import type { ExtensionAPI, ExtensionContext } from "@earendil-works/pi-coding-agent";
import { spawnSync } from "node:child_process";
import path from "node:path";
import { fileURLToPath } from "node:url";

const packageRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");

function ensurePiKbRoot(): string {
  process.env.PI_KB_ROOT = packageRoot;
  return packageRoot;
}

const HINT = `
## @suwenguang/pi-kb
- 包根环境变量：\`PI_KB_ROOT\`（脚本：\`node "$PI_KB_ROOT/scripts/...."\`）
- 斜杠命令：\`/kb-propose\`、\`/kb-design\`、\`/kb-plan\`、\`/kb-apply\`、\`/kb-archive\`、\`/kb-feedback\`、\`/kb-session-retro\`、\`/kb-evolve-setup\`、\`/kb-evomap-setup\`、\`/kb-deepseek-search-setup\`、\`/kb-cursor-setup\`、\`/kb-figma-setup\` 等（prompt templates）
- 流程反馈：\`/kb-feedback\` → Gitee Issue；**会话级失败经验** → \`/kb-session-retro\`（自动开 Issue）；本地改流程：\`/kb-evolve-setup\` 后源码仓 \`/kb-evolve\`；可选网络路径：\`/kb-evomap-setup\`（默认关闭，见 skills/.../kb-evomap.md）
- DeepSeek Search：本包已 bundled \`pi-deepseek-search\`（工具 \`web_search\`）；需 DeepSeek Key（\`/login\` 或 \`DEEPSEEK_API_KEY\`）；配置引导 \`/kb-deepseek-search-setup\`；实践见 skills/.../kb-deepseek-search.md
- Figma Remote MCP：本包已 bundled \`pi-figma-remote-auth\`（\`/figma-remote-auth\`）+ token 同步（\`/figma-oauth-sync\`，session_start 自动）；引导 \`/kb-figma-setup\`；实践见 skills/.../kb-figma-remote.md
- Cursor Agent：可选；业务仓 \`pi install npm:pi-cursor-sdk -l --approve\` + Cursor API Key；引导 \`/kb-cursor-setup\`；实践见 skills/.../kb-cursor-sdk.md（**不** bundled，因平台二进制）
- Gitee token：\`export GITEE_ACCESS_TOKEN=...\` 或一次配置 \`node "$PI_KB_ROOT/scripts/kb-config.mjs" set-token\`
- 工种 Agent：本包已 bundled \`pi-subagents\`；定义在 \`agents/\`（\`subagent(agent=kb-*)\`）
- 业务仓初始化：\`node "$PI_KB_ROOT/scripts/kb-bootstrap.mjs" --target "$(pwd)"\` 或 \`/kb-init\`
- 未初始化门禁：除 \`/kb-init\` 与反馈类（\`/kb-feedback\`、\`/kb-session-retro\`）及进化类（\`/kb-evolve*\`、\`/kb-evomap-setup\`）与 \`/kb-deepseek-search-setup\`、\`/kb-cursor-setup\`、\`/kb-figma-setup\` 外，\`/kb-*\` 须先通过 \`kb-bootstrap-check.mjs\`
`.trim();

const DEEPSEEK_SETUP_TIP =
  "DeepSeek Search 未就绪：请 /login 选择 DeepSeek，或设置 DEEPSEEK_API_KEY，然后 /reload。详情：/kb-deepseek-search-setup";

async function hasDeepSeekKey(ctx: ExtensionContext): Promise<boolean> {
  if (process.env.DEEPSEEK_API_KEY || process.env.ANTHROPIC_AUTH_TOKEN) return true;
  try {
    const key = await ctx.modelRegistry?.getApiKeyForProvider?.("deepseek");
    return Boolean(key);
  } catch {
    return false;
  }
}

/** 启发式：本轮对话是否像 KB 流程摩擦/失败（非编码业务 bug） */
const FRICTION_RE =
  /门禁失败|硬阻断|bootstrap-check|codegraph-check|manifest.*校验失败|阶段.*阻断|流程摩擦|禁止继续|kb-bootstrap|schema 失败|未通过.*门禁|\/kb-[\w-]+.*失败|重复.*\/kb-|口径歧义|步骤繁琐|不得.*archive|不得标\s*tested/i;

const RETRO_CMD_RE = /\/kb-session-retro\b/;

function messageText(message: unknown): string {
  if (!message || typeof message !== "object") return "";
  const m = message as { content?: unknown; role?: string };
  const c = m.content;
  if (typeof c === "string") return c;
  if (!Array.isArray(c)) return "";
  return c
    .map((part) => {
      if (!part || typeof part !== "object") return "";
      const p = part as { type?: string; text?: string };
      return p.type === "text" && typeof p.text === "string" ? p.text : "";
    })
    .join("\n");
}

