use super::helpers::allocations;
use super::helpers::fixtures::get_language;
use std::fmt::Write;
use tree_sitter::{
    Node, Parser, Query, QueryCapture, QueryCursor, QueryError, QueryMatch, QueryProperty,
};

#[test]
fn test_query_errors_on_invalid_syntax() {
    allocations::record(|| {
        let language = get_language("javascript");

        assert!(Query::new(language, "(if_statement)").is_ok());
        assert!(Query::new(language, "(if_statement condition:(identifier))").is_ok());

        // Mismatched parens
        assert_eq!(
            Query::new(language, "(if_statement"),
            Err(QueryError::Syntax(
                [
                    "(if_statement", //
                    "             ^",
                ]
                .join("\n")
            ))
        );
        assert_eq!(
            Query::new(language, "; comment 1\n; comment 2\n  (if_statement))"),
            Err(QueryError::Syntax(
                [
                    "  (if_statement))", //
                    "                ^",
                ]
                .join("\n")
            ))
        );

        // Return an error at the *beginning* of a bare identifier not followed a colon.
        // If there's a colon but no pattern, return an error at the end of the colon.
        assert_eq!(
            Query::new(language, "(if_statement identifier)"),
            Err(QueryError::Syntax(
                [
                    "(if_statement identifier)", //
                    "              ^",
                ]
                .join("\n")
            ))
        );
        assert_eq!(
            Query::new(language, "(if_statement condition:)"),
            Err(QueryError::Syntax(
                [
                    "(if_statement condition:)", //
                    "                        ^",
                ]
                .join("\n")
            ))
        );

        // Return an error at the beginning of an unterminated string.
        assert_eq!(
            Query::new(language, r#"(identifier) "h "#),
            Err(QueryError::Syntax(
                [
                    r#"(identifier) "h "#, //
                    r#"             ^"#,
                ]
                .join("\n")
            ))
        );

        assert_eq!(
            Query::new(language, r#"((identifier) ()"#),
            Err(QueryError::Syntax(
                [
                    "((identifier) ()", //
                    "                ^",
                ]
                .join("\n")
            ))
        );
        assert_eq!(
            Query::new(language, r#"((identifier) @x (eq? @x a"#),
            Err(QueryError::Syntax(
                [
                    r#"((identifier) @x (eq? @x a"#,
                    r#"                          ^"#,
                ]
                .join("\n")
            ))
        );
    });
}

#[test]
fn test_query_errors_on_invalid_symbols() {
    allocations::record(|| {
        let language = get_language("javascript");

        assert_eq!(
            Query::new(language, "(clas)"),
            Err(QueryError::NodeType("clas".to_string()))
        );
        assert_eq!(
            Query::new(language, "(if_statement (arrayyyyy))"),
            Err(QueryError::NodeType("arrayyyyy".to_string()))
        );
        assert_eq!(
            Query::new(language, "(if_statement condition: (non_existent3))"),
            Err(QueryError::NodeType("non_existent3".to_string()))
        );
        assert_eq!(
            Query::new(language, "(if_statement condit: (identifier))"),
            Err(QueryError::Field("condit".to_string()))
        );
        assert_eq!(
            Query::new(language, "(if_statement conditioning: (identifier))"),
            Err(QueryError::Field("conditioning".to_string()))
        );
    });
}

#[test]
fn test_query_errors_on_invalid_conditions() {
    allocations::record(|| {
        let language = get_language("javascript");

        assert_eq!(
            Query::new(language, "((identifier) @id (@id))"),
            Err(QueryError::Predicate(
                "Expected predicate to start with a function name. Got @id.".to_string()
            ))
        );
        assert_eq!(
            Query::new(language, "((identifier) @id (eq? @id))"),
            Err(QueryError::Predicate(
                "Wrong number of arguments to eq? predicate. Expected 2, got 1.".to_string()
            ))
        );
        assert_eq!(
            Query::new(language, "((identifier) @id (eq? @id @ok))"),
            Err(QueryError::Capture("ok".to_string()))
        );
    });
}

