import { loadConfig, memoryKey } from "../config.ts";
import { enqueue } from "../queue.ts";

interface ObserveInput {
  tool_name?: string;
  tool_input?: Record<string, unknown>;
  tool_response?: unknown;
  cwd?: string;
  session_id?: string;
}

// Read-only/inspection commands carry no memory signal — skip them so a single
// review or search turn doesn't flood memory.
const TRIVIAL_SHELL = [
  "cd", "ls", "pwd", "echo", "cat", "head", "tail", "which", "type",
  "grep", "rg", "find", "fd", "wc", "sed", "awk", "less", "more", "stat",
  "file", "tree", "du", "df", "env", "printf", "sort", "uniq", "cut", "jq",
  "open", "true", "sleep", "date",
  "git status", "git log", "git diff", "git show", "git branch",
];

// Codex names the shell tool "Bash" in hook payloads; "shell"/"local_shell"/
// "exec" are the API/rollout names. Match all so the filter actually applies.
const SHELL_TOOLS = new Set(["Bash", "shell", "local_shell", "exec"]);

function shellCommand(input: Record<string, unknown>): string {
  const cmd = input.command;
  if (Array.isArray(cmd)) return cmd.join(" ");
  if (typeof cmd === "string") return cmd;
  return "";
}

// Pure: a one-line observation for a tool call, or "" if not worth recording.
export function summarizeTool(name: string, input: Record<string, unknown>): string {
  if (!name) return "";

  // Don't record Honcho's own MCP calls — recording that we queried memory is
  // circular noise that pollutes the representation.
  if (name.startsWith("mcp__honcho")) return "";

  if (SHELL_TOOLS.has(name)) {
    const cmd = shellCommand(input).trim();
    if (!cmd) return "";
    if (TRIVIAL_SHELL.some((t) => cmd === t || cmd.startsWith(t + " "))) return "";
    return `ran: ${cmd.slice(0, 120)}`;
  }

  if (name === "apply_patch") {
    const patch = typeof input.input === "string" ? input.input : typeof input.patch === "string" ? input.patch : "";
    const files = [...patch.matchAll(/^\*\*\* (?:Add|Update|Delete) File: (.+)$/gm)].map((m) => m[1]);
    if (files.length) return `edited: ${files.slice(0, 5).join(", ")}`;
    return "applied a patch";
  }

  return `used ${name}`;
}

// PostToolUse: queue a terse observation of meaningful tool activity. Enqueue
// only — instant, no network. The next writeback (Stop) flushes it along with
// the turn, so frequent tool calls never trigger an upload of their own.
export async function observe(input: ObserveInput): Promise<string> {
  const config = loadConfig();
  if (!config || !config.enabled || !config.saveMessages) return "";

  const summary = summarizeTool(input.tool_name ?? "", input.tool_input ?? {});
  if (!summary) return "";

  const cwd = input.cwd || process.cwd();
  enqueue(memoryKey(config, cwd, input.session_id), [{ role: "tool", text: summary, at: new Date().toISOString() }]);
  return "";
}