/**
 * AI 助手：OpenAI 兼容 Chat Completions 客户端 + 用例生成。
 * 供应商配置保存在工作区设置（本地 localStorage），不经任何第三方中转。
 */
import type {
  AiProvider,
  Collection,
  HttpRequestData,
  RequestNode,
  TestAssertion,
  TestCase,
  TestStep,
} from "@opsxapi/core";
import { newTestCase, suggestAssertions } from "@opsxapi/core";

/** 常见供应商预设（均为 OpenAI 兼容协议） */
export const AI_PROVIDER_PRESETS: { name: string; baseUrl: string; model: string; hint: string }[] = [
  { name: "DeepSeek", baseUrl: "https://api.deepseek.com/v1", model: "deepseek-chat", hint: "性价比高，推荐" },
  { name: "智谱 GLM", baseUrl: "https://open.bigmodel.cn/api/paas/v4", model: "glm-4-flash", hint: "新用户有免费额度" },
  { name: "Moonshot Kimi", baseUrl: "https://api.moonshot.cn/v1", model: "moonshot-v1-8k", hint: "" },
  { name: "OpenAI", baseUrl: "https://api.openai.com/v1", model: "gpt-4o-mini", hint: "" },
  { name: "Ollama 本地", baseUrl: "http://127.0.0.1:11434/v1", model: "qwen2.5:7b", hint: "无需 API Key" },
];

export function newAiProvider(preset?: (typeof AI_PROVIDER_PRESETS)[number]): AiProvider {
  return {
    id: `ai-${Math.random().toString(36).slice(2, 10)}`,
    name: preset?.name ?? "自定义供应商",
    baseUrl: preset?.baseUrl ?? "",
    apiKey: "",
    model: preset?.model ?? "",
    enabled: true,
  };
}

type ChatMessage = { role: "system" | "user" | "assistant"; content: string };

/** 调用 Chat Completions（非流式），失败抛 Error */
export async function chatComplete(provider: AiProvider, messages: ChatMessage[], timeoutMs = 60000): Promise<string> {
  if (!provider.baseUrl.trim()) throw new Error("未配置 Base URL");
  const url = `${provider.baseUrl.trim().replace(/\/+$/, "")}/chat/completions`;
  const ctrl = new AbortController();
  const timer = setTimeout(() => ctrl.abort(), timeoutMs);
  try {
    const res = await fetch(url, {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        ...(provider.apiKey.trim() ? { Authorization: `Bearer ${provider.apiKey.trim()}` } : {}),
      },
      body: JSON.stringify({
        model: provider.model.trim() || "gpt-4o-mini",
        messages,
        temperature: 0.2,
        stream: false,
      }),
      signal: ctrl.signal,
    });
    if (!res.ok) {
      const text = await res.text().catch(() => "");
      throw new Error(`HTTP ${res.status}${text ? `：${text.slice(0, 200)}` : ""}`);
    }
    const data = (await res.json()) as {
      choices?: { message?: { content?: string } }[];
    };
    const content = data.choices?.[0]?.message?.content;
    if (!content) throw new Error("模型未返回内容");
    return content;
  } catch (e) {
    if (e instanceof DOMException && e.name === "AbortError") throw new Error("请求超时");
    throw e instanceof Error ? e : new Error(String(e));
  }
}

/** 连接测试：问一句并要求简答 */
export async function testProviderConnection(provider: AiProvider): Promise<string> {
  const reply = await chatComplete(
    provider,
    [
      { role: "system", content: "你是连通性测试助手，只输出：OK" },
      { role: "user", content: "ping" },
    ],
    20000,
  );
  return reply.trim().slice(0, 60) || "OK";
}

/* ---------------- AI 生成场景用例 ---------------- */

/** 汇总集合中的 HTTP 接口给模型看 */
function summarizeNodes(nodes: { node: RequestNode; path: string }[]): string {
  return nodes
    .map(({ node, path }) => {
      if (node.kind !== "http") return null;
      const d = node.data as HttpRequestData;
      const lines = [
        `- id: ${node.id} | ${d.method} ${d.url} | 名称: ${node.name}${path ? ` | 目录: ${path}` : ""}`,
      ];
      if (d.bodyMode === "json" && d.bodyRaw.trim()) {
        lines.push(`  body 示例: ${d.bodyRaw.replace(/\s+/g, " ").slice(0, 160)}`);
      }
      return lines.join("\n");
    })
    .filter(Boolean)
    .join("\n");
}

