command-validator

import type { GenerateInput, GenerateOutput, TemplateStyle } from "./types.js";

const ALLOWED_AGENTS = ["build", "plan", "general", "explore", "oracle"];

export function generateCommand(input: GenerateInput): GenerateOutput {
  const warnings: string[] = [];
  const opts = input.options || {};
  const text = input.text.trim();
  const template: TemplateStyle = opts.template || "basic";

  // Derive filename
  const baseName = opts.name || extractName(text);
  const filename =
    baseName
      .toLowerCase()
      .replace(/\s+/g, "-")
      .replace(/[^a-z0-9-]/g, "") + ".md";

  // Derive description
  let description = opts.description || "";
  if (!description) {
    description = extractDescription(text);
  }

  // Detect features in text
  const hasArgs = /\$ARGUMENTS\b/.test(text) || /\$\d\b/.test(text);
  const hasFileRefs = /@[^\s`"')\]}>]+/.test(text);
  const hasBashCmd = /!`[^`]+`/.test(text);

  // Generate frontmatter
  let frontmatter = "---\n";
  frontmatter += `description: ${escapeYamlValue(description)}\n`;

  const agent = opts.agent || undefined;
  if (agent && ALLOWED_AGENTS.includes(agent)) {
    frontmatter += `agent: ${agent}\n`;
  }

  if (opts.model) {
    frontmatter += `model: ${opts.model}\n`;
  }

  if (opts.subtask !== undefined) {
    frontmatter += `subtask: ${String(opts.subtask)}\n`;
  }

  frontmatter += "---\n";

  // Generate body based on template style
  let body: string;

  switch (template) {
    case "minimal":
      body = generateMinimalBody(text, hasArgs);
      break;
    case "detailed":
      body = generateDetailedBody(
        text,
        description,
        hasArgs,
        hasFileRefs,
        hasBashCmd,
      );
      break;
    case "basic":
    default:
      body = generateBasicBody(text, hasArgs);
      break;
  }

  const fullContent = frontmatter + body;

  // Post-generation checks
  const lineCount = fullContent.split("\n").length;
  if (lineCount > 150) {
    warnings.push(
      `Generated file exceeds 150 lines (${lineCount} lines). Consider splitting or using --template minimal.`,
    );
  }

  if (!description || description.length < 5) {
    warnings.push(
      "Description is very short. Use --description to provide a better one.",
    );
  }

  return { filename, content: fullContent, warnings };
}

// ---- Private helpers ----

function extractName(text: string): string {
  const cleaned = text.replace(/^["']/, "").replace(/["']$/, "").trim();
  const words = cleaned.split(/\s+/).slice(0, 4);
  if (words.length === 0) return "command";
  return words
    .join("-")
    .toLowerCase()
    .replace(/[^a-z0-9-]/g, "");
}

function extractDescription(text: string): string {
  const lines = text.split("\n").filter((l) => l.trim().length > 0);
  if (lines.length === 0) return "";

  let firstLine = lines[0].trim();
  firstLine = firstLine.replace(/^#+\s*/, "");
  const dotIndex = firstLine.indexOf(".");
  let desc = dotIndex > 5 ? firstLine.slice(0, dotIndex + 1) : firstLine;
  if (desc.length > 80) {
    desc = desc.slice(0, 77) + "...";
  }
  return desc.trim();
}

function escapeYamlValue(val: string): string {
  const needsQuoting =
    val.length > 50 ||
    val.includes(": ") ||
    val.includes("#") ||
    val.includes("'") ||
    val.includes('"') ||
    val.includes("\n");

  if (!needsQuoting) return val;

  if (val.includes("\n")) {
    return (
      "|\n" +
      val
        .split("\n")
        .map((l) => `  ${l}`)
        .join("\n") +
      "\n"
    );
  }

  const escaped = val.replace(/\\/g, "\\\\").replace(/"/g, '\\"');
  return `"${escaped}"`;
}

function generateBasicBody(text: string, hasArgs: boolean): string {
  let body = cleanBody(text);
  body += "\n";

  if (hasArgs) {
    body += "\n## Usage\n";
    body += "\n```\n/command <arguments>\n```\n";
  }

  return body;
}

function generateDetailedBody(
  text: string,
  _description: string,
  hasArgs: boolean,
  hasFileRefs: boolean,
  hasBashCmd: boolean,
): string {
  let body = "";

  body += "\n" + cleanBody(text) + "\n";

  if (hasArgs || hasFileRefs || hasBashCmd) {
    body += "\n---\n\n";

    if (hasArgs) {
      body += "## Usage\n\n";
      body += "| Argument | Description |\n";
      body += "|----------|-------------|\n";
      body += "| `$ARGUMENTS` | All arguments passed to the command |\n";
    }

    if (hasFileRefs) {
      body += "\n## Required files\n\n";
      body += "- Files referenced via `@path/to/file` syntax\n";
    }

    if (hasBashCmd) {
      body += "\n## Required tools\n\n";
      body += "- Commands executed via `` !`command` `` syntax\n";
    }
  }

  if (hasArgs) {
    body += "\n## Examples\n\n";
    body +=
      "```\n# Example 1\n/command <arg1>\n\n# Example 2\n/command <arg1> <arg2>\n```\n";
  }

  body += "\n## Notes\n\n";
  body += "- Follow the instructions precisely.\n";
  body += "- Do not modify files outside the specified scope.\n";

  return body;
}

function generateMinimalBody(text: string, _hasArgs: boolean): string {
  const cleaned = cleanBody(text);
  const firstLine = cleaned.split("\n")[0] || cleaned;
  return "\n" + firstLine.trim() + "\n";
}

function cleanBody(text: string): string {
  return text
    .split("\n")
    .map((l) => l.trimEnd())
    .join("\n")
    .trim();
}