#[test]
fn test_query_matches_with_simple_pattern() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            "(function_declaration name: (identifier) @fn-name)",
        )
        .unwrap();

        let source = "function one() { two(); function three() {} }";
        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(source, None).unwrap();

        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(source));

        assert_eq!(
            collect_matches(matches, &query, source),
            &[
                (0, vec![("fn-name", "one")]),
                (0, vec![("fn-name", "three")])
            ],
        );
    });
}

#[test]
fn test_query_matches_with_multiple_on_same_root() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            "(class_declaration
                name: (identifier) @the-class-name
                (class_body
                    (method_definition
                        name: (property_identifier) @the-method-name)))",
        )
        .unwrap();

        let source = "
            class Person {
                // the constructor
                constructor(name) { this.name = name; }

                // the getter
                getFullName() { return this.name; }
            }
        ";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(source));

        assert_eq!(
            collect_matches(matches, &query, source),
            &[
                (
                    0,
                    vec![
                        ("the-class-name", "Person"),
                        ("the-method-name", "constructor")
                    ]
                ),
                (
                    0,
                    vec![
                        ("the-class-name", "Person"),
                        ("the-method-name", "getFullName")
                    ]
                ),
            ],
        );
    });
}

#[test]
fn test_query_matches_with_multiple_patterns_different_roots() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            "
                (function_declaration name:(identifier) @fn-def)
                (call_expression function:(identifier) @fn-ref)
            ",
        )
        .unwrap();

        let source = "
            function f1() {
                f2(f3());
            }
        ";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(source));

        assert_eq!(
            collect_matches(matches, &query, source),
            &[
                (0, vec![("fn-def", "f1")]),
                (1, vec![("fn-ref", "f2")]),
                (1, vec![("fn-ref", "f3")]),
            ],
        );
    });
}

#[test]
fn test_query_matches_with_multiple_patterns_same_root() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            "
              (pair
                key: (property_identifier) @method-def
                value: (function))

              (pair
                key: (property_identifier) @method-def
                value: (arrow_function))
            ",
        )
        .unwrap();

        let source = "
            a = {
                b: () => { return c; },
                d: function() { return d; }
            };
        ";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(source));

        assert_eq!(
            collect_matches(matches, &query, source),
            &[
                (1, vec![("method-def", "b")]),
                (0, vec![("method-def", "d")]),
            ],
        );
    });
}

#[test]
fn test_query_matches_with_nesting_and_no_fields() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            "
                (array
                    (array
                        (identifier) @x1
                        (identifier) @x2))
            ",
        )
        .unwrap();

        let source = "
            [[a]];
            [[c, d], [e, f, g, h]];
            [[h], [i]];
        ";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(source));

        assert_eq!(
            collect_matches(matches, &query, source),
            &[
                (0, vec![("x1", "c"), ("x2", "d")]),
                (0, vec![("x1", "e"), ("x2", "f")]),
                (0, vec![("x1", "e"), ("x2", "g")]),
                (0, vec![("x1", "f"), ("x2", "g")]),
                (0, vec![("x1", "e"), ("x2", "h")]),
                (0, vec![("x1", "f"), ("x2", "h")]),
                (0, vec![("x1", "g"), ("x2", "h")]),
            ],
        );
    });
}

#[test]
fn test_query_matches_with_many() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(language, "(array (identifier) @element)").unwrap();

        let source = "[hello];\n".repeat(50);

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(&source));

        assert_eq!(
            collect_matches(matches, &query, source.as_str()),
            vec![(0, vec![("element", "hello")]); 50],
        );
    });
}

#[test]
fn test_query_matches_in_language_with_simple_aliases() {
    allocations::record(|| {
        let language = get_language("html");

        // HTML uses different tokens to track start tags names, end
        // tag names, script tag names, and style tag names. All of
        // these tokens are aliased to `tag_name`.
        let query = Query::new(language, "(tag_name) @tag").unwrap();
        let source = "
            <div>
                <script>hi</script>
                <style>hi</style>
            </div>";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(&source));

        assert_eq!(
            collect_matches(matches, &query, source),
            &[
                (0, vec![("tag", "div")]),
                (0, vec![("tag", "script")]),
                (0, vec![("tag", "script")]),
                (0, vec![("tag", "style")]),
                (0, vec![("tag", "style")]),
                (0, vec![("tag", "div")]),
            ],
        );
    });
}

