export const CONTENT_MODERATION_ERROR_CODE = "sensitive_words_detected";

export const CONTENT_MODERATION_MESSAGE = "内容审核未通过，本次平台积分未扣除或已退还。请修改提示词后重新生成。";

export type GenerationFailureMetadata = {
    errorDetails: string;
    generationErrorCode?: string;
    failedPromptFingerprint?: string;
};

export function generationFailureMetadata(error: unknown, prompt: string): GenerationFailureMetadata {
    const raw = error instanceof Error ? error.message : String(error || "生成失败");
    if (!isContentModerationError(raw)) return { errorDetails: raw || "生成失败" };
    return {
        errorDetails: CONTENT_MODERATION_MESSAGE,
        generationErrorCode: CONTENT_MODERATION_ERROR_CODE,
        failedPromptFingerprint: generationPromptFingerprint(prompt),
    };
}

export function generationErrorMessage(error: unknown) {
    const raw = error instanceof Error ? error.message : String(error || "生成失败");
    return isContentModerationError(raw) ? CONTENT_MODERATION_MESSAGE : raw || "生成失败";
}

export function isContentModerationError(value: unknown) {
    const text = value instanceof Error ? value.message : String(value || "");
    return text.toLowerCase().includes(CONTENT_MODERATION_ERROR_CODE) || text.includes("内容审核未通过");
}

export function unchangedModeratedPrompt(metadata: { errorDetails?: string; generationErrorCode?: string; failedPromptFingerprint?: string } | undefined, prompt: string) {
    const moderationFailure = metadata?.generationErrorCode === CONTENT_MODERATION_ERROR_CODE || isContentModerationError(metadata?.errorDetails);
    if (!moderationFailure) return false;
    if (!metadata?.failedPromptFingerprint) return true;
    return metadata.failedPromptFingerprint === generationPromptFingerprint(prompt);
}

// 指纹只用于识别“原样重试”，不是安全或鉴权用途。
export function generationPromptFingerprint(value: string) {
    const normalized = value.trim().replace(/\s+/g, " ");
    let hash = 2166136261;
    for (let index = 0; index < normalized.length; index += 1) {
        hash ^= normalized.charCodeAt(index);
        hash = Math.imul(hash, 16777619);
    }
    return `${normalized.length}:${(hash >>> 0).toString(36)}`;
}