import type { RuleFunction } from "@eslint-react/kit";
import { type TSESTree, AST_NODE_TYPES } from "@typescript-eslint/types";

/** Enforce `import * as React from "react"` only. */
export function preferNamespaceImport(): RuleFunction {
	return (context, { settings }) => {
		const { importSource } = settings;

		return {
			[`ImportDeclaration[source.value="${importSource}"]`](
				node: TSESTree.ImportDeclaration,
			) {
				const specifiers = node.specifiers;

				// already valid
				if (
					specifiers.length === 1 &&
					specifiers[0]?.type ===
						AST_NODE_TYPES.ImportNamespaceSpecifier
				) {
					return;
				}

				// choose React identifier:
				// import React from "react"     -> React
				// import { useState }           -> React
				// import Foo, { useState }      -> Foo
				const localName =
					specifiers.find(
						(s) =>
							s.type === AST_NODE_TYPES.ImportDefaultSpecifier ||
							s.type === AST_NODE_TYPES.ImportNamespaceSpecifier,
					)?.local.name ?? "React";

				context.report({
					node,
					data: { importSource },
					message: `Prefer importing React only as 'import * as ${localName} from "${importSource}"'`,

					fix(fixer) {
						const original = context.sourceCode.getText(node);
						const semi = original.endsWith(";") ? ";" : "";
						const quote = node.source.raw.at(0) ?? "'";
						const isTypeImport = node.importKind === "type";

						return fixer.replaceText(
							node,
							[
								`import${isTypeImport ? " type" : ""}`,
								`* as ${localName}`,
								`from ${quote}${importSource}${quote}${semi}`,
							].join(" "),
						);
					},
				});
			},
		};
	};
}