import { SCHEMA_VERSION } from "../core/constants.js";
import { GROUP_SUMMARIES, commandDocs, hasVisibleSubcommands, isHiddenPath } from "./docs.js";
import type { HelpPayload } from "../core/types.js";

export function helpPayload(pathParts: string[]): HelpPayload | null {
  const path = pathParts.join(" ");
  if (path && isHiddenPath(path)) return null;
  if (path && commandDocs.has(path)) return commandDocs.get(path)!;
  if (!path) {
    const seen = new Set<string>();
    const commands: Array<{ command: string; summary: string }> = [];
    for (const doc of [...commandDocs.values()].sort((a, b) => a.command.localeCompare(b.command))) {
      if (isHiddenPath(doc.command)) continue;
      const command = doc.command.split(" ")[0]!;
      if (seen.has(command)) continue;
      seen.add(command);
      commands.push({ command, summary: GROUP_SUMMARIES[command] ?? `${command} 可用子命令` });
    }
    return {
      ok: true,
      schema_version: SCHEMA_VERSION,
      summary: "可用一级菜单",
      menu_level: 1,
      commands,
    };
  }
  const prefix = path ? `${path} ` : "";
  const children: Array<{ command: string; summary: string; usage: string; example: string }> = [];
  const seen = new Set<string>();
  for (const doc of [...commandDocs.values()].sort((a, b) => a.command.localeCompare(b.command))) {
    if (isHiddenPath(doc.command)) continue;
    if (!doc.command.startsWith(prefix)) continue;
    const child = doc.command.slice(prefix.length).split(" ")[0]!;
    if (seen.has(child)) continue;
    seen.add(child);
    const childPath = path ? `${path} ${child}` : child;
    const isGroup = hasVisibleSubcommands(childPath);
    const childDoc = commandDocs.get(childPath) ?? doc;
    children.push({
      command: childPath,
      summary: isGroup ? (GROUP_SUMMARIES[childPath] ?? `${childPath} 可用子命令`) : childDoc.summary,
      usage: isGroup ? `tjwater-cli ${childPath} help` : childDoc.usage,
      example: isGroup ? `tjwater-cli ${childPath} help` : childDoc.examples[0]!,
    });
  }
  if (!children.length && path) return null;
  return {
    ok: true,
    schema_version: SCHEMA_VERSION,
    summary: GROUP_SUMMARIES[path] ?? `${path} 可用子命令`,
    commands: children,
  };
}