use ide_db::imports::merge_imports::try_normalize_import;
use syntax::{ast, AstNode};

use crate::{
    assist_context::{AssistContext, Assists},
    AssistId, AssistKind,
};

// Assist: normalize_import
//
// Normalizes an import.
//
// ```
// use$0 std::{io, {fmt::Formatter}};
// ```
// ->
// ```
// use std::{fmt::Formatter, io};
// ```
pub(crate) fn normalize_import(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> {
    let use_item = if ctx.has_empty_selection() {
        ctx.find_node_at_offset()?
    } else {
        ctx.covering_element().ancestors().find_map(ast::Use::cast)?
    };

    let target = use_item.syntax().text_range();
    let normalized_use_item =
        try_normalize_import(&use_item, ctx.config.insert_use.granularity.into())?;

    acc.add(
        AssistId("normalize_import", AssistKind::RefactorRewrite),
        "Normalize import",
        target,
        |builder| {
            builder.replace_ast(use_item, normalized_use_item);
        },
    )
}

#[cfg(test)]
mod tests {
    use crate::tests::{
        check_assist, check_assist_import_one, check_assist_not_applicable,
        check_assist_not_applicable_for_import_one,
    };

    use super::*;

    macro_rules! check_assist_variations {
        ($fixture: literal, $expected: literal) => {
            check_assist(
                normalize_import,
                concat!("use $0", $fixture, ";"),
                concat!("use ", $expected, ";"),
            );
            check_assist(
                normalize_import,
                concat!("$0use ", $fixture, ";"),
                concat!("use ", $expected, ";"),
            );

            check_assist_import_one(
                normalize_import,
                concat!("use $0", $fixture, ";"),
                concat!("use {", $expected, "};"),
            );
            check_assist_import_one(
                normalize_import,
                concat!("$0use ", $fixture, ";"),
                concat!("use {", $expected, "};"),
            );

            check_assist_import_one(
                normalize_import,
                concat!("use $0{", $fixture, "};"),
                concat!("use {", $expected, "};"),
            );
            check_assist_import_one(
                normalize_import,
                concat!("$0use {", $fixture, "};"),
                concat!("use {", $expected, "};"),
            );

            check_assist(
                normalize_import,
                concat!("use $0", $fixture, "$0;"),
                concat!("use ", $expected, ";"),
            );
            check_assist(
                normalize_import,
                concat!("$0use ", $fixture, ";$0"),
                concat!("use ", $expected, ";"),
            );
        };
    }

    macro_rules! check_assist_not_applicable_variations {
        ($fixture: literal) => {
            check_assist_not_applicable(normalize_import, concat!("use $0", $fixture, ";"));
            check_assist_not_applicable(normalize_import, concat!("$0use ", $fixture, ";"));

            check_assist_not_applicable_for_import_one(
                normalize_import,
                concat!("use $0{", $fixture, "};"),
            );
            check_assist_not_applicable_for_import_one(
                normalize_import,
                concat!("$0use {", $fixture, "};"),
            );
        };
    }

    #[test]
    fn test_order() {
        check_assist_variations!(
            "foo::{*, Qux, bar::{Quux, Bar}, baz, FOO_BAZ, self, Baz}",
            "foo::{self, bar::{Bar, Quux}, baz, Baz, Qux, FOO_BAZ, *}"
        );
    }

    #[test]
    fn test_redundant_braces() {
        check_assist_variations!("foo::{bar::{baz, Qux}}", "foo::bar::{baz, Qux}");
        check_assist_variations!("foo::{bar::{self}}", "foo::bar");
        check_assist_variations!("foo::{bar::{*}}", "foo::bar::*");
        check_assist_variations!("foo::{bar::{Qux as Quux}}", "foo::bar::Qux as Quux");
        check_assist_variations!(
            "foo::bar::{{FOO_BAZ, Qux, self}, {*, baz}}",
            "foo::bar::{self, baz, Qux, FOO_BAZ, *}"
        );
        check_assist_variations!(
            "foo::bar::{{{FOO_BAZ}, {{Qux}, {self}}}, {{*}, {baz}}}",
            "foo::bar::{self, baz, Qux, FOO_BAZ, *}"
        );
    }

    #[test]
    fn test_merge() {
        check_assist_variations!(
            "foo::{*, bar, {FOO_BAZ, qux}, bar::{*, baz}, {Quux}}",
            "foo::{bar::{self, baz, *}, qux, Quux, FOO_BAZ, *}"
        );
        check_assist_variations!(
            "foo::{*, bar, {FOO_BAZ, qux}, bar::{*, baz}, {Quux, bar::{baz::Foo}}}",
            "foo::{bar::{self, baz::{self, Foo}, *}, qux, Quux, FOO_BAZ, *}"
        );
    }

    #[test]
    fn not_applicable_to_normalized_import() {
        check_assist_not_applicable_variations!("foo::bar");
        check_assist_not_applicable_variations!("foo::bar::*");
        check_assist_not_applicable_variations!("foo::bar::Qux as Quux");
        check_assist_not_applicable_variations!("foo::bar::{self, baz, Qux, FOO_BAZ, *}");
        check_assist_not_applicable_variations!(
            "foo::{self, bar::{Bar, Quux}, baz, Baz, Qux, FOO_BAZ, *}"
        );
        check_assist_not_applicable_variations!(
            "foo::{bar::{self, baz, *}, qux, Quux, FOO_BAZ, *}"
        );
        check_assist_not_applicable_variations!(
            "foo::{bar::{self, baz::{self, Foo}, *}, qux, Quux, FOO_BAZ, *}"
        );
    }
}