import type { RuntimeDiagnostic } from "@arconym/core";
import { summarizeDiagnostics } from "@arconym/core";
import { colors } from "./colors.js";

export function printDiagnostics(diagnostics: RuntimeDiagnostic[]): void {
  if (diagnostics.length === 0) {
    console.log(colors.green("✓ All systems look good."));
    return;
  }

  const summary = summarizeDiagnostics(diagnostics);
  const parts = [
    summary.byLevel.error ? colors.red(`${summary.byLevel.error} error(s)`) : undefined,
    summary.byLevel.warning ? colors.yellow(`${summary.byLevel.warning} warning(s)`) : undefined,
    summary.byLevel.info ? colors.cyan(`${summary.byLevel.info} info message(s)`) : undefined,
  ].filter(Boolean);

  console.log(`Diagnostics: ${parts.join(", ")}`);

  for (const diagnostic of diagnostics) {
    const header = formatDiagnosticHeader(diagnostic);
    const message = formatDiagnosticMessage(diagnostic);
    console.log(`  ${header} ${message}`);
    if (diagnostic.suggestion) {
      console.log(`      ${colors.dim("Suggestion:")} ${diagnostic.suggestion}`);
    }
    if (diagnostic.details && Object.keys(diagnostic.details).length > 0) {
      console.log(`      ${colors.dim("Details:")} ${JSON.stringify(diagnostic.details)}`);
    }
  }
}

function formatDiagnosticHeader(diagnostic: RuntimeDiagnostic): string {
  const levelText = diagnostic.level.toUpperCase();
  switch (diagnostic.level) {
    case "error":
      return colors.red(levelText);
    case "warning":
      return colors.yellow(levelText);
    default:
      return colors.cyan(levelText);
  }
}

function formatDiagnosticMessage(diagnostic: RuntimeDiagnostic): string {
  const contextSegments = [];
  if (diagnostic.plugin) contextSegments.push(diagnostic.plugin);
  if (diagnostic.stage) contextSegments.push(diagnostic.stage);
  const context = contextSegments.length > 0 ? colors.dim(`[${contextSegments.join(" → ")}]`) : "";
  const message = diagnostic.message;
  return context ? `${context} ${message}` : message;
}