import chalk from 'chalk';
import fs from 'fs-extra';
import path from 'path';
import inquirer from 'inquirer';
import { applyAutoFixes } from '../engine/auto-fixer.js';
import { runVersionMigration } from '../engine/version-runner.js';
import { printTerminalSummary } from "../reporting/terminal-summary.js";
import { runNgUpdateStep } from "../engine/ng-update-runner.js";

export async function runMigrateMode(
  currentVersion: number,
  targetVersion: number,
  askStepConfirmation: boolean,
  enableAutofixer: boolean
) {
  console.log(chalk.cyanBright('\n🧬 MIGRATION MODE — Automatic migration with logs.'));

  if (targetVersion <= currentVersion) {
    console.log(chalk.red(`❌ Target version must be higher than current version (${currentVersion}).`));
    process.exit(1);
  }

  const logsDir = path.join(process.cwd(), 'migration-logs');
  await fs.ensureDir(logsDir);

  for (let v = currentVersion; v < targetVersion; v++) {
    const nextVersion = v + 1;
    const stepLabel = `${v} → ${nextVersion}`;

    console.log(chalk.blueBright(`\n🚀 Migrating ${stepLabel} ...`));

    try {
      // 1️⃣ Ask user if we should run Angular CLI update for this step
      const { runCliUpdate } = await inquirer.prompt([
        {
          type: 'confirm',
          name: 'runCliUpdate',
          message: `Do you want MigratorX to run "npx ng update @angular/core@${nextVersion} @angular/cli@${nextVersion}" for this step?`,
          default: true
        }
      ]);

      if (runCliUpdate) {
        try {
          await runNgUpdateStep(nextVersion);
        } catch (cliErr) {
          console.error(
            chalk.red(
              `💥 Angular CLI update failed for ${stepLabel}. You may need to fix issues and re-run.`
            )
          );
          console.error(cliErr);
          // Stop here because dependencies may be in partial state
          return;
        }
      } else {
        console.log(
          chalk.yellow(
            `⏭ Skipping Angular CLI update for ${stepLabel}. Angular packages might still be on v${v}.`
          )
        );
      }

      // 2️⃣ Run MigratorX scanner AFTER (or regardless of) CLI update
      const scanResult = await runVersionMigration(v, nextVersion);

      // 3️⃣ Apply autofixes (code-level)
      let autoFixesApplied = 0;
      if (enableAutofixer) {
        autoFixesApplied = await applyAutoFixes(scanResult.autoFixTargets);
      } else {
        console.log("\n⚠ Autofixer disabled — no code changes will be made for this step.");
      }

      // 4️⃣ Save report
      const logFile = path.join(logsDir, `${v}-to-${nextVersion}-report.md`);
      await fs.writeFile(logFile, scanResult.logContent);

      // 5️⃣ Pretty terminal summary
      printTerminalSummary({
        fromVersion: v,
        toVersion: nextVersion,
        deprecatedItems: scanResult.deprecatedItems,
        autoFixes: scanResult.autoFixTargets
      });

      console.log(chalk.green(`📄 Log saved: migration-logs/${v}-to-${nextVersion}-report.md`));
      console.log(chalk.yellowBright(`🔧 Fixes applied in this step: ${autoFixesApplied}`));

      // 6️⃣ Pause option before next step
      if (askStepConfirmation && nextVersion < targetVersion) {
        const { proceed } = await inquirer.prompt([
          {
            type: 'confirm',
            name: 'proceed',
            message: `Continue migration to ${nextVersion + 1}?`,
            default: true
          }
        ]);
        if (!proceed) {
          console.log(chalk.yellowBright('🛑 Migration stopped by user.'));
          return;
        }
      }
    } catch (err) {
      console.error(chalk.red(`💥 Migration failed at step ${stepLabel}`));
      console.error(err);
      return;
    }
  }

  console.log(chalk.magentaBright(`\n✨ Migration completed successfully!`));
  console.log(chalk.yellow(`📂 Full logs available in the "migration-logs/" directory.`));
}