#!/usr/bin/env node
import { readFileSync, readdirSync, statSync } from "fs";
import { resolve, extname } from "path";
import chalk from "chalk";
import { checkMigration } from "./checker.js";
import { ALL_CHECK_DEFINITIONS } from "./checks.js";
import type { Issue } from "./types.js";

function formatIssue(issue: Issue): string {
  const icon = issue.severity === "danger" ? chalk.red("✗") : issue.severity === "warning" ? chalk.yellow("⚠") : chalk.blue("ℹ");
  const label = issue.severity === "danger" ? chalk.red.bold(`[DANGER]`) : issue.severity === "warning" ? chalk.yellow.bold(`[WARNING]`) : chalk.blue.bold(`[INFO]`);
  const checkName = issue.check.replace(/_/g, " ").replace(/\b\w/g, (c) => c.toUpperCase());
  const lines = [
    `  ${icon} ${label} ${checkName} (line ${issue.line})`,
    `    ${chalk.dim(issue.statement.slice(0, 120))}`,
    `    ${chalk.cyan("↳")} ${issue.message}`,
    `    ${chalk.green("↳ Fix:")} ${issue.suggestion}`,
  ];
  return lines.join("\n");
}

function checkFile(filePath: string, jsonMode: boolean): number {
  const sql = readFileSync(filePath, "utf-8");
  const result = checkMigration(sql);

  if (jsonMode) {
    console.log(JSON.stringify({ file: filePath, ...result }, null, 2));
  } else {
    console.log(chalk.bold(`\nChecking: ${filePath}\n`));
    if (result.issues.length === 0) {
      console.log(chalk.green("  ✓ No issues found. Migration looks safe."));
    } else {
      for (const issue of result.issues) {
        console.log(formatIssue(issue));
        console.log();
      }
    }
    const { danger, warning, info } = result.summary;
    const safeLabel = result.safe ? chalk.green("SAFE") : chalk.red("NOT SAFE");
    console.log(
      chalk.bold(`Summary: ${danger} danger, ${warning} warning, ${info} info — ${safeLabel}`)
    );
  }

  if (result.summary.danger > 0) return 1;
  if (result.summary.warning > 0) return 2;
  return 0;
}

function listChecks(): void {
  console.log(chalk.bold("\nAll available checks:\n"));
  for (const def of ALL_CHECK_DEFINITIONS) {
    const icon = def.severity === "danger" ? chalk.red("✗") : def.severity === "warning" ? chalk.yellow("⚠") : chalk.blue("ℹ");
    const label = def.severity === "danger" ? chalk.red.bold("[DANGER]") : def.severity === "warning" ? chalk.yellow.bold("[WARNING]") : chalk.blue.bold("[INFO]");
    console.log(`  ${icon} ${label} ${chalk.bold(def.name)}`);
    console.log(`     ${def.description}`);
    console.log(`     ${chalk.green("Fix:")} ${def.suggestion}`);
    console.log();
  }
}

function main(): void {
  const args = process.argv.slice(2);
  const jsonMode = args.includes("--json");
  const filteredArgs = args.filter((a) => a !== "--json");

  if (filteredArgs.length === 0 || filteredArgs[0] === "--help" || filteredArgs[0] === "-h") {
    console.log(`
${chalk.bold("pg-safe-migrate")} — Catch unsafe PostgreSQL migrations before production

${chalk.bold("Usage:")}
  pg-safe-migrate check <file.sql>       Check a migration file
  pg-safe-migrate check <dir/>           Check all .sql files in a directory
  pg-safe-migrate list-checks            Show all available checks

${chalk.bold("Options:")}
  --json    Output results as JSON
  --help    Show this help

${chalk.bold("Exit codes:")}
  0  Safe (no dangers or warnings)
  1  DANGER issues found
  2  WARNING issues found (no dangers)
`);
    process.exit(0);
  }

  const command = filteredArgs[0];

  if (command === "list-checks") {
    listChecks();
    process.exit(0);
  }

  if (command === "check") {
    const target = filteredArgs[1];
    if (!target) {
      console.error(chalk.red("Error: specify a file or directory to check"));
      process.exit(1);
    }

    const targetPath = resolve(target);
    let files: string[] = [];

    try {
      const stat = statSync(targetPath);
      if (stat.isDirectory()) {
        files = readdirSync(targetPath)
          .filter((f) => extname(f) === ".sql")
          .map((f) => resolve(targetPath, f))
          .sort();
      } else {
        files = [targetPath];
      }
    } catch {
      console.error(chalk.red(`Error: cannot read ${targetPath}`));
      process.exit(1);
    }

    if (files.length === 0) {
      console.log(chalk.yellow("No .sql files found."));
      process.exit(0);
    }

    let maxCode = 0;
    for (const file of files) {
      const code = checkFile(file, jsonMode);
      if (code > maxCode) maxCode = code;
    }
    process.exit(maxCode);
  }

  console.error(chalk.red(`Unknown command: ${command}`));
  process.exit(1);
}

main();