import { existsSync, readFileSync } from "fs";
import { resolve } from "path";
import chalk from "chalk";
import { validateSkillContent } from "../lib/validate-skill.js";

/**
 * preview — shows how this skill will appear on the marketplace listing.
 * Operates entirely locally against the skill.md on disk.
 */
export async function previewCommand(filePath: string): Promise<void> {
  const absPath = resolve(filePath);

  if (!existsSync(absPath)) {
    console.error(chalk.red(`Error: File not found: ${absPath}`));
    process.exit(1);
  }

  const content = readFileSync(absPath, "utf-8");
  const validation = validateSkillContent(content);

  if (!validation.valid) {
    for (const e of validation.errors) {
      console.log(chalk.red(`✗  ${e}`));
    }
    console.log(chalk.red("\nValidation failed — cannot render preview."));
    process.exit(1);
  }

  const fm = validation.frontmatter!;
  const body = validation.body ?? "";

  const preview = body.slice(0, 500);
  const truncated = body.length > 500;

  const priceDisplay =
    fm.price === 0
      ? chalk.green("Free")
      : chalk.yellow(`$${(fm.price / 100).toFixed(2)}`);

  console.log(chalk.bold("\n══════════════════════════════════════════════════"));
  console.log(chalk.bold(`  Marketplace Preview: ${chalk.cyan(fm.name)}`));
  console.log(chalk.bold("══════════════════════════════════════════════════\n"));

  console.log(`  ${chalk.bold("Name:")}        ${fm.name}`);
  console.log(`  ${chalk.bold("Version:")}     ${fm.version}`);
  console.log(`  ${chalk.bold("Author:")}      ${fm.author}`);
  console.log(`  ${chalk.bold("Price:")}       ${priceDisplay}`);
  console.log(`  ${chalk.bold("License:")}     ${fm.license ?? "(not specified)"}`);
  console.log(`  ${chalk.bold("Model tier:")}  ${fm.model_tier}`);
  if (fm.tags?.length) {
    console.log(`  ${chalk.bold("Tags:")}        ${fm.tags.map((t) => chalk.dim(`#${t}`)).join("  ")}`);
  }
  if (fm.required_secrets?.length) {
    console.log(`  ${chalk.bold("Needs:")}       ${fm.required_secrets.join(", ")}`);
  }
  if (fm.references?.length) {
    console.log(`  ${chalk.bold("References:")}  ${fm.references.length} skill(s)`);
  }

  console.log();
  console.log(chalk.bold("  Description:"));
  console.log(`  ${fm.description}`);

  console.log();
  console.log(chalk.bold("  Content preview (first 500 chars):"));
  console.log(chalk.dim("  ─────────────────────────────────────────────────"));
  const indented = preview
    .split("\n")
    .map((l) => "  " + l)
    .join("\n");
  console.log(indented);
  if (truncated) {
    console.log(chalk.dim("  … (truncated) …"));
  }
  console.log(chalk.dim("  ─────────────────────────────────────────────────"));
  console.log();

  for (const w of validation.warnings) {
    console.log(chalk.yellow(`⚠  ${w}`));
  }
}