const TOKEN_KEY = "eth_hedge_token";
const USER_KEY = "eth_hedge_user";

export function getApiBase(): string {
  return window.location.origin;
}

export function getToken(): string | null {
  return localStorage.getItem(TOKEN_KEY);
}

export function setSession(token: string, username: string) {
  localStorage.setItem(TOKEN_KEY, token);
  localStorage.setItem(USER_KEY, username);
}

export function clearSession() {
  localStorage.removeItem(TOKEN_KEY);
  localStorage.removeItem(USER_KEY);
  localStorage.removeItem("eth_hedge_api_base");
}

export function getUsername(): string | null {
  return localStorage.getItem(USER_KEY);
}

export async function apiFetch<T>(
  path: string,
  options: RequestInit = {},
): Promise<T> {
  const base = getApiBase();
  const headers = new Headers(options.headers || {});
  if (!headers.has("Content-Type") && options.body) {
    headers.set("Content-Type", "application/json");
  }
  const token = getToken();
  if (token) headers.set("Authorization", `Bearer ${token}`);

  const res = await fetch(`${base}${path}`, { ...options, headers });
  if (res.status === 401) {
    clearSession();
    throw new Error("unauthorized");
  }
  const text = await res.text();
  let data: unknown = null;
  try {
    data = text ? JSON.parse(text) : null;
  } catch {
    data = { detail: text };
  }
  if (!res.ok) {
    const detail =
      typeof data === "object" && data && "detail" in data
        ? String((data as { detail: unknown }).detail)
        : res.statusText;
    throw new Error(detail || `HTTP ${res.status}`);
  }
  return data as T;
}

export type LoginResult = {
  token: string;
  username: string;
  expires_in: number;
  env_name: string;
  mode: string;
};

export async function login(username: string, password: string) {
  return apiFetch<LoginResult>("/api/auth/login", {
    method: "POST",
    body: JSON.stringify({ username, password }),
  });
}

export async function changeCredentials(input: {
  current_password: string;
  new_username: string;
  new_password: string;
}) {
  return apiFetch<LoginResult>("/api/auth/change-credentials", {
    method: "POST",
    body: JSON.stringify(input),
  });
}

export type MarketSnapshot = {
  connected: boolean;
  updated_at_ms: number | null;
  index_px: number | null;
  pair: {
    expiry_ymd: string;
    strike: number;
    call_inst_id: string;
    put_inst_id: string;
  } | null;
  perp: Quote | null;
  call: Quote | null;
  put: Quote | null;
  ask_compare: {
    call_ask: number | null;
    put_ask: number | null;
    bias: string;
  };
};

type Quote = {
  inst_id: string;
  bid: number | null;
  ask: number | null;
  bid_sz: number | null;
  ask_sz: number | null;
  mark_px: number | null;
};

export type PlanState = {
  running: boolean;
  phase: string;
  rounds_done: number;
  max_rounds: number;
  window_key: string | null;
  rest_left_sec: number;
  rest_seconds: number;
  exit_move_points: number;
  can_open: boolean;
  last_error: string | null;
  position: {
    has_position: boolean;
    group_id?: string;
    perp_side?: string;
    option_side?: string;
    perp_upl?: number;
    option_upl?: number;
    index_px?: number | null;
    entry_index_px?: number;
    move_points?: number;
    initial_premium?: number;
    premium_gap?: number;
  };
  ledger: { equity: number; available: number; reserved: number };
};

export type StrategySettings = {
  fee_rate: number;
  exit_move_points: number;
  rest_seconds: number;
  max_rounds: number;
  initial_equity: number;
  ledger: { equity: number; available: number };
};