import type { Rule } from 'eslint';
import type { Position } from 'estree';

const rule: Rule.RuleModule = {
  meta: {
    type: 'problem',
    docs: {
      description:
        "Ban useless import aliasing like `import { abc as abc } from 'module'`",
      category: 'Best Practices',
      recommended: true,
    },
    fixable: 'code',
  },
  create(context) {
    return {
      ImportDeclaration(node) {
        if (node.specifiers.length === 0) return;

        for (const specifier of node.specifiers) {
          if (specifier.type !== 'ImportSpecifier') continue;

          const { imported, local } = specifier;
          if (
            imported.name === local.name &&
            !arePositionsEqual(imported.loc!.start, local.loc!.start)
          ) {
            context.report({
              node: specifier,
              message: `Useless aliasing of '${imported.name}'?`,
              fix(fixer) {
                return fixer.removeRange([imported.range![1], local.range![1]]);
              },
            });
          }
        }
      },
    };
  },
};

const arePositionsEqual = (a: Position, b: Position) =>
  a.line === b.line && a.column === b.column;

export default rule;