//! Tests and test utilities for completions.
//!
//! Most tests live in this module or its submodules. The tests in these submodules are "location"
//! oriented, that is they try to check completions for something like type position, param position
//! etc.
//! Tests that are more orientated towards specific completion types like visibility checks of path
//! completions or `check_edit` tests usually live in their respective completion modules instead.
//! This gives this test module and its submodules here the main purpose of giving the developer an
//! overview of whats being completed where, not how.

mod attribute;
mod expression;
mod flyimport;
mod fn_param;
mod item;
mod item_list;
mod pattern;
mod predicate;
mod proc_macros;
mod raw_identifiers;
mod record;
mod special;
mod type_pos;
mod use_tree;
mod visibility;

use base_db::SourceDatabase;
use expect_test::Expect;
use hir::db::HirDatabase;
use hir::{PrefixKind, setup_tracing};
use ide_db::{
    FilePosition, MiniCore, RootDatabase, SnippetCap,
    imports::insert_use::{ImportGranularity, InsertUseConfig},
};
use itertools::Itertools;
use stdx::{format_to, trim_indent};
use test_fixture::ChangeFixture;
use test_utils::assert_eq_text;

use crate::{
    CallableSnippets, CompletionConfig, CompletionFieldsToResolve, CompletionItem,
    CompletionItemKind, resolve_completion_edits,
};

/// Lots of basic item definitions
const BASE_ITEMS_FIXTURE: &str = r#"
enum Enum { TupleV(u32), RecordV { field: u32 }, UnitV }
use self::Enum::TupleV;
mod module {}

trait Trait {}
static STATIC: Unit = Unit;
const CONST: Unit = Unit;
struct Record { field: u32 }
struct Tuple(u32);
struct Unit;
#[macro_export]
macro_rules! makro {}
#[rustc_builtin_macro]
pub macro Clone {}
fn function() {}
union Union { field: i32 }
"#;

pub(crate) const TEST_CONFIG: CompletionConfig<'_> = CompletionConfig {
    enable_postfix_completions: true,
    enable_imports_on_the_fly: true,
    enable_self_on_the_fly: true,
    enable_private_editable: false,
    enable_term_search: true,
    term_search_fuel: 200,
    full_function_signatures: false,
    callable: Some(CallableSnippets::FillArguments),
    add_semicolon_to_unit: true,
    snippet_cap: SnippetCap::new(true),
    insert_use: InsertUseConfig {
        granularity: ImportGranularity::Crate,
        prefix_kind: PrefixKind::Plain,
        enforce_granularity: true,
        group: true,
        skip_glob_imports: true,
    },
    prefer_no_std: false,
    prefer_prelude: true,
    prefer_absolute: false,
    snippets: Vec::new(),
    limit: None,
    fields_to_resolve: CompletionFieldsToResolve::empty(),
    exclude_flyimport: vec![],
    exclude_traits: &[],
    enable_auto_await: true,
    enable_auto_iter: true,
    minicore: MiniCore::default(),
};

pub(crate) fn completion_list(#[rust_analyzer::rust_fixture] ra_fixture: &str) -> String {
    completion_list_with_config(TEST_CONFIG, ra_fixture, true, None)
}

pub(crate) fn completion_list_no_kw(#[rust_analyzer::rust_fixture] ra_fixture: &str) -> String {
    completion_list_with_config(TEST_CONFIG, ra_fixture, false, None)
}

pub(crate) fn completion_list_no_kw_with_private_editable(
    #[rust_analyzer::rust_fixture] ra_fixture: &str,
) -> String {
    let mut config = TEST_CONFIG;
    config.enable_private_editable = true;
    completion_list_with_config(config, ra_fixture, false, None)
}

pub(crate) fn completion_list_with_trigger_character(
    #[rust_analyzer::rust_fixture] ra_fixture: &str,
    trigger_character: Option<char>,
) -> String {
    completion_list_with_config(TEST_CONFIG, ra_fixture, true, trigger_character)
}

fn completion_list_with_config_raw(
    config: CompletionConfig<'_>,
    #[rust_analyzer::rust_fixture] ra_fixture: &str,
    include_keywords: bool,
    trigger_character: Option<char>,
) -> Vec<CompletionItem> {
    let _tracing = setup_tracing();