#[test]
fn test_query_matches_with_too_many_permutations_to_track() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            "
            (array (identifier) @pre (identifier) @post)
        ",
        )
        .unwrap();

        let mut source = "hello, ".repeat(50);
        source.insert(0, '[');
        source.push_str("];");

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(&source));

        // For this pathological query, some match permutations will be dropped.
        // Just check that a subset of the results are returned, and crash or
        // leak occurs.
        assert_eq!(
            collect_matches(matches, &query, source.as_str())[0],
            (0, vec![("pre", "hello"), ("post", "hello")]),
        );
    });
}

#[test]
fn test_query_matches_with_anonymous_tokens() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            r#"
            ";" @punctuation
            "&&" @operator
            "#,
        )
        .unwrap();

        let source = "foo(a && b);";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(source));

        assert_eq!(
            collect_matches(matches, &query, source),
            &[
                (1, vec![("operator", "&&")]),
                (0, vec![("punctuation", ";")]),
            ]
        );
    });
}

#[test]
fn test_query_matches_within_byte_range() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(language, "(identifier) @element").unwrap();

        let source = "[a, b, c, d, e, f, g]";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();

        let mut cursor = QueryCursor::new();
        let matches =
            cursor
                .set_byte_range(5, 15)
                .matches(&query, tree.root_node(), to_callback(source));

        assert_eq!(
            collect_matches(matches, &query, source),
            &[
                (0, vec![("element", "c")]),
                (0, vec![("element", "d")]),
                (0, vec![("element", "e")]),
            ]
        );
    });
}

#[test]
fn test_query_matches_different_queries_same_cursor() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query1 = Query::new(
            language,
            "
            (array (identifier) @id1)
        ",
        )
        .unwrap();
        let query2 = Query::new(
            language,
            "
            (array (identifier) @id1)
            (pair (identifier) @id2)
        ",
        )
        .unwrap();
        let query3 = Query::new(
            language,
            "
            (array (identifier) @id1)
            (pair (identifier) @id2)
            (parenthesized_expression (identifier) @id3)
        ",
        )
        .unwrap();

        let source = "[a, {b: b}, (c)];";

        let mut parser = Parser::new();
        let mut cursor = QueryCursor::new();

        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();

        let matches = cursor.matches(&query1, tree.root_node(), to_callback(source));
        assert_eq!(
            collect_matches(matches, &query1, source),
            &[(0, vec![("id1", "a")]),]
        );

        let matches = cursor.matches(&query3, tree.root_node(), to_callback(source));
        assert_eq!(
            collect_matches(matches, &query3, source),
            &[
                (0, vec![("id1", "a")]),
                (1, vec![("id2", "b")]),
                (2, vec![("id3", "c")]),
            ]
        );

        let matches = cursor.matches(&query2, tree.root_node(), to_callback(source));
        assert_eq!(
            collect_matches(matches, &query2, source),
            &[(0, vec![("id1", "a")]), (1, vec![("id2", "b")]),]
        );
    });
}

#[test]
fn test_query_captures() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            r#"
            (pair
              key: * @method.def
              (function
                name: (identifier) @method.alias))

            (variable_declarator
              name: * @function.def
              value: (function
                name: (identifier) @function.alias))

            ":" @delimiter
            "=" @operator
            "#,
        )
        .unwrap();

        let source = "
          a({
            bc: function de() {
              const fg = function hi() {}
            },
            jk: function lm() {
              const no = function pq() {}
            },
          });
        ";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(source));

        assert_eq!(
            collect_matches(matches, &query, source),
            &[
                (2, vec![("delimiter", ":")]),
                (0, vec![("method.def", "bc"), ("method.alias", "de")]),
                (3, vec![("operator", "=")]),
                (1, vec![("function.def", "fg"), ("function.alias", "hi")]),
                (2, vec![("delimiter", ":")]),
                (0, vec![("method.def", "jk"), ("method.alias", "lm")]),
                (3, vec![("operator", "=")]),
                (1, vec![("function.def", "no"), ("function.alias", "pq")]),
            ],
        );

