import { parseResetAt } from "./resets-at";

export type ProviderFamily = "openai-codex" | "openai-compatible" | "anthropic" | "known" | "unknown";
export interface RuleMatch { matchedRule: string; providerHint: string; resetsAt?: number; }
export const RULE_IDS = {
  codexUsage: "codex-usage-limit",
  codexNotIncluded: "codex-not-included",
  codexTerminal: "codex-terminal-rate-limit",
  openaiQuota: "oai-insufficient-quota",
  anthropicCredit: "anthropic-credit-balance",
  outageText: "generic-outage-text",
  outageStatus: "generic-5xx-hint",
} as const;

const compatible = new Set(["openai", "openai-completions", "openai-responses", "azure-openai-responses"]);
const known = new Set(["google", "vertex", "mistral", "amazon-bedrock", "bedrock", "pi-messages"]);

export function providerFamily(provider: string): ProviderFamily {
  const value = provider.trim().toLowerCase();
  if (value === "openai-codex") return "openai-codex";
  if (compatible.has(value)) return "openai-compatible";
  if (value === "anthropic") return "anthropic";
  return known.has(value) ? "known" : "unknown";
}

export function normalizeProviderError(errorMessage?: string, diagnostics?: unknown): string {
  let diagnosticText = "";
  if (diagnostics !== undefined) {
    try { diagnosticText = typeof diagnostics === "string" ? diagnostics : JSON.stringify(diagnostics) ?? ""; } catch { diagnosticText = ""; }
  }
  return `${errorMessage ?? ""} ${diagnosticText}`.replace(/\s+/g, " ").toLowerCase();
}

export function isContextOverflow(text: string): boolean {
  return /context(?:[ _-]?(?:window|length|overflow|limit))|maximum[ _-]?context|prompt.{0,30}too (?:large|long)|too many tokens/.test(text);
}

export function matchQuotaRule(family: ProviderFamily, text: string, now: number): RuleMatch | undefined {
  if (family === "openai-codex") {
    if (text.includes("usage_limit_reached") || /usage limit (?:has been|is) reached/.test(text)) return { matchedRule: RULE_IDS.codexUsage, providerHint: family, resetsAt: parseResetAt(text, now) };
    if (text.includes("usage_not_included")) return { matchedRule: RULE_IDS.codexNotIncluded, providerHint: family };
    const resetsAt = text.includes("rate_limit_exceeded") ? parseResetAt(text, now) : undefined;
    if (resetsAt !== undefined) return { matchedRule: RULE_IDS.codexTerminal, providerHint: family, resetsAt };
  }
  if (family === "openai-compatible" && /\binsufficient_quota\b/.test(text)) return { matchedRule: RULE_IDS.openaiQuota, providerHint: family };
  if (family === "anthropic" && text.includes("credit balance is too low to use this model")) return { matchedRule: RULE_IDS.anthropicCredit, providerHint: family };
  return undefined;
}

const outageText = /(throttlingexception|overloaded|internal server error|service unavailable|serviceunavailable|econnreset|etimedout|fetch failed|socket hang up)/;

export function matchTransientRule(text: string, status?: number): string | undefined {
  if ([500, 502, 503, 529].includes(status ?? 0)) return RULE_IDS.outageStatus;
  return outageText.test(text) ? RULE_IDS.outageText : undefined;
}