//! Import-related lints: `collect_selective_import_names`,
//! `unused-import` autofix, and `import-order`.

use super::*;

#[test]
fn test_collect_selective_import_names() {
    let source = r#"
import { foo, bar } from "module_a"
import { baz } from "module_b"
import "wildcard_module"
fn local() { return foo() + bar() + baz() }
"#;
    let mut lexer = Lexer::new(source);
    let tokens = lexer.tokenize().unwrap();
    let mut parser = Parser::new(tokens);
    let program = parser.parse().unwrap();

    let names = collect_selective_import_names(&program);
    assert!(names.contains("foo"), "should contain foo");
    assert!(names.contains("bar"), "should contain bar");
    assert!(names.contains("baz"), "should contain baz");
    assert_eq!(names.len(), 3, "should have exactly 3 names: {names:?}");
}

#[test]
fn test_fix_unused_import_all_unused() {
    let source = "import { foo, bar } from \"mod\"\npipeline default(task) {\n  log(task)\n}";
    let diags = lint_source(source);
    assert!(
        count_rule(&diags, "unused-import") >= 1,
        "expected unused-import warnings"
    );
    // When all names are unused, the fix should remove the entire import line
    let fix = get_fix(&diags, "unused-import");
    assert!(fix.is_some(), "expected fix for unused-import");
    let edits = fix.unwrap();
    assert_eq!(edits.len(), 1);
    assert!(
        edits[0].replacement.is_empty(),
        "expected deletion, got: {:?}",
        edits[0].replacement
    );
}

#[test]
fn test_fix_unused_import_partial() {
    let source = "import { foo, bar } from \"mod\"\npipeline default(task) {\n  log(foo)\n}";
    let diags = lint_source(source);
    // bar is unused, foo is used
    assert_eq!(
        count_rule(&diags, "unused-import"),
        1,
        "expected 1 unused-import warning"
    );
    let fix = get_fix(&diags, "unused-import");
    assert!(fix.is_some(), "expected fix for unused-import");
    let result = apply_fixes(source, &diags);
    assert!(
        result.contains("{ foo }") || result.contains("{foo}"),
        "expected bar removed from import, got: {result}"
    );
    assert!(
        !result.contains("bar"),
        "bar should be removed, got: {result}"
    );
}

#[test]
fn test_import_used_in_destructuring_default_is_kept() {
    let source = r#"import { seed_registry } from "mod"
pipeline default(task) {
  let { registry = seed_registry(task), custom_rules = [] } = {}
  log(registry)
  log(custom_rules)
}
"#;
    let diags = lint_source(source);
    assert!(
        !has_rule(&diags, "unused-import"),
        "imports used in destructuring defaults should not be removed: {diags:?}"
    );
    assert!(
        !has_rule(&diags, "undefined-function"),
        "destructuring default calls should register imported function references: {diags:?}"
    );
}

#[test]
fn test_import_used_in_parameter_default_is_kept() {
    let source = r#"import { eval_repo_root } from "mod"

fn load_cases(root = eval_repo_root()) {
  return root
}

pipeline default(task) {
  log(load_cases())
}
"#;
    let diags = lint_source(source);
    assert!(
        !has_rule(&diags, "unused-import"),
        "imports used in parameter defaults should not be removed: {diags:?}"
    );
    assert!(
        !has_rule(&diags, "undefined-function"),
        "parameter default calls should register imported function references: {diags:?}"
    );
}

#[test]
fn test_import_order_fires_when_out_of_order() {
    let source = "import \"std/io\"\nimport \"std/fs\"\n\nfn a() -> int { return 1 }\n";
    let diags = lint_source(source);
    assert!(
        has_rule(&diags, "import-order"),
        "expected import-order when out of order, got: {diags:?}"
    );
}

#[test]
fn test_import_order_keeps_comments_by_disabling_unsafe_fix() {
    let source = "import \"std/io\"\n// keep with imports\nimport \"std/fs\"\n\nfn a() -> int { return 1 }\n";
    let diags = lint_source(source);
    let import_order = diags
        .iter()
        .find(|diag| diag.rule == "import-order")
        .expect("expected import-order diagnostic");
    assert!(
        import_order.fix.is_none(),
        "commented import block should not get a destructive fix"
    );
    let fixed = apply_fixes(source, &diags);
    assert!(fixed.contains("// keep with imports"));
}

#[test]
fn test_import_order_canonical_does_not_fire() {
    let source = "import \"std/fs\"\nimport \"std/io\"\n\nfn a() -> int { return 1 }\n";
    let diags = lint_source(source);
    assert!(
        !has_rule(&diags, "import-order"),
        "canonical order should not fire, got: {diags:?}"
    );
}

#[test]
fn test_import_order_single_import_does_not_fire() {
    let source = "import \"std/io\"\n\nfn a() -> int { return 1 }\n";
    let diags = lint_source(source);
    assert!(
        !has_rule(&diags, "import-order"),
        "single import should not fire, got: {diags:?}"
    );
}

#[test]
fn test_import_order_stdlib_before_third_party() {
    let source = "import \"mypkg/util\"\nimport \"std/io\"\n\nfn a() -> int { return 1 }\n";
    let diags = lint_source(source);
    assert!(
        has_rule(&diags, "import-order"),
        "stdlib should come before third-party, got: {diags:?}"
    );
}

#[test]
fn test_hostlib_prefix_skips_undefined_function_warning() {
    // `hostlib_*` names are runtime-registered VM builtins
    // (`harn_hostlib::install_default`); the lint's static call
    // graph cannot see them. Suppressing the warning matches the
    // existing `__`-prefix exemption.
    let source =
        "pipeline default(task) {\n  hostlib_code_index_stats({})\n  hostlib_ast_parse_file({})\n}\n";
    let diags = lint_source(source);
    assert!(
        !has_rule(&diags, "undefined-function"),
        "hostlib_-prefixed calls should not raise undefined-function, got: {diags:?}"
    );
}

#[test]
fn renamed_stdlib_symbol_warns_and_fixes_selective_import_and_call() {
    let source = "import { retry_with_backoff } from \"std/async\"\n\npipeline default() {\n  retry_with_backoff(1, 0, fn() { return true })\n}\n";
    let diags = lint_source(source);
    assert_eq!(
        count_rule(&diags, "renamed-stdlib-symbol"),
        2,
        "expected import and call rename diagnostics, got: {diags:?}"
    );
    let fixed = apply_fixes(source, &diags);
    assert!(
        fixed.contains("import { retry_predicate_with_backoff } from \"std/async\""),
        "expected import rename, got: {fixed}"
    );
    assert!(
        fixed.contains("retry_predicate_with_backoff(1, 0"),
        "expected call rename, got: {fixed}"
    );
    assert!(
        !fixed.contains("retry_with_backoff"),
        "old name should be fully removed, got: {fixed}"
    );
}