        let captures = cursor.captures(&query, tree.root_node(), to_callback(source));
        assert_eq!(
            collect_captures(captures, &query, source),
            &[
                ("method.def", "bc"),
                ("delimiter", ":"),
                ("method.alias", "de"),
                ("function.def", "fg"),
                ("operator", "="),
                ("function.alias", "hi"),
                ("method.def", "jk"),
                ("delimiter", ":"),
                ("method.alias", "lm"),
                ("function.def", "no"),
                ("operator", "="),
                ("function.alias", "pq"),
            ]
        );
    });
}

#[test]
fn test_query_captures_with_text_conditions() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            r#"
            ((identifier) @constant
             (match? @constant "^[A-Z]{2,}$"))

             ((identifier) @constructor
              (match? @constructor "^[A-Z]"))

            ((identifier) @function.builtin
             (eq? @function.builtin "require"))

             (identifier) @variable
            "#,
        )
        .unwrap();

        let source = "
          const ab = require('./ab');
          new Cd(EF);
        ";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();

        let captures = cursor.captures(&query, tree.root_node(), to_callback(source));
        assert_eq!(
            collect_captures(captures, &query, source),
            &[
                ("variable", "ab"),
                ("function.builtin", "require"),
                ("variable", "require"),
                ("constructor", "Cd"),
                ("variable", "Cd"),
                ("constant", "EF"),
                ("constructor", "EF"),
                ("variable", "EF"),
            ],
        );
    });
}

#[test]
fn test_query_captures_with_set_properties() {
    allocations::record(|| {
        let language = get_language("javascript");

        let query = Query::new(
            language,
            r#"
            ((call_expression (identifier) @foo)
             (set! name something)
             (set! cool))

            ((property_identifier) @bar
             (is? cool)
             (is-not? name something))"#,
        )
        .unwrap();

        assert_eq!(
            query.property_settings(0),
            &[
                QueryProperty::new("name", Some("something"), None),
                QueryProperty::new("cool", None, None),
            ]
        );
        assert_eq!(query.property_settings(1), &[]);
        assert_eq!(query.property_predicates(0), &[]);
        assert_eq!(
            query.property_predicates(1),
            &[
                (QueryProperty::new("cool", None, None), true),
                (QueryProperty::new("name", Some("something"), None), false),
            ]
        );
    });
}

#[test]
fn test_query_captures_with_duplicates() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            r#"
            (variable_declarator
                name: (identifier) @function
                value: (function))

            (identifier) @variable
            "#,
        )
        .unwrap();

        let source = "
          var x = function() {};
        ";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();

        let captures = cursor.captures(&query, tree.root_node(), to_callback(source));
        assert_eq!(
            collect_captures(captures, &query, source),
            &[("function", "x"), ("variable", "x"),],
        );
    });
}

#[test]
fn test_query_captures_with_many_nested_results_without_fields() {
    allocations::record(|| {
        let language = get_language("javascript");

        // Search for key-value pairs whose values are anonymous functions.
        let query = Query::new(
            language,
            r#"
            (pair
              key: * @method-def
              (arrow_function))

            ":" @colon
            "," @comma
            "#,
        )
        .unwrap();

        // The `pair` node for key `y` does not match any pattern, but inside of
        // its value, it contains many other `pair` nodes that do match the pattern.
        // The match for the *outer* pair should be terminated *before* descending into
        // the object value, so that we can avoid needing to buffer all of the inner
        // matches.
        let method_count = 50;
        let mut source = "x = { y: {\n".to_owned();
        for i in 0..method_count {
            writeln!(&mut source, "    method{}: $ => null,", i).unwrap();
        }
        source.push_str("}};\n");

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();

        let captures = cursor.captures(&query, tree.root_node(), to_callback(&source));
        let captures = collect_captures(captures, &query, &source);

        assert_eq!(
            &captures[0..13],
            &[
                ("colon", ":"),
                ("method-def", "method0"),
                ("colon", ":"),
                ("comma", ","),
                ("method-def", "method1"),
                ("colon", ":"),
                ("comma", ","),
                ("method-def", "method2"),
                ("colon", ":"),
                ("comma", ","),
                ("method-def", "method3"),
                ("colon", ":"),
                ("comma", ","),
            ]
        );

