// ClaudeCode 客户端兼容增强：让选择 ClaudeCode 请求头 profile 的 Anthropic 接入
// 同时具备 Snow CLI/ClaudeCode 中转常见的 body metadata 信号。

import { createHash, randomUUID } from "node:crypto";
import { isObjectRecord } from "./common.ts";
import { resolveClientHeaderProfile } from "./presets/client-headers.ts";
import type { StateDocument } from "./types.ts";

type ActiveModelRef = {
	provider: string;
	id: string;
	api: string;
};

type PayloadRecord = Record<string, unknown>;

let currentClaudeCodeUserId = createClaudeCodeUserId();

function createClaudeCodeUserId(): string {
	const sessionId = randomUUID();
	const hash = createHash("sha256").update(`anthropic_user_${sessionId}`).digest("hex");
	return `user_${hash}_account__session_${sessionId}`;
}

export function resetClaudeCodeMetadataSession(): void {
	currentClaudeCodeUserId = createClaudeCodeUserId();
}

function isPayloadRecord(payload: unknown): payload is PayloadRecord {
	return isObjectRecord(payload);
}

export function injectClaudeCodeMetadata(
	payload: unknown,
	model: ActiveModelRef | undefined,
	state: StateDocument,
): PayloadRecord | undefined {
	if (!model || model.api !== "anthropic-messages") return undefined;
	if (!isPayloadRecord(payload)) return undefined;
	if (payload.model !== model.id) return undefined;

	const provider = state.providers[model.provider];
	if (!provider) return undefined;
	if (resolveClientHeaderProfile(provider.clientHeaderProfile, "anthropic-messages") !== "claude-code") return undefined;

	const metadata = isObjectRecord(payload.metadata) ? payload.metadata : {};
	return {
		...payload,
		// ARN/new-api 的 ClaudeCode-only 限制会检查 body 信号；只补 metadata，
		// 不改写 system prompt，避免降低 Pi 系统提示词优先级。
		metadata: {
			...metadata,
			user_id: currentClaudeCodeUserId,
		},
	};
}