use crate::completion::{Completions, CompletionContext};

pub(super) fn complete_scope(acc: &mut Completions, ctx: &CompletionContext) {
    if !ctx.is_trivial_path {
        return;
    }
    let names = ctx.resolver.all_names(ctx.db);

    names.into_iter().for_each(|(name, res)| acc.add_resolution(ctx, name.to_string(), &res));
}

#[cfg(test)]
mod tests {
    use crate::completion::{CompletionKind, check_completion};

    fn check_reference_completion(name: &str, code: &str) {
        check_completion(name, code, CompletionKind::Reference);
    }

    #[test]
    fn completes_bindings_from_let() {
        check_reference_completion(
            "bindings_from_let",
            r"
            fn quux(x: i32) {
                let y = 92;
                1 + <|>;
                let z = ();
            }
            ",
        );
    }

    #[test]
    fn completes_bindings_from_if_let() {
        check_reference_completion(
            "bindings_from_if_let",
            r"
            fn quux() {
                if let Some(x) = foo() {
                    let y = 92;
                };
                if let Some(a) = bar() {
                    let b = 62;
                    1 + <|>
                }
            }
            ",
        );
    }

    #[test]
    fn completes_bindings_from_for() {
        check_reference_completion(
            "bindings_from_for",
            r"
            fn quux() {
                for x in &[1, 2, 3] {
                    <|>
                }
            }
            ",
        );
    }

    #[test]
    fn completes_generic_params() {
        check_reference_completion(
            "generic_params",
            r"
            fn quux<T>() {
                <|>
            }
            ",
        );
    }

    #[test]
    fn completes_generic_params_in_struct() {
        check_reference_completion(
            "generic_params_in_struct",
            r"
            struct X<T> {
                x: <|>
            }
            ",
        );
    }

    #[test]
    fn completes_module_items() {
        check_reference_completion(
            "module_items",
            r"
            struct Foo;
            enum Baz {}
            fn quux() {
                <|>
            }
            ",
        );
    }

    #[test]
    fn completes_extern_prelude() {
        check_reference_completion(
            "extern_prelude",
            r"
            //- /lib.rs
            use <|>;

            //- /other_crate/lib.rs
            // nothing here
            ",
        );
    }

    #[test]
    fn completes_module_items_in_nested_modules() {
        check_reference_completion(
            "module_items_in_nested_modules",
            r"
            struct Foo;
            mod m {
                struct Bar;
                fn quux() { <|> }
            }
            ",
        );
    }

    #[test]
    fn completes_return_type() {
        check_reference_completion(
            "return_type",
            r"
            struct Foo;
            fn x() -> <|>
            ",
        )
    }

    #[test]
    fn dont_show_both_completions_for_shadowing() {
        check_reference_completion(
            "dont_show_both_completions_for_shadowing",
            r"
            fn foo() -> {
                let bar = 92;
                {
                    let bar = 62;
                    <|>
                }
            }
            ",
        )
    }

    #[test]
    fn completes_self_in_methods() {
        check_reference_completion("self_in_methods", r"impl S { fn foo(&self) { <|> } }")
    }

    #[test]
    fn completes_prelude() {
        check_reference_completion(
            "completes_prelude",
            "
            //- /main.rs
            fn foo() { let x: <|> }

            //- /std/lib.rs
            #[prelude_import]
            use prelude::*;

            mod prelude {
                struct Option;
            }
            ",
        );
    }
}