    // filter out all but one built-in type completion for smaller test outputs
    let items = get_all_items(config, ra_fixture, trigger_character);
    items
        .into_iter()
        .filter(|it| it.kind != CompletionItemKind::BuiltinType || it.label.primary == "u32")
        .filter(|it| include_keywords || it.kind != CompletionItemKind::Keyword)
        .filter(|it| include_keywords || it.kind != CompletionItemKind::Snippet)
        .sorted_by_key(|it| {
            (
                it.kind,
                it.label.primary.clone(),
                it.label.detail_left.as_ref().map(ToOwned::to_owned),
            )
        })
        .collect()
}

fn completion_list_with_config(
    config: CompletionConfig<'_>,
    #[rust_analyzer::rust_fixture] ra_fixture: &str,
    include_keywords: bool,
    trigger_character: Option<char>,
) -> String {
    render_completion_list(completion_list_with_config_raw(
        config,
        ra_fixture,
        include_keywords,
        trigger_character,
    ))
}

/// Creates analysis from a multi-file fixture, returns positions marked with $0.
pub(crate) fn position(
    #[rust_analyzer::rust_fixture] ra_fixture: &str,
) -> (RootDatabase, FilePosition) {
    let mut database = RootDatabase::default();
    let change_fixture = ChangeFixture::parse(ra_fixture);
    database.enable_proc_attr_macros();
    database.apply_change(change_fixture.change);
    let (file_id, range_or_offset) = change_fixture.file_position.expect("expected a marker ($0)");
    let offset = range_or_offset.expect_offset();
    let position = FilePosition { file_id: file_id.file_id(), offset };
    (database, position)
}

pub(crate) fn do_completion(code: &str, kind: CompletionItemKind) -> Vec<CompletionItem> {
    do_completion_with_config(TEST_CONFIG, code, kind)
}

pub(crate) fn do_completion_with_config(
    config: CompletionConfig<'_>,
    code: &str,
    kind: CompletionItemKind,
) -> Vec<CompletionItem> {
    get_all_items(config, code, None)
        .into_iter()
        .filter(|c| c.kind == kind)
        .sorted_by(|l, r| l.label.cmp(&r.label))
        .collect()
}

fn render_completion_list(completions: Vec<CompletionItem>) -> String {
    fn monospace_width(s: &str) -> usize {
        s.chars().count()
    }
    let label_width = completions
        .iter()
        .map(|it| {
            monospace_width(&it.label.primary)
                + monospace_width(it.label.detail_left.as_deref().unwrap_or_default())
                + monospace_width(it.label.detail_right.as_deref().unwrap_or_default())
                + it.label.detail_left.is_some() as usize
                + it.label.detail_right.is_some() as usize
        })
        .max()
        .unwrap_or_default();
    completions
        .into_iter()
        .map(|it| {
            let tag = it.kind.tag();
            let mut buf = format!("{tag} {}", it.label.primary);
            if let Some(label_detail) = &it.label.detail_left {
                format_to!(buf, " {label_detail}");
            }
            if let Some(detail_right) = it.label.detail_right {
                let pad_with = label_width.saturating_sub(
                    monospace_width(&it.label.primary)
                        + monospace_width(it.label.detail_left.as_deref().unwrap_or_default())
                        + monospace_width(&detail_right)
                        + it.label.detail_left.is_some() as usize,
                );
                format_to!(buf, "{:pad_with$}{detail_right}", "",);
            }
            if it.deprecated {
                format_to!(buf, " DEPRECATED");
            }
            format_to!(buf, "\n");
            buf
        })
        .collect()
}

#[track_caller]
pub(crate) fn check_edit(
    what: &str,
    #[rust_analyzer::rust_fixture] ra_fixture_before: &str,
    #[rust_analyzer::rust_fixture] ra_fixture_after: &str,
) {
    check_edit_with_config(TEST_CONFIG, what, ra_fixture_before, ra_fixture_after)
}