/** 旁路写入摩擦候选（非阻塞；失败忽略） */
function recordFrictionCandidate(snippet: string, commandHint = ""): boolean {
  const script = path.join(packageRoot, "scripts", "kb-feedback-candidates.mjs");
  const args = [script, "add", "--snippet", snippet.slice(0, 400)];
  if (commandHint) args.push("--command", commandHint);
  try {
    const r = spawnSync(process.execPath, args, {
      cwd: process.cwd(),
      encoding: "utf8",
      timeout: 4000,
      env: process.env,
    });
    if (r.status !== 0) return false;
    const out = (r.stdout || "").trim();
    if (!out) return false;
    try {
      const parsed = JSON.parse(out) as { ok?: boolean; deduped?: boolean };
      return Boolean(parsed.ok) && !parsed.deduped;
    } catch {
      return true;
    }
  } catch {
    return false;
  }
}

function extractCommandHint(text: string): string {
  const m = text.match(/\/kb-[\w-]+/);
  return m ? m[0] : "";
}

export default function (pi: ExtensionAPI) {
  ensurePiKbRoot();

  let kbFrictionLikely = false;
  let retroDone = false;
  let candidateNotified = false;
  /** @type {Set<string>} */
  const seenSnippets = new Set();

  function resetSessionFlags() {
    kbFrictionLikely = false;
    retroDone = false;
    candidateNotified = false;
    seenSnippets.clear();
  }

  pi.on("session_start", async (_event, ctx) => {
    ensurePiKbRoot();
    resetSessionFlags();
    // 引导配置：无 DeepSeek Key 时提示（pi-deepseek-search 无 Key 则不注册 web_search）
    if (!(await hasDeepSeekKey(ctx))) {
      if (ctx.hasUI) ctx.ui.notify(DEEPSEEK_SETUP_TIP, "info");
      else console.warn(`[pi-kb] ${DEEPSEEK_SETUP_TIP}`);
    }
  });

  pi.on("before_agent_start", async (event) => {
    const root = ensurePiKbRoot();
    if (event.systemPrompt.includes("PI_KB_ROOT=")) {
      return;
    }
    return {
      systemPrompt: `${event.systemPrompt}\n\n${HINT}\n- PI_KB_ROOT=${root}\n`,
    };
  });

  pi.on("input", async (event) => {
    if (RETRO_CMD_RE.test(event.text)) {
      retroDone = true;
    }
  });

  pi.on("agent_end", async (event, ctx) => {
    let newlyRecorded = false;
    for (const msg of event.messages ?? []) {
      const text = messageText(msg);
      if (!text) continue;
      if (RETRO_CMD_RE.test(text) && /会话回顾|Issue\s*#|无明显 KB 流程摩擦/.test(text)) {
        retroDone = true;
      }
      if (!FRICTION_RE.test(text)) continue;
      kbFrictionLikely = true;
      const key = text.slice(0, 160);
      if (seenSnippets.has(key)) continue;
      seenSnippets.add(key);
      if (recordFrictionCandidate(text, extractCommandHint(text))) {
        newlyRecorded = true;
      }
    }
    if (newlyRecorded && !candidateNotified && !retroDone) {
      candidateNotified = true;
      const tip =
        "已旁路记录 KB 流程摩擦候选（不阻断）。离开会话时将自动 /kb-session-retro 开 Issue。";
      if (ctx?.hasUI) ctx.ui.notify(tip, "info");
      else console.warn(`[pi-kb] ${tip}`);
    }
  });

  async function offerSessionRetro(
    ctx: ExtensionContext,
    reason: string,
  ): Promise<{ cancel?: boolean } | void> {
    if (!kbFrictionLikely || retroDone) return;
    // 零确认：取消 /new|/resume，立刻注入会话回顾并自动开 Issue
    try {
      pi.sendUserMessage(
        "/kb-session-retro\n（由扩展在离开会话前自动触发，无需确认：请总结本会话 KB 流程失败经验，合并旁路候选并对可改进项自动提交 Gitee Issue。）",
      );
      if (ctx.hasUI) {
        ctx.ui.notify("已自动注入 /kb-session-retro（检测到流程摩擦）", "info");
      } else {
        console.warn(`[pi-kb] 已自动注入 /kb-session-retro（${reason}）`);
      }
    } catch {
      const tip = "自动注入失败，请手动执行 /kb-session-retro";
      if (ctx.hasUI) ctx.ui.notify(tip, "warning");
      else console.warn(`[pi-kb] ${tip}`);
      return;
    }
    return { cancel: true };
  }

  pi.on("session_before_switch", async (event, ctx) => {
    if (event.reason !== "new" && event.reason !== "resume") return;
    return offerSessionRetro(ctx, event.reason);
  });

  pi.on("session_shutdown", async (event, ctx) => {
    if (event.reason !== "quit") return;
    if (!kbFrictionLikely || retroDone) return;
    if (ctx.hasUI) {
      ctx.ui.notify("本会话疑似有 KB 流程摩擦，下次可开会话执行 /kb-session-retro 自动反馈", "warning");
    }
  });

  pi.registerCommand("kb-root", {
    description: "打印 @suwenguang/pi-kb 包根路径（PI_KB_ROOT）",
    handler: async (_args, ctx) => {
      const root = ensurePiKbRoot();
      if (ctx.hasUI) ctx.ui.notify(root, "info");
      else console.log(root);
    },
  });
}