const GEN_SYSTEM_PROMPT = `你是 API 自动化测试专家。根据给定的接口清单设计一个可执行的"场景用例"（按业务顺序编排多个接口步骤）。
只输出一个 JSON 代码块（\`\`\`json ... \`\`\`），不要输出其他解释文字。JSON 结构：
{
  "name": "用例名称（中文，简短）",
  "description": "一句话说明场景",
  "steps": [
    {
      "nodeId": "必须使用清单中的接口 id",
      "reason": "为什么这一步",
      "assertions": [
        { "target": "status|timeMs|header|body", "locator": "header名或JSONPath（其余为空）", "op": "eq|neq|lt|gt|contains|not_contains|exists|not_exists|jsonpath_eq|jsonpath_contains", "expected": "期望值" }
      ],
      "extracts": [ { "jsonpath": "$.data.id", "varName": "petId" } ]
    }
  ]
}
要求：步骤顺序符合业务依赖（如 先创建 → 再查询 → 再删除）；每步至少 1 条断言；跨步骤传值用 extracts 提取变量并在后续 URL/Body 用 {{变量名}}（如果原接口里已有 {{xxx}} 占位则沿用）；断言 4-8 条为宜，聚焦关键业务字段。`;

export type AiCaseDraft = { name: string; description?: string; steps: TestStep[]; notes: string[] };

/** 从模型回复中提取 JSON（容错：代码块 / 首尾杂文） */
export function extractJsonBlock(text: string): unknown {
  const fenced = /```(?:json)?\s*([\s\S]*?)```/.exec(text);
  const raw = fenced ? fenced[1] : text.slice(text.indexOf("{"), text.lastIndexOf("}") + 1);
  return JSON.parse(raw.trim());
}

export async function aiGenerateTestCase(
  provider: AiProvider,
  collection: Collection,
  instruction?: string,
): Promise<AiCaseDraft> {
  const nodes: { node: RequestNode; path: string }[] = [];
  const walk = (children: Collection["children"], path: string): void => {
    for (const n of children) {
      if (n.type === "folder") walk(n.children, path ? `${path}/${n.name}` : n.name);
      else if (n.kind === "http") nodes.push({ node: n, path });
    }
  };
  walk(collection.children, "");
  if (nodes.length === 0) throw new Error("集合中没有 HTTP 接口可供编排");

  const user = [
    `接口清单（共 ${nodes.length} 个）：`,
    summarizeNodes(nodes),
    instruction?.trim() ? `\n用户要求：${instruction.trim()}` : "",
    "\n请输出场景用例 JSON。",
  ]
    .filter(Boolean)
    .join("\n");

  const reply = await chatComplete(provider, [
    { role: "system", content: GEN_SYSTEM_PROMPT },
    { role: "user", content: user },
  ]);

  const parsed = extractJsonBlock(reply) as {
    name?: string;
    description?: string;
    steps?: {
      nodeId?: string;
      reason?: string;
      assertions?: { target?: string; locator?: string; op?: string; expected?: string }[];
      extracts?: { jsonpath?: string; varName?: string }[];
    }[];
  };

  const notes: string[] = [];
  const steps: TestStep[] = [];
  const validIds = new Set(nodes.map((n) => n.node.id));
  const nodeById = new Map(nodes.map((n) => [n.node.id, n.node]));

  for (const s of parsed.steps ?? []) {
    if (!s.nodeId) continue;
    if (!validIds.has(s.nodeId)) {
      notes.push(`已跳过未知接口：${s.nodeId}`);
      continue;
    }
    const node = nodeById.get(s.nodeId)!;
    const assertions: TestAssertion[] = (s.assertions ?? []).map((a) => ({
      id: `as-${Math.random().toString(36).slice(2, 10)}`,
      enabled: true,
      target: (["status", "timeMs", "header", "body"].includes(a.target ?? "") ? a.target : "status") as TestAssertion["target"],
      locator: a.locator ?? "",
      op: ([
        "eq", "neq", "lt", "gt", "contains", "not_contains", "exists", "not_exists", "jsonpath_eq", "jsonpath_contains",
      ].includes(a.op ?? "") ? a.op : "eq") as TestAssertion["op"],
      expected: a.expected ?? "",
    }));
    if (assertions.length === 0) {
      assertions.push(...suggestAssertions(node.data as HttpRequestData));
      if (s.reason) notes.push(`「${node.name}」未给断言，已补默认断言`);
    }
    steps.push({
      id: `st-${Math.random().toString(36).slice(2, 10)}`,
      enabled: true,
      nodeId: s.nodeId,
      assertions,
      extracts: (s.extracts ?? [])
        .filter((e) => e.jsonpath && e.varName)
        .map((e) => ({ id: `ex-${Math.random().toString(36).slice(2, 10)}`, jsonpath: e.jsonpath!, varName: e.varName! })),
    });
  }

  if (steps.length === 0) throw new Error("模型未生成有效步骤，请重试或补充要求");

  return {
    name: parsed.name?.trim() || `${collection.name} · AI 用例`,
    description: parsed.description?.trim(),
    steps,
    notes,
  };
}

/** 把 AI 草稿转成正式用例 */
export function draftToTestCase(draft: AiCaseDraft): TestCase {
  const tc = newTestCase(draft.name);
  tc.description = draft.description;
  tc.steps = draft.steps;
  return tc;
}