized.toUpperCase() : normalized,
  };

  const res = await fetch(
    `${API_BASE}/api/user-interest/remove?user=${encodeURIComponent(user)}&type=${encodeURIComponent(type)}&value=${encodeURIComponent(
      type === "symbol" ? normalized.toUpperCase() : normalized
    )}`,
    { cache: "no-store" }
  );

  if (!res.ok) throw new Error("Failed to delete interest");
  return res.json();
}

// ── Add a user interest (symbol or topic) ────────────────────────────────────
export async function addUserInterest(
  type: "symbol" | "topic",
  value: string,
  user: string = "frontend"
): Promise<AddInterestResponse> {
  const normalized = value.trim();
  if (!normalized) throw new Error(`${type} cannot be empty`);
  
  const body = {
    user,
    type,
    value: type === "symbol" ? normalized.toUpperCase() : normalized,
  };

  const res = await fetch(
    `${API_BASE}/api/user-interest/add?user=${encodeURIComponent(user)}&type=${encodeURIComponent(type)}&value=${encodeURIComponent(
      type === "symbol" ? normalized.toUpperCase() : normalized
    )}`,
    { cache: "no-store" }
  );
  
  if (!res.ok) throw new Error("Failed to add interest");
  return res.json();
}