        // Ensure that we don't drop matches because of needing to buffer too many.
        assert_eq!(captures.len(), 1 + 3 * method_count);
    });
}

#[test]
fn test_query_captures_with_many_nested_results_with_fields() {
    allocations::record(|| {
        let language = get_language("javascript");

        // Search expressions like `a ? a.b : null`
        let query = Query::new(
            language,
            r#"
            ((ternary_expression
                condition: (identifier) @left
                consequence: (member_expression
                    object: (identifier) @right)
                alternative: (null))
             (eq? @left @right))
            "#,
        )
        .unwrap();

        // The outer expression does not match the pattern, but the consequence of the ternary
        // is an object that *does* contain many occurences of the pattern.
        let count = 50;
        let mut source = "a ? {".to_owned();
        for i in 0..count {
            writeln!(&mut source, "  x: y{} ? y{}.z : null,", i, i).unwrap();
        }
        source.push_str("} : null;\n");

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();

        let captures = cursor.captures(&query, tree.root_node(), to_callback(&source));
        let captures = collect_captures(captures, &query, &source);

        assert_eq!(
            &captures[0..20],
            &[
                ("left", "y0"),
                ("right", "y0"),
                ("left", "y1"),
                ("right", "y1"),
                ("left", "y2"),
                ("right", "y2"),
                ("left", "y3"),
                ("right", "y3"),
                ("left", "y4"),
                ("right", "y4"),
                ("left", "y5"),
                ("right", "y5"),
                ("left", "y6"),
                ("right", "y6"),
                ("left", "y7"),
                ("right", "y7"),
                ("left", "y8"),
                ("right", "y8"),
                ("left", "y9"),
                ("right", "y9"),
            ]
        );

        // Ensure that we don't drop matches because of needing to buffer too many.
        assert_eq!(captures.len(), 2 * count);
    });
}

#[test]
fn test_query_captures_ordered_by_both_start_and_end_positions() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            r#"
            (call_expression) @call
            (member_expression) @member
            (identifier) @variable
            "#,
        )
        .unwrap();

        let source = "
          a.b(c.d().e).f;
        ";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();

        let captures = cursor.captures(&query, tree.root_node(), to_callback(source));
        assert_eq!(
            collect_captures(captures, &query, source),
            &[
                ("member", "a.b(c.d().e).f"),
                ("call", "a.b(c.d().e)"),
                ("member", "a.b"),
                ("variable", "a"),
                ("member", "c.d().e"),
                ("call", "c.d()"),
                ("member", "c.d"),
                ("variable", "c"),
            ],
        );
    });
}

#[test]
fn test_query_captures_with_matches_removed() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            r#"
            (binary_expression
                left: (identifier) @left
                operator: * @op
                right: (identifier) @right)
            "#,
        )
        .unwrap();

        let source = "
          a === b && c > d && e < f;
        ";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();

        let mut captured_strings = Vec::new();
        for (m, i) in cursor.captures(&query, tree.root_node(), to_callback(source)) {
            let capture = m.captures[i];
            let text = capture.node.utf8_text(source.as_bytes()).unwrap();
            if text == "a" {
                m.remove();
                continue;
            }
            captured_strings.push(text);
        }

        assert_eq!(captured_strings, &["c", ">", "d", "e", "<", "f",]);
    });
}

#[test]
fn test_query_captures_and_matches_iterators_are_fused() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            r#"
            (comment) @comment
            "#,
        )
        .unwrap();

        let source = "
          // one
          // two
          // three
          /* unfinished
        ";

