import { join, relative } from "node:path";
import { summarizeDiagnostics } from "@arconym/core";
import type { CommandExecutionOptions } from "../cli/run-cli.js";
import { createRuntimeFromOptions, emitJson } from "./shared.js";
import { CliError } from "../cli/errors.js";
import { printDiagnostics } from "../utils/diagnostics.js";
import { printArtifactSummary } from "../utils/artifacts.js";
import { colors } from "../utils/colors.js";
import { writeGeneratedArtifacts } from "../utils/codegen.js";

export async function runGenCommand(options: CommandExecutionOptions): Promise<void> {
  const runtime = await createRuntimeFromOptions(options);
  const artifacts = await runtime.build();

  if (options.json) {
    emitJson({ command: "gen", artifacts, cacheDir: runtime.cacheDir });
    return;
  }

  console.log(colors.cyan("▶ arconym gen"));
  printArtifactSummary(artifacts);
  printDiagnostics(artifacts.diagnostics);

  const summary = summarizeDiagnostics(artifacts.diagnostics);
  if (summary.hasErrors) {
    throw new CliError("Generation failed due to diagnostics.");
  }

  const outputDir = join(runtime.cacheDir, "codegen");
  const writtenFiles = await writeGeneratedArtifacts({ artifacts, outputDir });

  if (writtenFiles.length === 0) {
    console.log(colors.yellow("⚠ No artifacts were generated."));
  } else {
    console.log(colors.dim("Generated artifacts:"));
    for (const file of writtenFiles) {
      const relativePath = relative(runtime.cwd, file.filePath);
      console.log(`  ${file.stage}/${file.plugin} → ${relativePath}`);
    }
  }

  console.log(colors.green("✔ Code generation completed."));
}