#[track_caller]
pub(crate) fn check_edit_with_config(
    config: CompletionConfig<'_>,
    what: &str,
    ra_fixture_before: &str,
    ra_fixture_after: &str,
) {
    let ra_fixture_after = trim_indent(ra_fixture_after);
    let (db, position) = position(ra_fixture_before);
    let completions: Vec<CompletionItem> =
        hir::attach_db(&db, || crate::completions(&db, &config, position, None).unwrap());
    let Some((completion,)) = completions.iter().filter(|it| it.lookup() == what).collect_tuple()
    else {
        panic!("can't find {what:?} completion in {completions:#?}")
    };
    let mut actual = db.file_text(position.file_id).text(&db).to_string();

    let mut combined_edit = completion.text_edit.clone();

    resolve_completion_edits(&db, &config, position, completion.import_to_add.iter().cloned())
        .into_iter()
        .flatten()
        .for_each(|text_edit| {
            combined_edit.union(text_edit).expect(
                "Failed to apply completion resolve changes: change ranges overlap, but should not",
            )
        });

    combined_edit.apply(&mut actual);
    assert_eq_text!(&ra_fixture_after, &actual)
}

pub(crate) fn check(#[rust_analyzer::rust_fixture] ra_fixture: &str, expect: Expect) {
    let actual = completion_list(ra_fixture);
    expect.assert_eq(&actual);
}

pub(crate) fn check_with_base_items(
    #[rust_analyzer::rust_fixture] ra_fixture: &str,
    expect: Expect,
) {
    check(&format!("{BASE_ITEMS_FIXTURE}{ra_fixture}"), expect)
}

pub(crate) fn check_no_kw(#[rust_analyzer::rust_fixture] ra_fixture: &str, expect: Expect) {
    let actual = completion_list_no_kw(ra_fixture);
    expect.assert_eq(&actual)
}

pub(crate) fn check_with_private_editable(
    #[rust_analyzer::rust_fixture] ra_fixture: &str,
    expect: Expect,
) {
    let actual = completion_list_no_kw_with_private_editable(ra_fixture);
    expect.assert_eq(&actual);
}

pub(crate) fn check_with_trigger_character(
    #[rust_analyzer::rust_fixture] ra_fixture: &str,
    trigger_character: Option<char>,
    expect: Expect,
) {
    let actual = completion_list_with_trigger_character(ra_fixture, trigger_character);
    expect.assert_eq(&actual)
}

pub(crate) fn get_all_items(
    config: CompletionConfig<'_>,
    code: &str,
    trigger_character: Option<char>,
) -> Vec<CompletionItem> {
    let (db, position) = position(code);
    let res = hir::attach_db(&db, || {
        HirDatabase::zalsa_register_downcaster(&db);
        crate::completions(&db, &config, position, trigger_character)
    })
    .map_or_else(Vec::default, Into::into);
    // validate
    res.iter().for_each(|it| {
        let sr = it.source_range;
        assert!(
            sr.contains_inclusive(position.offset),
            "source range {sr:?} does not contain the offset {:?} of the completion request: {it:?}",
            position.offset
        );
    });
    res
}

#[test]
fn test_no_completions_in_for_loop_in_kw_pos() {
    assert_eq!(completion_list(r#"fn foo() { for i i$0 }"#), String::new());
    assert_eq!(completion_list(r#"fn foo() { for i in$0 }"#), String::new());
}

#[test]
fn regression_10042() {
    completion_list(
        r#"
macro_rules! preset {
    ($($x:ident)&&*) => {
        {
            let mut v = Vec::new();
            $(
                v.push($x.into());
            )*
            v
        }
    };
}

fn foo() {
    preset!(foo$0);
}
"#,
    );
}

#[test]
fn no_completions_in_comments() {
    assert_eq!(
        completion_list(
            r#"
fn test() {
let x = 2; // A comment$0
}
"#,
        ),
        String::new(),
    );
    assert_eq!(
        completion_list(
            r#"
/*
Some multi-line comment$0
*/
"#,
        ),
        String::new(),
    );
    assert_eq!(
        completion_list(
            r#"
/// Some doc comment
/// let test$0 = 1
"#,
        ),
        String::new(),
    );
}