        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(&source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let mut captures = cursor.captures(&query, tree.root_node(), to_callback(source));

        assert_eq!(captures.next().unwrap().0.captures[0].index, 0);
        assert_eq!(captures.next().unwrap().0.captures[0].index, 0);
        assert_eq!(captures.next().unwrap().0.captures[0].index, 0);
        assert!(captures.next().is_none());
        assert!(captures.next().is_none());
        assert!(captures.next().is_none());
        drop(captures);

        let mut matches = cursor.matches(&query, tree.root_node(), to_callback(source));
        assert_eq!(matches.next().unwrap().captures[0].index, 0);
        assert_eq!(matches.next().unwrap().captures[0].index, 0);
        assert_eq!(matches.next().unwrap().captures[0].index, 0);
        assert!(matches.next().is_none());
        assert!(matches.next().is_none());
        assert!(matches.next().is_none());
    });
}

#[test]
fn test_query_start_byte_for_pattern() {
    let language = get_language("javascript");

    let patterns_1 = r#"
        "+" @operator
        "-" @operator
        "*" @operator
        "=" @operator
        "=>" @operator
    "#
    .trim_start();

    let patterns_2 = "
        (identifier) @a
        (string) @b
    "
    .trim_start();

    let patterns_3 = "
        ((identifier) @b (match? @b i))
        (function_declaration name: (identifier) @c)
        (method_definition name: (identifier) @d)
    "
    .trim_start();

    let mut source = String::new();
    source += patterns_1;
    source += patterns_2;
    source += patterns_3;

    let query = Query::new(language, &source).unwrap();

    assert_eq!(query.start_byte_for_pattern(0), 0);
    assert_eq!(query.start_byte_for_pattern(5), patterns_1.len());
    assert_eq!(
        query.start_byte_for_pattern(7),
        patterns_1.len() + patterns_2.len()
    );
}

#[test]
fn test_query_capture_names() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            r#"
            (if_statement
              condition: (binary_expression
                left: * @left-operand
                operator: "||"
                right: * @right-operand)
              consequence: (statement_block) @body)

            (while_statement
              condition:* @loop-condition)
            "#,
        )
        .unwrap();

        assert_eq!(
            query.capture_names(),
            &[
                "left-operand".to_string(),
                "right-operand".to_string(),
                "body".to_string(),
                "loop-condition".to_string(),
            ]
        );
    });
}

#[test]
fn test_query_with_no_patterns() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(language, "").unwrap();
        assert!(query.capture_names().is_empty());
        assert_eq!(query.pattern_count(), 0);
    });
}

#[test]
fn test_query_comments() {
    allocations::record(|| {
        let language = get_language("javascript");
        let query = Query::new(
            language,
            "
                ; this is my first comment
                ; i have two comments here
                (function_declaration
                    ; there is also a comment here
                    ; and here
                    name: (identifier) @fn-name)",
        )
        .unwrap();

        let source = "function one() { }";
        let mut parser = Parser::new();
        parser.set_language(language).unwrap();
        let tree = parser.parse(source, None).unwrap();
        let mut cursor = QueryCursor::new();
        let matches = cursor.matches(&query, tree.root_node(), to_callback(source));
        assert_eq!(
            collect_matches(matches, &query, source),
            &[(0, vec![("fn-name", "one")]),],
        );
    });
}

fn collect_matches<'a>(
    matches: impl Iterator<Item = QueryMatch<'a>>,
    query: &'a Query,
    source: &'a str,
) -> Vec<(usize, Vec<(&'a str, &'a str)>)> {
    matches
        .map(|m| {
            (
                m.pattern_index,
                format_captures(m.captures.iter().cloned(), query, source),
            )
        })
        .collect()
}

fn collect_captures<'a>(
    captures: impl Iterator<Item = (QueryMatch<'a>, usize)>,
    query: &'a Query,
    source: &'a str,
) -> Vec<(&'a str, &'a str)> {
    format_captures(captures.map(|(m, i)| m.captures[i]), query, source)
}

fn format_captures<'a>(
    captures: impl Iterator<Item = QueryCapture<'a>>,
    query: &'a Query,
    source: &'a str,
) -> Vec<(&'a str, &'a str)> {
    captures
        .map(|capture| {
            (
                query.capture_names()[capture.index as usize].as_str(),
                capture.node.utf8_text(source.as_bytes()).unwrap(),
            )
        })
        .collect()
}

fn to_callback<'a>(source: &'a str) -> impl Fn(Node) -> &'a [u8] {
    move |n| &source.as_bytes()[n.byte_range()]
}